Medication Used Before, During, and After Radiation Treatment Helps Men with Prostate Cancer Maintain Overall Sexual Function

Pictured: Michael Zelefsky

Radiation oncologist Michael J. Zelefsky

Loss of some sexual function is a common concern among men undergoing radiation therapy for prostate cancer. In this type of therapy, high-energy beams of radiation or radioactive seeds are used to eliminate tumors. Recent advances in the precision of radiation therapy have reduced the risk for complications, but side effects such as erectile dysfunction (ED) are still an issue for many men.  

According to results from a recent multicenter study, however, the use of an oral erectile function medication before, during, and after radiation therapy for prostate cancer may help reduce side effects related to sexual dysfunction. Memorial Sloan Kettering radiation oncologist Michael J. Zelefsky presented the findings of the prospective trial at the annual American Society for Radiation Oncology (ASTRO) meeting in Boston on October 29, and the results are being submitted for publication in the coming months.

“This is a good first step in an effort to help patients find ways to improve their quality of life after treatment,” Dr. Zelefsky says.

A Multicenter Trial

In the clinical trial, 290 men treated at Memorial Sloan Kettering and three other New York–area hospitals were randomly assigned to receive either a placebo pill or a 50 milligram daily dose of sildenafil citrate (Viagra®) for three days before radiation treatment and continued daily for six months after treatment. Following the six months, the pill was taken on an as-needed basis. Men in the study had cancer confined to the prostate, and had not received previous treatment (including hormone therapy).

The participants were also asked to complete a set of questionnaires to assess their sexual function, which included questions about erectile function, ability to orgasm, sexual desire, satisfaction with intercourse, and overall sexual satisfaction. Their feedback was recorded before the first radiation therapy treatment, and at six, 12, and 24 months after treatment.

In total, 144 patients completed the questionnaires. An analysis of their responses showed that those who were prescribed Viagra before, during, and after treatment reported better overall sexual function, erectile function, sexual desire, and intercourse satisfaction after therapy. The most significant improvements were seen at the six- and 12-month marks, with a slight drop in improvement at the 24-month mark.

Back to top

Continuing to Improve Sexual Health for Patients

Dr. Zelefsky, along with urologic surgeon John P. Mulhall, director of the Male Sexual and Reproductive Medicine Program, and colleagues, points out that additional randomized trials will be needed to corroborate the findings and better define how long men should take the drug.

“A drop at the 24-month mark suggests that future trials should be conducted to demonstrate whether giving the drug for a longer period of time can further improve patient outcomes,” says Dr. Zelefsky. “In the meantime, we encourage physicians to discuss with their patients the potential benefit of this approach, which could be used to lessen the degree of erectile function loss that may occur after radiotherapy.”

Back to top


Commenting is disabled for this blog post.

2011 Radical Prostatectomy. My Doctor will not prescribe Viagra because I am taking Sotalol 80 mg twice a day. What are my options?
Thank you.

We are unable to answer specific medical questions on our blog. If you would like to make an appointment with a Memorial Sloan-Kettering physician, please call our Physician Referral Service at 800-525-2225.

After having cyber knife team at Winthrop Hospital in Mineola N.Y in 2006 .And nothing but problems such urinal track infections and two out patient for urethra blockage. There are suggesting Cryosurgery for the cancer is confined to the prostate after all the necessary tests .Please help me with some positive suggestions .Bob

Appreciate the info. Yet another item to consider when deciding upon treatment. Which brings me to a question--Why does the MSKCC nomogram on prostate cancer treatment include radical prostatectomy and brachytherapy but not IMRT? I have found it very helpful, but the lack of IMRT leaves a huge gap. If this is the wrong place for this query, please inform me to who I whould send it. I have scoured the website an found no better possibility.

Thank you for your comment. We are currently revising our prediction tools to make them easier to use and more helpful for patients.

What are the overall comparisons for incontinence and erectile dysfunction side effects for radiation vs surgery for stage 1 prostrate cancer Nationally and at Sloan-Kettering?

Thank you for your comment. We consulted with several of our prostate cancer experts, and they said that side effects ultimately depend on a patient’s age at treatment, baseline erectile function, and results of the biopsy and digital rectal examination. If you would like to make an appointment to consult with a Memorial Sloan-Kettering physician, please call 800-525-2225.

do you use human amniotic membrane during a robotic prostatectomy ,to enhance the healing of the nerve bundle?

Angelica, we shared your question with James Eastham, Chief of our Urology Service, and he said that Memorial Sloan-Kettering does not use this approach, adding that no human studies have shown a benefit to this and it use should only be in a research study. Thank you for your comment.

I have I core positive (80%) of the core- 9 core negative, location right base. Gleason 6 (3+3), PSA jumped .29 t0 1.15 last three years. 1- what is the changes thi being linked the outside the prostate? 2- Is Brachyteraphy sufficient or should it be combined with IMRT? In both cases, what is better outcome for urine control and ED?

I was treated by Dr. Zelefsky using brachytherapy 3 years ago and continue to have normal erectile and urinary functions as well as no appearance of blood in the stool. I was also part of this study. My respect for Dr. Zelefsky as a doctor, a researcher and a human being is of the highest order.

