Modern Radiation Therapy: Stereotactic Radiation, Brachytherapy and Short-Course Treatment

Modern radiation therapy is becoming more precise, helping doctors target tumours while reducing exposure to surrounding healthy tissue and protecting quality of life.

In this episode of The Wellness Algorithm, Anshu Bahanda speaks with radiation oncologist Dr Madhur Garg about how radiation treatment is planned and how newer approaches are changing cancer care. They explore stereotactic radiation therapy, hypofractionation, short-course radiation and brachytherapy, including the difference between HDR and LDR brachytherapy.

Dr Garg also explains how CT, MRI and PET imaging are used to define the treatment area, how radiation doses are shaped around a tumour and why some patients can complete treatment in fewer hospital visits.

The conversation offers a clear introduction to modern radiation oncology, side-effect reduction and personalised cancer treatment, while examining what these advances may mean for daily life during and after treatment.

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Transcript

AB: When we think about cancer treatment, it's like going down a crazy rabbit hole. It's so confusing, it's so upsetting. Your nervous system is fried anyway. So what we're going to talk about today is actually radiation therapy. And many of us still imagine these long, exhausting treatments when it comes to radiation: repeated hospital visits, difficult side effects, and the fear of how much the body may have to go through.

But cancer treatment is changing, and radiation is becoming more precise, more carefully planned, and more tailored to the individual patient. Doctors are now thinking about how to treat the cancer with greater accuracy and protect more of the surrounding body. And they're thinking about how to preserve quality of life during and after treatment.

So one of the important shifts is the move towards more focused and shorter forms of radiation therapy. Today on The Wellness Algorithm from Wellness Curated, we'll explore how radiation therapy is advancing, what makes treatment more precise, where different cutting-edge forms of radiation fit in, and what these developments can mean for patients.

To help us understand that, I'm joined today by Dr Madhur Garg, who's a radiation oncologist based in the US, and his work focuses on advanced cancer treatment and precision radiation. Welcome to the show, Dr Garg. Thank you so much for taking the time to be here with us today.

MG: Thank you for having me. It's a pleasure, and I'm looking forward to a productive conversation today.

AB: Fantastic. I'm delighted that you're here. Now, I'm going to start with the very basics because, as I said in the introduction, a lot of people hear the word radiation and they start freaking out. They have this picture of a particular kind of treatment. So I want you to tell us: how has radiation therapy changed in recent years? What was it, and what is it today?

MG: Yeah, that's a great question, and you would be surprised how many doctors who are not in our field have not seen a radiation machine, let alone a patient who's coming into the department for the first time.

Just broadly, the machines have undergone a very significant transformation over the years, especially in the last 30 years or so. A radiation machine today looks like a CT scan machine. Literally, it's a lot more open, though, so there's less likelihood of patients getting claustrophobic, and it's just like a CAT scan. You lie on a table, the machine rotates around you, gives radiation for a few minutes, the patient gets up and goes home. So, overall, technology really has changed how we deliver radiation very significantly.

AB: And I'm going to ask you a silly question. Does it hurt the patient when you give them radiation?

MG: Again, an excellent question. A lot of patients ask us that. It's like getting X-rays. Radiation is like getting X-rays. Overall, radiation is high-energy X-rays. You don't see or feel anything. You lie on the table, as I said, and the machine goes around and gives radiation for a few minutes. It does not hurt. You don't feel any heat, literally nothing.

AB: Okay, and tell me, what are some of the biggest advancements that have made radiation more precise than it used to be, which is really the focus of what we're going to be chatting about today?

MG: Yeah, so when I started—in fact, I started in the early 90s in this field—we were towards the end of the old technology, where we were using literally surface markings to treat the tumour inside the body.

So we would basically look at the scans of the patient, then figure out how deep the tumour was inside, and draw a field on the skin of the patient based on the location of the tumour inside the body. We used to call that surface anatomy and treat based on the surface anatomy.

Then came three-dimensional radiation in the 90s, where you could do a CAT scan or an MRI and plan the radiation on the scan. So on the scan, you would say, okay, this is the area you want to treat. You would contour or define the area and then set up the beams from outside.

