Author/Editor		Fras, AP; Kranjc, Simona; Čemažar, Maja; Serša, Gregor
Title		Cryosurgery combined with radiotherapy of tumors in mice
Translated title		Kriokirurgija mišjih tumorjev SA-1 v kombinaciji z obsevanjem
Type		članek
Source		Radiol Oncol
Vol. and No.		Letnik 33, št. 3
Publication year		1999
Volume		str. 221-5
Language		eng
Abstract		Tlle aim of this study zuas to determine antitumor effectiveness of cryosurgery alone and in comhination with radiotherapy. Cryosurgery of subcutaneous fibrosarcoma SA-1 tumors in A/J mice was moderately effective trcatmcnt. Tumor growth delay was 10.3 * 3.8 days after 5 minute treatment with nitrogen filled cryo-prohe. Shorter treatment times induced less, but dose dependent antitumor effect. In combined treat- ment, tumors were either first treated by cryosurgery for 3 minutes and then locally irradiated with 10 Gy for 5 minutes, or irradiated first and thereafter treated by cryosurgery. The antitumor effectiveness of com- bined treatrnent was sequence dependent; the irradiation of tumors before cryosurgery resulted in better antitumor effect than the irradiation after cryosurgery. These results indicate that radiosensitization may not be always expected, in spite of some reports demonstrating that cryosurgery may have radiosensitizing effect in vivo, and that some other mechanisms may be involved contributing to radiation damage when cryosurgery follows irradiation.
Summary		Namen naše raziskave je bil določiti protitumorsko delovanje kriokirurgije kot samostojne terapije in v kombinaciji z obsevanjem. Kriokirurgija podkožnih fibrosarkomskih tumorjev SA-1, ki smo jih nasadili v A/J miši, je bila učinkovita terapija. Zaostanek v rasti tumorjev po 5 minutnem zamrzovanju s tekočim dušikom je bil 10.3+- 3.8 dni. Časovno krajše zamrzovanje je bilo manj učinkovito, a odvisno od časa zamrzovanja. Pri kombinirani terapiji smo tumorje najprej zamrzovali 3 minute in jih po 5 minutah obsevali z 10 Gy, oziroma najprej obsevali in jih po 5 minutah zamrzovali. Protitumorsko delovanje je bilo odvisno od vrstnega reda kombinirane terapije, tumorji ki smo jih obsevali pred zamrzovanjem so rastli počasneje, kot tisti, ki smo jih obsevali po zmrzovanju. Kljub temu, da nekatere študije poročajo o povečani občutljivosti celic na obsevanje po kriokirurgiji, so naši rezultati pokazali, da te občutljivosti na sevanje in vivo ne moremo vedno pričakovati, ter da so v protitumorsko delovanje kombinirane terapije verjetno vpleteni tudi drugi mehanizmi, ki prispevajo k poškodbam zaradi obsevanja, če le-temu sledi kriokirurgija.
Descriptors		SARCOMA, EXPERIMENTAL MICE CRYOSURGERY