103 Impact of integration of fused FDG-PET and CT information for GTV delineation

is said to offer the best chance of cure/survival in early stage NSCLC (Stage I and II). However, some patients refuse surgery while others are deemed surgically (due to tumour size and/or location) or medically inoperable due to pre-existing co-morbidities such as significant cardiovascular disease and poor respiratory reserve. For these patients, radical radiotherapy is the next best option in managing early stage disease. Aim: The aim is to assess the demographic characteristics of patients undergoing radical radiotherapy, estimating the median survival in these patients and identifying any correlations between patient characteristics (such as performance status and tumour pathology) and outcomes including toxicities and survival. Method: The audit was carried out as a retrospective review of case notes and radiotherapy prescription sheets of patients receiving radical radiotherapy alone (no chemotherapy) from 2007 2010. Inclusion criteria required a diagnosis of stage I (T1 or T2, N0) or stage II (T1 or T2, N1; T3, N0) Non-Small Cell Lung Cancer and be treated with radical radiotherapy with curative intent. Result: Initial analysis shows a median overall survival of 18-months and an 83% survival at 1 year. We also show no significant difference in overall survival with increasing age; median overall survival of 18-months in those under 60, 16-months in 60 75 s and 21-months in over 75 s. Further analyses are underway to identify significant correlations with patient characteristics including tumour stage. Conclusion: To be drawn following full analysis of results. 103 Impact of integration of fused FDG-PET and CT information for GTV delineation G.J. Webster1 , M. Harris2 , D. Tout1 , P. Julyan1 , C. Rowbottom1 , P.A. Burt2 , P. Hulse3 , C. Faivre-Finn2 . 1 North Western Medical Physics, Christie NHS Foundation Trust, Manchester, United Kingdom, 2 Department of Clinical Oncology, Christie NHS Foundation Trust, Manchester, United Kingdom, 3 Department of Radiology, Christie NHS Foundation Trust, Manchester, United Kingdom Introduction: Integration of functional imaging (e.g. FDG-PET) with anatomical information derived from Computed Tomography (CT) scans can be beneficial for lung patients in situations in which the latter is insufficient to confidently identify disease. This work quantifies the impact on GTV delineation of the fusion of the radiotherapy planning CT (RTP) scan and the FDG-PET/CT scan. Methodology: 7 observers delineated GTV for 4 lung patients (2 patients had mediastinal lymph node involvement) using two different imaging setups: RTP, with FDG-PET/CT available on an adjacent monitor (unfused); fused RTP scan and FDG-PET/CT. The Inter-observer variation was quantified by (i) volume, (ii) delineation conformity (defined as ‘union/intersection’ of all observers), (iii) delineation time and (iv) user-rated case difficulty. Results: Mean GTV volume increased by 19.4% when functional and anatomical information were fused, while delineation conformity decreased (both changes were of increased magnitude for the 2 cases with mediastinal involvement). Visual inspection of overlaid GTV volumes indicated that there was systematic variation between observers in the size of delineated regions and disagreement about inclusion/exclusion of certain regions. The fused images allowed slightly faster delineation time and impacted positively on userrated case difficulty. No results were statistically significant, possibly due to the necessarily small scale of the study. Conclusions: Introduction of functional imaging into GTV delineation holds significant promise, with the current work further illustrating the systematic impact on delineated volumes, particularly for regions that appear equivocal on anatomical scans. However, the increasing inter-observer variability when functional imaging is used to directly define the GTV border highlights the importance of thorough training, group discussion and ongoing

Posters, 9th Annual BTOG Conference, 2011: Radiotherapy quality assurance required when integrating new modalities into clinical practice. 104 Palliative chemotherapy followed by consolidation radiotherapy in patients with advanced and metastatic non-small cell lung cancer not suitable for radical treatment H. Eldeeb, P. Camilleri, E. Mak, A. Siddiqui. Oncology Centre, Northampton General Hospital, Northampton, United Kingdom Objectives: This is a retrospective study to assess the effectiveness of consolidation radiotherapy following palliative chemotherapy in patients with metastatic or locally advanced non-small cell lung cancer (NSCLC) who are not suitable for radical treatment. Patients and Method: This review included 22 patients treated at Northamptonshire Centre for Oncology during the period of December 2009. Patients included in the review January 2005 must has received at least more than one cycle of chemotherapy without evidence of progression followed by consolidation radiotherapy of dose 39 or 36 Gy/12 13 fractions. Results: The study included 15 male and 7 females with an average age of 61. The average PS was 1. Six patients had a PS of 0, 8 had a PS of 1 and 8 PS of 2. Stage: One patient had stage II disease and was deemed to be medically inoperable. Five patients had stage IIIA, nine patients had stage IIIB and seven patients had stage IV disease. Histology: Nine patients had squamous cell carcinoma, seven had adenocarcinoma and six patients had non-specified NSCLC. Co-Morbidities: One patient had minimal co-morbidities, thirteen had mild co-morbidities, five had moderate co-morbidities and three had severe co-morbidities according to preset co-morbidity classification. Chemotherapy: All patients received first line chemotherapy while only seven received second line and one patient received third line chemotherapy. Radiotherapy: was given in a dose of 39 Gy over 13 fractions in six patients and 36 Gy over 12 fractions in 16 patients. Survival: The median overall survival for patients was 666 days. The mean survival was 704 days. Two years survival was 32%. 1.0

0.8

Cumulative survival

S36

0.6

0.4

0.2

1.0 1000 750 Survival (days) Figure: Survival function. 250

500

1250

Conclusion: Consolidation radiotherapy following palliative chemotherapy in a selected group of inoperable advanced and metastatic NSCLC patients seems to achieve a very good survival. A randomised trial nationally is proposed using high dose palliative radiotherapy.