Abstract Book

S763

ESTRO 37

Mean time to INF recurrence was 11.1 months (5-32 months). Looking specifically at NSCLC patients, there was a significant difference in the proportion of INF recurrences in patients with confirmed adenocarcinoma (n=5) compared to those in patients with confirmed squamous cell carcinoma (n=1, Chi-squared= 4.23, p= 0.039). Conclusion Our low INF rate after radical treatment is comparable with other studies. Preponderant INF regional lymph node failure sites included upper para-tracheal; hilar; and sub-carinal. The higher rate of INF recurrence in adenocarcinoma may warrant further investigation into target volume delineation and a consideration of PTV expansion in this subtype. EP-1399 HEmatologic paRaMeters as prEdictive biomarkerS in NSCLC (HERMES-Lung) for metastasis development A. Martino 1 , J. Lenkowicz 1 , G. Mattiucci 1 , A. Petrone 1 , A. Piras 1 , D. Smaniotto 1 , A. Alitto 1 , C. Mazzarella 1 , G. Palazzoni 1 , M. Congedo 2 , M. Chiappetta 2 , S. Margaritora 2 , V. Valentini 1 , G. Mantini 1 1 Policlinico Universitario Agostino Gemelli- Catholic University, Gemelli ART-Advanced Radiation Therapy, Roma, Italy 2 Policlinico Universitario Agostino Gemelli- Catholic University, Thoracic Surgery Unit, Roma, Italy Purpose or Objective Systemic inflammatory response has been confirmed to have prognostic value in several types of cancer, including lung cancer. This study was aimed to investigate the usefulness of circulating hematologic parameters in predicting distant metastasis development in patients with locally advanced non-small cell lung cancer (NSCLC). Material and Methods We retrospectively reviewed the medical records of 53 patients (38 (71.7%) male, median age 67) with stage IIIA/IIIB NSCLC, treated between March 2009 and October 2016. All patients underwent multimodality approach, including surgery. Peripheral complete blood count were collected at baseline and after two cycles of induction treatment: absolute neutrophil count (ANC), absolute platelet count (APC), absolute lymphocyte count (ALC), Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to- Lymphocyte Ratio (PLR). Patients were dichotomized according to the median value for each parameter. OS was estimated using the Kaplan-Meier method and logistic regression model was used for multivariable analysis. Results In the overall population, median OS (mOS) e median distant metastasis free survival (mDMFS) were respectively 14 and 13 months. Kaplan-Meier survival analysis suggested that patients who experienced baseline high-APC, in comparison with low-APC, showed significant reduction in OS (p=0.02) and those with high- ANC, in comparison with low-ANC, showed only marginally reduction in OS (p=0.05). Using a logistic regression model to predict distant metastasis development within 12 months from diagnosis we observed that increasing ANC (p=0.023) and increasing PLR (p=0.012) at baseline were significant predictive markers [AUC Area under the curve: 0.8581; 95% CI: 0.7537-0.9625 (DeLong)]. Conclusion Neutrophilia and elevated PLR might be potential predictive biomarkers for distant metastasis development in NSCLC. These findings allow to select patients, according to different risk group, for intensified local treatment and personalized therapy. The predictive value should be prospectively validated.

Conclusion We found a significant difference in local control and overall survival favouring stage I NSCLC patients treated with SBRT. Although staging procedure and technical improvements of radiation treatment could influence our results, SBRT has proven to be more efficient in local control and overall survival than EBRT. EP-1398 Isolated Nodal Failure rates following curative intent radiotherapy in a modern cohort S. McCauley 1 , K. Tumelty 1 , R. Eakin 1 , J. Harney 1 , L. Young 1 , J. McAleese 2 , G. Hanna 2 1 Northern Ireland Cancer Centre, Clinical Oncology, Belfast, United Kingdom 2 Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, United Kingdom Purpose or Objective Isolated nodal failure (INF) is defined as a recurrence in the regional lymph nodes without a synchronous local recurrence or distant metastases at time of first relapse. The incidence of INF is an uncommon occurrence after radical radiotherapy, even with advanced conformal techniques that increase target radiation. However such techniques do employ tighter clinical target volumes and reduced planning target volume (PTV) margins. We report our single institution INF rates for lung cancers in a modern radiotherapy cohort, and catalogue regional lymph node recurrences and their relation to treatment planning volumes. Material and Methods Using a prospective institutional database, we identified all patients with lung cancers who have received curative intent radiotherapy for the years 2011-2016 inclusive. In those patients with INF recurrence only, regional lymph nodes were classified using the Mountain and Dresler regional lymph node classification for lung cancer staging. We then compared follow-up image datasets (CT and PET/CT) with the PTV volumes on the treatment planning image sets. Pathological subtype and staging were also identified. Results We identified 694 patients with relapsed lung cancer for the years 2011-2016: 167 (24%) adenocarcinoma; 229 (32.9%) squamous cell carcinoma; 144 (20.7%) clinical lung cancer and 113 (16.2%) with confirmed small cell lung carcinoma (SCLC). Remaining 41 patients were subtyped as: other; poorly differentiated or NOS (Not otherwise specified). In total, there were 8 INFs (1.2%), 7 recurring in patients with Non-small cell carcinoma (NSLC) with 5 adenocarcinomas (3 stage III; 2 stage II); 1 squamous cell (stage III); 1 clinical lung carcinoma (stage III). There was 1 SCLC recurrence. There were 2 in-field INF recurrences (1 adenocarcinoma; 1 SCLC), with a further 2 recurring within 1cm of the PTV margin (1 adenocarcinoma; 1 squamous cell).