1 00:00:07,759 --> 00:00:10,800 Hello, and welcome to the Physics World weekly 2 00:00:10,800 --> 00:00:11,300 podcast. 3 00:00:11,759 --> 00:00:14,259 This episode features the medical physicist, 4 00:00:14,719 --> 00:00:15,219 inventor, 5 00:00:15,519 --> 00:00:16,684 and entrepreneur, 6 00:00:17,144 --> 00:00:19,564 Brian Pogue, who is in conversation 7 00:00:20,024 --> 00:00:22,125 with Physics World's Tammy Freeman. 8 00:00:22,824 --> 00:00:26,024 They explore some of the crucial roles that 9 00:00:26,024 --> 00:00:27,085 optical technologies 10 00:00:27,544 --> 00:00:28,925 play in medicine. 11 00:00:29,899 --> 00:00:32,560 But first, a message from One Physics, 12 00:00:33,020 --> 00:00:33,840 which generously 13 00:00:34,219 --> 00:00:34,719 supports 14 00:00:35,260 --> 00:00:36,000 this episode. 15 00:00:37,100 --> 00:00:38,719 One Physics is The USA's 16 00:00:39,420 --> 00:00:42,320 largest outsourced medical physics provider, 17 00:00:43,034 --> 00:00:44,975 trusted by over 4,000 18 00:00:45,034 --> 00:00:45,534 clients. 19 00:00:46,234 --> 00:00:50,494 We proudly deliver diagnostic and therapy physics services, 20 00:00:51,034 --> 00:00:52,814 linear accelerator commissioning, 21 00:00:53,354 --> 00:00:53,854 dosimetry 22 00:00:54,314 --> 00:00:58,494 treatment planning, and radiation safety officer services 23 00:00:59,170 --> 00:00:59,670 nationwide. 24 00:01:00,530 --> 00:01:03,270 We are experts in medical physics services 25 00:01:03,649 --> 00:01:07,670 and radiation safety and can support your organization 26 00:01:08,290 --> 00:01:11,650 whether you need annual physics testing to meet 27 00:01:11,650 --> 00:01:12,150 regulatory 28 00:01:12,530 --> 00:01:13,030 guidelines 29 00:01:13,650 --> 00:01:16,414 or are looking to implement a theranostics 30 00:01:16,795 --> 00:01:17,295 program. 31 00:01:17,994 --> 00:01:21,114 We are experts in all areas related to 32 00:01:21,114 --> 00:01:23,295 physics and radiation safety. 33 00:01:23,834 --> 00:01:26,414 With national scale and a local 34 00:01:26,795 --> 00:01:28,494 relationship driven approach, 35 00:01:28,969 --> 00:01:30,750 our best in class physicists 36 00:01:31,209 --> 00:01:35,390 bring precision and personalized care to every facility 37 00:01:35,530 --> 00:01:36,270 we serve. 38 00:01:36,810 --> 00:01:39,709 In the world of medical physics, precision 39 00:01:40,010 --> 00:01:40,990 isn't optional. 40 00:01:41,450 --> 00:01:42,430 It's everything. 41 00:01:43,174 --> 00:01:44,075 One physics, 42 00:01:44,375 --> 00:01:47,114 your trusted partner in medical physics, 43 00:01:47,494 --> 00:01:47,994 linear 44 00:01:48,295 --> 00:01:49,435 accelerator commissioning, 45 00:01:49,814 --> 00:01:51,435 and radiation safety. 46 00:01:52,215 --> 00:01:54,075 Learn more about our approach 47 00:01:54,454 --> 00:01:55,914 to radiation safety 48 00:01:56,290 --> 00:01:57,989 or schedule a personalized 49 00:01:58,450 --> 00:01:58,950 consultation 50 00:01:59,569 --> 00:02:00,789 at one physics 51 00:02:01,250 --> 00:02:01,989 dot com. 52 00:02:03,569 --> 00:02:06,789 Here is that conversation with Brian Pogue. 53 00:02:07,090 --> 00:02:08,949 It was recorded in association 54 00:02:09,569 --> 00:02:10,389 with the journal 55 00:02:10,754 --> 00:02:13,014 Physics in Medicine and Biology, 56 00:02:13,634 --> 00:02:15,735 which celebrates its seventieth 57 00:02:16,194 --> 00:02:16,694 anniversary 58 00:02:17,074 --> 00:02:17,895 this year. 59 00:02:29,150 --> 00:02:32,669 Optical technologies underlie many of today's routine medical 60 00:02:32,669 --> 00:02:33,169 procedures, 61 00:02:33,710 --> 00:02:36,830 from microscopic imaging of cells and tissues to 62 00:02:36,830 --> 00:02:37,889 clinical applications 63 00:02:38,270 --> 00:02:39,250 such as endoscopy, 64 00:02:39,764 --> 00:02:40,264 ophthalmology, 65 00:02:40,724 --> 00:02:44,085 blood oxygen monitoring, fluorescence guided surgery, and and 66 00:02:44,085 --> 00:02:44,824 many more. 67 00:02:45,444 --> 00:02:47,685 And the field of optics is also converging 68 00:02:47,685 --> 00:02:49,224 with the world of medical physics, 69 00:02:49,685 --> 00:02:53,830 enabling exciting new techniques for guidance, dosimetry, and 70 00:02:53,830 --> 00:02:54,889 in vivo verification 71 00:02:55,270 --> 00:02:55,909 of radio 72 00:02:56,310 --> 00:02:58,090 radiation therapy cancer treatments. 73 00:02:59,270 --> 00:03:01,530 I'm speaking today with Brian Pogue, 74 00:03:01,830 --> 00:03:05,144 professor of biomedical engineering at Dartmouth College and 75 00:03:05,144 --> 00:03:08,984 cofounder of several startups developing optics based systems 76 00:03:08,984 --> 00:03:09,644 for medicine. 77 00:03:10,185 --> 00:03:11,884 Welcome to the podcast, Brian. 78 00:03:12,824 --> 00:03:14,344 Well, thank you. It's a pleasure to be 79 00:03:14,344 --> 00:03:14,844 here. 80 00:03:15,465 --> 00:03:17,144 So can you tell us a little about 81 00:03:17,144 --> 00:03:19,780 your background? How did your interest in optics 82 00:03:19,780 --> 00:03:20,439 and medicine 83 00:03:20,740 --> 00:03:21,639 first begin? 84 00:03:22,580 --> 00:03:24,740 Sure. Yeah. Well, you know, I was trained 85 00:03:24,740 --> 00:03:26,900 as a physicist, and I wound up doing 86 00:03:26,900 --> 00:03:28,360 a master's in laser 87 00:03:28,819 --> 00:03:31,460 isotope separation. So I've learned a lot about 88 00:03:31,460 --> 00:03:32,599 lasers and optics, 89 00:03:33,375 --> 00:03:36,495 but then specifically pivoted into a PhD in 90 00:03:36,495 --> 00:03:39,055 medical physics. And so that's where I sort 91 00:03:39,055 --> 00:03:40,435 of blended my two 92 00:03:40,974 --> 00:03:43,715 interests in optics as well as medicine, 93 00:03:44,334 --> 00:03:46,254 which is, you know, at the time was 94 00:03:46,254 --> 00:03:48,014 a little bit of an unusual mix, but 95 00:03:48,014 --> 00:03:48,449 this 96 00:03:49,009 --> 00:03:51,250 advisers I had were experts in the field, 97 00:03:51,250 --> 00:03:54,550 and it was incredible opportunity. So I really, 98 00:03:55,569 --> 00:03:57,669 have enjoyed it and continued, 99 00:03:58,370 --> 00:03:59,509 through my postdoctoral 100 00:03:59,810 --> 00:04:00,310 training 101 00:04:00,764 --> 00:04:03,084 and today to to work at both medical 102 00:04:03,084 --> 00:04:05,905 physics and biomedical optics at the same time. 103 00:04:06,685 --> 00:04:08,924 Excellent. So, could you maybe give us a 104 00:04:08,924 --> 00:04:11,164 brief introduction to some of the more general 105 00:04:11,164 --> 00:04:13,104 applications of optics in medicine? 106 00:04:14,639 --> 00:04:16,480 Sure. Yeah. I mean, I you know, I 107 00:04:16,480 --> 00:04:16,980 routinely 108 00:04:17,600 --> 00:04:18,660 remind my 109 00:04:19,040 --> 00:04:22,399 radiology and radiation oncology and other folks in 110 00:04:22,480 --> 00:04:24,879 who work in medical physics that optics is 111 00:04:24,879 --> 00:04:28,355 actually an enormous field. It's much, much larger 112 00:04:28,894 --> 00:04:30,915 than the field of radiation and medicine. 