What Every Man Should Know about Radiation Therapy for Prostate Cancer

Memorial Sloan Kettering Radiation Oncology Vice Chair Michael Zelefsky

The optimal type of radiation therapy for prostate cancer depends on each patient’s specific disease.

When it comes to treatment for prostate cancer, men now have several good options. Advances in surgery, radiation, and endocrine therapy have greatly improved the prognosis for patients with this disease. Yet the many different choices — including the various types of radiation therapy — can be hard to sort out.

To help make sense of the options, we spoke with Michael Zelefsky, Vice Chair of Memorial Sloan Kettering’s Department of Radiation Oncology.

What are the different types of radiation therapy for prostate cancer?

Radiation treatments for prostate cancer can be divided into two main types: brachytherapy, or internal radiation, and external beam radiation.

Brachytherapy can be further subdivided into low dose rate and high dose rate. In low-dose-rate brachytherapy, seeds containing radiation are carefully placed within the prostate while the patient is under anesthesia. The seeds stay in the body and give off their radiation dose over a period of several months. For high-dose-rate brachytherapy, tubes or catheters are placed into the prostate, also while the patient is under anesthesia, and a high dose of radiation is delivered over a few minutes, often in several sessions. The radiation source is then removed from the body.

The main forms of external beam radiation for prostate cancer are intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery

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Do we know which treatment is better for prostate cancer, brachytherapy or external beam radiation?

VIDEO | 01:21
Learn why brachytherapy is the best form of treatment for some cancers.
Video Details

It’s not a question of which therapy is better but rather which therapy is the most tailored, pinpointed radiation for the patient’s specific disease.

When it comes to early stages of disease, patients very frequently do well with either brachytherapy or external beam radiation. Success rates of around 90% or higher can be achieved with either approach. When the disease is somewhat more advanced — based on the PSA level or the Gleason score or visible evidence of disease on an MRI — we have learned over the years that higher doses of radiation are critical to achieving better results. Some evidence suggests that for patients with intermediate- or high-risk prostate cancer, a combined approach using brachytherapy along with external beam radiation may be best.

Data that we have published recently show that for patients with intermediate-risk disease, the combination of external beam radiation with brachytherapy not only provides better biochemical control, in terms of PSA level, but also reduces the risk of distant metastases, or spread of the disease. Another recent study from Canada, which compared outcomes in patients who were treated with external beam radiation or a combination approach, found superior results when the combined approach was used. These studies provide strong evidence that higher doses of radiation provide an important benefit to patients with intermediate-risk and high-risk prostate cancers.

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Are there side effects of the combination approach?

There is a slightly higher chance that patients who receive the combined therapy will have rectal irritation or urinary side effects, both of which are common with any radiation treatment given to the prostate. But at MSK, we routinely use sophisticated planning techniques that help us reduce the dose given to normal tissues such as the rectum, bladder, and urethra, lessening the chances of side effects and complications.

In addition, at MSK, we routinely use a rectal spacer gel, which we inject between the prostate and the rectum while the patient is under mild anesthesia, to create a buffer between these two tissues. By creating this space, we can further reduce the dose of radiation that the rectum is exposed to. This leads to fewer side effects for the patient. The rectal spacer gel is biodegradable and after a few months dissolves on its own within the body, causing no harm or long-term effects.

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When is brachytherapy alone the right choice?

For a patient with disease that is confined to the prostate and not too aggressive, brachytherapy alone is a good option. With the use of sophisticated real-time computer-based planning, we can use brachytherapy to deliver radiation in an extraordinarily precise way, with minimal exposure to the surrounding normal tissues. It is also convenient for the patient as it is done in an outpatient setting and most people are able to get back to work the next day.

But brachytherapy is not right for everyone. For some patients with less-aggressive disease, a watch-and-wait approach would also be very reasonable. At MSK, our philosophy is that when the disease is caught very early — meaning a low PSA level, or nonaggressive disease as reflected by a Gleason score of 6 with evidence of cancer in only a few of the biopsy samples and no evidence from the MRI of a significant amount of disease — then it would be very appropriate to do active surveillance and hold off on treatment.

Hans’ Story
Doctors at Memorial Sloan Kettering recommended either surgery or radiation therapy to treat Hans’s prostate cancer – Hans opted for brachytherapy.

