Pilot study of local hyperthermia, radiation therapy, etanidazole, and cisplatin for advanced superficial tumours

Five patients (six hyperthermia sites) with advanced superficial tumours were treated with combined etanidazole, cisplatin, local hyperthermia, and radiation therapy as part of a Phase I pilot study. Treatment was given once weekly and consisted of etanidazole 3 gm/m2 IV bolus, cisplatin 50 mg/m2 IV bolus, hyperthermia for 60 min with a target temperature of 43 degrees C, and radiation therapy 500 cGy/fraction (median total dose 3000 cGy) for a total of six weeks. Blood levels of etanidazole were taken during treatment at week 1 and week 4. Etanidazole drug exposure was calculated using the trapezoidal rule and expressed as the area under the curve (AUC) of plasma concentration x time. Five of six treatment sites had received prior irradiation. Prior chemotherapy had been given in three patients and tamoxifen therapy given in the other two patients. The median follow-up time is 34 months; 3/5 patients have died of disease. The most significant toxicity was grade I or II nausea and vomiting associated with 19/32 treatments (59%) and a second degree burn in 2/6 fields. None of the five patients experienced peripheral neuropathy, skin ulceration, or needed surgical repair. In addition, there was mild renal toxicity; pharmacokinetic analysis showed a 28-75% increase in the week 1 to week 4 AUC in three patients, all of whom had a decrease in creatinine clearance over the same time of 15-47%. This pilot study suggests this combined modality therapy can be delivered without major complications and that renal function, determined by creatinine clearance, affects clearance of etanidazole and alters the AUC. Therefore, monitoring renal function is important in patients receiving etanidazole in addition to other nephrotoxic agents such as cisplatin. The impact of etanidazole on the therapeutic index of hyperthermia, radiation therapy and cisplatin may be worth of study, especially since a positive interaction between these modalities is found in laboratory models.

Local hyperthermia, radiation therapy, and chemotherapy in patients with local-regional recurrence of breast carcinoma

We retrospectively reviewed the response rate and the acute and long-term toxicity of combined treatment using radiation therapy, hyperthermia, and chemotherapy in 29 patients with locally or regionally recurrent or advanced adenocarcinoma of the breast who completed at least 4 of the 6 prescribed hyperthermia treatments as part of a Phase I-II trial. Thirty-nine separate hyperthermia treatment fields were evaluated. Cisplatin alone or cisplatin with etanidazole or bleomycin was delivered just prior to hyperthermia once weekly. Hyperthermia was delivered to a target minimum tumor temperature of 43 degrees C +/- 0.5 for 60 min. Following hyperthermia, a 400 cGy fraction of radiation was given. The radiation fraction size on other days was 200 cGy. Twenty-two fields had previously been irradiated and 17 fields had not. Prior chemotherapy had been given in 24 of 29 patients (83%) and hormonal therapy given in 21 (72%). The median follow-up time is 10 months; 16/29 patients (55%) have died of disease. The overall complete response rate for all fields was 53%. Response rate was not related to any clinical factor, radiation dose, microwave or ultrasound technique, type of chemotherapy, or tumor temperatures, but the number of patients in the study population was small. A statistically significant association between the likelihood of complications and the total radiation therapy dose (previous radiation and present radiation) was found. Persistent ulceration lasting greater than 1 month after completing treatment was seen in 67% of previously irradiated fields compared to 21% of fields that had not been previously treated (p = 0.015). Surgical wound repair was needed for 38% of fields with a history of prior irradiation versus 6% of those without prior treatment (p = 0.050). A statistically significant radiation therapy dose response was found for the likelihood of these complications. None of the hyperthermia temperature parameters studied correlated with an increased risk of complication. We conclude that the combination of radiation therapy, hyperthermia, and chemotherapy results in a high rate of complete response. However, in patients who have been treated with prior radiation therapy, this combination may be more locally toxic than treatment with hyperthermia and radiation therapy alone. The precise impact of chemotherapy on the therapeutic index of hyperthermia and radiation therapy remains to be determined in randomized clinical trials.