ESTRO 38 Abstract book

S639 ESTRO 38

EP-1152 Tumor volume as a prognostic factor in irradiated patient for locally advanced oral cavity cancer N. Janmunee 1 1 Songklanagarind hospital, Radiation Oncology, Hatyai, Thailand Purpose or Objective To determine the effect of the pretreatment tumor volume, in locally advanced oral cavity squamous cell carcinoma, on the survival in patients treated with concurrent chemoradiotherapy. Material and Methods Review of 74 patients, with histologically confirmed stage III-IV (AJCC 8 th edition) squamous cell carcinoma of oral cavity, receiving treatment at a tertiary radiation oncology center between January 2009 and March 2016. The patients were treated with either primary radiation or concurrent chemoradiation therapy. This study excluded patients with lip cancer, metastatic disease, and those who diagnosed with other second primary cancer, except non-melanoma cancer of skin. Pretreatment computed tomography (CT) scans were reviewed by experienced neurological diagnostic radiologist for TNM staging. For tumor volume delineation process, the pretreatment CT was delineated by consensus of at least three researchers with Eclipse Planning System (version 10). For statistical analysis, the survival analysis was determined by a Kaplan– Meier estimator. The optimal cutoff tumor volume was evaluated by receiver-operating curve analysis. In the associations of predictor variables, univariate and multivariate analysis were performed with Cox proportional hazards regression models. A p-value of less than 0.05 was considered significant. Results From 74 patients, 67 patients who received treatment with concurrent chemotherapy were analyzed. The majority of the patient were male (82%), age 59±12.6 years with ECOG score 0-1 (89%). Almost all of them had T stage 3-4 and N stage 2-3. A half of primary tumors site were oral tongue. The median Total Tumor Volume (TTV) was 73.25 cm3 (IQR 41.9, 132.3). The median survival was 1.04 years (95% CI 0.91 -1.69). The optimal cutoff TTV that significantly affect the overall survival rate was ≥ 59.8 cm3 (p <0.001) (Figure 1). Multivariate analysis showed TTV ≥ 59.8 cm3 (HR 3.19; 95% CI 1.59-6.4; P < 0.001) and IMRT/VMAT radiation technique (HR 3.5; 95% CI 1.38-9.08; P = 0.002) were considered to be the factors influencing the overall survival outcome.

1 Dr Ram Manohar Lohia institute of Medical Sciences, Radiation Oncology, Lucknow, India Purpose or Objective We aimed to retrospectively analyze the demographics, clinical outcome and compliance to treatment of elderly (≥ 65 years) head and neck squamous cell carcinoma (HNSCC) at our institution Material and Methods Data of 175 consecutive patients of HNSCC presenting to the radiation oncology clinic from February 2013-June 2017 were retrieved and analyzed. Patients with primary in nasopharynx/ para-nasal sinuses, those with metastatic disease at presentation and patients who underwent surgery were excluded from analysis. Following patient details were retrieved from the medical charts: patient demographics, co-morbidities, primary site, stage (AJCC 7th edition), radiation dose parameter, compliance and disease free survival (DFS). DFS was calculated from the date of diagnosis till the time of recurrence. Statistical analysis was done using SPSS (version 21.0). Kaplan Meier method was used for survival analysis and p<0.05 was considered significant Results Patient characteristics are summarized in Table 1. 76% of patients were ≥ 70 years of age. After registration and initial evaluation, 11 patients (6.3%) defaulted before initiation of treatment. Of remaining 164 patients, 128 (78%) were planned for a radical and 36 (22%) for palliative intent of therapy. Of 128 patients planned for definitive radiotherapy (107 patients) /chemoradiotherapy (21patients); 97 patients (75%) received ≥ 60 Gray of radiation dose. Neo-adjuvant chemotherapy (NACT) was administered in 70/107 patients receiving definitive radiotherapy alone. Median number of NACT cycles was 2 (range 2-3). Median number of concurrent chemotherapy (CCT) cycles was 5 (range 3-6). Median radiotherapy dose was 60 Gray (range 20-70 Gray). Regimens used during NACT were mainly taxane/platinum/5-Flurouracil based and during CCT was weekly cisplatin (35-40 mg/m 2 ). Of 36(22%) patients planned for palliative intent therapy, palliative radiotherapy (median dose 20 Gray in 5 fractions) was delivered in 25 patients; palliative chemotherapy in 20 patients and 9 patients received both. Median follow up was 13 months (range 4-26 months). Median DFS for entire cohort was 17.9 months. Median DFS for patients treated with radical intent was 26.7 months versus 5.5 months for palliative intent (p<0.001). On univariate analysis, site of disease (p=0.10; Oral cavity primary worse), stage of disease (p<0.001; stage IV worse) and radiation dose ≥ 60 Gray (p<0.001; better outcome) were significant predictors of DFS. Karnofsky performance score, age and presence of co-morbidities did not impact DFS (p=NS).

Conclusion TTV influenced on the overall survival of locally advanced oral cavity squamous cell carcinoma. In addition, TTV may be considered as a factor to select the appropriate treatment option for these patients. EP-1153 A retrospective single institutional analysis of 175 elderly head and neck squamous cell carcinoma A.K. Gandhi 1 , M. Rastogi 1 , S.S. Nanda 1 , R. Khurana 1 , R. Hadi 1 , K. Sahni 1 , A. Srivastava 1 , A. Bharati 1 , S. Mishra 1