So that was the second level. The third level was where we were able to modify the intensity of the radiation beam. Initially, the radiation beam was all uniform, so the entire region would get the same dose of radiation. If I were to treat, for example, the throat or tongue, I would create a box around the tumour and treat the entire box with the same dose of radiation.

With three-dimensional radiation and intensity-modulated radiation, where you could modify the intensity of the beam, we were able to—or we are able to now—sculpt the dose to the contours of the tumour.

Because the tumour is not a box or a circle; it's all uneven. So what we can do now is identify the tumour on these advanced images from CT scans, MRIs and PET scans. We use all advanced technologies for imaging. On that, we contour the tumour, whatever the contours are, however irregular they are, and then plan on that.

And with this intensity-modulated radiation beam, you can literally sculpt the dose to the contours of the tumour, thereby giving a high dose to the tumour and reducing the dose to the surrounding normal structures.

So the advancements have come in both areas. One is imaging-based, so you can identify the tumour so much better now, and the second is delivery techniques, where you can modify the intensity of the beam to sculpt according to the tumour contours.

AB: So, Dr Garg, one of the reasons I'm having this conversation with you is because I know a few people who went to Dr Greco in Portugal, and they have raved and raved about the treatment and about how easy it was.

So what I want to ask you now is: when you're planning radiation treatment for a patient, what factors shape the decision? For example, is it the tumour type? Is it the stage of the cancer? The patient's overall health? Do all these things affect your plan?

MG: Yes. Again, every tumour is different. Every patient is different. So the first step is identifying what stage the patient is in. Is the tumour localised? Has it spread out in the local area, or has it spread out in the body? And based on that, you define what areas you're going to treat with radiation.

And as I said, every patient is different, every tumour type is different, and its aggressiveness is different. Once we ascertain the stage and the aggressiveness of the cancer, based on hundreds of studies done over the years, we know that this particular tumour, in this particular location, needs to get this much radiation.

And this dose of radiation can be given over a few days, in one treatment sometimes, or over a few weeks. So this whole process of first identifying what area to treat, then how much dose and how you're going to do it, is all curated or personalised based on the patient's anatomy and based on the patient's condition.

AB: Wow. And I'm going to ask you another question here. From what I'm hearing, with the sort of radiation that you do, precision radiation, sometimes the patients don't need chemotherapy either. Is that right?

MG: That's true. There are lots of cancers where you don't need chemotherapy, and the patient can be treated with curative intent just using radiation, without any surgery and without any chemotherapy.

AB: Wow. That's fantastic. So before I carry on further, I want you to explain a few of the different kinds of radiation to me. These names of the new kinds of radiation are floating around, like stereotactic radiation, short-course radiation, and then, of course, what you do, which is brachytherapy, right?

MG: Yes, that too. So historically, radiation was delivered over weeks. It would be done over five to eight weeks, every day, five days a week, sometimes six days a week, little by little, every day.

And that was the standard way of delivering it, because the reason was that you were treating a bigger area and the surrounding structures were getting a higher dose of radiation. So you would do a little dose every day with the premise that the little dose was going to affect the tumour but was not going to affect the normal tissue around it on a daily basis.

And the normal tissue recovers the next day when you come for the treatment, whereas the tumour does not, because the tumour cells don't recover that well from that low dose. So that's why you used to do radiation little by little every day, over five to eight [or sometimes] nine weeks.

AB: Wow.

MG: Yep. Yeah. So now, what has happened with this technology, with imaging and with the delivery techniques, is that you can really focus the radiation and treat it with millimetre precision.

So what that has done is reduce the total number of treatments. Every day, the patient is getting a higher dose of radiation, but the total number of treatments or the duration is becoming shorter and shorter, to a point where a lot of cancers can now be treated with one to five treatments.

Some can be treated with just one treatment. Some can be treated with three to five. Yeah.

AB: Because the person who told me about it said to me, “I went to the doctor in the morning, had the radiation, and then I was out with my family for a meal.”

MG: Yes.

AB: Now, that was unheard of earlier.

MG: Yes, yes. Yeah. I'll tell you that nowadays, patients come during their lunch breaks, come in the morning before work or after work, get treatment and go back to work.

