title: Modified simultaneous integrated boost radiotherapy for unresectable locally advanced breast cancer: preliminary results of a prospective clinical trial.
abstract: BACKGROUND
  The purpose of this study was to evaluate the effect of modified simultaneous integrated boost (SIB) radiotherapy for patients with extensive breast cancer.
  
  
  METHODS
  Patients with macroscopic tumor and histologically proven adenocarcinoma of the breast were enrolled in the study. Patients were included whether they had or did not have previous surgery, chemotherapy, hormone therapy, or molecular targeted therapy; patients with past history of thoracic radiotherapy were excluded. Under conditions of not exceeding the tolerance dose for normal tissue, irradiation to the tumor was increased to the maximum possible extent using the modified SIB technique.
  
  
  RESULTS
  Three breast cancer patients were treated with the modified SIB technique. All patients were diagnosed as T4b (median maximum diameter of the tumor: 16 cm; range, 15.5-22 cm), and all patients exhibited symptoms because of the extremely large tumor. The median total dose to the part of tumor tissue was 128.8 Gy (range, 110-140 Gy). Total dose to normal tissue was < 72 Gy in all patients. Although large tumors were radio-resistant, it was macroscopically confirmed that all tumors eventually disappeared. Although skin defects persisted because of tumor disappearance, there were no Grade ≥ 3 toxicities due to radiotherapy.
  
  
  CONCLUSIONS
  Although much care is required in delivering extremely high doses of radiotherapy to the tumor, modified SIB radiotherapy was shown to be effective against extremely large tumors that could not be controlled using conventional radiotherapy. In future, an increase in the number of study patients and establishment of the technique will be required.
authors.affiliation: Department of Radiation Oncology, National Institute of Radiological Sciences, Chiba, Japan. Electronic address: t_nomiya@nirs.go.jp.
authors.forename: Takuma
authors.initials: T
authors.lastname: Nomiya
authors.affiliation: Department of Radiation Oncology, Yamagata University Hospital, Yamagata, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Akamatsu
authors.affiliation: Department of Radiation Oncology, Yamagata University Hospital, Yamagata, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Harada
authors.affiliation: Department of Radiation Oncology, Yamagata University Hospital, Yamagata, Japan.
authors.forename: Ibuki
authors.initials: I
authors.lastname: Ota
authors.affiliation: Department of Radiation Oncology, Yamagata University Hospital, Yamagata, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Hagiwara
authors.affiliation: Department of Radiation Oncology, Yamagata University Hospital, Yamagata, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Ichikawa
authors.affiliation: Department of Radiation Oncology, Yamagata University Hospital, Yamagata, Japan.
authors.forename: Misako
authors.initials: M
authors.lastname: Miwa
authors.affiliation: Department of Surgery, Yamagata University Hospital, Yamagata, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Department of Radiation Oncology, Yamagata University Hospital, Yamagata, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Nemoto
mesh_terms: D000230:Adenocarcinoma / Q000532:radiotherapy*; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*
keywords: Breast neoplasm; Clinical trial; Radiotherapy; Technique; Unresectable tumor