1 3 Int J Clin Oncol DOI 10.1007/s10147-016-1014-9 ORIGINAL ARTICLE Feasibility evaluation of hypofractionated radiotherapy with concurrent temozolomide in elderly patients with glioblastoma Megumi Uto 1 · Takashi Mizowaki 1 · Kengo Ogura 1 · Yoshiki Arakawa 2 · Yohei Mineharu 2 · Susumu Miyamoto 2 · Masahiro Hiraoka 1 Received: 28 December 2015 / Accepted: 21 June 2016 © Japan Society of Clinical Oncology 2016 experienced grade 4 neutropenia, lymphocytopenia, and thrombocytopenia. No grade 3 or higher nonhematological adverse event was noted. Conclusion Our analysis demonstrated the feasibility of HFRT with concurrent TMZ used to treat elderly patients with glioblastoma. Further prospective clinical trials are needed to define therapies that balance efficacy with tolerability. Keywords Glioblastoma · Elderly · Hypofractionated radiotherapy · Temozolomide Introduction Glioblastomas comprise about 50 % of all malignant neu- roepithelial tumors, and the median age at diagnosis is 64 years [1]. The standard treatment is surgery with postop- erative radiotherapy (RT) plus continuous daily temozolo- mide (TMZ), followed by six cycles of adjuvant TMZ. This treatment regimen is based on data from the randomized controlled trial conducted by Stupp et al. [2], which found that the median overall survival (OS) times after RT alone and combined therapy were 12.1 and 14.6 months, respec- tively. Although the median OS of the combined therapy group was thus better than that of patients receiving RT alone, the OS times of patients aged ≥60 years were simi- lar when RT alone or combined therapy was employed, and the prognosis of elderly patients was poorer than that of younger patients. In this treatment regimen, the survival benefit of concurrent TMZ thus seemed to be small in the elderly compared with younger patients. As the prognosis of elderly patients with glioblastoma was poor when they underwent conventionally fractionated RT (CFRT, 60 Gy in 30 fractions), recent attempts have Abstract Background Although hypofractionated radiotherapy (HFRT) is preferred to conventionally fractionated radio- therapy when treating elderly patients with glioblastoma, the benefits and tolerability of HFRT with concurrent temo- zolomide (TMZ) remain unknown for such patients. We assessed the feasibility and outcomes of elderly patients with glioblastoma treated with HFRT and concurrent TMZ. Methods We retrospectively reviewed the medical records of 11 patients aged ≥70 years who were treated with HFRT and concurrent TMZ. All patients had newly diagnosed and histologically confirmed glioblastoma and were treated at our institution between October 2011 and April 2015. The median age was 74 years (range, 70–85 years). Total resec- tion/subtotal resection/biopsy were performed in 2/5/4 patients, respectively. The planning target volume included the T1-enhancing tumor and the resection cavity plus 2-cm margins, and all surrounding edema. The median prescrip- tion dose was 35 Gy (range, 35–42.5 Gy), delivered in 10 fractions. Seven patients received TMZ at 150 mg/m 2 for 5 days and 4 received TMZ at 75 mg/m 2 during HFRT. Overall survival (OS) was defined as the time from surgery to death or the last follow-up. Results The median follow-up period was 13.2 months. The median OS and progression-free survival (PFS) times were 13.2 and 7.0 months, respectively. One patient * Takashi Mizowaki mizo@kuhp.kyoto-u.ac.jp 1 Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan 2 Department of Neurosurgery, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan