Chapters Transcript Video Advances in Radiation Oncology What to know about Proton & Photon Therapy in 2026 Welcome to Doc to Doc, where we explore the latest advances shaping cancer care. Today, we'll be discussing updates in breast cancer treatment using photon and proton therapy, including how modern photon-based techniques are improving precision and reducing toxicity. We'll also explore recent data comparing proton versus photon therapy and what these findings mean for clinical decision making and patient outcomes. Whether you're in academic medicine or community practice, this conversation aims to clarify how emerging evidence can guide your approach to radiation planning for breast cancer patients. Welcome to Baptist Health Doctor Doc, a podcast built for innovation and collaboration by physicians for physicians. Hello, I'm Joseph Panoff, radiation oncologist specializing in breast cancer with Miami Cancer Institute, part of Baptist Health South Florida, and I'm joined today by my colleague, Doctor Yusuf Zaiden, radiation oncologist with Eugene M and Christine E. Lynn Cancer Institute at Boca Raton Regional Hospital, part of Baptist Health. Hello there, Yusuf. Pleasure to be here. Great to see you. When I think about. Breast cancer treatment. And I think about radiation. I see these two things as a parallel course. Over the past 20 to 30 years, treatment advances in medical oncology and surgical oncology have advanced exponentially, and we've improved survival and reduced toxicity, and nowhere is this more profound than in radiation oncology where we have basically progressed from. Two-dimensional planning, to three-dimensional planning with the advent of the CT scan, to intensity modulated radiation therapy, and now the most modern intensity modulated radiation therapy, which is volumetric arc therapy, and we're able to Target the cancer in the most precise ways while sparing and reducing toxicity to normal tissues. Doctor Zaiden. Could you elaborate on some of the work that you've done utilizing uh photon therapy in your research? Yeah. Yeah, thank you, great question. Exciting times really to be in the breast cancer research field and the breast cancer medical field in general. As you said and alluded to, our field has been witnessing a revolution in the treatment and management of breast cancer. And I think when all cancer specialists talk about precision oncology, breast cancer community as a field has been an early adopter of precision oncology, probably the first adopter of precision oncology. So over the past 10 years, we've been excited about tailoring radiation therapy treatments to individual patient risks. What this means is delivering more effective radiation therapy and at the same time sparing patients who actually can avoid radiation therapy. Um, as you allude to Doctor Panoff early on, that, uh, the systemic therapies we're using today are much more effective compared to the systemic therapies we had 1020 years ago. And this is resulting in excellent and improved patient outcomes in some breast cancer subtypes we're seeing complete pathological responses nearing 60, 65%. So this is a great, so the question we've been asking is what does this mean in the era of modern systemic therapy to radiation oncologists and to patients seeking consultations with the radiation oncologists. So we had a study early on in patients with HER2 positive breast cancer. That had limited amount of axillary disease, what we call N1 disease, and they receive neoadjuvant systemic therapy and they convert to node negative disease. And we asked the question, what is the benefit of so-called post-mastectomy radiation therapy in this subset of patients, and we found very little to no significant benefits for local regional disease control for those patients that convert to node negative after receiving. A neoadjuvant systemic therapy. Now fortunately, we have a randomized trial that just got published last year, NSABPB51, which Baptist Health was also part of uh that trial, that confirmed these results in a bigger scale, again across multiple subtypes. So what this means for patients is that in the era of effective systemic therapies, we're really now able to de-escalate radiation therapy in the right patient that meet the criteria for omission of radiation therapy. Another front line we've been working on is those patients that have recurrent breast cancers. And for a long time, patients that have a recurrence in a breast that has been previously treated, the only standard of care that's been available to them is to have a total mastectomy. As one could imagine, total mastectomy is a big surgery. It could have body image and psychological effects. So now we have a trial that's Open for this subset of patients called the Brazil trial, essentially offering these women a chance for a second breast conservation, where they could have the uh recurrence or the new primary in the previously treated breast resected again, and then they could have partial breast irradiation, and we're really excited to have that trial open. That's very exciting. Um, recent data has also shown that when you compare toxicity of protons versus photons, there's some difference, and we have a large randomized trial called RDComp which recently reported results at the Astro annual meeting which was early in preliminary results showing no difference between the groups. However, there's emerging data. That shows that although proton therapy reduces cardiac dose, which we know very well, there's increased toxicity with other side effects such as capsular contracture and skin toxicity. And I think it's important to highlight that when we have this technology. It's not a one size fits all. We have to tailor the treatment to every patient because there's pluses and minuses and risks and benefits to each toxicity in each technology. And so, um, although there's Incredible benefits to proton therapy. There's also potential increased toxicity, and patients need to be aware of that. What data has shown regarding breast cancer patients with two rounds of radiation impacts the cardiac function? So people who've, um, require a second course of radiation that, that, and, and you just talked about a clinical trial that we have open called the Brazil trial, and that's very exciting. For people that have more locally advanced disease and might require a second course where we have to treat the lymph nodes, would you say that protons are a good option in this patient group to treat? Yeah, excellent questions. And now with the aging population, we're seeing more and more recurrences in breast cancer, but it's really two questions that are kind of folded in one