Abstract
Purpose/Objective(s)
While various retrospective and prospective studies have found that stereotactic body radiation therapy (SBRT) for liver metastases has high local control rates and relatively low toxicity, most of these series included a small number of patients. Only two reported on over 100 patients (DEGRO and RSSearch). We therefore intended to validate the outcomes of SBRT for liver metastases in a large multi-institution patient cohort treated with a common protocol.
Materials/Methods
From January 2013 - November 2018, patients from 13 centers (12 in the Netherlands and 1 in Belgium) were entered in a web-based registry. All institutions had previously agreed on the fractionation schemes and organs-at-risk constraints to be applied. Patients were treated with 3x18-20Gy, 5x11-12Gy, 8x7.5Gy or 12x5Gy. Follow-up was performed at the discretion of the different centers. Patient, tumor, and treatment characteristics were entered in the registry. Toxicity ≥ grade 3 was scored according to the Common Terminology Criteria for Adverse Events (v4.0). The Kaplan Meier estimate was used to measure local control and overall survival. The date of the last known radiology examination was regarded as the last follow-up date for local control. The Cox regression model was used to investigate whether local control differed significantly between the 4 groups of fractionation schemes.
Results
Although 516 patients were entered in the registry, 416 met all inclusion criteria and had at least one radiological examination for local control analysis. Median age was 70 years (30-92). The majority of patients had ECOG 0-1 (91%). Colorectal cancer (79%) was the most frequent primary tumor origin followed by lung (9%) and breast cancer (4%). A total of 560 metastases were included in the analysis. Median diameter was 2.5cm (0.3-9.9). The median number of metastases per treatment was 1 (1-5). The fractionation scheme most used was 3x18-20Gy (34%), followed by 8x7.5Gy (32%), 5x11-12Gy (27%) and 12x5Gy (8%). Median follow-up was 8 months for local control and 12 months for survival. Actuarial 1-year local control was 86%; for the groups treated in 3, 5, 8 and 12 fractions, it was 90%, 83%, 85% and 71%, respectively. There were no significant differences between the groups. Actuarial survival at 1 year was 81%. Grade ≥3 toxicity was found in 2.9% of the patients, 9 patients having grade 3 (abdominal pain, nausea, fatigue, bile duct stenosis, and hematoma); 2 patients having grade 4 (gallbladder and gastric perforation); and one having grade 5 (hepatobiliary disorder).
Conclusion
This large multi-institutional study of 560 liver metastases treated with SBRT confirms the high rates of local control and limited toxicity in a large patient cohort. In clinical practice, SBRT should thus be seen as a valuable part of the multidisciplinary approach to treating liver metastases.
While various retrospective and prospective studies have found that stereotactic body radiation therapy (SBRT) for liver metastases has high local control rates and relatively low toxicity, most of these series included a small number of patients. Only two reported on over 100 patients (DEGRO and RSSearch). We therefore intended to validate the outcomes of SBRT for liver metastases in a large multi-institution patient cohort treated with a common protocol.
Materials/Methods
From January 2013 - November 2018, patients from 13 centers (12 in the Netherlands and 1 in Belgium) were entered in a web-based registry. All institutions had previously agreed on the fractionation schemes and organs-at-risk constraints to be applied. Patients were treated with 3x18-20Gy, 5x11-12Gy, 8x7.5Gy or 12x5Gy. Follow-up was performed at the discretion of the different centers. Patient, tumor, and treatment characteristics were entered in the registry. Toxicity ≥ grade 3 was scored according to the Common Terminology Criteria for Adverse Events (v4.0). The Kaplan Meier estimate was used to measure local control and overall survival. The date of the last known radiology examination was regarded as the last follow-up date for local control. The Cox regression model was used to investigate whether local control differed significantly between the 4 groups of fractionation schemes.
Results
Although 516 patients were entered in the registry, 416 met all inclusion criteria and had at least one radiological examination for local control analysis. Median age was 70 years (30-92). The majority of patients had ECOG 0-1 (91%). Colorectal cancer (79%) was the most frequent primary tumor origin followed by lung (9%) and breast cancer (4%). A total of 560 metastases were included in the analysis. Median diameter was 2.5cm (0.3-9.9). The median number of metastases per treatment was 1 (1-5). The fractionation scheme most used was 3x18-20Gy (34%), followed by 8x7.5Gy (32%), 5x11-12Gy (27%) and 12x5Gy (8%). Median follow-up was 8 months for local control and 12 months for survival. Actuarial 1-year local control was 86%; for the groups treated in 3, 5, 8 and 12 fractions, it was 90%, 83%, 85% and 71%, respectively. There were no significant differences between the groups. Actuarial survival at 1 year was 81%. Grade ≥3 toxicity was found in 2.9% of the patients, 9 patients having grade 3 (abdominal pain, nausea, fatigue, bile duct stenosis, and hematoma); 2 patients having grade 4 (gallbladder and gastric perforation); and one having grade 5 (hepatobiliary disorder).
Conclusion
This large multi-institutional study of 560 liver metastases treated with SBRT confirms the high rates of local control and limited toxicity in a large patient cohort. In clinical practice, SBRT should thus be seen as a valuable part of the multidisciplinary approach to treating liver metastases.
| Original language | English |
|---|---|
| Pages (from-to) | S112-S113 |
| Journal | International Journal of Radiation Oncology Biology Physics |
| Volume | 105 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Sept 2019 |