The Current State of Radiation Oncology - Daniel Spratt

November 15, 2023

Daniel Spratt explains advances in radiation oncology for prostate cancer, explaining how techniques have evolved from whole pelvis radiation with high toxicity to conformal therapies like SBRT that precisely target the prostate and dramatically reduce side effects. He discusses research on further hypofractionation with as few as 1-2 treatments, ongoing trials of focal therapy boosting dominant nodules, and efforts to reduce erectile dysfunction.


Daniel Spratt, MD, Chair and Professor of Radiation Oncology, UH Cleveland Medical Center, Seidman Cancer Center, Case Western Reserve University, Cleveland, OH

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Jason Hafron: I would like to introduce the speaker for our next session, What's New in Radiation Oncology, Dr. Dan Spratt. Dr. Spratt is the Chairman and Professor of Radiation Oncology at University Hospitals Seidman Cancer Center and Case Western Reserve University. He has published over 300 peer-reviewed manuscripts, including practice-changing work in the New England Journal, JAMA Lancet, JAMA Oncology, JCO. Dr. Spratt is an international expert in the management of prostate cancer and the development and validation of prognostic and predictive biomarkers. He serves as the Chair for NRG Oncology's Intact Prostate Cancer Subcommittee and for the National Cancer Institute Genitourinary Steering Committee. Presently, he's also the senior editor for Radiation Oncology's premier medical journal. His Twitter handle is DrSpratticus, so I guess that would make you the Greek God of radiation oncology. With that being said, I'd like to introduce Dr. Dan Spratt.

Daniel Spratt: All right, appreciate it. Now, I want to see, okay, great, this is the first time I've had to not stand behind a podium giving a talk. This is my favorite meeting to be invited to and I wish radiation oncology had a meeting like this, because that last session I learned a tremendous amount and radiation causes tons of pelvic problems, especially in gynecologic cancer patients. But I intentionally threw in some controversial slides into this as probably one of fewer than, who knows, maybe 10 rad oncs in the audience, just to keep everyone's attention.

So what's new in radiation oncology, and I guess raise of hands, when I did this 2 or 3 years ago, it was about 50% of people owned radiation services in their practices. How many people own or we'll say are closely linked with radiation services in your practice? It's a lot. Okay. It's a smart move.

Our purpose as physicians, and it's very apparent at this meeting that you guys all recognize this and it's palpable, it's to improve the way cancer patients experience life. Here's the little bomb I'll drop to keep your attention for this slide. But right, we've got many treatment options for prostate cancer, and I think for low risk, there's not a lot of controversy anymore. We monitor these patients. For intermediate risk, the ProtecT trial, while an imperfect trial, actually 30% were intermediate risk. It was about 20-some odd percent were Gleason 7, so these patients just do so well, we're probably never going to prove something's better oncologically.

But I like to always walk through briefly the evolution of radiation therapy because we have people of all ages here, in how toxic and different radiation therapy used to be. Especially in smaller, maybe more rural or in radiation practices that are not giving state-of-the-art treatment, I think it's important for you to understand these differences, because whether you own the radiation services or whether you're sending patients to a radiation oncologist, you ultimately want those patients to have a good outcome.

So this is up until the 1980s, a guy many of you may know, Bill Shipley, he was at MGH, long retired, in, what we would call standard doses of radiation by today's standards, a third of guys had severe rectal bleeding. We burnt their rectum literally, and this is what it looked like. That's an X-ray. There were no CT scans, there was no MRI scans. We shot a beam through the whole pelvis. We helped some of these patients. Now, mind you, almost all these were T3, T4 patients, PSA wasn't being used.

Then we get into the era where the ProsQA data, the ProtecT trial data, all of this with 3D radiation, a 4-field box we use. So you got this little red box around the prostate. You spare some of the high dose from the rectum, just that little bit of sparing by not just blasting the entire pelvis. As you guys have seen in the ProtecT Trial, about 8% of guys had bothersome rectal side effects with this technology. It still took months to complete. That was probably the number one complaint when I was in training in New York at Sloan Kettering. They did 48 treatments of 10 weeks of radiation therapy, Monday through Friday. So they often would go to Peter Scardino and say, "Let's just have surgery. I need 10 weeks back in my life."

