Stereotactic Body Radiotherapy (SBRT) for unresectable liver metastases. Clinical outcomes.
Luis Alberto Perez-Romasanta,
Spain
PO-1358
Abstract
Stereotactic Body Radiotherapy (SBRT) for unresectable liver metastases. Clinical outcomes.
Authors: Luis Alberto Perez-Romasanta1, Blanca De la Plaza Villanueva1, Celia Nicolas Boluda1, Maria Belen Cuesta Picon1, Jorge Henandez Rodriguez2, Sofia Garcia Repiso2, Ana Rodriguez Gonzalez1, Angela Matias Perez1
1Hospital Universitario de Salamanca, Radiation Oncology, Salamanca, Spain; 2Hospital Universitario de Salamanca, Radiation Physics, Salamanca, Spain
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Purpose or Objective
Stereotactic body radiotherapy (SBRT) is an alternative treatment option for liver metastases in patients unsuitable for surgery and/or interventional procedures. We investigated factors associated with clinical outcomes for liver metastases treated with SBRT from a single center.
Material and Methods
Patients with liver metastases treated with SBRT were identified in hospital patient registry. Patient, tumor and treatment characteristics associated with treatment outcomes were assessed. Dose fractionations were normalized to BED10. Overall survival (OS), progression free survival (PFS) and local failure free survival (LFFS) were evaluated using Kaplan Meier analysis and log-rank test.
Results
The study included 24 patients, 77% males, with 48 liver metastases. Median age was 70 years (55–89 years). Colorectal adenocarcinoma (CRC) was the primary cancer for 34 metastatic lesions (70.8%) and synchronous/metachronous distribution was 52.1%/47.9%. Most patients had a previous history of metastatic disease, 77.1% oligo- and 18.8% polymetastatic. Most lesions (75%) had received prior treatment. Mean PTV volume was 65.4 cm3 (2.7–333.3 cm3) and mean SBRT dose was 46.8 Gy (40–54 Gy) delivered in a median of 5 fractions. At a median follow-up of 24 months (5-65 m.) the median PFS and OS were 6.7m. and 38m. respectively. Median OS for patients with CRC and with no-CRC were 38.6m. vs. 32.3m (p=0.209), and for patients with synchronous/metachronous metastases were 38.5m vs. 38.7 (p=0.833). Smaller PTV volumes (< 65 cm3) or higher BED did not correlate with improved OS (p=0.128 and p=0.522). Location of primary tumor (CRC vs. non-CRC) correlated with SLP (7.1m vs 3.8m; p=0.044). Local failure correlated with synchronous/metachronous lesion status (Median LFFS 25.1m vs. 32.7m; p=0.022). There was no difference in LFFS based on PTV volume or BED.
Conclusion
In this single institution series of patients with liver metastasis treated with SBRT, satisfactory outcomes were observed. Location of the primary tumor and metachronous development of metastases correlated with better disease control.