en Medical Physics Medical Physics تحقيق بديع Original Research <div style="text-align: justify;">Background: Hyperthermia plays a significant role in the chemo-radiotherapy effect in different malignancies. In this research, we treated Glioblastoma multiform (GBM) patients with hyperthermia (HT) along with the chemoradiation, in order to evaluate HT efficacy in terms of tumor volume changes, survival time, and probability. Materials and Methods: Thirty-eight GBM patients were distributed into two groups identified as chemoradiation (CRT), and also CRT plus HT (CRHT). The Karnofsky Performance Status Scale (KPS) was done before, immediately and three months after treatments. Capacitive hyperthermia device was used at frequency of 13.56 MHz (Celsius 42+ GmbH, Germany) for HT one hour before the radiotherapy for 10-12 sessions. Patients in both groups underwent MR imaging (1.5 Tesla) before, 3 and 6 months after the treatments. Thermal enhancement factors (TEF) were attained in terms of clinical target volume changes, TEF(CTV), and survival probability (SP) or TEF(SP). Results: Age ranges were from 27-73 years (Mean=50) and 27-65 years (Mean=50) for CRT and CRHT groups, respectively. For 53% and 47% of cases biopsy and partial resection were accomplished in both groups, respectively. Means and standard deviations of tumor volumes were 135.42&plusmn;92.5 and 58.4&plusmn;104.1cm³before treatment in CRT and CRHT groups, respectively, with no significant&nbsp; difference (P= 0.2). TEF(CTV) value was attained to be as 1.54 and 1.70 for three and six months after treatments, respectively, TEF(SP) was also equal to the 1.90. Conclusion: HT enhanced the chemoradiation effects throughout the patient survival probability and KPS. TEF may reflect the hyperthermia efficacy for a given radiation dose.</div> Hyperthermia, GBM, chemoradiotherapy, thermal enhancement factor. 255 262 http://ijrr.com/browse.php?a_code=A-10-2055-10&slc_lang=en&sid=1 S.R. Mahdavi 7900319475328460015754 7900319475328460015754 No Radiation Biology Research Center, and Department of Medical Physics, Iran University of Medical Sciences, Tehran, Iran L. Khalafi khalafi57@yahoo.com 7900319475328460015755 7900319475328460015755 Yes Department of Medical Physics, School of Medicine (International Campus), Iran University of Medical Sciences, Tehran, Iran A.R. Nikoofar 7900319475328460015756 7900319475328460015756 No Department of Radiation Oncology, Iran University of Medical Sciences, Tehran, Iran 4Roshana radiotherapy and Oncology Center, Tehran, Iran P. Fadavi 7900319475328460015757 7900319475328460015757 No Department of Radiation Oncology, Iran University of Medical Sciences, Tehran, Iran 4Roshana radiotherapy and Oncology Center, Tehran, Iran F. Arbabi Kalateh 7900319475328460015758 7900319475328460015758 No Roshana radiotherapy and Oncology Center, Tehran, Iran T. Aryafar 7900319475328460015759 7900319475328460015759 No Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences (International Campus), Tehran, Iran H. Foudazi 7900319475328460015760 7900319475328460015760 No Omid Radiation Oncology Clinics, Tehran, Iran B. Mofid 7900319475328460015761 7900319475328460015761 No Department of Radiation and Oncology, Shahid Beheshti University of Medical Sciences, Tehran, Iran G. Sharifi 7900319475328460015762 7900319475328460015762 No Department of Neurosurgery, Loghman Hakim Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran S. Shivaliloo 7900319475328460015763 7900319475328460015763 No Department of Medical Physics, School of Medicine (International Campus), Iran University of Medical Sciences, Tehran, Iran H. Abdollahi 7900319475328460015764 7900319475328460015764 No Department of Medical Physics, School of Medicine (International Campus), Iran University of Medical Sciences, Tehran, Iran