Ashesh B. Jani

The objective of this investigation is to compare acute genitourinary (GU) and gastrointestinal (GI) toxicity results of radiotherapy to localized fields delivered using intensity-modulated radiotherapy (IMRT) versus conventional radiotherapy (ConvRT). The records of 481 consecutive prostate cancer patients receiving RT to localized fields at a single institution were reviewed; 108 received IMRT and 373 received ConvRT. Acute GU and GI toxicity, as defined by the Radiation Therapy Oncology Group (RTOG) grading system, were compared using the chi-square test. Ordered logit regression analyses were performed using all major disease and treatment factors as covariates. Acute GU grade 0, 1, 2, 3, and 4 toxicity rates were 23%, 40%, 34%, 3%, and 0%, respectively, in the IMRT cohort and 31%, 37%, 30%, 1%, and 1%, respectively, in the ConvRT cohort - these rates were not significantly different (p=0.118). Acute GI grade 0, 1, 2, 3, and 4 toxicity rates were 42%, 37%, 22%, 0%, and 0%, respectively, in the IMRT cohort and 33%, 32%, 35%, 0%, and 0%, respectively, in the ConvRT cohort - this lower toxicity in the IMRT group was significant (p=0.013). The regression analyses showed that only IMRT use (p=0.046) predicted reduction in acute GI toxicity but no factors correlated with acute GU toxicity rate. In conclusion, in our retrospective single-institution analysis, IMRT was not associated with reduction of acute GU toxicity but was associated with a reduction of acute GI toxicity over ConvRT in the treatment of prostate cancer to localized fields.

The goals of this article are to review the application of the number needed to treat (NNT) concept to selected clinical problems in prostate cancer radiotherapy. Particular emphasis will be placed on () comparison of radiotherapy with other treatment options for early-stage disease, () the role of hormone therapy in addition to radiotherapy over a spectrum of disease presentation, and () systematic comparison of adjuvant versus salvage radiotherapy in the post-prostatectomy setting. Limitations of NNT calculations based on non-randomized comparisons also are discussed.

Purpose: To analyze the impact of neoadjuvant hormone therapy (HT) on acute gastrointestinal (GI) and genitourinary (GU) toxicity from radiotherapy (RT). Scope: The toxicity rates of 480 consecutive prostate cancer patients were reviewed and compared using the χ² test. Ordered logit regression analyses were performed including the major demographic, disease, and treatment factors. Although no reduction in acute GI toxicity from HT use was observed (P=0.067), a lower rate of acute GU toxicity was observed (P=0.002). No factor reached statistical significance on regression analysis. Conclusions: Observed toxicity rates were similar or lower in patients receiving HT. Thus, increased RT toxicity should not be a concern when deciding to add neoadjuvant HT to RT for prostate cancer.