113 00:04:31,694 --> 00:04:33,475 You know, if you think about surgical 114 00:04:33,855 --> 00:04:35,795 intervention, pretty much all tools 115 00:04:36,495 --> 00:04:38,975 use optics. If you if you even think 116 00:04:38,975 --> 00:04:41,235 about a family physician, pretty much 117 00:04:41,830 --> 00:04:44,090 most of the tools they use are optics 118 00:04:44,150 --> 00:04:46,470 based, either just looking in your ear, in 119 00:04:46,470 --> 00:04:47,930 your throat, in your eye, 120 00:04:48,949 --> 00:04:49,670 looking in, 121 00:04:50,069 --> 00:04:51,449 cat body cavities, 122 00:04:52,470 --> 00:04:52,970 or 123 00:04:53,430 --> 00:04:54,330 blood spectroscopy, 124 00:04:54,790 --> 00:04:55,689 pulse oximetry, 125 00:04:57,875 --> 00:05:00,535 and, pretty much all vision technology 126 00:05:01,475 --> 00:05:03,394 to work in the to image the back 127 00:05:03,394 --> 00:05:05,254 of the eye, the retina, the cornea. 128 00:05:05,714 --> 00:05:07,254 These are all optical tools. 129 00:05:07,634 --> 00:05:10,055 Laser surgery, an enormous field. 130 00:05:10,629 --> 00:05:12,810 Most people don't realize, but dermatologists 131 00:05:13,189 --> 00:05:15,290 are probably the biggest user of lasers 132 00:05:15,910 --> 00:05:18,230 in the world because they have a vast 133 00:05:18,230 --> 00:05:21,589 array of laser systems to to treat skin 134 00:05:21,589 --> 00:05:22,089 conditions. 135 00:05:23,029 --> 00:05:23,774 So it's just 136 00:05:24,654 --> 00:05:26,975 through to all of medicine, really, optics has 137 00:05:26,975 --> 00:05:30,014 a I I routinely say I I'm pretty 138 00:05:30,014 --> 00:05:31,954 sure this is true that it's the largest 139 00:05:32,014 --> 00:05:33,634 single technology sector 140 00:05:33,935 --> 00:05:36,354 in medicine today is biomedical optics. 141 00:05:36,975 --> 00:05:38,814 Yeah. Yeah. I guess people sort of like 142 00:05:38,814 --> 00:05:40,199 you say, it's not immediately obvious, 143 00:05:40,579 --> 00:05:42,339 but actually, yes, it's it's used in all 144 00:05:42,339 --> 00:05:44,579 sorts of things. So, I mean, what main 145 00:05:44,579 --> 00:05:48,099 advantages of using light for clinical applications such 146 00:05:48,099 --> 00:05:49,479 as diagnostic tests? 147 00:05:50,180 --> 00:05:52,099 Yeah. So the the, you know, the main 148 00:05:52,099 --> 00:05:54,439 applications are, hey. It's not dangerous. 149 00:05:54,904 --> 00:05:55,725 And so, 150 00:05:56,025 --> 00:05:56,525 it's 151 00:05:56,985 --> 00:05:59,245 used in, what I call point of care 152 00:05:59,384 --> 00:06:01,865 technologies where the physician and the patient are 153 00:06:01,865 --> 00:06:04,345 in the same room together. That's point of 154 00:06:04,345 --> 00:06:06,365 care, and they're doing some procedure. 155 00:06:06,985 --> 00:06:09,245 More often than not, that's an optical device, 156 00:06:09,305 --> 00:06:11,779 either taking a measurement or doing a treatment 157 00:06:12,319 --> 00:06:14,579 with a laser or an optical system. 158 00:06:15,120 --> 00:06:17,360 So point of care is one area. The 159 00:06:17,360 --> 00:06:19,539 other one is molecular diagnostics. 160 00:06:19,919 --> 00:06:20,819 You know, most 161 00:06:21,120 --> 00:06:22,099 molecular diagnostics 162 00:06:22,399 --> 00:06:23,860 use optical wavelengths 163 00:06:24,205 --> 00:06:25,025 to do spectroscopy 164 00:06:25,965 --> 00:06:28,705 to take those measurements, either Raman or, 165 00:06:30,285 --> 00:06:31,425 scatter or, 166 00:06:31,965 --> 00:06:32,465 fluorescence 167 00:06:33,004 --> 00:06:33,504 diagnostics. 168 00:06:36,285 --> 00:06:37,745 So molecular features, 169 00:06:38,460 --> 00:06:40,160 point of care technology, 170 00:06:40,939 --> 00:06:42,060 and just the, 171 00:06:43,500 --> 00:06:45,660 usability too. The fiber op the fact that 172 00:06:45,660 --> 00:06:47,600 you can use fiber optics for delivery 173 00:06:48,060 --> 00:06:48,720 or recovery, 174 00:06:49,900 --> 00:06:52,540 means that you can do endoscopy or minimally 175 00:06:52,540 --> 00:06:53,680 invasive procedures. 176 00:06:54,805 --> 00:06:55,704 And so, again, 177 00:06:56,564 --> 00:06:58,884 you know, has transformed medicine. Let's face it. 178 00:06:58,884 --> 00:07:00,504 It's transformed medicine completely 179 00:07:01,125 --> 00:07:04,245 by its ability to get information in or 180 00:07:04,245 --> 00:07:06,504 out of the body through fiber optics. 181 00:07:08,485 --> 00:07:09,704 Okay. And then 182 00:07:10,139 --> 00:07:10,639 looking 183 00:07:10,939 --> 00:07:14,399 specifically now at optics within medical physics, particularly 184 00:07:14,459 --> 00:07:15,519 radiation therapy, 185 00:07:15,979 --> 00:07:17,979 what are some of the uses of lights 186 00:07:17,979 --> 00:07:18,959 in this field? 187 00:07:20,539 --> 00:07:22,459 Yeah. So, again, I think it's, 188 00:07:23,899 --> 00:07:25,759 not widely appreciated, but 189 00:07:26,115 --> 00:07:27,495 most detector systems 190 00:07:27,795 --> 00:07:28,855 in their core, 191 00:07:29,555 --> 00:07:32,535 they're either the detected signal is electrical 192 00:07:32,995 --> 00:07:33,735 or optical 193 00:07:34,194 --> 00:07:35,014 or both. 194 00:07:35,875 --> 00:07:39,654 But, you know, specs and PET systems all 195 00:07:40,040 --> 00:07:40,939 use scintillation, 196 00:07:42,120 --> 00:07:45,800 to turn x, gamma ray into an optical 197 00:07:45,800 --> 00:07:48,759 signal. And so there's optical detectors at the 198 00:07:48,759 --> 00:07:51,660 back end of most nuclear medicine devices, 199 00:07:52,455 --> 00:07:54,154 often previously photomultiplier 200 00:07:54,455 --> 00:07:57,175 tubes, but now more and more solid state, 201 00:07:57,495 --> 00:07:57,995 silicon 202 00:07:58,694 --> 00:07:59,194 devices. 203 00:08:02,214 --> 00:08:04,154 Radiation detectors in general, 204 00:08:04,819 --> 00:08:07,800 Again, the once the radiation is 205 00:08:08,180 --> 00:08:10,819 converted to something, it's usually an electrical or 206 00:08:10,819 --> 00:08:11,960 an optical signal. 207 00:08:12,420 --> 00:08:13,160 And so, 208 00:08:13,779 --> 00:08:14,420 a lot of, 209 00:08:15,220 --> 00:08:17,879 personal radiation monitors like film badges, 210 00:08:18,504 --> 00:08:19,004 thermoluminescent 211 00:08:19,464 --> 00:08:19,964 detectors, 212 00:08:20,425 --> 00:08:21,485 optical sent 213 00:08:22,025 --> 00:08:22,745 to, optical, 214 00:08:24,585 --> 00:08:25,085 OSLDs 215 00:08:25,625 --> 00:08:26,365 are are, 216 00:08:27,145 --> 00:08:29,085 optical in their nature. 