ESTRO 37 Abstract book

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ESTRO 37

EP-1378 Stereotactic body radiotherapy in an Australia centre for biopsy proven non-small cell lung cancer J. Croker 1 , S. Mincham 1 , C. Harper 1 , R. Chee 1 , E. Ng 1 , T. Lim 1 1 Fiona Stanley Hospital, Department of Radiation Oncology, MURDOCH, Australia Purpose or Objective To assess local control and survival in patients treated with stereotactic body radiotherapy in a single Australian institution for biopsy proven early stage non-small cell lung cancer. Material and Methods A retrospective analysis was undertaken of patients treated with stereotactic body radiotherapy for Stage I (T1N0M0 or T2N0M0) non-small cell lung cancer at a single Western Australian institution from late 2010 to mid-2015. All patients had attempted biopsy of treated lesions and cases were discussed at a lung cancer multi- disciplinary clinic prior to treatment. Patients were 4D-CT inverse planned and treated to a dose of 48Gy in 4 fractions (12Gy per fraction), 2 fractions per week over 2 weeks, utilising intensity- modulated radiation therapy, prescribed to the 65-82% isodose. Patients were followed post-treatment with 3-monthly follow-up imaging (CT and PET CT) until July 2017 or death. Local control, survival, cause of death information was collected. Frequencies, means, standard deviations for gender, smoking status, tumour stage, histology, location and local control were calculated and Kaplan- Meier survival analysis was undertaken. Results Forty four patients were treated from December 2010 to August 2015. The median age was 79 years (range 57-97). Fifty-two percent of patients were females and 48% males. The majority (86%) were present or past smokers. There was biopsy proven malignancy in 40 of 44 patients (91%). Adenocarcinoma (61%) was the most common pathology followed by squamous cell carcinoma (23%) and carcinoma, not otherwise specified (7%). Two-thirds of patients were staged as T1N0M0 (68%), 21% were T2N0M0 and 11% was treatment of recurrent disease. The median tumour size was 20mm (range 9-54mm). The most common location was right upper lobe (36%) followed by left upper lobe (32%). Local control was achieved in 96% of patients with only 2 patients having local failure. Nine patients (20%) had no residual mass seen at last follow-up imaging, whilst 33 (75%) had partial response or stable disease. Eleven patients (25%) failed distantly, with 6 patients failing in the distant lung and/or mediastinum and 5 patients failing both in the distant lung and outside the thorax. For the entire cohort, the overall survival rate was 61%. Median survival was 23 months and the 3 year overall survival rate was 65% (Figure 1). The 3 year disease-free survival rate was 41%. Six deaths were lung cancer related, eight due to non-lung cancer causes and three patients died of unknown causes .

Conclusion In a cohort of biopsy-proven, relatively elderly patients with a strong representation of females and adenocarcinoma, stereotactic radiotherapy offers an excellent modality of treatment for local control for early stage non-small cell lung cancer in patients that are either unable or unwilling to undergo radical surgery. Our local control and survival rates compare favourably with published international series. EP-1379 stereotactic radiotherapy for oligometastases in the lung: analysis of 279 patients (647 lesions). F. Casamassima 1 , C. Menichelli 1 , G. Pastore 1 , A. Fanelli 1 1 Radioterapia Istituto Ecomedica, radiotherapy, Empoli, Italy Purpose or Objective The lung is a frequent site of metastases from solid tumors. Recent observations suggest the existence of a disease phase where metastatic diffusion stops leaving limited number of foci (oligometastatic state). Eradicative therapies of all these limited metastatic sites may have positive effects on disease progression and OS. For these purpose, patient selection and relationship with systemic therapies are very important. We study the results in term of LC, OS, toxicity and progression modalities in 279 patients treated with SABR for pulmonary oligometastases from different primary tumors. Material and Methods 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%. The median number of treated lesions in the same patients was 2 (range 1-5). 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 Results 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 pts 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

Figure 1. Overall survival.