So things have changed very significantly in a lot of cancers, where you can really pinpoint the radiation and focus the radiation in a way that the side effects are minimal, quality of life is unaffected, and the cure rates are very high—in a lot of cases, better than surgery.

Overall, when you look at the balance of cure rates and side effects, that balance is shifting a lot in favour of radiation, because the side effects and the downtime are much less compared to what they used to be, or even now with treatments like surgery.

AB: And the three different types of radiation which people are talking about—the brachytherapy, the short [course] radiation and the stereotactic radiation—is that just something that the doctor decides, which one is relevant, or is there a drastic difference between them?

MG: No, it depends on what you are treating and what area needs to be treated.

So, for example, brachytherapy is something which is done close to the body. Brachy means close, right? Close to the body, and therapy. So in brachytherapy, what you do is put radiation sources close to the body or inside the body, in the cavities.

So it's used for skin cancers, for example, because you can see the skin and you know what needs to be treated. You don't need to go very deep inside the body. So you put a radiation source on the skin. There are technologies and techniques to do that, but you're literally putting the radiation source close to the skin for a few minutes, taking it off, and that's it. It does not go deep into the body. It treats the surface, and the patient is done.

Similarly, in patients where you need to treat inside a cavity, for example, in women with cervical cancer or uterine cancer, we treat inside the cavity. We put a radiation source inside the cervix through a thin tube for a few minutes. It treats from the inside out, you take out the source, and the patient goes home.

Again, it can be done over one treatment. Sometimes it needs four to five treatments. That's brachytherapy, given close to the body.

In some cases, we put radiation sources in and just leave them there. In the prostate, for example, we have these tiny radiation sources the size of a grain of rice, and we insert them inside the prostate and leave them there. They give radiation over a period of a few weeks, from the inside out, and then they decay and the radiation from them goes away. And that's about it.

So the patient does not have to come back and forth every day for treatment. That's another type of brachytherapy, because it's done close to the body.

Stereotactic or intensity-modulated radiation therapy is done using these machines, which are delivering high-energy X-rays that come from the outside in. Brachytherapy is inside out or on the surface.

AB: Right. Tell me something. Now that the patient may not even need chemotherapy, typically, what are the side effects of the new precision radiation therapies that we're talking about?

MG: So the side effects of radiation depend on what area you are treating, because you are very precise now.

One misconception is, “Oh, you lose your hair when you get radiation.”

AB: Right.

MG: So I tell patients, you'll only lose your hair if I'm treating the head or the skull. If I'm treating any other part of the body, the side effects are related to that particular region and what normal structures are there in that region.

So, for example, if I'm treating the head and neck or a tongue cancer, the side effects will be related to the mouth or mucosa. Patients might have a little soreness or dryness in the mouth, or the skin over here on the side might get a little dark. So those are the side effects.

In prostate [cancer], when you're treating the pelvis, patients might have some urinary issues or some bowel issues. But again, because of the precision associated with these new technologies, the likelihood of these side effects has dropped very dramatically.

For example, with the old technology, 40–50% of patients would have significant side effects in prostate cancer. They would say, “Oh, I'm noticing some blood in the urine or blood in the stool.”

Now, with the new technology, it's less than 1% who will have blood in the urine or blood in the stools. So that's the dramatic decrease in any serious side effects that used to happen in the past with radiation.

AB: Wow, that is just amazing. But why is it—can I ask you—why is it that people don't know enough about this?

People still think—I mean, even I didn't know so much about it until I had friends who went to Portugal and then told me, and I was blown away. So why don't enough people know?

MG: Yeah, I think the advancements, first of all, have happened so quickly that people have not been able to keep pace with them, especially in other specialties.

In medical school, for example, there are no organised rotations in radiation oncology departments. So if a medical student wants to take an elective, they can come to a department to see what radiation oncologists do, but there is no mandatory elective.

So we are trying, at the medical school level, to see how we can go and give lectures in the school and tell them about radiation. We've started doing that over here. So that's one reason, because people don't know about it from the beginning.

The second is that the patients don't come directly to us. So if a patient has some sort of cancer, their primary doctor will diagnose or suspect it and send them to the surgeon, and the surgeon is the person telling them about the treatment options.

And that can sometimes be counterproductive. If the surgeon doesn't know or has an inherent bias, it becomes difficult for them to tell the patient about all the options and discuss everything.

