ESTRO 38 Abstract book

S756 ESTRO 38

130, PMNs > 5 and adenocarcinoma histology have a better outcome. EP-1387 Managing isolated local/regional recurrences after SBRT for inoperable early lung tumors -a dilemma R. Harjani Hinduja 1 , J. Zheng 1 , J. Pantarotto 1 , R. MacRae 1 1 University of Ottawa, Radiation Oncology, Ottawa, Canada Purpose or Objective Stereotactic Body Radiation Therapy (SBRT) is an accepted standard treatment for treatment of stage I medically inoperable non-small cell lung cancers (NSCLC). The most common mode of failure for these patients is distant failure. Among the few percentage of patients who fail locally or regionally, salvage treatment options are limited in this frail population. We aim to evaluate our experience in salvage treatments at local or regional isolated failures after SBRT. Material and Methods We retrospectively reviewed failure patterns and subsequent treatments for our early NSCLC patients treated with SBRT/ hypo-fractionated radiation therapy between 2009 and 2015 in a research ethics board approved study. Local and regional recurrences were noted and then were categorized into isolated local/regional /loco-regional versus widespread progression (along with distant metastases). Salvage treatments offered to loco-regional recurrences were reviewed. Results 511 patients who received SBRT/hypo-fractionated radiation therapy were eligible for the study. 475 (92.95%) of the tumours were treated with SBRT. 395 (77.6%) were peripheral tumours and 114 (22.4%) were central. The median BED was 132Gy. With a mean follow up of 4.5 years, 47(9.2%), 47 (9.2%) and 85 (16.7%) experienced local, regional and distant failures respectively. Of these, 38 patients experienced isolated local and/or regional failure (21- local, 11- regional and 6 local and regional failure; with no distant failure). 21.05% (8) tumours received salvage treatment with modalities like RFA (3), re-irradiation with or without chemotherapy (5). Of the non-salvaged tumours (30), 16 (53.33%) received palliative treatments (7- palliative radiation, 9- palliative chemotherapy). The most common reason for non- salvaged tumors was poor performance score (Eastern Co- operative Oncology Group score 3 or 4), followed by dearth of local options. 13 additional patients developed loco regional failure with time- separated distant metastases (with distant failure at minimum 3 months after loco-regional failure), of which 6 were salvaged locally. Conclusion Although, the outcomes for stage I medically inoperable patients are impressive with the advent of stereotactic body radiation therapy, management of local and regional recurrences remains a dilemma owing to poor performance status and overall frailty of this population. EP-1388 SABR Following Pneumonectomy: A Systematic Review of Clinical and Toxicity Outcomes A. Louie 1 , A. Ariffin 1 , F. Al-Shafa 1 , R.G. Boldt 1 , A. Warner 1 , G. Rodrigues 1 , D. Palma 1 1 London Health Sciences Centre South West Regional Cancer Program, Department of Radiation Oncology, London, Canada Purpose or Objective Survivors of lung cancer are at risk of second primary lung cancers (SPLCs), which are often curable. However, in patients who have previously undergone pneumonectomy, treatments options are limited. The aim of this study is to perform a systematic review of publications examining

Conclusion Even if pneumonitis incidence is maybe higher in irradiated lung patients treated with nivolumab, the finding of clear factors that could cause this event needs to be identified. Moreover, research of preliminary predictive factors (functional tests, RT technique, patients intrinsic factors) could be useful to improve treatment option choices and also toxicity occurrence prevention. EP-1386 Stereotactic body radiation therapy for central early non small cell lung cancers- Yes! Its possible R. Harjani Hinduja 1 , J. Zheng 1 , G. Cook 1 , R. MacRae 1 , J. Pantarotto 1 1 University of Ottawa, Radiation Oncology, Ottawa, Canada Purpose or Objective Stereotactic Body Radiation Therapy(SBRT) is a standard treatment for early non small cell lung cancers. Concerns exist about its use in centrally located tumours. RTOG 0813 demonstrated the efficacy and tolerability of SBRT in centrally located tumours. However, there is a reluctance in many institutions regarding its widespread adoption into clinical practice. We report our institutional experience with treatment of central tumors. Material and Methods We retrospectively reviewed consecutive medically inoperable early central NSCLC patients treated with SBRT in an ethics approved study. All tumours were biopsy proven and adequately staged by Positron Emission Tomography (PET) scan. The end points of interest were Local Recurrence Free Survival (LRFS) and Overall Survival (OS). The outcomes were compared based on ECOG status, left versus right sided tumours, histology, age adjusted Charlson Comorbidity index, SUVmax and pre-treatment Hemoglobin and Poly-Morpho-Nuclear (PMN) leucocytes. Results 92 patients who underwent SBRT for centrally located lung tumours were eligible. The median age was 75 years, (56 to 90 years). 40(43.5%) were males. The median age adjusted comorbidity index was 5. 86% were current/former smokers. 28, 34, 27 and 3 patients had ECOG 0, 1, 2 and 3 respectively. 52.2% had left and 47.8 % had right sided tumours. 28.3% were squamous cell carcinomas, 50% were adenocarcinomas and remaining 21.7% included large cell and NSCLC-NOS. All patients were PET staged and the median SUVmax was 6.85. The most common dose schedule was 60Gy in 8 fractions. The dose fractionation was increased in 14 patients to deliver treatment in 15-20 fractions. The median BED was 105Gy. The median OS was 47 months as compared to 53 months for peripheral tumours in the database(p-0.08). The median local recurrence free survival (LRFS), Regional recurrence free survival (RRFS) and Distant relapse free survival (DRFS) was 40 months, 47 months and 45 months, respectively. Lower ECOG score patients had better OS as compared to higher ECOG score (median OS- 42, 61, 35 and 18 months, respectively p-0.05) and a trend towards better LRFS (P-0.07). Patients with pre-treatment hemoglobin >130g/L and PMN leucocyte count > 5*10 9 /L were associated with improved OS (p- 0.03 and p- 0.003 respectively). Adenocarcinomas had a higher LRFS and OS as compared to squamous cell carcinomas, however this was not statistically significant (median OS- 65 and 47 months respectively, p- 0.2), (median LRFS of 47 and 35 months respectively, p- 0.10). There was no difference in LRFS or OS when stratified by age adjusted Charlson comorbidity score, SUVmax or location of left/right side. Conclusion SBRT for centrally located tumours is feasible with outcomes comparable to published literature. Lower ECOG performance score, pre treatment hemoglobin >