Sabr For Oligometastatic Patients On The Lung: Clinical Experience On 279 Patients (647 Lesions)

Patients with oligometastases to the lung from solid tumors are now considered candidates for curative therapy. Uncertainties on the patients selection and the relationship with systemic therapies are still not well defined. We study the results in terms of LC, OS, toxicity and progression modality in 279 pts treated by SABR for pulmonary oligometastases from different primary tumors. Between December 2010 and April 2016, 279 pts (172 male and 76 female)were treated by SABR on 647 lesions. Primary cancer was lung in 45%, colonrectal in 24%, breast in 5%, H&N in 3%, Kidney in 2,5% and 16% others. The histological type was Adenocarcinoma in 63%, Squamosus carcinoma in 20%, other in 17%. Median target volume was 3,18 cc. The median dose of 33,2Gy was prescribed to 70% isodose with median BED to isocenter of 118Gy in 1 to 3 fx (median 1fx). Treatment was delivered by 6MV linac with beam modulator. Set up and isocenter position assessed by CBCT. Toxicity was evaluated using CTCAE vs2. With median follow up of 19 month (range3-56), median OS was 56m, DFS was 16m and median LC 18m. 36 pt relapsed in the treatment field, 74 pt in the chest and 219 showed extra pulmonary recurrences. Statistically signicative differences on OS was observed between patient with primary controlled or not (2y, OS 89% vs 61%; p=0.001), with metacronous vs synchronous metastases (2y, OS 98% vs 64%, p=0.001), chemotherapy or not after SABR (2y, OS 87% vs 53%, p=0.02). 5y OS for patients treated for breast metastases was 88%, for colorectal cancer 52% and for NSCLC 62%. Not significant differences on LC was detected between different primary tumors.LC rates appears to be related only to BED value. Toxicity was mild and not exceeded the grade 2. The SABR appears as safe and effective therapy with high rates of LC of pulmonary metastases using BED value exceeding 100Gy. The influence on OS appears to be related to the time of metastases appearance (synchronous vs metacronous), primary tumor controlled or not and the use of chemotherapy after SABR. The rate of OS, confirms the possibility to use the SABR with curative intent in well selected oligometastatic patients. The better rates of OS occurs in pt treated for breast cancer. The majority of failures was represented by extra thoracic spread, leading to necessity of more effective systemic therapies. y>> for colorectal cancer 52% and for NSCLC 62%. No significant differences on LC was detected between different primary tumors.LC rates appears relate only to BED value. Toxicity was mild and not exceeded the grade 2.