Those patients with very large prostates or those who have a significant amount of urinary symptoms may experience more side effects with brachytherapy. In these situations, we often steer such patients toward other kinds of treatment such as surgery or external beam radiotherapy. Surgery to remove a large prostate may be the better approach, to avoid the urinary symptoms that could be associated with radiation treatments. In some cases, where the prostate is moderately enlarged, hormonal therapy can be effectively used to shrink the prostate down over a period of several months. This can then be followed by brachytherapy or external beam radiotherapy.

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What is stereotactic body radiation therapy (SBRT) and what advantages does it offer?

Traditionally, we deliver external beam radiation in 45 to 48 sessions over a span of ten weeks, using very sophisticated computer-based planning and enhanced imaging techniques and tumor tracking during the treatment. This is called image-guided IMRT and it is the current standard of care.

But there is increasing interest in giving this radiation in shorter courses of treatment. Many of the people we care for have a type of radiation therapy called MSK PreciseTM. MSK Precise is a form of SBRT that can be given in five sessions instead of the usual 45 to 50. MSK has been doing this for the past nine years, and the results in the several hundred people who’ve been treated have been excellent so far. The treatment is very well tolerated, with outcomes that are at least equivalent to and possibly better than the standard ten weeks of treatment. Because of its superior precision, MSK Precise has less side effects than more conventional radiation techniques, with extremely low rates of incontinence (urinary leakage) and rectal problems. The sexual side effects are low and similar to what is experienced with conventional external radiation techniques. And of course, it’s much more convenient for patients.

VIDEO | 01:01
Learn what it means to receive hypofractionated radiation therapy in this short animation.
Video Details

MSK Precise is not simply short-course, high-dose treatment. It takes advantage of innovations in planning, imaging, and mapping to enhance the precision and safety of the treatment. It includes MRI-based planning, in which the therapy is mapped only with MRI and not CT scanning — something we are the only one in the world to do routinely at this time. We also use what are called fiducial markers, placed in the prostate, to track the location of the prostate before and during the treatment. And as I said, we use a rectal spacer gel to move the rectum out of the way of the high doses of radiation.

For patients with more-advanced tumors, we are completing a phase II trial in which we’re combining sophisticated brachytherapy approaches with MSK Precise. This kind of combination of dose-intense or escalated radiation may end up being a very effective regimen.

We’ll soon be rolling out a new program in which, in selected patients, we will use MSK Precise to intensify radiation doses to portions of the prostate while at the same time significantly reducing doses to normal tissues such as the bladder neck region next to the prostate, the nerves and blood vessels controlling erectile function, and the rectum. This is really novel — a new paradigm, really, in radiation therapy. It requires a great deal of collaboration with our medical physics team to try to get the most accurate positioning of the prostate during the actual three or four minutes of the treatment.

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What should patients know about MSK’s approach to treating prostate cancer?

At MSK, we manage prostate cancer in a very comprehensive way, tailored to each patient’s disease and to the individual person. There is no one specific therapy that is best for everyone.

Our initial assessment includes a carefully evaluated biopsy and a very detailed MRI to show the location of the disease, the integrity or soundness of the capsule surrounding the prostate, and the amount of disease. Then, based on that information — and with input from the urologist, the radiation oncologist, and the medical oncologist — we can provide a comprehensive recommendation.

The radiotherapy we do here at MSK is state-of-the-art and unparalleled. We are the only center in the world to do MRI-based treatment planning. When we give brachytherapy, we use computer software that provides us with real-time information about the quality and accuracy of the seed implant during the procedure. This allows us to make adjustments while the patient is still under anesthesia, so that when the procedure is completed, we have been able to achieve ideal placement of the radiation seeds. This translates into improved outcomes.

For more advanced disease, we have ongoing studies in which we combine novel hormonal therapy agents with radiation to achieve better results. Even the way we follow our patients after treatment is unique, with carefully sequenced MRI checks that give us opportunities to monitor patients extremely closely.

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So we do it all….

Yes, that’s the unique part of our program — we have expertise in multiple areas of prostate cancer radiotherapy management. Some places just focus on external radiation alone. Some just do seed implants. Other centers do combined therapies for everybody. It’s our expertise in all of these areas that gives us an opportunity to provide an approach that’s not one-size-fits-all, but tailored to the individual.

The thrust of our approach is to try to reduce the burden of therapy on our patients. And if we can utilize the most sophisticated technologies and innovations in radiotherapy to condense the radiotherapy program from sometimes two and a half months down to a week, or to combine some of these therapies, we can provide added benefit and value for our patients.

