Original Article
Intraoperative radiotherapy in locally-advanced and recurrent rectal cancer: retrospective review of 68 cases
Abstract
Background: The addition of intraoperative radiation therapy (IORT) to the multimodal treatment of locally advanced or recurrent rectal cancer may improve local control. Although electron beam IORT is the most common modality, technological advances now permit the use of photon beam IORT. However, few studies have investigated these devices in rectal cancer.
Methods: Retrospective review of patients (pts) treated with surgery and IORT for stage T3-T4 rectal cancer or pelvic recurrence between December 2012 and December 2014. Patients with distant metastasis were excluded. IORT was delivered with the Intrabeam Photon Radiosurgery System (PRS). The study sample included 68 pts (41 males, 27 females) ranging in age from 33 to 82 (median, 67) years. Most patients (47) had stage II primary rectal cancer (PRC), while 21 pts had stage III disease. Nine of this pts presented recurrent rectal cancer (RRC). Wanebo staging for the nine PRC cases was: Tr3 (6 pts), Tr4 (2 pts), and Tr5 (1 pt). A dose of 5.07 Gy was prescribed to a depth of 1 cm (surface dose range was 9.4-17.0 Gy; median, 14.8 Gy). Median duration of IORT was 31.9 (range, 15-36) minutes. The spherical applicator was 5 cm in diameter in 61 cases and 4.5 in seven cases. A subgroup analysis (23 pts) was performed to assess those patients with the longest follow-up (range, 17-28 minutes; median, 20.7 minutes). Of these, 18/23 (78%) received adjuvant chemotherapy. Overall survival (OS) and disease-free survival were calculated with the Kaplan-Meier method.
Results: In 18 of the 68 pts (26.4%), the tumour was attached to the sidewall. Margins were positive in 7 pts (10.3%). In the 23 pts subgroup with long-term follow-up, OS was 87.0%. Local recurrence occurred in 3 of 23 pts (13%). Four cases (17.4%) of distant metastasis (lung: 3 cases; liver: 1 case) were recorded. No intraoperative complications attributable to IORT were registered. Median postsurgical discharge time was 17.7 (range, 9-25) days. No cases of hydronephrosis or ureter fibrosis after IORT were documented.
Conclusions: Intrabeam PRS appears to be a safe technique for delivering IORT in rectal cancer patients. Although operating time increased slightly, outcomes in terms of toxicity, local recurrence, and survival were all quite good in comparison with other IORT delivery methods.
Methods: Retrospective review of patients (pts) treated with surgery and IORT for stage T3-T4 rectal cancer or pelvic recurrence between December 2012 and December 2014. Patients with distant metastasis were excluded. IORT was delivered with the Intrabeam Photon Radiosurgery System (PRS). The study sample included 68 pts (41 males, 27 females) ranging in age from 33 to 82 (median, 67) years. Most patients (47) had stage II primary rectal cancer (PRC), while 21 pts had stage III disease. Nine of this pts presented recurrent rectal cancer (RRC). Wanebo staging for the nine PRC cases was: Tr3 (6 pts), Tr4 (2 pts), and Tr5 (1 pt). A dose of 5.07 Gy was prescribed to a depth of 1 cm (surface dose range was 9.4-17.0 Gy; median, 14.8 Gy). Median duration of IORT was 31.9 (range, 15-36) minutes. The spherical applicator was 5 cm in diameter in 61 cases and 4.5 in seven cases. A subgroup analysis (23 pts) was performed to assess those patients with the longest follow-up (range, 17-28 minutes; median, 20.7 minutes). Of these, 18/23 (78%) received adjuvant chemotherapy. Overall survival (OS) and disease-free survival were calculated with the Kaplan-Meier method.
Results: In 18 of the 68 pts (26.4%), the tumour was attached to the sidewall. Margins were positive in 7 pts (10.3%). In the 23 pts subgroup with long-term follow-up, OS was 87.0%. Local recurrence occurred in 3 of 23 pts (13%). Four cases (17.4%) of distant metastasis (lung: 3 cases; liver: 1 case) were recorded. No intraoperative complications attributable to IORT were registered. Median postsurgical discharge time was 17.7 (range, 9-25) days. No cases of hydronephrosis or ureter fibrosis after IORT were documented.
Conclusions: Intrabeam PRS appears to be a safe technique for delivering IORT in rectal cancer patients. Although operating time increased slightly, outcomes in terms of toxicity, local recurrence, and survival were all quite good in comparison with other IORT delivery methods.