217 00:08:30,185 --> 00:08:32,924 So, you know, optics has a major role. 218 00:08:33,320 --> 00:08:35,959 And then even just very simple things like 219 00:08:35,959 --> 00:08:38,120 positioning of patients in the room. You know, 220 00:08:38,120 --> 00:08:38,779 we use 221 00:08:39,080 --> 00:08:39,980 laser lines 222 00:08:40,440 --> 00:08:41,820 to align patients, 223 00:08:42,440 --> 00:08:44,919 to millimeter level precision when they sit on 224 00:08:44,919 --> 00:08:47,504 a CT scanner or an MRI or a 225 00:08:47,745 --> 00:08:49,605 radiation therapy device. So, 226 00:08:50,625 --> 00:08:52,884 optical systems are used for patient alignment. 227 00:08:53,264 --> 00:08:54,485 And then more and more, 228 00:08:55,105 --> 00:08:58,225 we are using optical systems for alignment where 229 00:08:58,225 --> 00:09:01,285 there's some kind of a surface scanning technology 230 00:09:01,940 --> 00:09:03,879 where the body entire body is, 231 00:09:04,419 --> 00:09:04,919 scanned 232 00:09:05,379 --> 00:09:08,839 with, stereo vision or with, speckle patterns 233 00:09:09,539 --> 00:09:09,940 to, 234 00:09:11,139 --> 00:09:13,379 verify the position of the patient in the 235 00:09:13,379 --> 00:09:15,794 treatment device or the imaging device. 236 00:09:16,514 --> 00:09:17,014 Okay. 237 00:09:17,875 --> 00:09:18,115 And, 238 00:09:18,834 --> 00:09:20,054 is it used within 239 00:09:20,434 --> 00:09:20,934 dosimetry 240 00:09:21,394 --> 00:09:22,134 in radiotherapy? 241 00:09:23,794 --> 00:09:25,575 Yeah. So so in dosimetry, 242 00:09:26,034 --> 00:09:26,534 again, 243 00:09:27,954 --> 00:09:28,454 scintillators 244 00:09:28,959 --> 00:09:31,220 are probably the most one of the most 245 00:09:31,440 --> 00:09:31,940 ubiquitous. 246 00:09:32,720 --> 00:09:36,000 Ionization chambers are most commonly used as reference 247 00:09:36,000 --> 00:09:36,500 dosimeters, 248 00:09:37,039 --> 00:09:38,740 but to do basic 249 00:09:39,120 --> 00:09:40,580 measurements that are undistorted 250 00:09:40,959 --> 00:09:41,459 by, 251 00:09:42,404 --> 00:09:45,764 radiation fields or magnetic fields, scintillators are very 252 00:09:45,764 --> 00:09:46,664 commonly used. 253 00:09:48,884 --> 00:09:49,384 Film 254 00:09:49,764 --> 00:09:52,004 is also commonly used in a lot of 255 00:09:52,004 --> 00:09:54,745 the probably one of the oldest optical detectors 256 00:09:54,804 --> 00:09:56,105 that exists. Is film 257 00:09:57,649 --> 00:10:00,070 still, routinely used for surface dosimetry, 258 00:10:00,450 --> 00:10:02,149 and then it gets read out. 259 00:10:02,610 --> 00:10:04,850 The types of film we use today are 260 00:10:04,850 --> 00:10:07,190 different than the old types that needed development, 261 00:10:07,329 --> 00:10:09,429 but it's still an optical readout 262 00:10:10,049 --> 00:10:10,529 of, 263 00:10:10,929 --> 00:10:12,149 radiation dose. 264 00:10:13,684 --> 00:10:16,245 And then, you know, in the last couple 265 00:10:16,245 --> 00:10:18,904 of decades, people have developed these gel dosimeters 266 00:10:19,524 --> 00:10:21,524 that are three-dimensional. It's sort of like a 267 00:10:21,524 --> 00:10:22,745 three-dimensional film 268 00:10:23,204 --> 00:10:23,605 that, 269 00:10:24,485 --> 00:10:26,904 is exposed to radiation and then turns color 270 00:10:27,320 --> 00:10:29,980 or turn either absorption or fluorescence, 271 00:10:30,600 --> 00:10:32,759 and that can be read out optically to 272 00:10:32,759 --> 00:10:33,580 get a three-dimensional 273 00:10:34,039 --> 00:10:34,539 image 274 00:10:35,000 --> 00:10:36,379 of radiation delivery. 275 00:10:37,080 --> 00:10:38,679 So, you know, all the way from point 276 00:10:38,679 --> 00:10:39,179 detectors 277 00:10:39,720 --> 00:10:41,785 to surface dose to three-dimensional 278 00:10:42,165 --> 00:10:42,665 dose, 279 00:10:44,485 --> 00:10:47,945 optical devices are used throughout radiation therapy. 280 00:10:48,485 --> 00:10:48,985 And 281 00:10:49,445 --> 00:10:49,945 then 282 00:10:50,245 --> 00:10:54,509 one really interesting development is, harnessing Cherenkov light 283 00:10:54,750 --> 00:10:55,809 to image radiation. 284 00:10:56,350 --> 00:10:58,110 So, first of all, can you just explain 285 00:10:58,110 --> 00:10:59,730 what Cherenkov light is? 286 00:11:00,910 --> 00:11:03,250 Sure. Yeah. So Cherenkov light is, 287 00:11:03,790 --> 00:11:04,290 this, 288 00:11:04,910 --> 00:11:06,529 a funny little light signal 289 00:11:06,954 --> 00:11:10,254 that comes off when ionizing radiation is incident 290 00:11:10,315 --> 00:11:11,294 in any material. 291 00:11:12,315 --> 00:11:13,034 And we 292 00:11:13,595 --> 00:11:15,294 almost everybody routinely 293 00:11:15,674 --> 00:11:16,654 thinks of 294 00:11:17,115 --> 00:11:18,954 when you think of radiation, you think of 295 00:11:18,954 --> 00:11:21,674 a blue glow. And in fact, that blue 296 00:11:21,674 --> 00:11:22,174 glow 297 00:11:22,779 --> 00:11:25,980 is Cerenkov light. So we implicitly most of 298 00:11:25,980 --> 00:11:26,480 us 299 00:11:27,019 --> 00:11:28,000 know of radiation 300 00:11:28,700 --> 00:11:30,160 in Cerenkov light already, 301 00:11:31,419 --> 00:11:33,820 and it's because we've seen pictures of used 302 00:11:33,820 --> 00:11:36,460 nuclear fuel bundles in water where there's a 303 00:11:36,460 --> 00:11:37,519 blue glow happening, 304 00:11:38,164 --> 00:11:41,464 or, there's pictures in the public media about 305 00:11:41,764 --> 00:11:42,485 radiation and, 306 00:11:43,924 --> 00:11:45,524 you know, this blue glow is sort of 307 00:11:45,524 --> 00:11:46,824 used to illustrate 308 00:11:47,125 --> 00:11:49,524 the presence of radiation. But in fact, it's 309 00:11:49,524 --> 00:11:50,024 real. 310 00:11:50,404 --> 00:11:52,350 It's it comes from soft 311 00:11:52,809 --> 00:11:56,029 collisions of high energy electrons with matter, and, 312 00:11:57,209 --> 00:11:58,269 the electromagnetic 313 00:11:58,809 --> 00:12:01,529 torque, if you will, of the medium emits 314 00:12:01,529 --> 00:12:03,629 this blue light as the electrons, 315 00:12:05,455 --> 00:12:08,434 collide. And and so it's a direct measurement 316 00:12:08,495 --> 00:12:09,315 of radiation 317 00:12:09,855 --> 00:12:11,634 dose in any material. 318 00:12:13,215 --> 00:12:16,894 Okay. So when this happens within tissue in 319 00:12:16,894 --> 00:12:18,815 a in a body, how can this light 320 00:12:18,815 --> 00:12:20,360 be used in radiotherapy 321 00:12:20,899 --> 00:12:21,379 for, 322 00:12:21,940 --> 00:12:22,919 measuring dose? 323 00:12:23,940 --> 00:12:27,059 Yeah. So, you it's possible to image. It's 324 00:12:27,059 --> 00:12:28,820 very low. You know, if you if you 325 00:12:28,820 --> 00:12:30,759 were actually standing in the room, 326 00:12:31,460 --> 00:12:33,539 you wouldn't be able to see Crenkov light 327 00:12:33,539 --> 00:12:35,595 unless you turned the room lights off. And 328 00:12:35,595 --> 00:12:38,034 it was pitch black and the radiation beam 329 00:12:38,034 --> 00:12:40,434 is hitting the patient. You actually could see 330 00:12:40,434 --> 00:12:42,514 the blue glow. You could see Cerenkov light 331 00:12:42,514 --> 00:12:45,654 coming off them. Patients for years have, 332 00:12:46,674 --> 00:12:48,514 commented on the fact that when their eyes 333 00:12:48,514 --> 00:12:50,970 are closed and there's radiation to their head, 334 00:12:51,049 --> 00:12:53,289 that they can see blue light in their 335 00:12:53,289 --> 00:12:56,269 eye, and that's a Cherenkov light, we believe. 