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Commenting is disabled for this blog post.

Thanks for the information. I have had my cancerous prostate removed at UTSW Dallas,Texas 6 yrs ago in addition follow up with 7 weeks of radiation 5 days per week I have been cancer free but now have neuropathy in my feet. I now know this is a side effect. Can you comment why it's never mentioned in the past I researched prostare cancer very heavily since my father and grandfather both died of this cancer

Dear William, sending you our deepest sympathies for the loss of your loved ones to cancer.

We are sorry to hear that you are experiencing neuropathy. Everyone reacts differently to treatment, although some types are known — based on other patients’ experiences — to have a higher likelihood of causing certain side effects than others. We do have some good resources on our website that may be helpful in addressing neuropathy symptoms:

Patient Education materials on managing peripheral neuropathy: https://www.mskcc.org/cancer-care/patient-education/patient-guide-perip…

Blog post - which includes a video - on managing peripheral neuropathy: https://www.mskcc.org/blog/managing-chemotherapy-induced-peripheral-neu…

We hope this information is helpful. Thank you for reaching out to us.

I am being treated at MSKCC. I can say that the amount of expertise and specialized equipment can be found in very few places. In the picture is Dr. Micheal Zelefsky. He is a world class researcher who applies his research to healing his patients. His standing in the profession does not prevent him being a kind and compassionate physician.
I have found that same quality in the Doctors and Nurses at MSKCC. I am sorry I have to go there. I am also glad that I have a place like this to go.

Dear Bob, we are glad to know that you have felt well-cared for at MSK. Thank you for sharing your thoughts and experience on our blog.


I had IMRT treatment for prostate cancer at Sloan in Basking Ridge in 2007. I had 48 treatments and had the gold piece inserted. My doctor was Sang Sim, who I know has left Sloan. He was great.

I reached my nadir, 2 years after treatment completion. It was 0.45. Since then, it bumped up a couple of times. As of last November, it was 0.8. I am 65 years old.

I exercise as much as I can, both at the gym and at home. I try and eat a fairly healthy diet. I try and eat fruits and vegetables, particularly those from the cruciferous family, as well as tomatoes.

I was wondering if you could help define for me the difference between moderate and vigorous exercise. I do both weight bearing exercises, as well as plenty of aerobic

For example, when I am on the treadmill, I start out putting it up to 15 percent while walking 2.6 miles. With each increase in speed, I bring the level down, u Gil I am walking 4.3 miles an hour while having a level of 6. I try and keep that up over and over u till I have burned 800 to a thousand calories. I do not have weight issues; I watch calorie burn to measure how hard I am working.

When working weight, I go lighter with many, many reps. I have been working this way, since I had my double brain aneurysm in 2001.

I keep my weight on the lighter side and try to get enough sleep.

Thanks - Roland

Dear Roland, we are glad to know that you have felt well-cared for by your treatment team at MSK Basking Ridge. We applaud and encourage you to continue your efforts to make healthy lifestyle choices! Thanks for sharing your thoughts and experience on our blog.

Hi guys I am based in the U.K. What a great informative site you have, you have clarified the different treatments for me and I now think I can choose the right treatment for me.
I've was diagnosed 2 years ago with T2 intermediate risk cancer with a gleeson score of 4+3 I have been on hormone treatment for 2 years and my PSA level is stable at .03.
I see my oncologist on Monday 20th Feb 2017 I,m hoping that she will allow me to have Brachytherepy.
Continue with your good work.

Best Regards Ed Ford

I have been diagnosed with high grade prostate
cancer with a T2A grade but a high Gleason
reading of 9. I am well into a hormonal treatment
Eligard 45 plus bicalutamide daily. My oncologist
Suggests external radiation will serve me well, but
that brachytherapy after the external would give
me an even better prognosis.
My challenge is that the external radiation might
start shortly while combining the two processes
would not be available for 15 weeks ( total plan
one month of radiation, 1 1/2 month recovery with
Brachytherapy time projected as July 25). I am
concerned that the Gleason 9 cancer is not completely managed by the hormonal treatment
and that the risk of metastasis over the delaying
period might not justify my wait. Your thoughts?

Dear Walter, we are not able to offer medical opinions on our blog. If you have any questions or concerns about what your doctor is telling you, we recommend that you seek out a second opinion at a major cancer center. If you’d like to arrange to talk to a doctor at MSK, you can call 800-525-2225 or go to https://www.mskcc.org/experience/become-patient/appointment for more information on making an appointment. Thank you for your comment and best wishes to you.

