500 kHz hyperthermia assisted HDR brachytherapy in the treatment of recurrent cervical and endometrial cancer in previously irradiated fields

Abstract

Background

The biological effectiveness of elevated temperature (hyperthermia) on cancer cells is a well documented issue. Nevertheless, it is still not widely used in clinical practice, mainly due to technical difficulties. The main limiting factor is the protection of healthy tissue during the hyperthermia procedure. Hyperthermia, used as an adjuvant treatment with brachytherapy, provides the possibility of lowering total radiation doses, without reducing biological effects.

Aim

The aim of this work was to present the advantages of using 500 kHz hyperthermia in HDR brachytherapy of cervical & endometrial cancer.

Materials/Methods

Hyperthermia procedures were performed in 8 endometrial cancer patients and 2 cervical cancer patients with early recurrent local disease in previously irradiated areas. One or two interstitial hyperthermia procedures were performed using rigid metal needles, both for brachytherapy and temperature elevation. The total radiation dose was 30 Gy, delivered in 3 or 6 Gy per fraction. In the case of 3 Gy per fraction, a scheme of two fractions per day, separated by at least 8 hours, was used. The total treatment time ranged from 5 to 14 days. Hyperthermia was performed concurrently with brachytherapy.

Results

During the treatment, no acute reactions were observed. In each case, tumour regression over 50% was noted. During the 3 to 14 month follow-up period, complete vaginal tumour regression was seen in 8 of 10 cases.

Conclusions

500 kHz hyperthermia assisted interstitial brachytherapy can be regarded as effective and safe procedure, especially when applied as secondary (salvage) treatment. More cases and longer observation time are needed to make definite conclusions.