அவசர மருத்துவம்: திறந்த அணுகல்
திறந்த அணுகல்

சுருக்கம்

Stereotactic body radiotherapy in liver metastasis

Neeraj Jain

Abstract

Stereotactic Body Radiation Therapy (SBRT) also known as stereotactic ablative Radiotherapy (SABR) is a newer modality of delivering radiation therapy for many primary and secondary tumors, with good results. Liver metastases from colorectal, breast and lung cancer are most common. Studies focusing on SBRT for liver metastases from a single primary tumor type colorectal cancer have been published. Regardless of age, patients should have good performance status (Eastern Cooperative Oncology Group 0-1 or Karnofsky >70), with absent or stable extra hepatic disease and adequate hepatic volume and function. Number of metastasis should be less than three and size less than 6 cm. Prescribed dose is generally very high in range of 30 to 60 Gy in three fractions. The toxicity profile is generally low with a G3 toxicity rate of 1-10% and the incidence of Radiation Induced Liver disease less than 1%. The most common G2 toxicities included a transient hepatic enzyme levels increase over three months of SBRT and gastrointestinal, soft-tissue and bone complications, related to lesions close to the duodenum, bowel, skin and ribs. Duodenal ulceration and intestinal perforation is observed in patients with maximum doses greater than 30 Gy in three fractions to the duodenum and bowel. In few patients, non-traumatic rib fractures were experienced for maximum doses of 51.8 Gy and 66.2 Gy in six fractions to 0.5 cm3 of rib. Local control rates varied from 70% to 100% at one year and 60% to 90% at two years and correlated to lesion size

This Work is presenting at 32nd Euro Congress on Cancer Science & Therapy (Cancer Meeting 2020- Webinar) on June 29-30, 2020

Methods

Patients with liver metastases treated with SBRT were identified in the RSSearch® Patient Registry. Patient, tumor and treatment characteristics associated with treatment outcomes were assessed. Dose fractionations were normalized to BED10. Overall survival (OS) and local control (LC) were evaluated using Kaplan Meier analysis and log-rank test.

Results

The study included 427 patients with 568 liver metastases from 25 academic and community-based centers. Median age was 67 years (31–91 years). Colorectal adenocarcinoma (CRC) was the most common primary cancer. 73% of patients received prior chemotherapy. Median tumor volume was 40 cm3 (1.6–877 cm3), median SBRT dose was 45 Gy (12–60 Gy) delivered in a median of 3 fractions [1,2,3,4,5]. At a median follow-up of 14 months (1–91 months) the median overall survival (OS) was 22 months. Median OS was greater for patients with CRC (27 mo), breast (21 mo) and gynecological (25 mo) metastases compared to lung (10 mo), other gastro-intestinal (GI) (18 mo) and pancreatic (6 mo) primaries (p < 0.0001). Smaller tumor volumes (< 40 cm3) correlated with improved OS (25 months vs 15 months p = 0.0014). BED10 ≥ 100 Gy was also associated with improved OS (27 months vs 15 months p < 0.0001). Local control (LC) was evaluable in 430 liver metastases from 324 patients. Two-year LC rates was better for BED10 ≥ 100 Gy (77.2% vs 59.6%) and the median LC was better for tumors < 40 cm3 (52 vs 39 months). There was no difference in LC based on histology of the primary tumor.

Conclusions

In a large, multi-institutional series of patients with liver metastasis treated with SBRT, reasonable LC and OS was observed. OS and LC depended on dose and tumor volume, while OS varied by primary tumor. Future prospective trials on the role of SBRT for liver metastasis from different primaries in the setting of multidisciplinary management including systemic therapy, is warranted.