Morikawa Lisa K, Zelefsky Michael J, Cohen Gil'ad N, Zaider Marco, Chiu Johnny, Mathur Nitin, Worman Michael F, Goodman Karyn A
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
Brachytherapy. 2013 Jan-Feb;12(1):1-7. doi: 10.1016/j.brachy.2012.04.011. Epub 2012 Nov 17.
Intraoperative radiation therapy (IORT) allows delivery of tumoricidal doses of radiation to areas of potential residual microscopic disease while minimizing doses to normal tissues. IORT using high-dose-rate (HDR) brachytherapy allows dose modulation and delivery of concomitant boosts to high-risk areas. This study describes a novel technique of HDR-IORT with dose painting (DP) (HDR-IORT-DP) and evaluates the clinical outcomes.
Sixteen patients with recurrent cancers received HDR-IORT-DP at the time of radical resection. Of these patients, 13 had colorectal cancer, 2 had head and neck cancer, and 1 had a gynecologic malignancy. All received external beam radiation previously. Negative margin (R0) was obtained in 12 patients (75%) and microscopically positive margins (R1) in 4 patients (25%).
The median total target and boost area were 45 and 8.5cm(2), and HDR-IORT and boost dose were 1500 and 1750cGy, respectively. Median followup was 14.9 months. The 2-year local control and overall survival were 80% and 20%, respectively. Eleven patients (69%) developed distant metastasis and were deceased at the time of the last followup. A total of 13 patients (19%) developed Grade 3 toxicity related to HDR-IORT; no grade 4+ toxicities were observed.
HDR-IORT-DP technique is feasible, safe, and allows for dose escalation in locally advanced or recurrent previously irradiated tumors. To our knowledge, this is the first clinical report on HDR-IORT-DP. Further studies are warranted to evaluate efficacy in a larger patient cohort. Local control was encouraging in our patients.
术中放射治疗（IORT）能够将杀灭肿瘤剂量的辐射传递至潜在残留微小病灶区域，同时将对正常组织的剂量降至最低。使用高剂量率（HDR）近距离放射治疗的IORT可实现剂量调节，并向高危区域同步给予增敏剂量。本研究描述了一种采用剂量描绘（DP）的HDR-IORT新技术（HDR-IORT-DP）并评估其临床疗效。
16例复发癌患者在根治性切除时接受了HDR-IORT-DP治疗。其中，13例为结直肠癌，2例为头颈癌，1例为妇科恶性肿瘤。所有患者此前均接受过外照射。12例患者（75%）切缘阴性（R0），4例患者（25%）镜下切缘阳性（R1）。
总靶区和增敏区的中位面积分别为45和8.5cm²，HDR-IORT和增敏剂量分别为1500和1750cGy。中位随访时间为14.9个月。2年局部控制率和总生存率分别为80%和20%。11例患者（69%）发生远处转移，在最后一次随访时死亡。共有13例患者（19%）发生与HDR-IORT相关的3级毒性反应；未观察到4级及以上毒性反应。
HDR-IORT-DP技术可行、安全，且能使局部晚期或既往接受过照射的复发性肿瘤实现剂量递增。据我们所知，这是关于HDR-IORT-DP的首份临床报告。有必要开展进一步研究以评估更大患者队列中的疗效。我们患者的局部控制情况令人鼓舞。