So, in an academic place like ours, we are trying to address this by discussing patients in a multidisciplinary tumour board. All the specialists are there, trying to figure out what the best option for the patient is going to be.

And now, I'm hoping that with technology, AI, all these advancements and awareness, this is bound to get better. But you are absolutely right. The awareness still is not there.

In fact, there was some data recently where people looked at, for example, if there were 100 cancer patients who would benefit from radiation, how many of them would really get radiation? And the number is 50 to 60%.

AB: Oh, my God.

MG: Yeah. Because patients don't know or they are unaware, their doctors are unaware, and they get something else or are not referred to us.

AB: You know, we’ve spoken about this in a few episodes, actually, we did an episode on integrated cancer care. And one of the biggest issues that cancer patients have is that they are sent from one doctor to another doctor to another doctor.

And it’s exactly what you're saying: there's no integrated care happening. So they're seeing individual people. And even for them to find out what is available is like this crazy rabbit hole.

But I want to ask you another question about radiation therapy. Now, in traditional, older radiation treatment, there were huge amounts of planning involved before the treatment—before the patient got there and had the treatment.

Is that the case with modern radiation therapies as well? 

MG: The amount of work has only increased when it comes to the planning process and what we do behind the scenes. It is the technology that has shortened everything—the time it takes—because a lot of it is computerised now.

So when we decide, okay, this patient needs treatment or this patient is going to benefit from this treatment, we discuss the options and the whole process with the patient, including the risks and benefits. So we spend all that time.

Then the first step is a planning session, where the patient gets a scan and an immobilisation device. If he's going to get head and neck radiation, we make a mask for the patient, and then we do a scan of the area—the head and neck area.

Sometimes it's just a CT scan. Sometimes it's a combination of CT, MRI and even a PET scan. So we do those scans, fuse all of those scans together on the computer in the back, and then define the target.

Okay, this is the region I'm going to treat with 100% of the dose. This is the region where I need 70% of the dose because there might be some microscopic disease in this area.

So we define those regions, and then we define the normal structures. So, okay, the parotid gland or the spinal cord can only take this much dose. We define those and give constraints to those normal structures.

Once all that mapping and defining is done, we have a team of physicists who [create] the plan. They basically set up the radiation beams on that scan to see which direction they need to bring the beams from, what intensity the beams should be, and how many beams they're going to use to deliver that dose to the tumour and avoid delivering a dose to the normal structures.

They do all of that, they come up with the best possible scenario, they show it to the physician, and the physician likes it and approves it.

Then there is a dry run or a QA process, where we do the treatment on the treatment machine using a phantom. It's the final step because we need to make sure that whatever we have planned on the CT scan using computers is what the patient is going to get on the machine.

So we deliver the radiation dose to the phantom, and that phantom has radiation detectors or a film inside it which measures the dose, [to determine] how much dose the patient is going to get.

So we match all of that, then we bring the patient in and start the radiation. The process has multiple steps and several things happen.

But all of this has become shorter because of technology. A lot of mapping can be done automatically using AI and some of the other algorithms. So things have improved that way and shortened the whole course of planning.

AB: Wow. And tell me, from all the developments that we're hearing about in cancer care, what are you most excited about that's coming up or that already exists?

MG: I think what I am most excited about is the personalisation or the curation of treatment based on the individual patient.

So that's where we are moving towards the molecular side or the genetic side of cancer research, where what we are doing now is taking a pathology specimen or blood from the patient to see what is going to be the best treatment for this patient.

How much radiation dose does this patient need? Does this patient need chemotherapy, immunotherapy or anything else? And what are the chances?

So I think that personalisation is what I'm excited about, because it treats patients individually based on their cancer.

AB: So I did an interview on gene therapy, and even that blew me away because he was saying that, potentially, in the next 15 years, we could be removing the cancer gene from people before they get it.

MG: Yeah. You know, in certain cancers which are genetic or genetically induced because of mutations, there is definitely potential to change some of that.

But there are some cancers which happen because of the environment or because of patients' habits.

AB: Right.

MG: Or a person's personal habits or surroundings. And those will be hard to treat, obviously. And that's why this personalisation in treatment is important.

