Robotic radiosurgery of liver metastases of solid tumors

Abstract

e15049 Background: The number of patients (pts) suffering from isolated liver metastases is growing. Although surgical excision is the treatment of choice many pts do not qualify for surgery. So local ablative techniques like radiofrequency ablation, laser induced thermal ablation therapy, brachytherapy and different external beam radiation therapies have been employed. We here report the therapeutic efficacy of a robotic radiosurgery device for local control of liver metastases of solid tumors. Methods: Patients with liver metastases not qualifying for surgery were treated with single session radiosurgery (24 Gy) using robotic image-guided real-time tumor tracking. In a prospective analysis, follow-up was done by MRI scanning at two months after the treatment, and subsequently at 3-month intervals to evaluate local control. For inclusion into the radiosurgery treatment protocol, tumor volumes had to be smaller than 80cc. Results: 27 pts (median age 62 years) with a total of 43 target lesions were evaluated. 17 pts were treated with single, 10 pts with multiple targets. Metastases (n=27) originated from: colon (12), rectum (2), pancreas (2), lung (1), bladder (2), malignant melanoma (1), stomach (1), cholangiocellular carcinoma (2), breast (1), ovary (1), appendix (1) and endometrium (1). Median tumor volume was 21cc (range 2.2–79.3). Median KPS was 100% (range 80–100). The median follow up was 12 months. 23 pts (85%) reached local control of the disease, 4 pts (15%) had local recurrence. Grade 2–4 adverse events due to cyberknife treatment were not observed. Conclusions: Robotic radiosurgery with image-guided real-time tumor tracking of liver metastases is a new and promising treatment approach for pts not eligible for surgical resection and might enhance the possibilities of multidisciplinary oncological treatment concepts. No significant financial relationships to disclose.