question. Here. So every time we see a breast cancer patient, our ultimate goal is to deliver the most effective treatment with the least amount of toxicity. So we have to keep in mind that our goal is to transition the patient to a normal uh and long life after they finish with the treatment with the least amount of short and long-term morbidity. Um, and for a long time, unfortunately, because of the older techniques that were used in the 70s and the 80s, there were reports tying radiation therapy to long-term cardiotoxic effects. Ah, it's been estimated that for every one gray of mean heart dose increase, there is a 7.4% increase in major coronary artery events, that means a myocardial infarction or an ischemic event for the heart, which obviously could lead to a tremendous. deleterious effects for the patients. Now, fortunately with the new techniques that we have available nowadays, these cardiotoxic effects have been reduced to a bare minimum, and we and others have shown that the, the, the, using modern techniques, you could really lower the cardiotoxic effects of radiation therapy. So some of the techniques we use in our daily clinics are things like breath hold technique, or the prone position technique which can cut off the mean heart dose up to 50%. However, in certain patients, the anatomy, ah, can be unfavorable, particularly in the setting where you're treating locally advanced disease, where you really have to include the internal memory chain nodes, or a very medial target where you have the dose of radiation sitting very close to the heart. And here in this setting, proton therapy can be advantageous, because essentially using the biophysical properties of. On therapy with the BRC peak effect, you could carve that dose to your target tissue at risk while minimizing the spill dose that goes to the tissues beyond the target tissues such as the heart and the lungs. So, yes, that we have a major advantage by using protons, however, as you alluded to, it's not for every patient, so we really have to tailor those technologies to the right setting. And to the right, uh, patients. Uh, as we alluded earlier, uh, we have now options for those patients that have recurrent early stage of breast cancer, they don't have to go through mastectomy. They could have a second round of, uh, radiation therapy after having a second round of lumpectomy on a clinical trial that we have both open at Miami Cancer Institute and Lin Cancer Institute as well. When I think of radiation therapy. I look at it as a. Incredible technological transformation. And we are now in 2026 able to. Customize our treatment based on what the patient has and what stage they are and what anatomical areas we need to treat and what organs we need to spare and and at uh Miami Cancer Institute and Lynn Cancer Institute, Baptist Health South Florida, we have access to all the bells and whistles and tools that we need to do that. But the most exciting thing that I think of, uh, when I think of radiation research and progress within the past year and a half is the group of people we don't need to treat and as we previously talked about the NSABPB51 trial which was published in the New England Journal of Medicine this past year. Gave us a way to not treat a large group of people. We also had the Supremo trial, which has recently published in the last year, which is another population in the post-mastectomy setting that we no longer need to treat. And so I think that in this, there's other trials that are ongoing that are trying to de-escalate treatment so that we don't have to even radiate people moving forward and especially with molecular genomic profiling. And I think that this is just so exciting and um I'm extremely optimistic about the future of breast cancer research and treatment. Um, what do you think proton therapy coming to the Boca Raton community means for the patient community? Yeah, uh, honestly, I think this is gonna be the highlight of cancer care in the Palm Beach County region. We've been waiting for this for years to, to come to our area. So, it's gonna be equally exciting for our patients, but also for the physicians working in the area as well. For patients, it means they could have the latest technology right next to their backyards without having the need to relocate and commute long distances for two months or even longer sometimes to be closer to a proton therapy facility. And then for physicians, it's gonna be that finally we have all the technologies that we need in order to treat the breast cancer in a more effective way and in a a lower toxicity to the to our patients. So we're gonna have all the tools needed all under one roof, so it's gonna be really comprehensive, you know, from A to Z, uh, for, for our patients and, uh, also at the same time for the physicians, it's gonna open a Pandora box for, Conducting clinical trials and being part of a global clinical trials network for proton therapy for uh breast cancer, so it's really very exciting time for us as well as our patients. It's also gonna allow us to go to kind of touched territories, such as patients that have recurrent tumors that have been previously irradiated heavily in the past, or patients that require extensive radiation fields like craniospinal radiation. For those patients that unfortunately have lepto meningeal dissemination of their disease. So these are also some other uh indications that sometimes proton therapy will have a, a more shining effect as compared to, to photon therapy, and it's really good to have that. I am also certain that my colleagues that treat other disease sites share the same excitement to have the proton therapy uh facility opening in Boca Raton in spring of 2026. Well, thank you, Doctor Ziden. Um, I think that the future of radiation oncology is bright, and the future of patient care is bright, and breast cancer research and progress in curing this disease, it's, uh, moving quickly in the right direction. As we've discussed, photon therapy continues to demonstrate remarkable precision and reliability in the management of breast cancer, offering excellent local control with favorable toxicity profiles. The emerging comparative data with proton therapy underscores the importance of individualized treatment planning rather than a one size fits all approach. Ultimately, our goal remains to integrate evolving evidence and technology in a way that maximizes therapeutic benefit while preserving. Quality of life. Ongoing trials and long-term outcomes will further refine how we apply these modalities in practice. To find out more about the topics covered on BaptistHealth.toc, please visit physicianresources.baptisthealth.net. Created by