Efficacy Of Pulmonary Sabr Follow Up: A Single Institution Review

The use of Pulmonary SABR has increased dramatically over the last decade to treat early stage non-small cell lung cancer (NSCLC). Post SABR imaging in this population could enable early detection of local recurrences, metastatic disease or second primary lung cancers. Early detection of local recurrences or disease progression is important with the increasing number of salvage options available. However, evidence is still lacking as to the appropriate follow up (FU) protocol of this population, thus our aim was to evaluate the efficacy of our post SABR institutional FU. A random sample of 117 pts. with NSCLC who were pet staged and treated with SABR between 2014 -2016 at our institution were reviewed. As per our FU, pts. post SABR for NSCLC have CT imaging at 2-3 mths. 5-6 mths. 9 mths. and 12 mths. within in the first year. Every 6 mths. in year 2 and then yearly from years 3-5. PET CT is imaging of choice at 5-6 mths. The post SABR scans were reviewed to assess the efficacy of FU. Gender was evenly distributed 49% female and 51% male. The median age at the time of SABR completion was 74.5 (39-88). Ex-smokers accounted for 70% of cases, smokers 27% and non-smokers 3%. The majority of cases were biopsy proven 85.5%, adenocarcinoma 43.6% and squamous cell carcinoma 41.9%. Most pts. were staged as cT1N0M0 (63%) followed by cT2N0M0 (34%) and cT3N0M0 (3%). Tumors were mainly peripheral 79.5%. With regard to tumor location 34.2% were in the left upper lobe, followed by right upper lobe 29.1%, left lower lobe 17.1%, right lower lobe 14.5% and right middle lobe 5.1%. Seven pts. were lost to FU, had FU in another institution or died before FU began. Calculated from completion of radiation, the median time to FU CT 1 was 3.1 mths. (1.5-37.9), to CT 2 was 5.3 mths. (3-19.7), to CT 3 was 11.3 mths. (5-30.8), to CT 4 was 18.3 mths. (11-55.6). Compliance with FU was largely related to radiology scheduling rather than patient or clinician. At CT 1, 12 pts. (10%) had progression, at CT 2, 14 pts. (12%) had progression, at CT 3, 7 pts. (6%) had progression and at CT 4, 6 pts. (5.1%) had progression. From CT 6 - CT 8 of those documented < 5% per CT had progression. Overall local control was 91% and in those with progression local control was achieved in all but 7. There was pulmonary progression in 14.5%, 9% had mediastinal (nodal) progression and 8.2% had distant failure. Two pts. (1.8%) were diagnosed with a new primary. There was no association between pathology or stage and progression. We documented 58 deaths from our population with 34 (59%) of those having progression on FU imaging. Our analysis highlights generally good compliance of an intense protocol in a generally frailer population and the importance of short interval FU within the first year post SABR, particularly within the first 6 months to detect disease progression and optimize further treatment options and management.Abstract 3179; Table 1Progression (N)LocalNodalLungDistantLocal & NodalLocal & LungNew CancerCT 1121432101CT 2140344111CT 370322000CT 462130000 Open table in a new tab