Urinary and bowel quality of life after image-guided, intensity modulated radiation therapy to the prostate bed.

Abstract

312 Background: Majority of patients with adverse pathological features on radical prostatectomy do not receive post-prostatectomy radiation due to concerns of negative impact on their quality of life (QOL). The purpose of this study is to evaluate QOL after post-prostatectomy intensity modulated radiation therapy (IMRT) in the “adjuvant”(ADJ) setting for positive surgical margins, extraprostatic extension, or seminal vesicle invasion with a PSA < 0.2 ng/mL and a “salvage”(SAL) setting for a PSA ≥ 0.2 ng/mL at the start of IMRT. Methods: Between 2004 and 2013, 130 patients underwent IMRT to the prostate bed. Sexual Health Inventory for Men (SHIM), International Prostate Symptom Score (IPSS), and Expanded Prostate cancer Index Composite-26 for bowel (EPIC-26-bowel) scores were recorded before radiation and at 3-month intervals after completion of treatment to assess sexual, urinary, and rectal QOL, respectively. A mixed model for repeated measurements was used to compare QOL scores over time among various subgroups. Results: ADJ and SAL radiation were delivered to 48 (37%), 82 (63%) respectively. Total radiotherapy doses were 64.8-68.4 Gy using 1.8-Gy daily in 56 (43%) patients and 70.2-72.0 Gy in 74 (57%) patients. Androgen deprivation therapy (ADT) was given to 4/48 (8%) ADJ patients and 9/82 (11%) SAL patients. Fiducials were placed in prostate bed for image guidance in 42 (32%) patients. Median follow up was 46 months. Total radiation dose did not significalntly affect QOL. SAL IMRT was associated with worse mean SHIM scores (3 points, p = 0.002) and ADJ IMRT was associated with lower mean IPSS scores (2 points, p = 0.03). Mean EPIC-26-bowel scores were lower without fiducial markers (16 points, p < 0.0001). Conclusions: SAL IMRT was associated with worse sexual QOL, possibly due to less frequent usage of phosphodiesterase-5 inhibitors. ADJ IMRT was associated with worse urinary QOL, possibly due to a shorter post-operative recovery period. Fiducial marker resulted in better rectal QOL due to greater rectal sparing. Urinary and rectal QOL with post-prostatectomy, image-guided IMRT compare favorably with previous QOL reports involving three-dimensional conformal radiation therapy.