ESTRO 36 Abstract Book

S370 ESTRO 36 _______________________________________________________________________________________________

Of the 156 eligible patients, 133 (85.3%) responded to at least one of the questionnaires. Non-response included patients who didn’t return the questionnaires (8.3%) or had missing values in the WAI questionnaire (6.4%). Of the responders, 107 patients (80.5%) had paid employment. These patients had a mean age of 56.2 years and 73.8% were male. All patients underwent neoadjuvant therapy of which 64.5% chemoradiation, 30.8% short-course radiation and 4.7% other regimes. Surgery was performed in 89.7% of the patients, mostly by low anterior (50.5%) or abdominoperineal resection (33.6%). At baseline, the mean WAI score was 32.3, which was substantially lower than the reference population score of 40.9. Workability was poor in 27.5% of the patients, and moderate, good and excellent in resp. 34.1%, 34.1% and 4.4% (Figure 1). Corresponding scores of the Dutch reference population were 2.8%, 14.2%, 47.2% and 35,8% resp. Workability was limited by illness in 82.4% of the patients, and 23.1% completely stopped working. At 3 months, the mean WAI score decreased significantly to 27.1 (p<.001) and was poor in 54.7% of the patients. Here after, at 6 and 12 months, the mean WAI score increased to resp. 29.1 and 34.6. At 12 months, 55.3% of the patients reported absenteeism of 100-365 days as result of health problems in the past year compared to 2.3% in the reference population. Only 14.9% of the patients reported no absenteeism. Stratification by neoadjuvant regimen and surgical procedure did not modify the results. Conclusion Workability in patients with rectal cancer is negatively affected by treatment but seems to recover towards baseline levels at 12 months after diagnosis. Compared to the Dutch population, rectal cancer patients report a much lower workability and a higher level of absenteeism. PO-0706 Assessing the impact of sentinel lymph-node and inguinal irradiation in patients with anal cancer C. Gumina 1 , N. Slim 1 , G.M. Cattaneo 2 , P. De Nardi 3 , C. Canevari 4 , M. Ronzoni 5 , A. Fasolo 5 , C. Fiorino 2 , L. Perna 2 , A.M. Tamburini 3 , R. Rosati 3 , P. Passoni 1 , N. Di Muzio 1 1 San Raffaele Scientific Institute, Radiotherapy, Milan, Italy 2 San Raffaele Scientific Institute, Medical Physics, Milan, Italy 3 San Raffaele Scientific Institute, Surgery, Milan, Italy 4 San Raffaele Scientific Institute, Nuclear Medicine, Milan, Italy 5 San Raffaele Scientific Institute, Medical Oncology, Milan, Italy Purpose or Objective To evaluate the role of sentinel lymph-node biopsy (SLNB) in staging and the impact of inguinal irradiation. Material and Methods Patients with anal squamous cell carcinoma and without gross inguinal lymph-nodes metastases were considered for SLNB after staging with standard imaging procedures and FDG-PET. The Clinical Target Volume (CTV) included the Gross Tumor Volume (GTV: primary tumour and positive lymph-nodes) and pelvic ± inguinal lymph-nodes. Planning Target Volume (PTV)1 and PTV2 corresponded to GTV and CTV, respectively, with a margin of 0.5-1.0 cm.

Prescribed dose was 50.4 Gy in 28 fractions to the PTV2 and 64.8 Gy in 36 fractions to the PTV1, delivered with IMRT or VMAT. Concomitant chemotherapy consisted of Mito-C 10 mg/m 2 and continuous infusion 5-FU 1000 mg/m 2 for 4 consecutive days. Results From 03/2008 to 02/2014, 48 consecutive patients were treated. FDG-PET was performed in 42 out of 48 patients. Pathologic inguinal uptake was shown in 15/42 (36%) and 9 of them underwent lymphoscintigraphy: SLNB confirmed inguinal metastases only in 3/8 (37.5 %) (SLN not found in 1 patient). FDG-PET did not show inguinal uptake in 27/42 (64%) patients and 17 of them underwent lymphoscintigraphy: SLNB found metastases in 2/17 (12%). Thirty-one patients received prophylactic or curative radiotherapy to the groins (Inguinal RT group) and 17 patients did not (No inguinal RT group). Sixteen/17 patients of the No inguinal RT group had a negative SLNB. At a median follow-up of 41 months no relapse was observed in the “No inguinal RT”. No significant differences in terms of toxicities, apart from inguinal dermatitis, were observed between the two groups. Conclusion SLNB improves the PET-based staging and is highly accurate in identifying the true negative patients for which the inguinal irradiation could be avoided. The use of advanced radiotherapy techniques, sparing inguinal lymph-nodes reduces dramatically the inguinal skin toxicity while no differences were found for other side effects. PO-0707 Magnetic Resonance Imaging Texture Analysis Parameters for predicting risk of Anal Cancer recurrence K. Owczarczyk 1 , D. Prezzi 1 , M. Siddique 1 , J. Stirling 1 , G. Cook 1 , R. Glynne-Jones 2 , A. Gaya 1 , M. Leslie 1 , V. Goh 1 1 Guy's and St.Thomas' Hospital NHS Foundation Trust, Department of Cancer Imaging, LONDON, United Kingdom 2 Mount Vernon Cancer Center, Department of Oncology, London, United Kingdom Purpose or Objective Despite advances in the management of anal squamous cell carcinoma (ASCC), roughly 25% of patients undergoing standard chemoradiotherapy (CRT) will experience disease recurrence. Currently, there is no established way of predicting disease outcome. Quantitative magnetic resonance (MR) imaging texture analysis (TA) parameters have shown promise in assessing the risk of recurrence in other cancer types. This study was carried out to assess their role in evaluating recurrence risk in patients with We used baseline high-resolution T2-weighted MR images from 42 patients with ASCC undergoing CRT to identify TA parameters with the best ability to predict disease recurrence. Multi-slice regions of interest (ROI) were drawn around the tumours, generating a whole tumour volume. 3D volume statistical and fractal heterogeneity parameters were derived using in-house software.We calculated False Discovery Rate (FDR) p -value for all TA parameters using the Benjamini-Hochberg correction to adjust for multiple tests and used a FDR p-value cut-off of 0.15 to identify candidate parameters.We then analysed baseline T2-W MR images from further 33 patients to independently cross-validate performance of the identified TA parameters. We calculated replication FDR p-values for the validation cohort as well as p values for the pooled cohort. Results Two patients in the test cohort and three patients in the replication cohort had to be excluded based on lack of visible tumour (n=2) and palliative treatment intent (n=3). 40 patients in the test cohort and 30 patients in the replication cohort were included in the final analysis. All ASCC undergoing CRT. Material and Methods