336 00:12:57,209 --> 00:12:58,589 And so it is 337 00:12:59,129 --> 00:13:01,929 possible to image it. It's but it's very, 338 00:13:01,929 --> 00:13:04,329 very low. And so to do it, 339 00:13:04,730 --> 00:13:05,654 so we developed 340 00:13:06,055 --> 00:13:07,514 systems back in the, 341 00:13:08,134 --> 00:13:09,754 2012, 2014 342 00:13:10,055 --> 00:13:10,795 time frame 343 00:13:11,175 --> 00:13:13,195 to image this, and they have to be, 344 00:13:13,894 --> 00:13:15,355 especially time gated 345 00:13:15,735 --> 00:13:18,535 to linear accelerator pulses. And so that is 346 00:13:18,535 --> 00:13:19,195 the unique 347 00:13:19,870 --> 00:13:22,429 aspects that allows it to be detectable as 348 00:13:22,429 --> 00:13:24,610 you have to time gate your acquisition 349 00:13:25,230 --> 00:13:27,409 to the, delivery of the radiation. 350 00:13:27,949 --> 00:13:30,269 But it's it it comes off of everything 351 00:13:30,269 --> 00:13:31,169 that gets irradiated 352 00:13:31,485 --> 00:13:32,464 at some level. 353 00:13:32,924 --> 00:13:35,184 It's just a really small light 354 00:13:35,565 --> 00:13:37,325 signal. And and can you use, like, the 355 00:13:37,325 --> 00:13:39,245 sort of the level of this signal to 356 00:13:39,245 --> 00:13:41,964 indicate the dose that's been delivered? Is is 357 00:13:41,964 --> 00:13:43,259 one proportional to the other? 358 00:13:44,139 --> 00:13:46,399 That's right. So the the emission of Cherenkov 359 00:13:46,460 --> 00:13:47,919 light is directly proportional 360 00:13:48,540 --> 00:13:49,360 to the dose. 361 00:13:50,620 --> 00:13:52,620 It could you know, the signal can be 362 00:13:52,620 --> 00:13:55,179 distorted by the object that it's coming out 363 00:13:55,179 --> 00:13:58,444 from, but the production of Cherenkov is directly 364 00:13:58,444 --> 00:14:00,704 proportional to the radiation dose. So 365 00:14:01,084 --> 00:14:02,704 if you collect it properly, 366 00:14:03,164 --> 00:14:05,884 it can be a direct indicator of dose 367 00:14:05,884 --> 00:14:06,384 delivery. 368 00:14:07,245 --> 00:14:07,745 Okay. 369 00:14:08,620 --> 00:14:11,259 So, I mean, you are cofounder and president 370 00:14:11,259 --> 00:14:13,980 of a a Dartmouth spin off company called 371 00:14:13,980 --> 00:14:14,720 Dose Optics, 372 00:14:15,179 --> 00:14:18,320 which is commercializing this drink of imaging technology. 373 00:14:18,940 --> 00:14:20,959 So can you tell us about the company's 374 00:14:21,019 --> 00:14:22,095 BeamSight product? 375 00:14:23,134 --> 00:14:24,414 Sure. Yeah. So we, 376 00:14:24,894 --> 00:14:26,034 as I said, we 377 00:14:26,495 --> 00:14:29,154 developed the techniques of how to optimize 378 00:14:29,615 --> 00:14:31,634 collection of Cherenkov light and radiotherapy 379 00:14:32,414 --> 00:14:35,154 back in about 2012 to 2014, 380 00:14:35,454 --> 00:14:39,370 and we, developed patents around that as as 381 00:14:39,669 --> 00:14:42,250 every technology person should do, 382 00:14:43,190 --> 00:14:46,149 and then realized there was an opportunity there 383 00:14:46,149 --> 00:14:48,389 to spin off this as a as a 384 00:14:48,389 --> 00:14:51,769 unique dosimetry technology for radiation therapy. 385 00:14:52,184 --> 00:14:54,605 So this was really exciting for us because 386 00:14:55,225 --> 00:14:57,625 we had invented it in our lab and 387 00:14:57,625 --> 00:14:59,945 realized that there really should be a product 388 00:14:59,945 --> 00:15:00,445 here. 389 00:15:01,144 --> 00:15:02,044 And so 390 00:15:02,504 --> 00:15:03,725 myself with 391 00:15:04,105 --> 00:15:06,284 a a couple of other people from Dartmouth, 392 00:15:07,139 --> 00:15:10,259 spun out a company. And we were very 393 00:15:10,259 --> 00:15:12,339 lucky to get a pilot a series of 394 00:15:12,339 --> 00:15:13,860 pilot grants from the, 395 00:15:14,259 --> 00:15:16,360 NIH, National Institute of Health 396 00:15:16,820 --> 00:15:18,360 to kick off the company. 397 00:15:18,835 --> 00:15:19,554 And we, 398 00:15:19,955 --> 00:15:21,955 embarked for the next few years on sort 399 00:15:21,955 --> 00:15:24,514 of perfecting the product. And so we now 400 00:15:24,595 --> 00:15:26,054 it's gonna I'll call BeamSight, 401 00:15:26,514 --> 00:15:28,615 and it's really it's a camera system 402 00:15:29,315 --> 00:15:30,534 that's very sensitive, 403 00:15:31,379 --> 00:15:32,519 has a intensifier 404 00:15:32,899 --> 00:15:34,420 built into it to, 405 00:15:35,540 --> 00:15:37,480 both time gate the acquisition 406 00:15:37,940 --> 00:15:39,000 and amplify 407 00:15:39,379 --> 00:15:40,040 the intensity. 408 00:15:40,660 --> 00:15:43,940 Time gating is critical because the room is 409 00:15:43,940 --> 00:15:46,465 well lit, so we didn't. We knew we 410 00:15:46,465 --> 00:15:48,485 didn't wanna we couldn't ask 411 00:15:48,865 --> 00:15:51,105 the therapy people to turn the room lights 412 00:15:51,105 --> 00:15:53,605 off. So we have to capture this Trinkoff 413 00:15:53,745 --> 00:15:55,445 light signal that's really tiny 414 00:15:55,904 --> 00:15:59,825 in a massive ambient room background light. 415 00:16:00,649 --> 00:16:01,309 And so 416 00:16:01,769 --> 00:16:03,309 the key is time gating, 417 00:16:03,929 --> 00:16:06,509 and temporal sequencing of that, 418 00:16:06,970 --> 00:16:07,690 and then, 419 00:16:08,169 --> 00:16:11,289 pretty massive amount of image processing and signal 420 00:16:11,289 --> 00:16:13,710 processing on the back end. So these cameras, 421 00:16:14,250 --> 00:16:16,269 as most high end cameras are, 422 00:16:16,835 --> 00:16:19,095 they have a what's called a field programmable 423 00:16:19,394 --> 00:16:21,975 gate array. It's like a little programmable computer 424 00:16:22,355 --> 00:16:24,514 on board on the back end of the 425 00:16:24,514 --> 00:16:25,014 camera, 426 00:16:25,394 --> 00:16:27,634 and that does a a quite a bit 427 00:16:27,634 --> 00:16:28,774 of image processing, 428 00:16:29,939 --> 00:16:31,639 to make the image usable. 429 00:16:32,179 --> 00:16:32,919 And so, 430 00:16:33,459 --> 00:16:36,019 it's quite striking because the patients in the 431 00:16:36,019 --> 00:16:36,519 room, 432 00:16:37,220 --> 00:16:39,079 they're getting radiation therapy treatment. 433 00:16:39,620 --> 00:16:42,179 They are, I would say, unaware that there's 434 00:16:42,179 --> 00:16:44,595 this light signal coming off of them, but 435 00:16:44,595 --> 00:16:47,495 the camera picks it up, locks into it, 436 00:16:47,954 --> 00:16:48,454 rejects, 437 00:16:49,554 --> 00:16:51,794 you know, 99.99% 438 00:16:51,794 --> 00:16:53,334 of the background room light 439 00:16:53,634 --> 00:16:54,034 and, 440 00:16:54,595 --> 00:16:56,695 displays an image of that Cherenkov 441 00:16:57,910 --> 00:16:59,690 light coming off of their tissue. 