What are your thoughts on "salvage" radiation to the prostate bed after the gland has been removed?

Dear Ken, in men who experience one or more signs that their prostate cancer is back after prostatectomy, such as a rising level of prostate-specific antigen (PSA) or evidence on a scan, we may offer radiation therapy to eliminate or control it. We may also offer radiation therapy in cases where the cancer cannot be completely removed during surgery. If you would like to learn more about our approach to treating prostate cancer, you can go to: https://www.mskcc.org/cancer-care/types/prostate/treatment

If you are interested in arranging a consultation to learn more, you can call 800-525-2225 or go to https://www.mskcc.org/experience/become-patient/appointment for more information on making an appointment. Thank you for your comment.

Between 12/27/16 and 01/02/17 I underwent CyberKnife radiation treatment (5 sessions) at the Providence Alaska Medical CyberKnife Center in Anchorage.

The procedure included MRI based planning and rectal gel between he prostate and rectum. It also included tracking the prostate during treatments for more accurate and precise placement of the radiation. It looks like you are not any longer the only center in the world using MRI planning, but I am happy that you are keeping up with Anchorage.

Seriously, I am sure that your research and work has contributed to the center here in Anchorage and for that I am extremely grateful.

My treatments went very well. I have had zero negative side effects both during and after treatment. Positive side effects include great reductions in prostate/bladder issues. I sleep much better because I no longer get up every 30 to 60 minutes all night long and I can now sit through a 3 hour business meeting without interruption whereas five months ago I was lucky if I could go for an hour. That alone is enough to make me very grateful for the treatment.

After all of the treatments, including placement of the markers I was able to drive and return to work with no problems. I have just had my first 3-month follow up and PSA has gone from 7.8 to 1.29.

I am acutely aware of how much has been accomplished in prostate cancer treatment. My father died from prostate cancer almost 40 years ago, after a series of surgeries to remove organs as the cancer progressed to them.

What I found distressing was the resistance of my physician and Medicare to the procedure (Medicare would not cover it). A recent NYT article, reprinted in the Alaska Dispatch News also labeled SBRT treatment, in general as unproven and attributed a high risk of the side effects associated with other radiation therapies to SBRT including, by inference SHARP.

I understand that insurance companies are not joyous about SHARP radiation because, as my doctor told me, if I did nothing about the cancer I would probably die of something else before the prostate cancer killed me. Treatment this effective and this comfortable encourages people who might otherwise die without having treatment to get treatment that might not extend their life span. I also understand that there is a great deal of money invested in older radiation treatments that might be replaced by competition from SHARP type treatments but find the false and misleading information about these new treatments reprehensible.

Men should be encourage to get regular prostate and PSA exams so prostate cancer is detected early and treated effectively.

On June 2nd 2016 I had prostate cancer surgery, and from Jan.16th 2017 to March 15th I had radiation therapy. My surrounding nerves were saved,how soon will I regain all sexual functions. Thank You. Gary Cohen

Dear Gary, we’re sorry to hear you’re going through this. Unfortunately, because every patient is different, we’re not able to provide advice on your recovery. We recommend you discuss your concerns with the doctor who did your surgery. Thank you for your comment, and best wishes to you.

2 yrs ago I had prostate surgery and radiation for 8 weeks because of Gleason 9 with capsule invasion. Now I am fine with psa less than .06. Is chemo now recommended for men with high Gleason and capsule invasion? Are there statistics? Are there open clinical trials?

Dear Don, we are not able to make recommendations about treatment on our blog, because every case is different. We recommend you discuss this with your healthcare team. If you are interested in having a consultation with an expert at MSK, including finding out about clinical trials here, you can call 800-525-2225 or go to https://www.mskcc.org/experience/become-patient/appointment for more information. Thank you for your comment, and best wishes to you.

Thanks for this forum.
At age 65 with a Gleason 3+4 score, my first instinct was to have surgery. The surgeon I met with suggested I also talk to a radiation therapist. Having spoken to both, I can't decide which whether surgery or radiation makes more sense for me.
How does MSK work with a patient in that situation? Would both specialists be in a room at the same time discussing the case?

