Rectal Spacers Show Acceptable Safety in Locally Advanced Prostate Cancer Radiotherapy
核心洞察
A prospective single-centre study of 181 men found biodegradable rectal spacers achieved comparable prostate-to-rectum separation in cT3 and cT1c/cT2 prostate cancer (搜索) patients undergoing external beam radiotherapy.
No grade 3 or higher gastrointestinal toxicity occurred in either group, with acute grade 1–2 toxicity reported in 12.9% of cT3 patients versus 5.0% of cT1c/cT2 patients.
Early oncological outcomes were reassuring, with freedom from biochemical failure of 98.1% in cT3 and 100% in cT1c/cT2 patients over a median 8-month follow-up.
Biodegradable rectal spacers achieved comparable prostate-to-rectum separation and demonstrated an acceptable short-term safety profile in patients with cT3 prostate cancer (搜索) undergoing external beam radiotherapy, according to findings from a prospective cohort study published in Scientific Reports.
Rectal spacers are widely used in localised prostate cancer (搜索) to increase the distance between the prostate and rectum, thereby reducing unintended rectal irradiation. However, evidence in locally advanced disease has remained limited. To address this gap, researchers conducted a prospective single-centre study between 2022 and 2024 involving 181 men with biopsy-confirmed cT1 to cT3 prostate cancer scheduled for external beam radiotherapy. All participants underwent insertion of either a polyethylene glycol hydrogel spacer (搜索) or a hyaluronic acid spacer (搜索) before treatment.
Comparable Spacing Across Disease Stages
Among the cohort, 62 patients had cT3 disease and 119 had cT1c or cT2 disease. Post-insertion rectal spacing was largely comparable between groups. At the mid-gland, spacing measured 1.00 cm ± 0.36 in the cT3 group versus 1.05 cm ± 0.37 in the cT1c/cT2 group. At the apex, measurements were 0.52 cm ± 0.27 and 0.59 cm ± 0.30, respectively. A significantly greater separation at the base was observed in the cT3 cohort (0.94 cm ± 0.32 versus 0.82 cm ± 0.30).
Encouraging Safety Outcomes
Researchers reported no significant differences in gastrointestinal toxicity between disease stages. Acute grade 1 or 2 gastrointestinal toxicity occurred in 12.9% of patients with cT3 disease compared with 5.0% of patients with cT1c/cT2 disease. Late toxicity rates were 4.3% and 1.1%, respectively. Importantly, no grade 3 or higher toxicity was recorded in either group, and procedure-related complications were similarly low.
Temporary urinary retention requiring catheterisation occurred in 17.7% of patients with cT3 disease and 13.4% of those with cT1c/cT2 disease. No patients experienced refractory urinary retention, infective complications, or rectal mucosal injury.
Clinical Implications for Radiotherapy Practice
Notably, patients with cT3 disease were more likely to receive higher dose radiotherapy regimens, yet toxicity outcomes remained comparable. Researchers suggested this may indicate that rectal spacers retain their protective effect across varying treatment intensities and disease stages.
Early oncological outcomes were also reassuring. Freedom from biochemical failure was 98.1% in the cT3 group and 100% in the cT1c/cT2 group during a median follow-up of 8 months. The researchers emphasised that longer follow-up will be required to assess long-term cancer control and late toxicity outcomes.
Overall, the findings suggest that rectal spacers could play an increasingly important role in supporting safer, more precise external beam radiotherapy for patients with locally advanced prostate cancer (搜索) as longer-term evidence continues to emerge.