Development of a new heating needle for interstitial hyperthermia compatible with interstitial radiotherapy.
OBJECTIVE
We have developed a new heating needle for interstitial hyperthermia compatible with brachytherapy. We studied the heating characteristics of interstitial needles and the usefulness of these needles for interstitial hyperthermia.


METHODS
As heating needles, we used MicroSelectron HDR interstitial needles. These needles were only heated at the metal tip, and were insulated in the middle and grounded from the top. The hyperthermia system was based on the principles of RF capacitive heating, and we used a Thermotron RF-8. We examined whether the temperature and the heating area could be elevated to a level required for hyperthermia.


RESULTS
Good heating was obtained around the metal tip of the needle. The heating area of the longitudinal axis of the needle varied with the length of the metal part, while the transverse heating area of the needle was almost unchanged. If heating was performed while maintaining the elevation of temperature in each needle at the same level using variable coils (tuning box), heating was homogeneous over the regions in accordance with the arrangement of the needles.


CONCLUSIONS
With this heating system, the temperature rises easily, and a uniform temperature distribution can be obtained.
Ikeda
H
H
Department of Radiology, Saiseikai Nakatsu Hospital, Osaka, Japan.
Tanaka
M
M
Matsuo
R
R
Fukuda
H
H
Yamada
R
R
Yamamoto
I
I
D001918:Brachytherapy / Q000295:instrumentation* / Q000379:methods*; D003131:Combined Modality Therapy; D004867:Equipment Design; D004869:Equipment Safety; D006361:Heating / Q000379:methods*; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation* / Q000379:methods*; D009339:Needles; D019047:Phantoms, Imaging; D013696:Temperature; D013995:Time