But definitely, a lot of research is happening to look at treatments at a more molecular and genetic level.

AB: And tell me, I would love to hear some stories where the treatment you do, precision radiation, has even blown you away, where you felt, oh, my God, how is this possible?

MG: Yeah, so there are lots of stories. You know, in general, obviously, I've treated thousands of patients over the last 25 or 30 years, and there are lots of wins and then there are some losses, right? So it keeps you humble, because obviously there is a lot which needs to be done.

But on a regular basis, you see patients who have been cured of their cancers, and you're seeing them 15 or 20 years down the road. They're sending their family members to you. They are happy, they're appreciative.

It's a mixed bag, but there are a lot of positive and good stories, especially in cancers where you didn't expect the response.

Because there are certain cancers where you know that there will be a 90% response or a 100% response—or close to a 100% response, I should say. And then there are some cancers where you know it is going to be a 25% response or a 30% response.

So when they respond and when you see their cancer has gone away, it is very heartening.

In fact, in the old days, there were certain cancers, like cancers of the kidney, renal cell cancers, or cancers of the skin, like melanomas, where people thought that these were radioresistant because they would not respond to standard radiation—the standard radiation given over eight to nine weeks.

But then, with research, we saw that when you use higher doses, when you treat them in three days or five days and deliver a high dose of radiation, which we can now do with precise and stereotactic radiation, these tumours also respond.

So a recent advancement is that we now even treat kidney cancers with radiation, without any surgery, which five or 10 years ago was not possible.

AB: Wow.

MG: So, yeah, some of those things are definitely mind-blowing, and they are advances from research and technology that we are seeing.

AB: And tell me, we were saying that there are very few side effects of this kind of precision radiation. So people could go home after three or five treatments and just lead a completely normal life.

MG: Yes. Most of the time, there would be some acute effects because of swelling or inflammation in the region. And patients might say, oh, it hurts or it's uncomfortable.

But the majority of those acute side effects go away within four to six weeks of radiation. And those acute side effects, most of the time, are not severe enough to affect quality of life in a significant way.

It depends on how big an area you are treating and what region you're treating. As I said, every area has structures which have different tolerances to radiation.

But in certain cases—in a lot of cases, for example, as we were discussing—patients come, get radiation and go home. A lot of patients don't feel anything.

They sometimes ask, “Doc, did you do anything? Because I didn't really feel anything except for a little burning during urination, which was very minor.”

So that's where we are moving towards, and they go about their normal life and routine immediately.

AB: You know, what amazes me is when I meet oncologists and radiation therapists and things like that, what amazing work you do and how many lives you save. So we're so grateful for the sort of thing you do. Okay, so now—

MG: From our side—no, I was saying, it's very exciting and, as I said, it's a mixed bag. There's a lot more work to be done, but it's a very exciting time to be in this field.

AB: One lifestyle habit that can make recovery easier. Actually, give me five lifestyle habits, because that is very useful for people.

MG: [This is something] which I've been very actively involved in over the last five years, especially the nutrition part in cancer.

And so, if you ask me, the two main [ones] are physical activity and exercise. Patients have this misconception that, oh, I have cancer, I'm getting cancer treatment, I should just rest.

That is a misconception because you need to be physically active. Lots of studies have shown that people who are physically active—in fact, going to the gym and doing some strenuous exercise, even for a few minutes—is helpful. So physical activity.

Nutrition is another. How do you maintain nutrition? A high-protein diet, making sure all the nutrients are there in your diet, and taking some of the superfoods which help in healing. So that's another big thing. Always ask for a dietitian.

The third is stress, right? How do you cope with stress? Proper counselling, spending time with the physician and asking the right questions help with that.

Fourth is sleep. Sleep is obviously highly, highly important, because as you're sleeping, you recover. Your body recovers very well. So that's the fourth.

And the fifth, in general, I think, is mindfulness. It's connected, obviously, to stress and sleep also. 

So those are the things I would say to focus on during treatment. Keeping a positive attitude in general definitely helps.

AB: So, Dr Garg, very few oncologists talk about what you're talking about.

And again, in the podcast, we talked about it and how difficult it is because patients have to go to six or seven different people to get all these different things.