442 00:17:00,310 --> 00:17:01,850 And and then this is used 443 00:17:02,230 --> 00:17:05,769 and displayed at the therapy console so the 444 00:17:05,990 --> 00:17:08,890 radiation therapy team can actually see what's happening. 445 00:17:09,029 --> 00:17:10,244 And it and it's, 446 00:17:11,045 --> 00:17:13,365 developed so it can image at 30 frames 447 00:17:13,365 --> 00:17:15,144 per second. So it's real time video, 448 00:17:16,484 --> 00:17:19,045 and and they can see the radiation treatment 449 00:17:19,045 --> 00:17:20,984 as it happens. And so, 450 00:17:21,525 --> 00:17:24,805 you know, most radiation treatments are just fine, 451 00:17:24,805 --> 00:17:26,109 perfect, you know, 452 00:17:26,570 --> 00:17:28,570 but that patients have to come in every 453 00:17:28,570 --> 00:17:31,049 single day for thirty days in a row 454 00:17:31,049 --> 00:17:32,910 and get millimeter level 455 00:17:33,609 --> 00:17:34,990 accuracy in their delivery. 456 00:17:35,450 --> 00:17:37,769 And so this camera system allows them to 457 00:17:37,769 --> 00:17:38,910 actually just see 458 00:17:39,214 --> 00:17:41,775 what's happening each day and and and help 459 00:17:41,775 --> 00:17:42,275 verify 460 00:17:42,894 --> 00:17:45,615 that the treatment is truly accurate. And, you 461 00:17:45,615 --> 00:17:47,934 know, I mean, let's face it. They're not 462 00:17:47,934 --> 00:17:50,494 all treatments are perfectly accurate, and so this 463 00:17:50,494 --> 00:17:52,670 camera can pick up little, 464 00:17:53,210 --> 00:17:56,330 incidents and help the therapy team, fix it 465 00:17:56,330 --> 00:17:57,309 when it does happen. 466 00:17:58,330 --> 00:18:00,490 Okay. So and is this in a routine 467 00:18:00,490 --> 00:18:01,789 clinical use yet? 468 00:18:02,650 --> 00:18:03,930 Yeah. So we, 469 00:18:04,809 --> 00:18:05,470 the company 470 00:18:06,134 --> 00:18:07,434 developed it as BeamSight. 471 00:18:08,134 --> 00:18:09,335 It got picked up, 472 00:18:09,654 --> 00:18:12,535 and is distributed by a British company called 473 00:18:12,535 --> 00:18:13,355 Vision RT, 474 00:18:14,134 --> 00:18:16,154 and they market it as DOSRT. 475 00:18:16,855 --> 00:18:17,734 It is now, 476 00:18:18,055 --> 00:18:20,789 in worldwide sales as of 2025, 477 00:18:21,109 --> 00:18:23,750 and I think the number is it's installed 478 00:18:23,750 --> 00:18:26,630 or being installed in over 40 cancer centers 479 00:18:26,630 --> 00:18:27,130 today. 480 00:18:27,430 --> 00:18:29,130 Oh, wow. That's that's impressive. 481 00:18:29,750 --> 00:18:30,250 Yeah. 482 00:18:31,029 --> 00:18:33,130 So, I mean, what's next in the pipeline 483 00:18:33,269 --> 00:18:34,650 for Cherenkov Imaging? 484 00:18:35,029 --> 00:18:36,470 Are there other things you can do with 485 00:18:36,470 --> 00:18:36,765 this 486 00:18:37,565 --> 00:18:40,445 technique? Yeah. So, I mean, I think we're 487 00:18:40,445 --> 00:18:43,884 in a a deployment phase where, you know, 488 00:18:43,884 --> 00:18:46,785 it's there were a couple early adopter academic 489 00:18:47,005 --> 00:18:49,164 medical centers that picked it up and used 490 00:18:49,164 --> 00:18:51,470 it, but we're really now in a phase 491 00:18:51,470 --> 00:18:52,529 where regular 492 00:18:52,909 --> 00:18:56,289 cancer therapy clinics are installing it, using it, 493 00:18:56,669 --> 00:18:57,150 and, 494 00:18:58,589 --> 00:19:01,390 they're using it in everyday radiotherapy. So that 495 00:19:01,390 --> 00:19:03,474 pay you know, every single day when a 496 00:19:03,474 --> 00:19:05,894 patient's getting treated, they can see it. And, 497 00:19:07,634 --> 00:19:10,674 we actually have a consortium of users now, 498 00:19:10,674 --> 00:19:13,714 and they sure sort of share stories and 499 00:19:13,714 --> 00:19:16,434 tips on how to use the technology and 500 00:19:16,434 --> 00:19:17,309 make sure that, 501 00:19:18,269 --> 00:19:21,009 they use it to effectively make their 502 00:19:21,309 --> 00:19:22,769 therapy as safe as possible. 503 00:19:23,070 --> 00:19:25,009 So we're in this kind of phase where 504 00:19:25,630 --> 00:19:27,090 there's a a growing 505 00:19:27,549 --> 00:19:29,570 slate of adopters, and those adopters 506 00:19:30,184 --> 00:19:30,845 are sharing 507 00:19:31,144 --> 00:19:32,924 use cases with each other. 508 00:19:33,785 --> 00:19:34,525 We are 509 00:19:35,704 --> 00:19:37,785 doing a couple different studies. You know, we're 510 00:19:37,785 --> 00:19:38,285 actually 511 00:19:38,744 --> 00:19:41,404 doing a study at Dartmouth now on contralateral 512 00:19:41,865 --> 00:19:44,369 breast dose. So, you know, the biggest use 513 00:19:44,369 --> 00:19:46,470 of radiation therapy is in breast cancer. 514 00:19:47,170 --> 00:19:50,470 And so women who get lumpectomy for 515 00:19:50,769 --> 00:19:51,750 a a cancer 516 00:19:52,130 --> 00:19:54,690 in the breast go on to radiation almost 517 00:19:54,690 --> 00:19:55,190 always. 518 00:19:56,464 --> 00:19:58,785 And the design of that radiation therapy is 519 00:19:58,785 --> 00:20:01,505 to treat the diseased breast, but do not 520 00:20:01,505 --> 00:20:04,404 treat the normal breast on the contralateral 521 00:20:04,785 --> 00:20:07,424 side. And but, you know, sometimes the alignment 522 00:20:07,424 --> 00:20:09,265 isn't as good as it should be, and 523 00:20:09,265 --> 00:20:11,285 and there can be dosed to the contralateral 524 00:20:11,505 --> 00:20:14,250 breast. And so we're doing a study now 525 00:20:14,869 --> 00:20:17,269 to minimize that to or to well, a 526 00:20:17,269 --> 00:20:19,130 a, to identify when it happens, 527 00:20:19,509 --> 00:20:21,690 and then the second step will be to 528 00:20:22,070 --> 00:20:26,095 develop techniques to minimize that and using Cherenkov 529 00:20:26,154 --> 00:20:27,775 as a tool. Again, 530 00:20:28,075 --> 00:20:31,055 you know, the the benefit of Cherenkov is 531 00:20:31,355 --> 00:20:33,855 that prior to its invention, 532 00:20:34,795 --> 00:20:37,279 radiation therapy is completely invisible. So 533 00:20:37,660 --> 00:20:39,519 the patient gets lined up on the 534 00:20:39,820 --> 00:20:41,279 patient treatment couch, 535 00:20:42,059 --> 00:20:44,380 and everybody walks out of the room, and 536 00:20:44,380 --> 00:20:46,000 the patient's lying there by themselves. 537 00:20:46,380 --> 00:20:49,144 Radiation therapy device is doing the treatments to 538 00:20:49,144 --> 00:20:49,644 them, 539 00:20:50,024 --> 00:20:52,825 and there's a video camera, you know, in 540 00:20:53,464 --> 00:20:54,764 displaying the patient, 541 00:20:55,944 --> 00:20:58,345 view to the therapy team, but they're outside 542 00:20:58,345 --> 00:21:00,125 the room, you know, a few 543 00:21:00,505 --> 00:21:01,404 meters away. 544 00:21:02,390 --> 00:21:04,470 And and nobody can see the treatment, you 545 00:21:04,470 --> 00:21:06,710 know, because the X rays aren't visible. So 546 00:21:06,710 --> 00:21:09,269 the TranKov allows the team to just very 547 00:21:09,269 --> 00:21:10,250 simply intuitively 548 00:21:10,710 --> 00:21:11,769 see the treatment. 