Deep regional hyperthermia for the whole thoracic region using 8 MHz radiofrequency-capacitive heating device: relationship between the radiofrequency-output power and the intra-oesophageal temperature and predictive factors for a good heating in 59 patients.
OBJECTIVE
To assess the relationship between the radiofrequency (RF) output power and the intra-oesophageal temperature for hyperthermia of the whole thoracic region, and also to evaluate the patients' characteristics associated with adequate heating.


METHODS
Fifty-nine patients with thoracic cancer treated with radiotherapy plus hyperthermia were retrospectively analysed. The 8-MHz RF capacitive heating device was applied, both the upper and lower electrodes were 300 mm in diameter, placed on opposite sides of the whole thoracic region. All the patients also underwent intra-oesophageal temperature measurements.


RESULTS
All thermal parameters, T(min), T(max), T(ave), and %T ≥ 41°C, of the intra-oesophageal temperature highly correlated with the median RF output power (p < 0.0001), and the relations were independent in the multivariable analyses including clinical characteristics (p < 0.01). The performance status showed a statistically significant association on T(max), T(ave) and %T ≥ 41°C (p < 0.05). The patient age and subcutaneous fat at some levels were inversely correlated with the thermal parameters (p < 0.05).


CONCLUSIONS
The RF output power was significantly correlated with the intra-oesophageal temperature; it could be used as a promising parameter to assess the efficacy of hyperthermia for the whole thoracic region. Higher intra-oesophageal temperature may be achieved in patients with good performance status, younger age and thinner subcutaneous fat.
Ohguri
Takayuki
T
Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Kitakyushu, Japan. ogurieye@med.uoeh-u.ac.jp
Yahara
Katsuya
K
Moon
Seung Dae
SD
Yamaguchi
Shinsaku
S
Imada
Hajime
H
Terashima
Hiromi
H
Korogi
Yukunori
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001831:Body Temperature; D003131:Combined Modality Therapy; D004938:Esophageal Neoplasms / Q000628:therapy*; D004947:Esophagus; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation; D008175:Lung Neoplasms / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011846:Radio Waves