Wednesday, December 10, 2014

Radiation Therapy after Prostate Surgery, Part IV: Radiation Side Effects


Some men prostate cancer are faced with the realization that treatment of their prostate cancer may require multimodal treatment including some combination of surgery, radiation therapy and/or hormone therapy. The combined ASTRO/AUA (American Society for Therapeutic Radiology and Oncology/American Urological Association) Guideline for "Adjuvant and Salvage Radiotherapy after Radical Prostatectomy" makes a number of statements regarding the use of radiation therapy after surgery that can be confusing to patients and practitioners. 

In the fourth part in this blog series, we review the statements from the ASTRO/AUA Guideline regarding radiation toxicity, side effects and the data supporting them.

To read Part I: Adjuvant Radiation following Surgery for Prostate Cancer click here.
To read Part II: Subgroup Analyses of Adjuvant Radiation for Prostate Cancer click here.
To read Part III: Salvage Radiation Therapy for Prostate Cancer click here.

 

The last portion of the ASTRO/AUA Guidelines focuses on radiation-related toxicities or side effects.

The Guideline Statements

Guideline Statement 9. Patients should be informed of the possible short-term and long-term urinary, bowel, and sexual side effects of radiotherapy as well as of the potential benefits of controlling disease recurrence. (Clinical Principle)


The Evidence

Radiation therapy can cause both acute (short-term) and chronic (long-term) side effects. Most short-term side effects are minor in nature, do not require additional treatment, and improve spontaneously within a few weeks of radiation therapy. Minor, short-term side effects include irritative voiding symptoms, rare urinary retention, irritative bowel habits (most commonly frequency including diarrhea) and minor bleeding in the urine or stool.  

There are a few problematic chronic side-effects that can be serious. These side effects are related to the ability of radiation therapy to destroy tissues, specifically the microscopic blood supply, that keeps many tissues healthy and functional. Loss of microscopic blood supply can lead to scarring and strictures, non-healing wounds and fistulae, and subsequent problems like urinary retention and the need for operations to bypass radiation-induced problems. The SWOG study presents the best data regarding these post-radiation toxicities.

Rectal bleeding or proctitis requiring intervention occurs in approximately 3% of patients following adjuvant radiation therapy. Urethral stricture occurs in upwards of 18% of patients receiving radiation (and 9.5% of patients with surgery alone). Strictures can lead to urinary retention, urinary incontinence or fistulae between the bladder and rectum. Strictures can also occur in the ureters causing blockage of one or both ureters; or can occur in the rectum – thankfully these strictures are rare, <1% of patient post-radiation will develop bowel or ureter strictures.

Urinary incontinence (without evidence of stricture) occurs in 6.5% of men post-radiation (and 2.8% of men following surgery alone). In other studies the rates of incontinence following adjuvant radiation therapy can be as high as 40-50%.[1] For that reason, most practitioners will recommend waiting for continence to return after radical prostatectomy before undergoing adjuvant radiation therapy. Radiation therapy before the return of continence increases the risk of permanent incontinence dramatically.

Summary


  • Radiation therapy after radical prostatectomy can be associated with both short- and long-term side effects.
  • Most short-term side effects are mild in nature and pass without treatment.
  • Rarely, serious long-term side effects can occur including rectal bleeding, proctitis, stricture disease (of the urethra, ureters or rectum), and urinary incontinence.
  • Radiation therapy can affect the return of urinary continence following surgery, therefore most practitioners recommend allowing the return of urinary function prior to initiating radiation therapy.


This blog was written by Mark W. Ball, MD.  Mark is a 5th year urology resident at the Brady Urological Institute at Johns Hopkins and looking forward to a career in urologic oncology.
 


 







[1] Suardi N, Gallina A, Lista G, Gandaglia G, Abdollah F, Capitanio U, Dell'Oglio P, Nini A, Salonia A, Montorsi F, Briganti A. Impact of adjuvant radiation therapy on urinary continence recovery after radical prostatectomy. Eur Urol. 2014 Mar;65(3):546-51. doi: 10.1016/j.eururo.2013.01.027. Epub 2013 Feb 4.

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