Intraoperative high-dose rate interstitial irradiation of hepatic metastases from colorectal carcinoma.Results of a phase I–II trial

Abstract

Background. Resection of liver metastases from colorectal carcinoma can be curative. Unresectable but liverconfined metastases might be ablated by high‐dose radiation with a similar curative result. Methods. At Georgetown University Hospital, 22 patients with unresectable hepatic metastases from colorectal carcinoma underwent 24 interstitial irradiation procedures at laparotomy in a Phase I–II study. A single dose was administered with a high‐dose rate iridium‐192 afterloader. Dose to the tumor periphery was 20 Gy, 25 Gy, and 30 Gy in 13, 9, and 2 procedures, respectively. Results. No acute or chronic radiation toxicity has occurred at a median follow‐up of 11 months. Median actuarial local control at irradiated sites was 8 months, with 26% actuarial local control at 26 months by computed tomography (CT) or magnetic resonance imaging (MRI) scanning. In the two patients undergoing two procedures each, a second biopsy of previously irradiated areas demonstrated tumor eradication. Conclusions. This innovative, radical approach to unresectable colorectal hepatic metastases proved safe. Additional study is needed to determine whether interstitial irradiation is as effective as surgical resection, or whether it alters the natural history of the disease or longevity.

Options for radiotherapy in the treatment of liver metastases

“…High-dose radiation can also be delivered to focal liver metastases, using interstitial brachytherapy, in which radiation is delivered from radioactive sources placed within or near the tumour [29][30][31][32][33]. High dose rate iridium 192, afterloaded to applicators, placed at the time of laparotomy, has been used to deliver 20-30 Gy in 2-13 settings.…”

Internal radiation therapy for patients with primary or metastatic hepatic cancer

“…In two other studies, interstitial treatment was administered during laparotomy. 15,16 The treatment appeared safer than a resection, as there was no operative mortality. Patients who were not suitable candidates for resection because of poor liver function could also be treated by this method.…”

“…Delivery of 20 -30 Gy to the periphery of tumors with a high dose rate 192 Ir afterloader produced good local control of liver metastases in 22 patients. 16 Tumor eradication was histologically documented in 2 patients who underwent two procedures. 90 Y emits pure beta radiation with a high average energy (937 keV) and a short half-life of 64 hours, making it an ideal agent for the treatment of liver tumors.…”

Interventionelle Radiotherapie bei hepatozellulärem und cholangiozellulärem Karzinom

“…Hierbei wurde nach Laparotomie und Katheterpositionierung eine interstitielle HDR-Brachytherapie mit Iridium-192 (Tumorzieldosis 20-30 Gy) durchgeführt [10]. Es wurde keine akute oder chronische Strahlentoxizität im Verlaufszeitraum von 11 Monaten beobachtet; die mediane lokale Kontrolle betrug 8 Monate.…”