IMRT had greater effect on bowel function than proton therapy

Hoppe BS. Cancer. 2013;dpi:10. 1002/cncr.28536.

Men with prostate cancer who underwent intensity-modulated radiation therapy reported similar quality-of-life summary scores as those who underwent proton therapy, according to results of a prospective study

However, problems with rectal urgency and bowel frequency were more common among men who underwent IMRT.

The analysis included 1,243 men who underwent proton therapy (76 Gy to 82 Gy) and 204 men who underwent IMRT (75.6 Gy to 79.4 Gy). All patients completed the Expanded Prostate Cancer Index Composite questionnaire during the first 2 years after treatment.

Men who underwent IMRT were older (median age, 69 vs. 66 years; P˂.001), had larger mean prostate volumes (49.5 g vs. 41.5 g; P=.0014), wereless likely to be white (81% vs. 91%;P˂.001), were more likely to receive androgen-deprivation therapy (24% vs. 15%; P=.00013), and received lower median minimum doses (70.9 Gy vs. 74.1 Gy; P˂.001) and lower median maximum doses (81.5 Gy vs. 83.2 Gy;P˂.001) of the planning target volume.

At baseline, more men in the IMRT cohort reported moderate or big problems with hematuria (P=.04), daily urine leakage (P=.02), bloody stools (P=.02), rectal pain (P=.04), and moderate or big problems within the sexual domain (P˂.01).

When researchers controlled results for age, prostate size and ADT, summary score changes for bowel, urinary incontinence, urinary irritative/obstructive and sexual domains were similar between the cohorts.

However, moderate or big problems with rectal urgency (P=.02) and bowel frequency (P=.05) were more common among men in the IMRT cohort.

“The findings from this study provide evidence of excellent and comparable quality of life outcomes for patients with prostate cancer who receive either contemporary IMRT or proton therapy,” the researchers wrote. “Although similar bowel, urinary and sexual scores were observed with IMRT and proton therapy, potential differences in specific functional outcomes, such as bleeding, rectal urgency and bowel frequency, also were observed and may reflect differences in radiation dose distributions between IMRT and proton therapy, differences in patient characteristics, or both.”

Disclosure: The researchers report honoraria and payment from, board membership with, and lecture and consultant roles with Bayer Health, Eviti, MedicaMetrix, Medivation, Millennium, Myriad Health, ProCure, Proton Collaborative Group, Sanofi-Aventis and Varian Health.


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