Two-Fraction SBRT: Prostate Cancer Toxicity Results
HereS a breakdown of the key findings from the provided text, focusing on the comparison between 2-fraction and 5-fraction SBRT for prostate cancer:
Key Findings:
* Feasibility & Tolerability: 2-fraction SBRT appears feasible and tolerable for intermediate/lower high-risk prostate cancer with visible gross tumor volume on MRI, comparable to 5-fraction SBRT.
* severe Toxicities: No grade 3 genitourinary (GU) or gastrointestinal (GI) toxicities were observed in either group (47 patients total).
* Grade 2+ GU Toxicities: Rates were similar between the groups:
* 2-fraction SBRT: 27.3% (6/22 patients)
* 5-fraction SBRT: 29.2% (7/24 patients)
* Timing of GU Toxicities: Grade 2+ GU toxicities peaked at 4 weeks with 2-fraction SBRT and 2 weeks with 5-fraction SBRT.
* Urinary Frequency: Higher rates of grade 2+ urinary frequency were observed at week 4 with 2-fraction SBRT (13.6%) compared to 5-fraction SBRT (12.5% at week 4, 16.7% at week 2).
* Grade 2+ GI Toxicities: None in the 2-fraction group, while 6.8% (3%-32% CI) experienced them in the 5-fraction group.
* Late Adverse Effects (AEs): Few late grade 2+ GU AEs were observed at 6 and 12 months, with no grade 3 or higher late toxicities reported.
In essence, the study suggests that 2-fraction SBRT is a viable option with a similar safety profile to the more standard 5-fraction SBRT for this patient population.