And, you know, one of the people I spoke to is trying to create an integrated cancer care centre so that people get access to all of this under one roof, which would probably make their lives much easier.

MG: Yes, yes. And that's something a lot of cancer centres are trying to develop, this coordinated care.

So, first of all, the patient knows how their journey is going to be, because now the treatments sometimes can go on for months. Some patients are getting targeted therapy, surgery, radiation—a combination of things.

So [it is about] how the journey is going to be, and then how the lifestyle factors, as we were discussing, are going to be integrated into all of this.

Because patients want to know what they can do. Patients ask, “Okay, Doc, you're going to do the treatment, and I trust you, I understand, but what can I do?”

So that's where I like to discuss nutrition, physical activity, mindfulness, sleep and all of these other things which they can do, which science is now showing improve outcomes both in quality of life and how they're going to beat the cancer overall.

AB: So let's do a quick rapid-fire round before we end. So, I’m going to ask you a question, and just try to give me as short an answer as possible.

One misconception about radiation therapy you wish would disappear.

MG: Just one misconception, I would say, the misconception that all sorts of radiation cause side effects, which is not true.

AB: Okay. I would say another one is probably that it always has to be a long course. A lot of people I know think there's going to be a really long course of radiation.

MG: Oh, yes, absolutely. Absolutely, yes.

AB: One question every cancer patient should ask before choosing treatment.

MG: What are my options? Because most cancer treatments now will have multiple options. So it's always good to ask about the various options and always get a second opinion before starting treatment.

AB: Okay. One thing patients often underestimate about radiation therapy.

MG: The curative potential of it. A lot of people think radiation is only for palliation, or that it's going to stabilise the cancer but will not really cure it.

But a lot of cancers nowadays will get cured or disappear with radiation.

AB: Yes, I think you're absolutely right. People don't realise that radiation is enough to sort out a lot [of cancers]. Because previously it wasn't, right? They used to combine it with chemotherapy.

The biggest change you have seen in cancer treatment during your career?

MG: I think the biggest change is the advancement in technology and how quickly we are able to adopt new treatments because of that, [as well as] the personalisation of care.

AB: What gives you hope about the future of precision cancer care?

MG: The advancements which are coming. So last year, in 2025, we had 17 new cancer treatments approved.

So it's more than one new cancer treatment getting approved every month. Fifteen years ago, this used to be one or two in a year. That would be a big thing.

So those advancements and the speed with which this is happening are, I think, very promising, and I feel very optimistic about beating cancer or at least making it a chronic disease in the near future.

AB: So, of these 17 treatments, which cancer treatments are you most excited about? The ones that came out last year.

MG: Some of the cancers where we had very little hope, like pancreatic [cancer], for example. There's very little hope and very few treatments.

There's a new treatment now for pancreatic [cancer], a targeted therapy which has been shown to improve outcomes. There are some preliminary, very promising results, so that's something which is really good.

Then there are some cancers of the blood and some cancers of the brain. So there are a bunch of advancements in some of the diseases—or cancer types—where there was little hope.

AB: Wonderful. Thank you so much for this conversation, Dr Garg.

I'm just blown away by what you've talked about today, and what I'm taking from this conversation is that radiation therapies have changed far more than so many of us realise. Even those of us connected to the field didn't know about it.

And it's no longer just whether someone receives treatment; it's about what kind of radiation is right for them, how precisely it needs to be delivered, how many sessions are needed, what organs need to be protected and what matters for that person's quality of life.

And thank you for highlighting to us how cancer care has evolved into something which is very, very personalised.

And also for highlighting to us that people should ask what their options are, because that's very important, and not just take the surgeon's word as the word of God.

And thank you again for being here and for making time to be here.

MG: It's a pleasure, and thanks for doing this. This is a wonderful forum.

AB: Thank you. I hope we reach lots and lots of people, and I hope we manage to help lots of people.

And to those of you listening in, if this has helped you in any way, or if it's something you didn't know about, please share it with friends, family or someone it could help.

I know cancer is still a scary word, but it doesn't have to be, with all the treatments that exist.

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I'm Anshu Bahanda, and as in everything else, I try to simplify things as much as possible so that you can be more aligned in all your decisions, medical or otherwise.

And life flourishes when you're aligned. Thank you.