title: Assessment of myocardial metabolic disorder associated with mediastinal radiotherapy for esophageal cancer -a pilot study.
abstract: BACKGROUND
  To evaluate the dose-effect relations for myocardial metabolic disorders after mediastinal radiotherapy (RT) by performing iodine-123 β-methyl-iodophenyl pentadecanoic acid (I-123 BMIPP) scintigraphy.
  
  
  METHODS
  Between 2011 and 2012, we performed I-123 BMIPP scintigraphy for patients with esophageal cancer before and six months after curative mediastinal RT. Single photon emission computed tomography (SPECT) images of pre-RT and post-RT were registered into RT dose distributions. The myocardium was contoured, and the regional RT dose was calculated. Normalization is required to compare pre- and post-RT SPECT images because the uptake pattern is changed due to the breathing level. Normalization was applied on the mean of SPECT counts in regions of the myocardium receiving less than 5 Gy. Relative values in each dose region (interval of 5 Gy) were calculated on the basis of this normalization for each patient. The reduction in the percent of relative values was calculated.
  
  
  RESULTS
  Five patients were enrolled in this study. None of the patients had a past history of cardiac disease. The left ventricle was partially involved in RT fields in all patients. The patients received RT with median total doses of 60-66 Gy for the primary tumor and metastatic lymph nodes. Concomitant chemotherapy consisting of cisplatin or nedaplatin and 5-fluorouracil with RT was performed in 4 patients. All patients had reduced uptake corresponding to RT fields. Dose-effect relations for reduced uptake tended to be observed at 6 months after RT with mean decreases of 8.96% in regions at 10-15 Gy, 12.6% in regions at 20-25 Gy, 15.6% in regions at 30-35 Gy, 19.0% in regions at 40-45 Gy and 16.0% in regions at 50-55 Gy.
  
  
  CONCLUSIONS
  Dose-effect relations for myocardial metabolic disorders tended to be observed. We may need to make an effort to reduce high-dose mediastinal RT to the myocardium in RT planning.
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. reirei513@hotmail.com.
authors.forename: Rei
authors.initials: R
authors.lastname: Umezawa
authors.affiliation: Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan. pfpmf6212000@yahoo.co.jp.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Takanami
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. kadoya.n@rad.med.tohoku.ac.jp.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kadoya
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. y.nakajima@med.tohoku.ac.jp.
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Nakajima
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. m.saito@med.tohoku.ac.jp.
authors.forename: Masahide
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan. otahide@gmail.com.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ota
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. harumatsu2001@yahoo.co.jp.
authors.forename: Haruo
authors.initials: H
authors.lastname: Matsushita
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. sugatosi772288@yahoo.co.jp.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sugawara
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. satoharuapple@yahoo.co.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Kubozono
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. priere_for@yahoo.co.jp.
authors.forename: Takaya
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. y02614111@yahoo.co.jp.
authors.forename: Yojiro
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: Department of Radiological Technology, School of Health Sciences, Faculty of Medicine, Tohoku University, Sendai, Japan. takedak41@yahoo.co.jp.
authors.forename: Ken
authors.initials: K
authors.lastname: Takeda
authors.affiliation: Department of Developmental Cognitive Neuroscience Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan. ytaki@idac.tohoku.ac.jp.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Taki
authors.affiliation: Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan. ktakase@rad.med.tohoku.ac.jp.
authors.forename: Kei
authors.initials: K
authors.lastname: Takase
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. kjingurad@yahoo.co.jp.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Jingu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy / Q000009:adverse effects*; D004307:Dose-Response Relationship, Radiation; D004938:Esophageal Neoplasms / Q000150:complications / Q000188:drug therapy / Q000532:radiotherapy*; D005227:Fatty Acids / Q000493:pharmacokinetics; D006331:Heart Diseases / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007462:Iodobenzenes / Q000493:pharmacokinetics; D008297:Male; D008479:Mediastinal Neoplasms / Q000150:complications / Q000188:drug therapy / Q000532:radiotherapy*; D008659:Metabolic Diseases / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D010865:Pilot Projects; D011832:Radiation Injuries / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D005227:Fatty Acids; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; C049338:iodofiltic acid