Antitumor effect of new local hyperthermia using dextran magnetite complex in hamster tongue carcinoma.
OBJECTIVE
This study was performed to clarify the usefulness of Dextran magnetite (DM) for the oral cancer hyperthermia.


METHODS
Tumors were induced in golden hamster tongue by 9,10-dimethyl 1-1,2-benzanthracene (DMBA) application. DM suspension was locally injected into the tumor-bearing tongue and tongues were heated up to 43.0-45.0 degrees C, by AC magnetic field of 500 kHz.


RESULTS
The average time taken for the temperature to rise to 43.0 degrees C or above was 162 s (n = 17) at the margin of the tumor and 420 s (n = 17) at the center of the tumor. According to the tumor volume, the time required for an increase in the central temperature of tumor to 43.0 degrees C tended to be prolonged. Both temperatures could be maintained at approximately 43.0-45.0 degrees C for 30 min. The inhibition of the growth of tongue carcinoma in the four-time heating group was significantly greater than in the control group (P < 0.01). Moreover, the survival rate was significantly higher in the heated groups than in the control group (P < 0.01). Histological examination revealed a brown uniform DM accumulation at the stroma in the margin of the tumors. Many of tumor cells disappeared at the site adjacent to this accumulation.


CONCLUSIONS
These results strongly suggest the usefulness of this local hyperthermic system in the oral region that is accessible to this treatment.
Wada
S
S
Department oqf Dentistry and Oral Surgery, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Toyama, Japan. swada-tym@umin.ac.jp
Tazawa
K
K
Furuta
I
I
Nagae
H
H
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D001831:Body Temperature / Q000502:physiology; D002273:Carcinogens; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000628:therapy*; D006224:Cricetinae; D006979:Hyperthermia, Induced / Q000379:methods*; D007505:Iron-Dextran Complex / Q000627:therapeutic use*; D008280:Magnetics / Q000295:instrumentation / Q000627:therapeutic use; D008297:Male; D008647:Mesocricetus; D015996:Survival Rate; D013821:Thermometers; D013997:Time Factors; D014062:Tongue Neoplasms / Q000473:pathology / Q000628:therapy*
D002273:Carcinogens; D015127:9,10-Dimethyl-1,2-benzanthracene; D007505:Iron-Dextran Complex