ESTRO 36 Abstract Book

S583 ESTRO 36 2017 _______________________________________________________________________________________________

radiotherapy arm were not inferior results. Therefore definitive radiotherapy may be considered alternative treatment modality in patients with inoperable adenoid cystic carcinoma of head and neck. EP-1068 Hypoxic imaging obtained at 2-h postinjection in FMISO-PET M. Kawamura 1 , M. Yoshimura 1 , T. Katagiri 1 , T. Mitsuyoshi 1 , H. Inokuchi 2 , T. Ishimori 3 , Y. Nakamoto 3 , T. Mizowaki 1 , M. Hiraoka 2 1 Kyoto University- Graduate School of Medicine, Radiation Oncology and Image-Applied Therapy, Kyoto, Japan 2 Japanese Red Cross Wakayama Medical Center, Radiation Oncology, Wakayama, Japan 3 Kyoto University- Graduate School of Medicine, Diagnostic Imaging and Nuclear Medicine, Kyoto, Japan Purpose or Objective Positron emission tomography (PET) / computed tomography (CT) using 18F-fluoromisonidazole (FMISO) has been used as an imaging tool for tumor hypoxia. It has been reported that several quantitative values in FMISO- PET at 4-h postinjection were reproducible. However, it is controversial whether they are reproducible when scanning is performed in earlier time, e.g. 2-h postinjection. If quantitative values at 2-h postinjection are equivalent with those at 4-h postinjection, the total examination time in FMISO-PET can be shortened. The purpose of this study was to investigate the difference of quantitative values in FMISO-PET at 2-h and 4-h postinjection in patients with head and neck cancer. Material and Methods A total of 10 patients with untreated locally-advanced head and neck cancer who underwent FMISO-PET/CT scan from August 2015 to October 2016 in our institute were analyzed. Image acquisition was performed twice, 2-h and 4-h after administration of FMISO using a combined PET/CT scanner (Discovery IQ, GE Healthcare). After taking a region of interest in a primary tumor, the maximum standardized uptake value (SUVmax), SUVmean, SUVpeak, tumor-to-blood ratio (TBR), tumor-to-muscle ratio (TMR), metabolic tumor volume (MTV) and total lesion hypoxia (TLH) were measured. We evaluated the Spearman's rank correlation coefficients of these quantitative values, and also calculated the percent difference defined as difference between the two values divided by average of two values. Results SUVmax (mean±SD) at 2-h and at 4-h were 2.4±0.8, and 2.6±1.0, respectively, in this population. The Spearman's rank correlation coefficients of SUVmax, SUVmean, SUVpeak, TBR, TMR, MTV, and TLH were 0.97, 0.97, 0.97, 0.93, 0.93, 0.95, and 0.95, respectively. The percent differences (mean±SD) of these values were 8.3±5.6%, 6.8±6.3%, 4.1±5.1%, 16.8±12.5%, 17.1±9.1%, 42.7±52.7%, and 41.7±58.1%, respectively. Quantitative values were highly correlated between the two scans; however, there were two cases in which %differences of MTV and TLH exceeded 50%, i.e. 62.1% and 166.7% in MTV and 57.1% and 180.0% in TLH.

Conclusion Our preliminary data demonstrate that quantitative values at 2-h and 4-h were highly reproducible. In a few patients, volumetric parameters had moderate percent difference, so it needs careful evaluation to measure hypoxic tumor volume at 2-h after administration of FMISO.

EP-1069 Survival-weight health profile in nasopharyngeal cancer patients C.H. Lai 1 , W.C. Chen 1 , M.F. Chen 1 1 Chang-Gung Memorial Hospital- Chiayi branch, Radiation Oncology, Chiayi Conuty, Taiwan

Purpose or Objective This

study was designed to estimate the life expectancy (LE), quality-adjusted life expectancy (QALE) and survival- weight psychometric scores (SWPS) in nasopharyngeal

cancer (NPC) patients. Material and Methods

A sample of 875 non-metastatic NPC patients diagnosed between January 1, 2009 and June 30, 2013 was collected from the cancer registry database in four branch hospitals of our hospital system for estimation of lifetime survival function. All 875 patients were followed up until death or censored on December 31, 2015. To obtain the utility and psychometric score for estimation of LE, QALE and SWPS, eighty-seven patients were measured with the Taiwanese version of the EuroQol instrument (EQ-5D) and the Taiwan Chinese versions of the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 and QLQ-H&N35 between