Hi, 61 prostate removed 14 days ago, hormone shot , Leuprolide, and in 3 months, Doc wants to do 40 rounds radiation. Kinda nervous, bathroom issues, etc. wondering if I’m doin this right I do like my docs, but. This is a total changing , in my. Life. I know I have to trust. But. Thanks for listening

Hi, new. Looking for some thoughts. Prostate removed 12 days, kinda worried.

Is there a age limit for this type of treatment? I am 80.

I had my second biopsy in April 2018. One core out of 12 is G 4+3. Urologist suggests brachytherapy. I requested a Prolaris test. My inclination is to wait on treatment and biopsy next year. What is standard policy for this situation?
Thank you

Hello MSK,
I am recently diagnosed with prostate cancer (T1C) 3+4 Gleson 7 and have been to Syracuse & Buffalo for consults.
I'm told my prostate is to small for brachytherapy at 18cc volume.
Was told 20cc is the smallest size to perform the procedure...
Question - Can't fewer seeds be implanted for a smaller prostate?
Please advise
Thank you in advance.

Just had a Radical Prostatectomy, gleason score of 9...Possibly a leak in one area of capsule...recommended I have radiation treatment...Standard EBRT. Would IMRT, or Proton therapy be the best choice??? Thanks, very concerned about side effects of standard EBRT. Gary

Looks like I have a node in pelvic bed around prostate involved, started on Casodex and will begin Lupron in 2 weeks, then radiation...EBRT, but not sure if IG_IMRT or Proton therapy would be safest and most effective. Also not sure if I need to be on hormones for 2 years. Also, Axumin PT is negative. Was Gleason 9 however.w/ PSA of 9.4

I recently underwent a prostatectomy. The pathology report showed there was patchy neuroendocrine differentiation and focal transformation to small cell carcinoma.
From my understanding small cell carcinoma is a very rare, aggressive cancer. Does MSK have any current research or doctors who specialize in the treatment of SCC?

I have 3-4 gleason score and doctors inform me that I am a great candidate for either surgery or radiation. The possible deciding factor is my prostate is very large. Would radiation shrink it to allevieate my urinary issues? Thanks

For an individual who is 64 yrs of age (but with the overall health and vigor of a 55 yr old) with a 3+4 Gleason score , what are the pros and (particularly) cons of radiation therapy Vs radical prostatectomy? I read on your site that the best “cure” for prostatic cancer is radical prostatectomy since it removes the disease altogether ( provided it has not escaped the prostate) . What are the comparative results of these two options ?
MSK prides itself on performing the difficult procedure of salvage radical prostatectomy. So would it make sense to try the radiation therapy for all its convenience and fall back on salvage in case it doesn’t quite go right ?

I had a prostatectomy and now have a biochemical recurrence, as shown by my rising PSA. My medical oncologist has recommended a PSMA PET/CT scan. What imaging studies does MSKCC offer for men in my situation?

Dear Richard, to learn about MSK’s approach to diagnostic imaging, you can go to this page:https://www.mskcc.org/cancer-care/types/prostate/diagnosis/prostate-bio…

If you are interested in speaking with someone about arranging a consultation with doctors at MSK, you can call 800-525-2225 or go to https://www.mskcc.org/experience/become-patient/appointment for more information. Thank you for your comment and best wishes to you.

I am 72 and just completed 28 weeks of radiation therapy at Cedars Sinai Med Center in L.A. I was diagnosed with PSA of 5.1,(6.0 4K Score) T1c with Gleason of 3+4/. Also Decipher of low risk 0.37.
I am feeling great! Side effects manageable. So for those who are going through this, or thinking about what to do, anxiety will pass once you engage. Talk to people in the waiting area before treatment. It is encouraging. Good Luck!

Gleason of 3+3 ...48 radiation therapy treatments starting tomorrow. 56 years old, no pain, no symptoms. Just PSA increased 2014 JULY ( 3) 2018 JULY (4.3) 2018 AUG (5.9).

My husband was treated for Stage 4, undifferentiated prostate cancer with 45 radiation treatments & ADT hormone treatments. 4 mths following radiation his oncologist ordered a PET scan and while his PSA has gone down from 36.332 to .33 the prostate was at 48. Is this the radiation showing a high read or, does he need a radical prostatectomy?

Dear Carol, we are not able to answer individual medical questions on our blog. We recommend that you discuss this with your husband’s care team. If he would like to have a consultation with someone at MSK to discuss this, you can make an appointment online or call 800-525-2225. Thank you for your comment and best wishes to both of you.