Brachyterapy in the treatment of liver metastases

OBJECTIVES SIRT (Selective Internal Radiation Therapy) is a new mini-invasive therapy for the treatment of unresectable colorectal liver metastases, using local ablative treatment in combination with the interventional radiology and radiotherapy. By using catheters inserted CT-guided are positioned Yttrium 90 microspheres, radioactive isotope that emits pure beta radiation, within the hepatic artery, which tumor cells selectively sprays. The capsules with the radionuclide is concentrated in the arterial capillaries realising radiation that hit a targeted tumor cells without damaging the surrounding healthy tissue. Effect of Yttrium lasts about 10 days and irradiated cells become necrotic. MATERIALS AND METHODS The patient treaty in our study (B. P., male, 80 years), already made a left colectomy for adenocarcinoma, after 2 years showed recurrence, for which he was subjected to surgery omentectomy and resection of the lower part of the gastric greater curvature, left parietal peritonectomy, excision “en bloc” of left kidney and first jejunal loop. CT showed multiple hypodense lesions “on target” in the liver parenchyma referable to metastases. The patient underwent a dose-rate brachytherapy in ultra-low (Ultra-Low Dose Rate, ULDR). Intervention was performed in a single session lasting about 90 minutes, in local anesthesia. Microspheres were introduced in femoral artery through a flexible catheter and moved forward until the hepatic artery. RESULTS There were no reported disturbance of liver function before and after treatment, except a moderate increase in liver enzymes and bilirubin without obvious clinical signs. For the follow-up MRI has been used every 6 weeks, which showed a reduction of the tumour mass by third month. The range of lesions treated was 5.5-11 mm. CONCLUSIONS Patients who received SIRT (Selective Internal Radiation Therapy) with radioactive Yttrium 90 seeds for the treatment of unresectable colorectal cancer liver metastases, don’t have big trouble, and the quality of life is excellent. Unlike conventional chemotherapy, selective brachytherapy have a low toxicity and compared with external radiation therapy, long action treatment makes the techinique more effective and safer to tolerate.