Adverse Effects of Primary IMRT

A recent commentary listed some of the most common adverse effects of prostatectomy, some of which (e.g., perceived penile shrinkage, climacturia, Peyronie's, stress incontinence) are seldom mentioned by urologists to prospective patients, and are not routinely included in standardized quality-of-life questionnaires. In the interest of providing equal time to the potential adverse effects of radiation, below is a list of such effects, ranked by approximate incidence, for primary IMRT.

This list only applies to primary IMRT and not to salvage treatments, which may have a very different side effect profile. These data are not purely for IMRT – they include some patients treated with 3D CRT as well. Some patients in these studies may have had adjuvant ADT, so it is impossible to distinguish the effects of radiation from the effects of concurrent hormone treatment. None of this applies to SBRT or brachytherapy.

Most of the data on acute side effects are pulled from the Sanda et al. study, which represents the patient-reported outcomes at 9 of the top US institutions, and is not indicative of community practice. Many of the late-terms side effects are given as their absolute incidence. Acute side effects are given as increases over baseline function (indicated by “+”). Unless otherwise specified, they are acute side effects (within 3 months of treatment), rather than late-term or chronic side effects. Acute side effects are typically transient. Contrary to “common knowledge,” new side effects rarely emerge after 2 years.

In general, urinary, rectal and sexual adverse effects will be worse among men whose function is impaired before treatment, and those with certain comorbidities. Radiation dose, image guidance techniques, margins, anatomic differences, and sensitivity to radiation contribute to individual variances in side effects. Most of the side effects are attributable to inflammation (cystitis, urethritis, proctitis), spasms (diarrhea, bladder spasms), and the destruction/fibrosis of vascular and other tissues (ED, urinary retention). There are treatments available for many of these adverse effects. Patients are advised to discuss them with their doctors.

Loss of semen (5 yrs) 89%

Fatigue 32%

Sexual function- big/moderate problem (1 yr) 31%

Frequent urination +18%

Vitality/hormonal function – big/moderate problem (1 yr) 18%

Bowel urgency  +15%

Bowel frequency +14%

Urinary irritation or obstruction – big/moderate problem (1 yr) 14%

Bowel/rectal function – big/moderate problem (1 yr) 11%

Dysuria (pain while urinating) +11%

Weak stream +10%

Leaking >1x per day +9%

Rectal pain +5%

Fecal incontinence +5%

Dribbling +4%

Urinary incontinence – big/moderate problem (1 yr) 4%

Any pad use +3%

Bloody stools +2%

Other rare effects with <1% incidence:

Rectourethral fistula

Bladder neck contracture requiring surgical intervention

Second primary pelvic cancer

------------

Sources:

Prospective evaluation of the prevalence and severity of fatigue in patients with prostate cancer undergoing radical external beam radiotherapy and neoadjuvant hormone therapy.

Quality of Life and Satisfaction with Outcome among Prostate-Cancer Survivors (Sanda et al.)

Preliminary Toxicity Analysis of 3DCRT versus IMRT on the High Dose Arm of the RTOG 0126 Prostate Cancer Trial

Radiotherapy-induced second primary cancer (RTSPC) risk is low and may differ by radiation technique.

Urorectal fistulae following the treatment of prostate cancer

Second primary cancers after radiation for prostate cancer: A systematic review of the clinical data and impact of treatment technique