International Journal of Radiation Research

en Equivalent uniform dose and normal tissue complication probability of acute esophagitis in head-and-neck radiotherapy: Sensitivity to dose calculation accuracy Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;">Background: To quantify the influence of photon dose-calculation algorithm selection on the cervical esophagus (CE) dose indices and the derived equivalent uniform dose (EUD) and normal-tissue complication probability (NTCP) for acute esophagitis in patients with head-and-neck cancer (HNC). Materials and Methods: The Fast Photon Effective Path (FPEP) and Collapsed-Cone Convolution Superposition (CCCS) algorithms on the Prowess Panther treatment planning system were compared for 30 patients (six tumor sites). The Lyman-Kutcher-Burmann (LKB) model was used to calculate the EUDs and NTCPs. Results: On average, the more simplistic FPEP algorithm overestimated the mean dose to CE planning organ-at-risk volumes (PRVs) by 2.0% (p = 0.003). The average absolute difference in mean dose was 2.7% and the maximum difference was 9.3%. The V5Gy, V10Gy, V15Gy, V20Gy, V25Gy and V30Gy values were significantly higher with FPEP, while the point-dose and D2cc hot spots were similar. In turn, the dose differences led to an underestimation of the LKB-model prediction of the EUD by 1.4% (p = 0.297). The mean absolute difference in EUD was 4.5% and the maximum difference was 15.3%. In the 14-50 Gy mean dose range, the resulting NTCPs with FPEP were lower on average by 2.6% than CCCS (p = 0.041). Conclusions: In the group of HNC patients considered in this study, the EUD and NTCP for acute esophagitis showed to be moderately sensitive to the choice of dose-calculation algorithm. Despite an overestimated mean dose by the simpler algorithm, the NTCP underestimation, which can be large in some patients, is of clinical concern.</div> Dose calculation model, NTCP, EUD, Head-and-neck cancer. 447 454 http://ijrr.com/browse.php?a_code=A-10-1-928&slc_lang=en&sid=1 M.A. Mosleh-Shirazi 7900319475328460021666 7900319475328460021666 No Ionizing and Non-ionizing Radiation Protection Research Center, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran A. Sheikholeslami arefeh.1373@yahoo.com 7900319475328460021667 7900319475328460021667 No Department of Radiology and Radiobiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran E. Fathipour 7900319475328460021668 7900319475328460021668 No Department of Radiology and Radiobiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran M. Mohammadianpanah 7900319475328460021669 7900319475328460021669 No Department of Radio-oncology, Shiraz University of Medical Sciences, Shiraz, Iran M. Ansari maansari@sums.ac.ir 7900319475328460021670 7900319475328460021670 Yes Department of Radio-oncology, Shiraz University of Medical Sciences, Shiraz, Iran S. Karbasi 7900319475328460021671 7900319475328460021671 No Department of Radio-oncology, Shiraz University of Medical Sciences, Shiraz, Iran S.H. Hamedi 7900319475328460021672 7900319475328460021672 No Department of Radio-oncology, Shiraz University of Medical Sciences, Shiraz, Iran N. Khanjani 7900319475328460021673 7900319475328460021673 No Department of Radio-oncology, Shiraz University of Medical Sciences, Shiraz, Iran M.R. Sasani 7900319475328460021674 7900319475328460021674 No Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran P. Jafari 7900319475328460021675 7900319475328460021675 No Department of Biostatistics, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran R. Fardid 7900319475328460021676 7900319475328460021676 No Ionizing and Non-ionizing Radiation Protection Research Center, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran