title: Output-limiting symptoms induced by radiofrequency hyperthermia. Are they predictable?
abstract: BACKGROUND
  During radiofrequency (RF) hyperthermia treatment, hot-spot phenomena may occur and prevent treatment continuation if the output is not lowered. We previously reported a significant correlation between the initial energy output at which output-limiting symptoms occurred and patient status. Patients with a complete clinical response had significantly increased temperature, while some patients with partial clinical response and stable disease had increased temperature, depending on the occurrence of output-limiting symptoms. To predict the initial energy output at which output-limiting symptoms occur, we performed multiple regression analysis with the parameters of patients' physical status.
  
  
  METHODS
  Hyperthermia alone or concomitant with chemotherapy and/or radiotherapy was applied in 62 patients with malignant disease for a total of 310 treatments with a Thermotron RF-8 between December 2011 and April 2014.
  
  
  RESULTS
  No output-limiting symptoms were shown in 65.5% of 310 treatments. Pain (29.7%), micturition desire (1.9%), skin discomfort (0.6%), subcutaneous induration (1.6%), cold sensation (0.6%), and nausea (0.3%) were reported in the 310 treatments. A good predictive equation for initial energy output at which output-limiting symptoms occur was determined with two parameters, initial time of an output-limiting symptom onset, and thickness of the fat of the abdominal wall. Multiple regression analysis showed an adjusted R(2 )= 0.99 and variance inflation factor < 2.
  
  
  CONCLUSIONS
  We present a good predictive equation for initial energy output at which output-limiting symptoms occur. It is critical to prevent RF hyperthermia-induced output-limiting symptoms and establish new prevention strategies.
authors.affiliation: a Division of Surgery , Hidaka Hospital , Gunma .
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shoji
authors.affiliation: a Division of Surgery , Hidaka Hospital , Gunma .
authors.forename: Masahiko
authors.initials: M
authors.lastname: Motegi
authors.affiliation: a Division of Surgery , Hidaka Hospital , Gunma .
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Osawa
authors.affiliation: b Division of Radiology , Hidaka Hospital , Gunma .
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Okonogi
authors.affiliation: b Division of Radiology , Hidaka Hospital , Gunma .
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okazaki
authors.affiliation: a Division of Surgery , Hidaka Hospital , Gunma .
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Andou
authors.affiliation: c Department of Oncology Clinical Development , Graduate School of Medicine, Gunma University , Gunma .
authors.forename: Takayuki
authors.initials: T
authors.lastname: Asao
authors.affiliation: d Department of General Surgical Science , Graduate School of Medicine, Gunma University , Gunma .
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kuwano
authors.affiliation: e Department of Radiation Oncology , Saitama Medical Center, Saitama Medical University , Saitama , Japan , and.
authors.forename: Takeo
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: f Division of Cancer Diagnosis and Cancer Treatment , Hidaka Hospital , Gunma , Japan.
authors.forename: Kyoji
authors.initials: K
authors.lastname: Ogoshi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*
chemical_list: D000970:Antineoplastic Agents
keywords: Output-limiting symptoms; physical status; prediction; radiofrequency hyperthermia