title: Nerve tolerance to high-dose-rate brachytherapy in patients with soft tissue sarcoma: a retrospective study.
abstract: BACKGROUND
  Brachytherapy, interstitial tumor bed irradiation, following conservative surgery has been shown to provide excellent local control and limb preservation in patients with soft tissue sarcomas (STS), whereas little is known about the tolerance of peripheral nerves to brachytherapy. In particular, nerve tolerance to high-dose-rate (HDR) brachytherapy has never been properly evaluated. In this study, we examined the efficacy and radiation neurotoxicity of HDR brachytherapy in patients with STS in contact with neurovascular structures.
  
  
  METHODS
  Between 1995 and 2000, seven patients with STS involving the neurovascular bundle were treated in our institute with limb-preserving surgery, followed by fractionated HDR brachytherapy. Pathological examination demonstrated that 6 patients had high-grade lesions with five cases of negative margins and one case with positive margins, and one patient had a low-grade lesion with a negative margin. Afterloading catheters placed within the tumor bed directly upon the preserved neurovascular structures were postoperatively loaded with Iridium-192 with a total dose of 50 Gy in 6 patients. One patient received 30 Gy of HDR brachytherapy combined with 20 Gy of adjuvant external beam radiation.
  
  
  RESULTS
  With a median follow-up of 4 years, the 5-year actuarial overall survival, disease-free survival, and local control rates were 83.3, 68.6, and 83.3%, respectively. None of the 7 patients developed HDR brachytherapy-induced peripheral neuropathy. Of 5 survivors, 3 evaluable patients had values of motor nerve conduction velocity of the preserved peripheral nerve in the normal range.
  
  
  CONCLUSIONS
  In this study, there were no practical and electrophysiological findings of neurotoxicity of HDR brachytherapy. Despite the small number of patients, our encouraging results are valuable for limb-preserving surgery of unmanageable STS involving critical neurovascular structures.
authors: Department of Orthopaedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan. kubot@hiroshima-u.ac.jp
authors: Tadahiko
authors: T
authors: Kubo
authors: Takashi
authors: T
authors: Sugita
authors: Shoji
authors: S
authors: Shimose
authors: Toshihiro
authors: T
authors: Matsuo
authors: Ken
authors: K
authors: Hirao
authors: Hiroaki
authors: H
authors: Kimura
authors: Masahiro
authors: M
authors: Kenjo
authors: Mitsuo
authors: M
authors: Ochi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D018572:Disease-Free Survival; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D051642:Histiocytoma / Q000532:radiotherapy; D006801:Humans; D007496:Iridium Radioisotopes; D008080:Liposarcoma / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000378:metabolism*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012509:Sarcoma / Q000532:radiotherapy*; D012983:Soft Tissue Neoplasms / Q000532:radiotherapy*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D007496:Iridium Radioisotopes