Abstract Book

S882

ESTRO 37

6 National Cancer Center Hospital, Radiation Therapy, Tokyo, Japan 7 Cancer Institute Hospital, Radiation Therapy, Tokyo, Japan 8 Shonan Kamakura General Hospital, Radiotherapy, Kamakura, Jersey 9 Nagoya University Hospital, Radiology, Nagoya, Japan 10 Japanese Red Cross Ise Hospital, Radiotherapy, Ise, Japan 11 Mie University Hospital, Radiation Therapy, Z, Japan 12 Kyoto Prefectural University of Medicine, Radiology, Kyoto, Japan 13 Kyoto University Hospital, Radiation Therapy, Kyoto, Japan 14 Osaka City General Hospital, Radiation Oncology, Osaka, Japan 15 Osaka University Hospital, Radiation Therapy, Osaka, Japan 16 Hyogo Prefectural Cancer Center, Radiation Therapy, Akashi, Japan 17 Hiroshima University Hospital, Radiation Therapy, Hiroshima, Japan 18 Kyushu University Hospital, Radiology, Fukuoka, Japan 19 Kurume University Hospital, Radiology, Kurume, Japan Purpose or Objective In 2013, childhood cancer core-center hospitals in Japan were selected to consolidate patients and improve treatment standards. Fifteen core-enters are selected, six of which are pediatric hospitals, eight are university hospitals, and the other one is municipal general hospital. In order to investigate whether patients were concentrated by making the core-center selection, we conducted a survey in the JASTRO research. Material and Methods We sent a questionnaire to each doctor responsible for pediatric radiotherapy by e-mail, and asked them to reply to the answered questionnaire. Questionnaire fills in the number of children who underwent radiation therapy under 15 years of age in each year according to International Classification of Childhood Cancer (ICCC-3,) and also fills in each year the period of no radiation treatment for children. Results As a result, the total number of patients in the three years (2010-2012) prior to the selection of 15 centers was 274, 285, 316, while in the 4 years after selection (2013- 2016) was 334, 342, 308, and 324 patients. There were fewer than 50 pediatric patients per year in each core- center. Since it is estimated that the number of pediatric patients irradiated at core-centers is about 1/3 that of childhood cancer patients in Japan, it is estimated that there are about 1000 pediatric radiation therapy patients in the country in 2016. Because of the small number of patients treated at each core-center, there are few institutions conducting radiotherapy for children without breaks for a year. From our survey, the patient concentration has not necessarily progressed after designation of a childhood cancer core-center hospital. Conclusion The future task is to prevent outcome-difference among core-center hospitals in pediatric radiotherapy. Childhood cancer patients are less likely to perform follow-up observations after treatment by radiation oncologists, so it is difficult to know the results including side effects after treatment. Even if an excellent radiation plan can be made, we will find that it is extremely difficult to fix and rest as planned for the actual irradiation. How precise radiotherapy is to be done

Results Treatment course was well tolerated; all pts completed PT without breaks related to acute side effects. A conventional fractionation technique was used for 38 treatments, in 7 cases a Simultaneous Integrated Boost technique was used. All pts were treated with active beam scanning PT using a median of 3 fields with single field optimization technique. Mean high-risk (HR) PTV volume was 621,8 cc (range, 53,3 -2551,95 cc); mean low-risk (LR) PTV volume was 1099,2 cc (range, 72,9 – 3011,08 cc). Mean prescribed total dose was 67,7 GyRBE (range: 50-78 GyRBE) for HR PTV and 52,7 GyRBE (range, 50-54 GyRBE) for LR PTV. Acute G3 cutaneous toxicity was experienced in 9 pts. No other ≥ G3 acute side effects were reported. No late Grade ≥ 3 toxicities were recorded. Acute and late side effects are reported in the attached table. Pain was experienced in 8 pts during PT and the maximum grade was 8 NRS in one case and it persisted in 3 pts, grade1, 2 and 5 NRS. Median follow-up was 7,76 months (range, 0-25,3). Of the 33 lesions treated with radical intent, 22 are locally controlled, in 4 cases there was local progression, one pt had local and distant progression during PT, 4 pts died for the disease and 2 died of other causes. Of the 12 pts treated with adjuvant intent all are free of disease. Acute G1 G2 G3 G4 Cutaneous 15 8 9 - Fatigue 12 - - - Disphagia 5 2 - - Gastro-enteric 3 - - - Paresthesia 3 - - - Laryngitis 1 - - - Chronic G1 G2 G3 G4 Cutaneous 11 2 - - Hypoesthesia/Paresthesia 5 - - - Conclusion Our very preliminary data confirm that proton therapy for spine malignancies is a feasible irradiation modality associated with an excellent treatment tolerance and compliance. A longer follow-up is obviously needed to gain more robust data for late toxicity and long term disease control. EP-1639 Current situation and issues for promotion of childhood cancer radiation therapy in Japan H. Sekine 1 , T.H. Hashimoto 2 , K.J. Jingu 3 , M.K. Kita 4 , H.F. Fuji 5 , H.I. Igaki 6 , M.S. Sumi 7 , M.O. Omura 8 , M.K. Kawamura 9 , N.I. II 10 , A.T. Takada 11 , G.S. Suzuki 12 , T.M. Mizowaki 13 , M.T. Tanaka 14 , F.I. Isohashi 15 , T.S. Soejima 16 , T.K. Kimura 17 , S.O. Oga 18 , E.O. Ogo 19 , Y. Nagata 17 1 Jikei University Daisan Hospital, Department of Radiology and Radiotherapy, Komae, Japan 2 Hokkaido University Hospital, Radiation Therapy, Hokkaido, Japan 3 Tohoku University Hospital, Radiation Oncology, Sendai, Japan 4 Tokyo Metropolitan Tama Medical Center, Radiology, Fucyu, Japan 5 National Center for Child Health and Development, Radiation Therapy, Setagaya, Japan Electronic Poster: Clinical track: Paediatric tumours