Then IMRT, which is by no means new, it was used in the 1990s. And as you see here, this is a patient where the red is the full dose, the blue is half the dose. This is the rectum, as you can see, and on the right there, that's the full dose. So you're skimming. The high dose is touching that rectum. There's no way to avoid it, unless you are blessed with a very obese patient with tons of visceral fat playing, they have their own rectal spacing. But this is what it looked like. And just by doing this, and we have many trials, some with 20 years of follow-up, most, though, are more like 10 years, that's about 1-3% high grade, grade 3. An intervention, not just meds, an intervention is needed like holmium laser or some other coagulation.

I apologize, ignore that this. This is supposed to just say SpaceOAR. There are multiple SpaceOAR gels on the market that can be used to separate the prostate from the rectum. Right now it's estimated over half of all patients that get radiation therapy for prostate cancer in the United States have a spacer. So it's the most successful company product, et cetera, device that's entered this space. And so you see the pink here. This is one of my patients. That's the spacer gel before we started using a contrast-enhanced gel, that's the rectum. So half the dose we give doesn't even touch the rectum. The full dose, obviously, is not touching the rectum. And now there have been multiple randomized trials, but there's not even any grade 2 rectal side effects. Grade 2, that's giving an IMODIUM.

This is the randomized trial. So pretty much all of my patients, and I collaborate closely with urology to do this and we set it up so that we are very fortunate, our urologist, Dr. Yoni Shoag, he gets two rooms. He does it under anesthesia because guys don't like manipulation down there, back-to-back does 10 of these fiducials and spacers, and it's about 6 RVUs a pop for him, so 60 RVUs, never has to do a consult, never has to see him for follow-up, and he goes home at noon and I keep working.

The treatments, it is now, you will not find a guideline in the US, and it's even more strict if you go to Europe, that now recommends what people would call conventional fractionation. The NCCN prefers moderate hypofractionation based on randomized trials. I live in Cleveland. Cleveland Clinic, their standard treatment for over 15 years has been moderate hypofractionation. This is not new. We just published about a month ago in JAMA Oncology that as of 2019, the minority of practices in the US use this long course, and it's SBRT, which is this at the bottom, which is, I'll show you, based on now multiple phase III randomized trials that's been in NCCN guidelines for a number of years. The adoption of SBRT is outpacing even moderate hypofractionation.

I got to give a shout-out. That's Yoni Shoag urologist in the middle, he does all the spacers. And so we adopted a contrast-enhanced spacer gel, you can see here. We try to be very cost conscious in that we get an MRI or urology usually gets an MRI before the biopsy. This lets me not get a treatment planning MRI, so it spares one more cost to the patient and delays. Probably 90-95% of all of my patients I do SBRT for. Why?

Well, big randomized trial in Europe, they're going to put out their next report with over 10 years of follow-up, but 1200 men, big phase III trial. It was actually kind of outdated techniques. Not a lick of difference in giving eight weeks versus about a week and a half of treatment. This is the PACE-B trial. This is the European trial. This is the most contemporary trial. There's no rectal spacers or anything. I don't like how they always publish this with these shapes, but the red is the 4 to 8 week course of radiation, the blue is the SBRT, grade 3 are these these little trials at the bottom. Basically, almost no patient had a grade 3 side effect on this trial regardless of arm. At our ASTRO meeting that just happened a little bit ago, earlier this year, they presented longer-term results. Basically everything has stayed the same.

So radiation has changed a ton. I probably speak to, I don't know about 40, 50 advocacy groups around the country, it was just in DC, patients are familiar with SBRT and I don't mean CyberKnife branding or things like that. They're hearing it because in many cancers, especially as I'll get to in the metastatic setting, SBRT is playing more and more of a role. So the treatment has changed quite a bit.

I show you this, it was presented. Obviously some people did not like this. This is Noel Clarke and the PACE team in the United Kingdom. They somehow pulled off a randomized trial of surgery versus SBRT, no spacers. Now, I've worked very closely with many urologists and they will all say these incontinence rates of 40% at whatever that is a year or two is out of this world high. And I agree. Like many, I was super surprised. I'll also say, though, I've never seen, whatever that is, 3% with SBRT have incontinence. So I don't know how they're measuring their scale. Someone's really, really asking, "Is there a little drip when you shake?" But the point of it is SBRT is not really causing incontinence that some brachytherapy patients actually will have.

