Hyperthermia and radiation therapy for inoperable or recurrent parotid carcinoma. A phase I/II study

Abstract

Background. The treatment of advanced, inoperable, or recurrent parotid tumors represents a clinical challenge. The results obtained with conventional radiotherapy are disappointing. To improve the early response and local control of parotid tumors, local microwave hyperthermia was used in combination with ionizing radiation in a biinstitutional Phase I/II study. Methods. From 1984 to 1991, 13 patients (20 lesions) with advanced (10 lesions) or recurrent (10 lesions) parotid tumors (15 primaries and the remaining 5 nodal metastases), were treated with 300‐915 MHz of external hyperthermia after external irradiation. Heat was applied twice weekly at a minimum desired temperature of 42.0°C for 30 minutes at steady state. Ionizing radiation was delivered using photon, electron, or mixed electron‐photon beams; the prescribed total dose was 70 Gy and 30 Gy for untreated and previously treated lesions, respectively; the median computed total dose was 66 Gy for previously untreated patients (range, 56‐70 Gy) and 30 Gy for previously irradiated patients (range, 28‐32 Gy). Results. Acute side effects were limited. Major acute toxicities included three patients (15%) with superficial necrosis, two of three who healed spontaneously in 4 and 6 months. Clinical response evaluated during the third month after the completion of therapy found that 16/20 patients (80%) had a complete response (CR), and 4 (20%) had a partial response. Four out of 16 patients who had CRs (20%) had a local recurrence, resulting in an actuarial local control at 5 years of 62.3 ± 13.2%. Conclusions. The combined treatment of local microwave hyperthermia and ionizing radiation proved to be feasible and moderately toxic for patients with advanced, inoperable, or recurrent parotid tumors. Even if clinical result evaluation was not the study endpoint, early response, and 5‐year local control rates were encouraging. Cancer 1995;75:908‐13.

Surgery and Radiotherapy in the Treatment of Malignant Parotid Tumors: A Retrospective Multicenter Study

“…Other new methods of irradiation have been explored with promising results such as interstitial brachytherapy, neutrons, radio-chemotherapy association, carbon ions and hyperthermia [47][48][49][50] . The studies have shown im-portant results in terms of local-regional control, with a possible reduction of esthetic-functional deficits.…”

Localized hyperthermia induced by microwave diathermy in osteoarthritis of the knee: a randomized placebo-controlled double-blind clinical trial

“…Techniques for heat therapy include the application of superficial heat and application of electromagnetic energy. Frequencies historically used in electromagnetic therapy have been 2,450 [39], 915 [31], 433.92 and 27.12 MhZ [15, 37, 48]. These frequencies differ because of the range of tissue depth in which they can produce heat within tissues [33].…”

Clinical Evidence for Thermometric Parameters to Guide Hyperthermia Treatment

“…Further, retrospective analyses indicate that thermal dose is a significant predictor of different clinical endpoints (Table 8) [33,36]. A few studies did not find such significant relationships between clinical endpoints and thermal dose [103,109,110]. For example, in the prospective study of Maguire et al, a total CEM43 • CT 90 with a threshold above 10 min did not show a significant effect on CR [110].…”