ESTRO 37 Abstract book

S13

ESTRO 37

and received radiotherapy as part of the treatment where the majority of staff are either colleagues or past students. The purpose of this talk is to critically evaluate personal experience of the breast cancer pathway and discuss how we can involve patients in the organisation of the department more. I received high quality care on a daily basis and the radiographers made sure a difficult time was made as bearable as possible. However, once treatment ends I feel there is a lack of support and advice moving forwards. Patients struggle to come to terms with the 'new normal' and remaining vigilant to symptoms without being seen as overly anxious is a fine balance to achieve. Speaking as a patient, I believe there is value in patients being utilised to support and advise other patients going through a similar thing - a kind of 'cancer buddy' but with the added benefit of hindsight and experience in managing late effects. Speaking as a health care educator, patients can also be used to assist in student recruitment - they know how they would like to be treated in the department and can work with HEI's and clinical partners to assist in selection events, thereby ensuring we recruit to the highest professional calibre which ultimately improves the patient experience. PV-0036 The effect of tumour laterality on survival for non-small cell lung cancer patients A. McWilliam 1 , E. Vasquez Osorio 1 , M. Aznar 1 , C. Faivre- Finn 1 , M. Van Herk 1 1 The University of Manchester, Division of Cancer Science, Manchester, United Kingdom Purpose or Objective The effect of tumour laterality on the survival of non- small cell lung cancer patients (NSCLC) after radiotherapy has not been investigated. We have performed a laterality analysis on a large cohort of patients treated with curative-intent radiotherapy, including investigating the effect of dose on the left and right lungs. Material and Methods 1101 NSCLC patients were randomly selected from the clinical archive, all patients were treated with 55Gy in 20 fractions. Contours for lungs (right and left combined) and GTV (or motion adapted-GTV, including primary and nodal disease) were present. Tumour laterality was defined by determining whether the centre of mass coordinates of the GTV was on the right or left lung. Individual right and left lungs were segmented from the overall lung contour and mean dose received to each lung computed. The effect of laterality on patient survival was investigated in a multi-variable cox-regression, including patient and tumour characteristics. Kaplan-Meier survival curves were plotted for laterality with a log-rank test used to assess significance. A second multi-variable cox-regression included the effect of dose on the right and left lungs. Results 618 right-sided and 483 left-sided tumours were identified; this ratio is consistent with the difference in lung volume. Tumour volume and patient characteristics were well balanced between left and right sided tumours. Multi-variable cox-regression analysis showed laterality was significant (p<0.01), with right-sided tumours showing worse survival, hazard ratio (HR) 1.25 (95%CI 1.08-1.48), table 1. Poster Viewing : Poster viewing 1: Lung

The Kaplan-Meier survival curve for left versus right-sided tumours showed a significant split with a log-rank p=0.008, figure 1. Median survival was 18 months (95%CI 16-21 months) for left-sided and 15 months (95%CI 13-17 months) for right-sided patients. Including lung mean doses in the multi-variable analysis resulted in HR 1.02 (95%CI 1.01-1.03, p=0.03) for the right lung and for HR 1.00 (95%CI 0.99-1.1, p=0.65) the left lung. In this model laterality was no longer significant, indicating it is a surrogate for individual lung mean doses. In both analysis, tumour volume (continuous, p<0.001), age (continuous, p<0.01), gender (p<0.04), performance status (categorical, p<0.05) and nodal stage (categorical, p<0.01) were also significant.

Conclusion To our knowledge, our study is the first to show that laterality has a significant impact on survival of lung cancer patients post curative-intent radiotherapy, with right sided lung tumours showing worse survival. Our analysis indicates the effect of laterality is through a difference in dose-response for individual lungs. The right lung is larger, and the same amount of excess dose, compared to the left lung, has a greater impact on patient survival. These results suggest toxicity of the normal lung tissue may display a serial component, where dose can affect lung function throughout the organ’s structure. PV-0037 Correlation between coronary artery doses and survival in locally advanced lung cancer patients M. Aznar 1 , E. Vasquez Osorio 1 , J. Kennedy 1 , J. Mahil 1 , M. Swinton 1 , C. Faivre-Finn 1 , M. Van Herk 1 , A. McWilliam 1 1 The University of Manchester c/o Christie Hospital- Dept 58- Floor 2A, Division of Cancer Sciences, Manchester, United Kingdom