Harrison L B, Minsky B D, Enker W E, Mychalczak B, Guillem J, Paty P B, Anderson L, White C, Cohen A M
Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA.
Int J Radiat Oncol Biol Phys. 1998 Sep 1;42(2):325-30. doi: 10.1016/s0360-3016(98)00211-9.
Primary unresectable and locally advanced recurrent rectal cancer presents a significant clinical challenge. Local failure rates are high in both situations. Under such circumstances, there is a significant need to safely deliver tumoricidal doses of radiation in an attempt to improve local control. For this reason, we have incorporated a new approach utilizing high dose rate intraoperative radiation therapy (HDR-IORT).
Between 11/92-12/96, a total of 112 patients were explored, of which 68 patients were treated with HDR-IORT, and 66 are evaluable. The majority of the 44 patients were excluded for unresectable disease or for distant metastases which eluded preoperative imaging. There were 22 patients with primary unresectable disease, and 46 patients who presented with recurrent disease. The histology was adenocarcinoma in 64 patients, and squamous cell carcinoma in four patients. In general, the patients with primary unresectable disease received preoperative chemotherapy with 5-fluorouracil (5-FU) and leucovorin, and external beam irradiation to 4500-5040 cGy, followed by surgical resection and HDR-IORT (1000-2000 cGy). In general, the patients with recurrent disease were treated with surgical resection and HDR-IORT (1000-2000 cGy) alone. All surgical procedures were done in a dedicated operating room in the brachytherapy suite, so that HDR-IORT could be delivered using the Harrison-Anderson-Mick (HAM) applicator. The median follow-up is 17.5 months (1-48 mo).
In primary cases, the actuarial 2-year local control is 81%. For patients with negative margins, the local control was 92% vs. 38% for those with positive margins (p = 0.002). The 2-year actuarial disease-free survival was 69%; 77% for patients with negative margins vs. 38% for patients with positive margins (p = 0.03). For patients with recurrent disease, the 2-year actuarial local control rate was 63%. For patients with negative margins, it was 82%, while it was 19% for those with positive margins (p = 0.02). The disease-free survival was 47% (71% for negative margins and 0% for positive margins) (p = 0.04). Prospective data gathering indicated that significant complications occurred in approximately 38% of patients and were multifactorial in nature, and manageable to complete recovery.
HDR-IORT using our technique is versatile, safe, and effective. The local control rates for primary disease compare quite well with other published series, especially for patients with negative margins. For patients with recurrent disease, locoregional control and survival are especially encouraging in patients with negative resection margins. Further follow-up is needed to see whether these encouraging data will continue.
原发性无法切除及局部进展性复发性直肠癌是一项重大的临床挑战。在这两种情况下局部失败率都很高。在这种情形下，迫切需要安全地给予肿瘤致死剂量的放疗，以试图改善局部控制。因此，我们采用了一种利用高剂量率术中放疗（HDR-IORT）的新方法。
在1992年11月至1996年12月期间，共对112例患者进行了探查，其中68例患者接受了HDR-IORT治疗，66例可评估。44例患者中的大多数因无法切除的疾病或术前影像学检查未发现的远处转移而被排除。有22例原发性无法切除疾病患者，46例复发性疾病患者。64例患者的组织学类型为腺癌，4例为鳞状细胞癌。一般来说，原发性无法切除疾病的患者接受术前5-氟尿嘧啶（5-FU）和亚叶酸化疗，外照射剂量为4500-5040 cGy，随后进行手术切除和HDR-IORT（1000-2000 cGy）。一般来说，复发性疾病患者仅接受手术切除和HDR-IORT（1000-2000 cGy）。所有手术均在近距离放疗套房的专用手术室进行，以便使用哈里森-安德森-米克（HAM）施源器进行HDR-IORT。中位随访时间为17.5个月（1-48个月）。
在原发性病例中，精算2年局部控制率为81%。切缘阴性的患者局部控制率为92%，切缘阳性的患者为38%（p = 0.002）。2年精算无病生存率为69%；切缘阴性的患者为77%，切缘阳性的患者为38%（p = 0.03）。对于复发性疾病患者，2年精算局部控制率为63%。切缘阴性的患者为82%，切缘阳性的患者为19%（p = 0.02）。无病生存率为47%（切缘阴性的患者为71%，切缘阳性的患者为0%）（p = 0.04）。前瞻性数据收集表明，约38%的患者发生了严重并发症，其性质是多因素的，且可控制至完全康复。
使用我们的技术进行HDR-IORT具有通用性、安全性和有效性。原发性疾病的局部控制率与其他已发表的系列研究相比相当不错，尤其是对于切缘阴性的患者。对于复发性疾病患者，切缘阴性的患者局部区域控制和生存率尤其令人鼓舞。需要进一步随访以观察这些令人鼓舞的数据是否会持续。