But the bigger thing is when you compare to things like the ProtecT trial, again, no rectal spacing here, 1 patient had a moderate to big GI problem 2 years later, 1 patient, and this is patient-reported quality of life. So things have definitely changed in erectile dysfunction for SBRT. Only 12% at 2 years. And obviously we care longer than 2 years, but only 12%. Now, there's no hormone therapy, as I'm going to get to in a sec, used on this, but pretty minimal impact given how conformal this treatment is.

So what's happening? Already, as I'll show you, there's five randomized trials undergoing to get down to two treatments. In post prostatectomy, I already, since 2019, only do 20 treatments. They just published, in the United Kingdom, the RADICALS trial data, and there's trials ongoing, randomized trials, of five treatments post prostatectomy. I've done that on patients and they do amazingly well. That's not primetime, but that's going to be coming soon. As I was telling someone, ASTRO is putting forth something called a rocker model. That's our quality model that's going to bundle payments, so prostate cancer gets a flat fee. So for all of those that think I'm crazy talking about all this hypofractionation, the second that's approved, I can promise you it will be a hundred percent of everyone is like, "Are we ready for two fractions? Can we just do two now?" These are just various trials that are ongoing.

I will say, there are groups, I put a big cautionary tale, that are trying, and this is a group in Europe, it's the lamest name I've ever heard called a virtual prostatectomy. They did one fraction and they put this huge balloon in the guy's rectum so the rectum wouldn't move, they gave him dexamethasone, all these drugs, and it still didn't look that great. So end of the day, I don't think this is coming anytime soon.

There's a lot of interest. I mean, radiation, no question can cause erectile dysfunction. And so just like with surgery, you guys have favorable anatomy and unfavorable anatomy. Some patients are, no question, going to keep their erectile function. Some, no matter what you guys do, we'll lose it. There's a lot of work going in. This is a paper, now 7 years ago based on a trial we did, single arm. So this is all men that had good erectile function going in. We did this vessel-sparing technique. There's a whole bunch of anatomic structures we push the dose away from. And the point of the slide is that almost 90% of men 5 years later were still sexually active. It didn't use, unfortunately, the EPIC-26 questionnaire, are the erections firm enough for intercourse? So I don't tell patients that that's prime time.

This randomized trial called POTEN-C run out of UT Southwestern, one of my co-residents decide to launch it and it's SBRT, everybody gets a spacer gel and half the guys get this vessel-sparing radiation, half do not. There's, I think, only 2 left to enroll. It'll be a 2-year sexual function endpoint. I'll say I'm cautiously optimistic, but this would be a huge win for patients.

All of the stuff I'm talking about, you need to make sure your radiation oncologists, just like I have seen great surgeons, average surgeons, horrific surgeons, there's the exact same in radiation oncology. There's radiation oncologists, it is absolutely frightening what I see, and there's ones, obviously, doing phenomenal work.

Other ways that it is changing. I kind of intentionally dropped that little bomb initially about focal therapy, is I hear a lot of people say focal therapy, it's like breast cancer. Okay, well as a radiation oncologist who trained to treat breast cancer, breast cancer is you do a focal treatment, you take the tumor out with the lumpectomy, and then you radiate the whole breast. Because if not, it's like a 20-30% recurrence rate. And that's what we're seeing with focal therapy, whether it's focal radiation, et cetera. So trials that are ongoing now.

This is already a randomized published phase III trial, essentially, I don't want to call it the brachytherapy killer, but in the US it's only about 1.5% of men with newly diagnosed prostate cancer get brachytherapy in the United States now. Part of it is SBRT, part of it is we can do this now where we can use technology to give higher doses to the dominant nodule. And this had basically the exact same benefit observed by boosting with brachytherapy, but no increase in toxicity. Other trials that is trying to, instead of improve tumor control, they're saying, "Well, wait, do we really need to give all of that dose to the whole prostate? Can we give a microscopic dose," we'll call it half the dose, "So we're very unlikely to cause as much urinary bother rectal lower-grade side effects and just give a high dose?" And so these trials are ongoing as well. Because, and they ran one out of my institution, the pure SBRT focal trials, half the guys, like every trial, with Gleason 7 disease end up recurring. The tumor's dead, but it doesn't address the rest of the gland.