549 00:21:12,070 --> 00:21:13,830 And that, I think, is the main benefit 550 00:21:13,830 --> 00:21:14,330 is, 551 00:21:14,710 --> 00:21:15,610 you know, safety, 552 00:21:16,845 --> 00:21:18,305 really needs to be simple. 553 00:21:19,325 --> 00:21:21,505 If the safety tools you're using 554 00:21:21,805 --> 00:21:22,545 are complicated, 555 00:21:22,924 --> 00:21:24,924 it means there's lots of room for human 556 00:21:24,924 --> 00:21:27,085 error. You know? So I think the the 557 00:21:27,085 --> 00:21:28,144 value of Chernkoff 558 00:21:28,605 --> 00:21:30,785 is that it makes safety simple, 559 00:21:31,570 --> 00:21:33,190 and very visual and intuitive. 560 00:21:33,570 --> 00:21:35,809 And, I think that will be the the 561 00:21:35,809 --> 00:21:37,830 lasting power of it as a technology. 562 00:21:38,369 --> 00:21:40,369 And I guess this light is just it's 563 00:21:40,369 --> 00:21:43,029 generated within the patient. You're not doing anything 564 00:21:43,170 --> 00:21:45,445 extra other than detecting it. It's sort of 565 00:21:45,445 --> 00:21:47,065 there for you to use already. 566 00:21:47,605 --> 00:21:50,005 That's right. It's it's always there. It just 567 00:21:50,005 --> 00:21:52,085 needs a camera system to pick it up 568 00:21:52,085 --> 00:21:54,325 and display it, and every every patient who 569 00:21:54,325 --> 00:21:57,285 gets radiation therapy could benefit from it just 570 00:21:57,285 --> 00:21:59,465 to verify that the treatment was accurate. 571 00:22:00,509 --> 00:22:02,590 And and, again, the the important piece of 572 00:22:02,590 --> 00:22:04,910 this is patients come in for many days 573 00:22:04,910 --> 00:22:06,830 in a row, typically thirty days in a 574 00:22:06,830 --> 00:22:08,830 row. So, you know, if if you make 575 00:22:08,830 --> 00:22:09,330 one 576 00:22:09,710 --> 00:22:12,509 small positioning error, you you can fix it 577 00:22:12,509 --> 00:22:13,994 for the other 29. 578 00:22:14,875 --> 00:22:17,214 And that's the key is is the tool 579 00:22:17,994 --> 00:22:19,694 because positioning is so 580 00:22:20,154 --> 00:22:21,855 is supposed to be so high precision, 581 00:22:22,954 --> 00:22:25,454 we need tools to verify that high precision, 582 00:22:25,835 --> 00:22:27,674 and then it's gotta be done every single 583 00:22:27,674 --> 00:22:29,700 day for thirty days in a row. So, 584 00:22:30,659 --> 00:22:33,380 that is where why it's so important to 585 00:22:33,380 --> 00:22:35,880 have a intuitive and easily used tool 586 00:22:36,259 --> 00:22:37,639 like Cherenkov Imaging. 587 00:22:38,980 --> 00:22:39,480 Excellent. 588 00:22:40,019 --> 00:22:40,679 And then 589 00:22:41,460 --> 00:22:43,960 shifting focus now, you you've also cofounded 590 00:22:44,259 --> 00:22:47,134 another company called Hypoxia Surgical, 591 00:22:47,755 --> 00:22:50,315 and this company is developing an imaging system 592 00:22:50,315 --> 00:22:53,515 to visualize oxygen levels in tissue in real 593 00:22:53,515 --> 00:22:54,015 time. 594 00:22:54,555 --> 00:22:57,055 So could you explain how this technology works? 595 00:22:58,009 --> 00:22:59,929 Sure. Yeah. So I I, you know, so 596 00:22:59,929 --> 00:23:02,089 I I'm an optics person in general, not 597 00:23:02,089 --> 00:23:03,230 really necessarily 598 00:23:03,769 --> 00:23:04,750 married to one 599 00:23:05,289 --> 00:23:08,029 therapy. I I work in surgical guidance technologies 600 00:23:08,250 --> 00:23:08,909 as well, 601 00:23:09,769 --> 00:23:12,075 and and there's a whole field of what 602 00:23:12,075 --> 00:23:15,275 is sometimes referred to as molecular guided surgery, 603 00:23:15,275 --> 00:23:17,694 where you wanna give the surgeon 604 00:23:18,394 --> 00:23:21,134 a view of what they're cutting or doing 605 00:23:21,434 --> 00:23:24,335 based on the molecular signatures of the tissue. 606 00:23:25,194 --> 00:23:27,990 And and that's really what this technology is 607 00:23:27,990 --> 00:23:28,470 is, 608 00:23:29,269 --> 00:23:32,710 we have, developed a, again, a time gated 609 00:23:32,710 --> 00:23:33,210 technique 610 00:23:33,750 --> 00:23:35,369 to image a light signal 611 00:23:35,750 --> 00:23:37,049 that comes out of tissue 612 00:23:37,590 --> 00:23:38,250 that is 613 00:23:39,494 --> 00:23:42,134 amplified when there's no oxygen. So it's high 614 00:23:42,295 --> 00:23:44,615 when the tissue is hypoxic or no oxygen 615 00:23:44,615 --> 00:23:45,275 in it, 616 00:23:45,654 --> 00:23:48,934 this special light signal comes out. And we 617 00:23:48,934 --> 00:23:49,674 we induce, 618 00:23:50,775 --> 00:23:53,255 where we amplify that light signal by giving 619 00:23:53,255 --> 00:23:54,154 the the patients 620 00:23:54,829 --> 00:23:55,490 a metabolic 621 00:23:55,789 --> 00:23:56,930 drug called aminolubalinic 622 00:23:57,470 --> 00:24:00,529 acid. It's a very, commonly used agent, 623 00:24:01,549 --> 00:24:04,750 for a number of diagnostic and therapeutic conditions. 624 00:24:04,750 --> 00:24:07,089 So it's in wide human use. 625 00:24:08,750 --> 00:24:10,609 The cameras that we have developed, 626 00:24:11,204 --> 00:24:13,065 again, pick up when 627 00:24:13,845 --> 00:24:16,505 a signal from the tissue when it's hypoxic. 628 00:24:16,724 --> 00:24:20,265 And, you know, oxygen is ubiquitous in living 629 00:24:20,724 --> 00:24:23,220 organisms and tissue. Right? So when there's a 630 00:24:23,220 --> 00:24:26,200 lack of oxygen, that's a a disease state. 631 00:24:26,579 --> 00:24:27,880 And so tumors 632 00:24:28,259 --> 00:24:30,519 or peripheral vascular disease 633 00:24:31,140 --> 00:24:31,640 or, 634 00:24:32,420 --> 00:24:33,640 compromised lymphatics, 635 00:24:34,579 --> 00:24:35,400 have hypoxia. 636 00:24:35,859 --> 00:24:37,079 And so that's where 637 00:24:37,454 --> 00:24:38,674 this imaging tool, 638 00:24:39,534 --> 00:24:42,414 could have, its potential. So we're in early 639 00:24:42,414 --> 00:24:43,714 stage of this company, 640 00:24:44,575 --> 00:24:45,714 Hypoxia Surgical. 641 00:24:46,335 --> 00:24:47,875 The camera systems developed 642 00:24:48,255 --> 00:24:51,134 were exploring a couple different sort of medical 643 00:24:51,134 --> 00:24:52,349 use cases of it. 644 00:24:52,910 --> 00:24:53,809 But we know 645 00:24:54,109 --> 00:24:56,829 that the lack of oxygen is indicative of 646 00:24:56,829 --> 00:24:58,609 damage or disease. 647 00:24:58,990 --> 00:25:01,390 And so there's we're pretty confident that it 648 00:25:01,390 --> 00:25:02,210 will have 649 00:25:02,509 --> 00:25:03,809 its role in medicine. 