Hyperthermic enhancement of tumour growth inhibition by accelerated carbon-ions in transplantable human esophageal cancer.
The study examined the effects of combination of hyperthermia (42 degrees C) and 290 MeV/u carbon-ion (C-) beams or 200 kVp X-rays on tumour regrowth delay of transplantable human esophageal cancer as an in vivo model for radiotherapy of cancer. The C-beams were more effective in the tumour growth inhibition than X-rays. The relative biological effectiveness (RBE) of C-beams against X-rays was 2.00. It was observed that the interactive hyperthermic (42 degrees C, for 30 min) enhancement of tumour regrowth delay by high-linear energy transfer (LET) C-beams was similar to that of combination of low-LET X-rays with hyperthermia. The thermal enhancement ratios (TER) were 6.10 and 5.57 for X-rays and C-beams, respectively. These results suggest that hyperthermic treatment is effective in radiotherapy not only by low-LET radiation but also by high-LET radiation such as C-beams. In conclusion, the depression of the tumour growth by the combined treatment of hyperthermia (42 degrees C) and the C-beams strongly suggests the available possible application of interdisciplinary cancer therapy for refractory tumours.
Ohnishi
T
T
Department of Biology, Nara Medical University, Japan.
Takahashi
A
A
Yano
T
T
Matsumoto
H
H
Wang
X
X
Ohnishi
K
K
Tamamoto
T
T
Tsuji
K
K
Furusawa
Y
Y
Yukawa
O
O
D000368:Aged; D000818:Animals; D002455:Cell Division / Q000502:physiology; D004195:Disease Models, Animal; D004938:Esophageal Neoplasms / Q000628:therapy*; D006801:Humans; D006979:Hyperthermia, Induced; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000628:therapy*; D011878:Radiotherapy; D016378:Tissue Transplantation / Q000502:physiology; D014965:X-Rays