Regional hyperthermia for deep-seated malignancies using the BSD annular array

Abstract

Forty-four patients were treated using the BSD-1000 Annular Phased Array between April 1983 and December 1986. There were 32 pelvic, nine abdominal, two extremity, and one thoracic sites treated. Mean tumour volume was 646 cc. Thirty-nine patients had concurrent radiation therapy, receiving a mean dose of 38 Gy. Mean average temperature was 41.0 +/- 1.4 degrees C. Most patients experienced local or systemic toxicity, requiring temporary treatment interruption in 33 patients, and termination of treatment in eight. Chronic complications were seen in four, but these were in patients receiving high total radiation doses as well. There were six complete and five partial responses. Among the 32 patients with pelvic tumours, mean tumour volume was 317 cc, mean radiation dose was 42 Gy, and mean average temperature was 41.3 +/- 1.2 degrees C. There were five complete and four partial responses. Achieving tumour temperatures greater than or equal to 42 degrees C with the annular array is difficult, due to both systemic and local toxicity. To improve clinical hyperthermia for thoracic, abdominal, and pelvic tumours, new technologies such as steerable phased array microwave systems; scanned, focused ultrasound; and permanently implantable thermoregulating ferromagnetic seeds, or new approaches such as using drugs to alter blood flow, or combining hyperthermia with antineoplastic drugs or biological agents, will be necessary.

The History of Hyperthermia Rise and Decline

“…Insufficient heating in view of inadequate technique had been considered the only reason of the trials fail and it was a false conclusion. Toxicity was the reason of the insufficient heating as it was directly stated earlier in Stanford [216] and Shimm et al [219] reports. This was not a technical problem and not a problem of thermometry: this was the inherent problem of hyperthermia itself and its real name is the narrow therapeutic range.…”

“…Average temperature 39.6-42.1 ∘ C in deep tumors had been obtained only with three devices. In 1989, a report on BSD-1000 use [219] had been published. Average temperature was 41 ∘ C and toxicity, both systemic and local, had been directly named as the reason of the insufficient heating.…”

Radiotherapeutic management in carcinoma of the uterine cervix: current status

“…The technical problem of heating deep-seated tumors such as cancer of the cervix has prevented a universally accepted method of administering the therapy in a consistent fashion. External hyperthermia for heating deep-seated cancer is currently under investigation, but has encountered significant problems (77)(78)(79). To date, intracavitary hyperthermia (s°'sl) has been the simplest means for highly localized heating of tumors located near natural body orifices.…”

Design and characterisation of a phased antenna array for intact breast hyperthermia

“…An advantage of FUS systems is that the small acoustic wavelength ($mm) affords precise focussing of energy delivery to targets. Microwave applicators [21] offer the advantage of heating broader volumes without requiring complex control strategies as needed with FUS.…”

“…Systems incorporating multiple antennas facilitate electronic steering of power deposition within the breast. The focussing may be achieved through simultaneous operation of multiple antenna applicators as a phased array [21][22][23][24][25], or by sequentially activating individual antennas [26], and they can be broadly classified into narrowband systems (i.e. operating at a fixed frequency) [27][28][29][30][31][32] or ultra-wideband systems [33][34][35][36].…”