650 00:25:04,109 --> 00:25:04,724 It's just, 651 00:25:05,365 --> 00:25:07,924 determining which one it is. And right now, 652 00:25:07,924 --> 00:25:10,345 we're looking at surgical guidance for, 653 00:25:11,125 --> 00:25:12,984 cancer or lymph nodes 654 00:25:13,285 --> 00:25:14,984 as one of the more compelling 655 00:25:15,444 --> 00:25:18,339 application areas for it. Yeah. But is there 656 00:25:18,339 --> 00:25:20,200 a way it could be used in radiotherapy 657 00:25:20,579 --> 00:25:22,359 as well? Because, obviously, hypoxia 658 00:25:23,220 --> 00:25:25,720 is a big important part of such treatments. 659 00:25:26,259 --> 00:25:28,994 Yeah. Great question. So oxygen is a is 660 00:25:28,994 --> 00:25:32,035 a very important molecule in radiation therapy. It 661 00:25:32,035 --> 00:25:34,835 increases the effect of radiation by close to 662 00:25:34,835 --> 00:25:35,894 a factor of three. 663 00:25:36,355 --> 00:25:39,795 So the lack of oxygen would increase would 664 00:25:39,795 --> 00:25:42,115 would indicate that radiation therapy would not be 665 00:25:42,115 --> 00:25:44,960 very as effective. And so we are exploring 666 00:25:45,099 --> 00:25:46,220 that use in, 667 00:25:46,619 --> 00:25:47,119 radiotherapy 668 00:25:47,660 --> 00:25:49,599 as a adjuvant tool as well. 669 00:25:50,539 --> 00:25:53,519 And this is more in early stage investigation, 670 00:25:54,059 --> 00:25:56,480 you know, studies in animals right now. 671 00:25:56,865 --> 00:25:59,505 But, for sure, we we can use it 672 00:25:59,505 --> 00:26:00,005 to, 673 00:26:01,025 --> 00:26:03,444 see when radiotherapy will be less effective. 674 00:26:04,224 --> 00:26:05,744 And then there's this, 675 00:26:06,144 --> 00:26:09,204 ultra high dose rate radiotherapy that actually consumes 676 00:26:09,265 --> 00:26:10,484 oxygen very rapidly, 677 00:26:10,869 --> 00:26:13,669 and so we're using the hypoxia surgical cameras 678 00:26:13,669 --> 00:26:15,130 to image that as well. 679 00:26:16,470 --> 00:26:18,009 So it's been a great tool. 680 00:26:19,190 --> 00:26:21,589 You know, figuring out its use case in 681 00:26:21,589 --> 00:26:23,589 radiotherapy will take a little bit of time, 682 00:26:23,589 --> 00:26:26,089 but we're certainly working on that right now. 683 00:26:27,575 --> 00:26:28,075 Excellent. 684 00:26:28,695 --> 00:26:29,195 So 685 00:26:29,734 --> 00:26:31,115 many of these developments 686 00:26:31,894 --> 00:26:34,695 would have been published in the journal Physics 687 00:26:34,695 --> 00:26:36,154 in Medicine and Biology, 688 00:26:36,615 --> 00:26:40,359 which is celebrating its seventieth anniversary this year. 689 00:26:40,359 --> 00:26:41,799 So so with that in mind, I wonder 690 00:26:41,799 --> 00:26:43,400 if you could give us an example of 691 00:26:43,400 --> 00:26:45,559 some exciting research that you or your team 692 00:26:45,559 --> 00:26:47,179 has has published in PMB. 693 00:26:48,440 --> 00:26:49,960 Sure. Yeah. I mean, we've, 694 00:26:50,359 --> 00:26:51,179 I've published 695 00:26:51,535 --> 00:26:54,255 so many articles in PMB. It's actually hard 696 00:26:54,255 --> 00:26:54,914 to choose, 697 00:26:55,535 --> 00:26:56,595 which one exactly. 698 00:26:57,134 --> 00:26:57,954 But, certainly, 699 00:26:59,055 --> 00:27:00,115 the use of, 700 00:27:00,575 --> 00:27:02,674 oxygen imaging and flash radiotherapy 701 00:27:03,055 --> 00:27:05,830 has been a big one. And, we recently 702 00:27:05,970 --> 00:27:07,670 published a paper where we 703 00:27:07,970 --> 00:27:09,910 looked at the oxygen consumption 704 00:27:10,289 --> 00:27:12,230 in flash radiotherapy and, 705 00:27:12,690 --> 00:27:14,549 how it can be a limitation 706 00:27:15,570 --> 00:27:16,710 in, delivery. 707 00:27:18,515 --> 00:27:20,275 In in the field of flash radiation therapy, 708 00:27:20,275 --> 00:27:22,755 people are trying to figure out, what's going 709 00:27:22,755 --> 00:27:26,035 on. Like, in flash radiotherapy, if you give 710 00:27:26,035 --> 00:27:28,134 very high dose rate radiation, 711 00:27:28,835 --> 00:27:31,555 you reduce the damage to normal tissue, but 712 00:27:31,555 --> 00:27:33,815 you don't reduce the damage to tumor tissue. 713 00:27:33,900 --> 00:27:36,539 So that's the mystery. Like, why nobody can 714 00:27:36,539 --> 00:27:39,180 explain why that's true. Why do we reduce 715 00:27:39,180 --> 00:27:41,200 damage to normal tissue but not tumors? 716 00:27:41,660 --> 00:27:44,320 And so we're looking at the oxygen effect 717 00:27:44,859 --> 00:27:46,320 and its role, 718 00:27:46,835 --> 00:27:49,954 and that's what we published recently in, 719 00:27:50,355 --> 00:27:50,855 PMB, 720 00:27:52,355 --> 00:27:54,355 to try to explain that we we don't 721 00:27:54,355 --> 00:27:55,095 have the 722 00:27:55,394 --> 00:27:56,755 solution yet. It's like, 723 00:27:57,154 --> 00:27:59,394 we're writing a mystery novel, but we don't 724 00:27:59,394 --> 00:28:01,174 have the last chapter. You know? 725 00:28:01,880 --> 00:28:02,700 But, certainly, 726 00:28:03,240 --> 00:28:05,019 the pieces of the story 727 00:28:05,399 --> 00:28:06,859 are that oxygen is involved, 728 00:28:07,240 --> 00:28:08,779 and the consumption of oxygen 729 00:28:09,319 --> 00:28:12,039 changes when you change the dose rate. And 730 00:28:12,039 --> 00:28:14,244 so we think that's an important piece. We 731 00:28:14,244 --> 00:28:16,804 think it's a we know it's a major 732 00:28:16,804 --> 00:28:19,464 factor, but we we don't know the underlying 733 00:28:19,605 --> 00:28:22,565 mechanism yet. And, hopefully, that'll be our next 734 00:28:22,565 --> 00:28:25,765 paper once we discover the mystery of flash 735 00:28:25,765 --> 00:28:28,680 and publish that in PMB as well. Excellent. 736 00:28:28,740 --> 00:28:30,180 Yes. I want to keep an eye out 737 00:28:30,180 --> 00:28:30,660 on, 738 00:28:31,140 --> 00:28:33,140 I guess, what once the mystery is solved, 739 00:28:33,140 --> 00:28:35,000 then maybe we'll see FLASH 740 00:28:35,299 --> 00:28:35,799 radiotherapy 741 00:28:36,660 --> 00:28:38,519 in you being used in the clinic perhaps. 742 00:28:39,299 --> 00:28:41,720 It is. Yeah. There are clinical trials ongoing, 743 00:28:42,855 --> 00:28:44,934 but like most things in medicine, you know, 744 00:28:44,934 --> 00:28:46,634 you don't have to know the mechanism 745 00:28:47,095 --> 00:28:49,575 to use it clinically. So it is being 746 00:28:49,575 --> 00:28:50,555 explored clinically, 747 00:28:51,335 --> 00:28:53,654 but I think it would most people would 748 00:28:53,654 --> 00:28:55,440 agree it'd be more comforting if we sort 749 00:28:55,440 --> 00:28:57,960 of had at least a really solid guess 750 00:28:57,960 --> 00:29:00,460 about the underlying mechanism for how it works. 751 00:29:00,839 --> 00:29:03,419 And so we wanna do both, really. 752 00:29:04,039 --> 00:29:04,539 Exactly. 753 00:29:05,079 --> 00:29:08,059 Okay. And then finally, looking into the future, 754 00:29:08,595 --> 00:29:10,855 where do you see optics having the biggest 755 00:29:10,914 --> 00:29:13,954 impact in impact in medical physics? So, 756 00:29:14,275 --> 00:29:17,815 will the techniques that we discussed become increasingly 757 00:29:17,954 --> 00:29:21,015 common perhaps for guiding and improving radiotherapy? 