Does an organism increasing your PSA. i.e. increase your testosterone levels.

Larry, we are not able to answer personal medical questions on our blog. We recommend that you check with your doctor about whether you should abstain from sexual activity before having a PSA test. You might also want to contact the National Cancer Institute’s Cancer Information Service at 800-4CANCER or to get more information on this topic. Thanks for your comment.

Dr. Zelefsky, I have been diagnoised with malignant neoplasm prostate cancer.
My PSA is 12.4. Clinical stage is T2b. GS: is 5+5=10. Could I be a candiate for this type of treatment.
Thank You,
Blaine McCurry

Dear Blaine, we are sorry to hear of your diagnosis. Unfortunately, we are unable to answer personal medical questions on the blog. If you would like to make an appointment with one of our specialists, please call our Physician Referral Service at 800-525-2225. Thank you for your comment.

What does research indicate at age >75 if gleason score Gleasson grade 4+3 =7 /10. And is the percent of core given above a variable. I gather that 4+3 is called intermediate risk t is that modified as result of what age it is discovered from the research done. Does the research show a distinction of threat given the above Gleason score a function of age.

The 2nd question: What does the research show given relatively speaking localalized treatment of whatever kind that the combination of MRI with rectal coil and Galodium plus increase PSA will diagnose a possible return of CA that is localized assumiing it was localized at the time of initial intervention with localized therepy.

3rd question: What does the research show about the reliability of the above mentioned MRI in detecting Pros Ca outside of the Prostrate.

Notice: I asked about the research.


Adenocarcinoma of prostate Gleasson grade 4+3 =7 /10.

The tumor involves 60 % of the cores.


Adenocarcinoma of prostate Gleasson grade 3 + 3 =6 /10.

The tumor involves 10 % of the cores

Dear Leonard, we sent your inquiries to Dr. Zelefsky and he responded:

Q_1. “In general when the Gleason grade is classified as 4+3 or 3+4 and the PSA is less than 10 and the disease on rectal exam is confined to the prostate, then we say that the disease is characterized as intermediate risk. It doesn’t appear that the aggressiveness of the tumor is affected in any way by the age of the patient.”

Q_2 “Research has indicated that a good quality MRI of the prostate often performed with a rectal coil can be quite effective in diagnosing recurrences of cancer in the gland after therapy. We are actively doing research in this area to see if novel MRI imaging approaches can be used to diagnose these recurrences at even earlier states.”

Q-3 “MRIs and sometimes PET scans can be helpful when PSA becomes elevated after therapy to decide whether the disease spread to areas outside of the prostate.”

Please note that these are general responses. If you would like to make an appointment with one of our specialists to discuss your individual situation and treatment, please call our Physician Referral Service at 800-525-2225.

Thanks for your comment.

I have prostate cancer and took chemo and radiation but notice that I am passing blood and also passing blood in urine. What does is means?

Salim, we are not able to answer personal medical questions on our blog. We recommend that you speak with your healthcare providers about this. If you’d like to make an appointment to see an MSK doctor, you can call 800-525-2225 during regular business hours or go to for more information. Thank you for your comment.

Would the placement of gold fiducial markers in the prostate disqualify me for brachytherapy if one were to change their mind and opt for brachytherapy instead of SBRT?

Dear Kevin, we forwarded your question to Dr. Michael Zelefsky, Chief of MKS’s Brachytherapy Service, and he responded:

“The gold fiducial markers would not disqualify someone from brachytherapy. The gold markers can actually be well distinguished from the seeds as well to allow for adequate treatment planning.”

If you would like to make an appointment with one of our specialists for further discussion of which treatment options may be appropriate for you, please call our Physician Referral Service at 800-225-2225.

Thank you for reaching out to us.

I had seed implants by Dr Zelefsky and radiation at MSKCC in 2009.Today I can not pee because I have excessive scar tissue from the radiation in my urethra tube in my penis .What is MSKCC advice as to removing this scar tissue and what about TURP.. I will await your response.

Dear George, we’re sorry to hear you’re going through this. We recommend that you make an appointment with Dr. Zelefsky so that you can discuss this with him. He’ll be able to refer you to other experts at MSK. Thank you for your comment and best wishes to you.

My gleason score was 3+4 what does that mean I am 63 yrs

I have a question about the cyberknife, was told by a nurse that the entire prostate would be irradiated, but that only the cancer cells would be destroyed the healthy cells would be injured BUT they would recover. OK I had two questions then 1. Since the healthy cells would recover, did that mean my ejaculate would return to normal (in most radiation treatments the prostrate is killed so you no longer have an ejaculate)? He did not know how to answer, but said there would no longer be an ejaculate! SECOND question, Since the prostate is not killed (assuming they are right now) say if in 25-30 years the prostate gets cancer again can I undergo the treatment again? His answer was that its never coming back since there is nothing there to develop cancer! Sounds again like there is total destruction of the prostate. Is this true?

Dear Douglas, we recommend that you discuss this with the doctor who will be performing your radiation treatments. Thank you for your comment and best wishes to you.