Abstract：
OBJECTIVE: A history of prior pelvic radiation therapy (RT) for rectal cancer is a relative contraindication for definitive RT for prostate cancer. High-dose-rate (HDR) brachytherapy can significantly limit the dose to surrounding tissues compared to external beam RT. However, there is limited data surrounding its safety in patients with prior pelvic RT.
METHODS: A retrospective chart review was performed at the University of California, San Francisco to identify patients diagnosed with prostate cancer with a history of pelvic RT for rectal cancer who were treated with high-dose-rate brachytherapy (HDR-BT) between 2006 and 2022. Inclusion criteria were biopsy-confirmed prostate cancer with no evidence of distant disease on clinical examination or imaging, and at least one post-treatment clinic appointment.
RESULTS: Seven patients were treated with salvage HDR-BT at a median interval of 17.7 years after RT for rectal cancer. HDR-BT doses included 3600 cGy in six fractions (n = 5), 2700 cGy in 2 fractions (n=1), or 2800 cGy in four fractions (n = 1). There was no acute grade ≥2 gastrointestinal toxicity, and 1 patient developed late grade 2 rectal bleeding. Two patients developed acute grade 2 genitourinary toxicity consisting of urinary frequency and urgency, which persisted through long-term follow up. At a median follow up of 29.5 months after HDR brachytherapy, one patient developed regional and distant failure, and another had seminal vesicle recurrence.
CONCLUSIONS: HDR-BT is a safe treatment for patients with prostate cancer who previously received RT for rectal cancer. Further studies are needed to better characterize the long-term toxicity of HDR-RT in this population.
METHODS: A retrospective chart review was performed at the University of California, San Francisco to identify patients diagnosed with prostate cancer with a history of pelvic RT for rectal cancer who were treated with high-dose-rate brachytherapy (HDR-BT) between 2006 and 2022. Inclusion criteria were biopsy-confirmed prostate cancer with no evidence of distant disease on clinical examination or imaging, and at least one post-treatment clinic appointment.
RESULTS: Seven patients were treated with salvage HDR-BT at a median interval of 17.7 years after RT for rectal cancer. HDR-BT doses included 3600 cGy in six fractions (n = 5), 2700 cGy in 2 fractions (n=1), or 2800 cGy in four fractions (n = 1). There was no acute grade ≥2 gastrointestinal toxicity, and 1 patient developed late grade 2 rectal bleeding. Two patients developed acute grade 2 genitourinary toxicity consisting of urinary frequency and urgency, which persisted through long-term follow up. At a median follow up of 29.5 months after HDR brachytherapy, one patient developed regional and distant failure, and another had seminal vesicle recurrence.
CONCLUSIONS: HDR-BT is a safe treatment for patients with prostate cancer who previously received RT for rectal cancer. Further studies are needed to better characterize the long-term toxicity of HDR-RT in this population.
摘要：
目的：既往有盆腔放疗（RT）的直肠癌病史是前列腺癌明确RT的相对禁忌症。与外部射束RT相比,高剂量率(HDR)近距离放射治疗可以显著限制对周围组织的剂量。然而,关于其在既往盆腔RT患者中的安全性的数据有限.
方法：在加州大学进行了回顾性图表审查，旧金山确定在2006年至2022年间接受高剂量率近距离放射治疗（HDR-BT）治疗的患有前列腺癌的患者，这些患者有盆腔RT直肠癌病史。纳入标准是活检证实的前列腺癌，在临床检查或影像学上没有远处疾病的证据。和至少一个治疗后诊所预约。
结果：7例患者在接受直肠癌放疗后的中位间隔为17.7年接受挽救性HDR-BT治疗。HDR-BT剂量包括6个部分的3600cGy（n=5），2个馏分中的2700cGy(n=1)，或四个部分中的2800cGy(n=1)。无急性≥2级胃肠道毒性,1例患者出现晚期2级直肠出血。两名患者出现急性2级泌尿生殖系统毒性，包括尿频和尿急，通过长期随访持续。在HDR近距离放射治疗后29.5个月的中位随访中，一名患者出现区域性和远处衰竭，另一个有精囊复发。
结论：HDR-BT对于以前接受过直肠癌放疗的前列腺癌患者是一种安全的治疗方法。需要进一步的研究来更好地表征HDR-RT在该人群中的长期毒性。
方法：在加州大学进行了回顾性图表审查，旧金山确定在2006年至2022年间接受高剂量率近距离放射治疗（HDR-BT）治疗的患有前列腺癌的患者，这些患者有盆腔RT直肠癌病史。纳入标准是活检证实的前列腺癌，在临床检查或影像学上没有远处疾病的证据。和至少一个治疗后诊所预约。
结果：7例患者在接受直肠癌放疗后的中位间隔为17.7年接受挽救性HDR-BT治疗。HDR-BT剂量包括6个部分的3600cGy（n=5），2个馏分中的2700cGy(n=1)，或四个部分中的2800cGy(n=1)。无急性≥2级胃肠道毒性,1例患者出现晚期2级直肠出血。两名患者出现急性2级泌尿生殖系统毒性，包括尿频和尿急，通过长期随访持续。在HDR近距离放射治疗后29.5个月的中位随访中，一名患者出现区域性和远处衰竭，另一个有精囊复发。
结论：HDR-BT对于以前接受过直肠癌放疗的前列腺癌患者是一种安全的治疗方法。需要进一步的研究来更好地表征HDR-RT在该人群中的长期毒性。