758 00:29:21,829 --> 00:29:23,509 Or do you think perhaps there's another area 759 00:29:23,509 --> 00:29:26,150 of medical physics in which optics could play 760 00:29:26,150 --> 00:29:27,609 a a really important role? 761 00:29:28,869 --> 00:29:31,109 Yeah. That's a great question. It's a question 762 00:29:31,109 --> 00:29:33,269 I think about all the time because I 763 00:29:33,269 --> 00:29:34,890 live in both of these worlds. 764 00:29:36,255 --> 00:29:38,894 It's almost impossible for me to pick one 765 00:29:38,894 --> 00:29:40,755 area, you know, but I I would just, 766 00:29:41,215 --> 00:29:43,634 leave off perhaps by saying, you know, 767 00:29:44,414 --> 00:29:47,535 the use of optics is much, much larger 768 00:29:47,535 --> 00:29:48,755 than the use of radiation 769 00:29:49,055 --> 00:29:51,269 in medicine. Right? And so the tools 770 00:29:52,210 --> 00:29:53,190 for imaging 771 00:29:53,569 --> 00:29:56,309 or diagnosing things with optics are incredible. 772 00:29:57,650 --> 00:29:58,470 And so 773 00:29:58,849 --> 00:29:59,670 the intersection 774 00:30:00,369 --> 00:30:01,829 between radiation medicine 775 00:30:02,695 --> 00:30:03,914 and optical diagnostics 776 00:30:04,215 --> 00:30:06,394 or therapeutics is really wide open. 777 00:30:06,775 --> 00:30:08,795 You know, we're looking at some, 778 00:30:09,894 --> 00:30:12,875 we're looking at some areas now where optical 779 00:30:12,934 --> 00:30:13,434 photosensitizers 780 00:30:14,535 --> 00:30:16,315 can become radiation sensitizers. 781 00:30:16,849 --> 00:30:19,009 You know, that's one really exciting area to 782 00:30:19,009 --> 00:30:21,750 me. But even more broadly than that, just 783 00:30:22,049 --> 00:30:23,750 the idea that optical, 784 00:30:24,690 --> 00:30:27,190 diagnostics and treatments can be combined 785 00:30:27,570 --> 00:30:28,230 with radiation 786 00:30:28,930 --> 00:30:31,865 therapy or diagnostics or treatments. To me, that's 787 00:30:31,865 --> 00:30:34,444 the intersection that is really fertile 788 00:30:35,065 --> 00:30:37,164 and and really quite unexplored. 789 00:30:38,184 --> 00:30:41,065 There's only a handful of researchers I know 790 00:30:41,065 --> 00:30:43,085 working at that intersection space, 791 00:30:43,464 --> 00:30:46,130 but it's huge because both fields are enormous. 792 00:30:46,190 --> 00:30:48,929 You know, again, the optical devices are just 793 00:30:49,230 --> 00:30:49,730 everywhere. 794 00:30:50,109 --> 00:30:52,130 Radiation is incredibly powerful. 795 00:30:53,710 --> 00:30:56,190 And and and often, they kill tissue in 796 00:30:56,190 --> 00:30:57,409 a complimentary ways 797 00:30:57,950 --> 00:30:58,929 or the diagnostic 798 00:30:59,309 --> 00:31:00,904 measurements are complimentary. 799 00:31:01,365 --> 00:31:03,625 You know? X rays are good at structure. 800 00:31:04,005 --> 00:31:06,025 Optics is good at molecular signatures. 801 00:31:06,404 --> 00:31:08,485 You know? So why not combine them to 802 00:31:08,485 --> 00:31:10,424 get more detailed information? 803 00:31:11,445 --> 00:31:13,365 That those those are the areas that excite 804 00:31:13,365 --> 00:31:15,319 me the most and I think has 805 00:31:15,940 --> 00:31:17,079 the enormous potential 806 00:31:17,380 --> 00:31:18,919 for, future development. 807 00:31:20,740 --> 00:31:23,380 Brilliant. Well, thank you very much for speaking 808 00:31:23,380 --> 00:31:24,279 with us today. 809 00:31:24,819 --> 00:31:26,740 Sure. Well, thank you, Tammy. It's been a 810 00:31:26,740 --> 00:31:27,240 pleasure. 811 00:31:35,264 --> 00:31:37,044 That was the medical physicist 812 00:31:37,345 --> 00:31:41,105 Brian Pogue in conversation with Physics World's Tammy 813 00:31:41,105 --> 00:31:41,605 Freeman. 814 00:31:42,339 --> 00:31:45,159 It was recorded in association with the journal 815 00:31:45,460 --> 00:31:47,639 Physics in Medicine and Biology, 816 00:31:48,259 --> 00:31:49,159 which celebrates 817 00:31:49,539 --> 00:31:50,359 its seventieth 818 00:31:50,740 --> 00:31:52,200 anniversary this year. 819 00:31:52,740 --> 00:31:55,779 I'm Hamish Johnston, and our producer is Fred 820 00:31:55,779 --> 00:31:56,279 Iles. 821 00:31:56,965 --> 00:31:58,744 The theme music for this podcast 822 00:31:59,045 --> 00:32:01,684 is called one three seven, and it was 823 00:32:01,684 --> 00:32:03,144 composed and performed 824 00:32:03,445 --> 00:32:04,424 by the physicist 825 00:32:05,045 --> 00:32:06,184 Philip Moriarty. 826 00:32:07,285 --> 00:32:08,105 This episode 827 00:32:08,485 --> 00:32:10,825 is supported by One Physics. 828 00:32:11,940 --> 00:32:13,799 One Physics is The USA's 829 00:32:14,419 --> 00:32:14,919 largest 830 00:32:15,220 --> 00:32:17,319 outsourced medical physics provider, 831 00:32:17,940 --> 00:32:20,019 trusted by over 4,000 832 00:32:20,019 --> 00:32:20,519 clients. 833 00:32:21,220 --> 00:32:25,480 We proudly deliver diagnostic and therapy physics services, 834 00:32:26,125 --> 00:32:27,904 linear accelerator commissioning, 835 00:32:28,365 --> 00:32:28,865 dosimetry 836 00:32:29,325 --> 00:32:33,424 treatment planning, and radiation safety officer services 837 00:32:34,044 --> 00:32:34,544 nationwide. 838 00:32:35,484 --> 00:32:38,304 We are experts in medical physics services 839 00:32:38,789 --> 00:32:42,650 and radiation safety and can support your organization, 840 00:32:43,350 --> 00:32:46,710 whether you need annual physics testing to meet 841 00:32:46,710 --> 00:32:48,009 regulatory guidelines 842 00:32:48,630 --> 00:32:51,369 or are looking to implement a theranostics 843 00:32:51,830 --> 00:32:52,330 program. 844 00:32:53,085 --> 00:32:56,044 We are experts in all areas related to 845 00:32:56,044 --> 00:32:58,304 physics and radiation safety. 846 00:32:58,845 --> 00:33:01,424 With national scale and a local 847 00:33:01,804 --> 00:33:03,424 relationship driven approach, 848 00:33:03,884 --> 00:33:05,744 our best in class physicists 849 00:33:06,269 --> 00:33:10,369 bring precision and personalized care to every facility 850 00:33:10,509 --> 00:33:11,330 we serve. 851 00:33:11,789 --> 00:33:13,890 In the world of medical physics, 852 00:33:14,269 --> 00:33:14,769 precision 853 00:33:15,070 --> 00:33:15,970 isn't optional. 854 00:33:16,509 --> 00:33:17,410 It's everything. 855 00:33:18,269 --> 00:33:19,009 One Physics, 856 00:33:19,394 --> 00:33:22,055 your trusted partner in medical physics, 857 00:33:22,515 --> 00:33:23,654 linear accelerator 858 00:33:23,955 --> 00:33:24,455 commissioning, 859 00:33:24,835 --> 00:33:26,455 and radiation safety. 860 00:33:27,154 --> 00:33:29,095 Learn more about our approach 861 00:33:29,394 --> 00:33:30,934 to radiation safety, 862 00:33:31,315 --> 00:33:32,934 or schedule a personalized 863 00:33:33,394 --> 00:33:33,894 consultation 864 00:33:34,619 --> 00:33:36,960 at 1physics.com.