Greco Carlo, Pares Oriol, Pimentel Nuno, Louro Vasco, Nunes Beatriz, Kociolek Justyna, Marques Joao, Fuks Zvi
The Champalimaud Centre for the Unknown, Department of Radiation Oncology, Lisbon, Portugal.
Memorial Sloan Kettering Cancer Department of Radiation Oncology Center, New York, NY, United States.
Front Oncol. 2022 Oct 6;12:984917. doi: 10.3389/fonc.2022.984917. eCollection 2022.
To explore whether prostate motion mitigation using the rectal distension-mediated technique is safe and effective in stereotactic ablative radiation therapy (SABR) salvage treatment of intraprostatic cancer recurrences following initial radiotherapy for primary prostate cancer.
Between July 2013 and December 2020, 30 patients received salvage SABR for Ga- PSMA-11 PET/CT-detected intra-prostatic relapses. Median time from primary RT to salvage reirradiation was 70.2 (IQR, 51.3-116.0) months. Median PSA at retreatment was 3.6 ng/mL (IQR, 1.9-6.2). Rectal distension-mediated SABR was achieved with a 150-cm air-inflated endorectal balloon and a Foley catheter loaded with 3 beacon transponders was used for urethra visualization and on-line tracking. MRI-based planning employed a 2-mm expansion around the planned target volume (PTV), reduced to 0-mm at the interface with critical organs at risk (OARs). Volumetric Modulated Arc Therapy (VMAT) permitted a 20% dose reduction of the urethra. VMAT simultaneous integrated boost (SIB) of the dominant intraprostatic lesion was deployed when indicated. Median SABR dose was 35 Gy (7 Gy per fraction over 5 consecutive days; range 35-40 Gy). Toxicity assessment used CTCAE v.4 criteria.
Median follow-up was 44 months (IQR, 18-60). The actuarial 3- and 4-year biochemical relapse free survival was 53.4% and 47.5%, respectively. Intraprostatic post-salvage relapse by PSMA PET/CT was 53.3%. Acute grade 2 and 3 genitourinary (GU) toxicities were 20% and 0%, respectively. There were no instances of acute grade ≥2 rectal (GI) toxicity. Late grade 2 and 3 GU toxicities occurred in 13.3% and 0% of patients, respectively. There were no instances of grade ≥2 late rectal toxicity. Patient-reported QOL measures showed an acute transient deterioration in the urinary domain 1 month after treatment but returned to baseline values at 3 months. The median IPSS scores rose over baseline (≥5 points in 53% of patients) between month 6 and 12 post-treatment as a result of urinary symptoms flare, eventually receding at 18 months. The bowel domain metrics had no appreciable changes over time.
Pursuit of local control in intraprostatic failures is feasible and can be achieved with an acceptably low toxicity profile associated with effective OAR sparing.
探讨在立体定向消融放疗（SABR）挽救性治疗原发性前列腺癌初次放疗后前列腺内癌复发中，使用直肠扩张介导技术减轻前列腺运动是否安全有效。
2013年7月至2020年12月期间，30例患者接受了针对镓-PSMA-11 PET/CT检测到的前列腺内复发的挽救性SABR治疗。从初次放疗到挽救性再照射的中位时间为70.2（四分位间距，51.3 - 116.0）个月。再次治疗时的中位前列腺特异性抗原（PSA）为3.6 ng/mL（四分位间距，1.9 - 6.2）。使用150厘米充气式直肠内球囊实现直肠扩张介导的SABR，并用装有3个信标应答器的Foley导管进行尿道可视化和在线跟踪。基于磁共振成像（MRI）的计划在计划靶区（PTV）周围采用2毫米的外放，在与危及器官（OAR）的界面处缩小至0毫米。容积调强弧形放疗（VMAT）可使尿道剂量降低20%。如有指征，对主要前列腺内病变进行VMAT同步整合加量（SIB）。SABR的中位剂量为35 Gy（连续5天，每天7 Gy；范围35 - 40 Gy）。毒性评估采用美国国立癌症研究所常见不良反应事件评价标准（CTCAE）第4版。
中位随访时间为44个月（四分位间距，18 - 60）。3年和4年的精算无生化复发生存率分别为53.4%和47.5%。PSMA PET/CT显示前列腺内挽救性治疗后复发率为53.3%。急性2级和3级泌尿生殖系统（GU）毒性分别为20%和0%。无急性≥2级直肠（GI）毒性病例。晚期2级和3级GU毒性分别发生在13.3%和0%的患者中。无≥2级晚期直肠毒性病例。患者报告的生活质量（QOL）指标显示，治疗后1个月泌尿系统领域出现急性短暂恶化，但在3个月时恢复到基线值。治疗后6至12个月，由于泌尿系统症状发作，国际前列腺症状评分（IPSS）中位数较基线升高（53%的患者升高≥5分），最终在18个月时下降。肠道领域指标随时间无明显变化。
在前列腺内失败病例中追求局部控制是可行的，并且可以通过与有效保护OAR相关的可接受的低毒性特征来实现。
