Clinical experience with interstitial thermoradiotherapy for localized implantable pelvic tumors.

Twenty-six patients (20 females, 6 males) with localized tumors of the pelvis, including 3 primary advanced (PRIM), 7 persistent (PERS), 10 recurrent (REC), and 6 metastatic (MET) tumors, were treated with a combination of low-dose rate (LDR) iridium 192 interstitial radiotherapy (IRT), interstitial 915 MHz microwave hyperthermia (IHT), and external beam radiotherapy (RT). Histological diagnoses were squamous cell carcinoma in 13 (50%), adenocarcinoma in 12 (46%) and soft tissue sarcoma in 1 (4%) lesion. Tumor sites were cervix in 8 (31%), colorectum in 6 (23%), vagina in 4 (15%), anus in 3 (12%), ovary in 2 (8%), and other sites in 3 (12%) lesions. IHT was administered immediately before iridium 192 was placed and after its removal for 45-60 minutes at 41-44 degrees C. On December 31, 1991 median follow-up was 25 months (mean: 23 months; range: 5-65 months). At 3 months follow-up (FU), complete remission (CR) occurred in 17 (65%), partial remission (PR) in 7 (27%), and no change or progressive disease (NC/PD), in 2 (8%) lesions. At 12 months FU, in 16 of 21 patients (76%) local control (LC) was achieved, with 1 (5%) patient exhibiting a slow tumor regression. After combined IRT-IHT locoregional relapse or tumor regrowth occurred in 8/26 (31%): 5 (19%) outside and 3 (12%), inside the previously treated volume; relapses occurred within 8-30 (mean: 18) months of follow-up. Factors influencing initial (3 months FU) and long-term tumor response (12 months FU) included tumor class, tumor volume, total radiation dose, and thermal parameters with "good quality of heating" (TQ 41 degrees C > or = 75%) and high minimum tumor temperature (Tmin(av) > or = 41 degrees C). Treatment toxicity was acceptable: whereas 8 (31%) patients experienced acute side effects, which subsided within weeks, 7 (27%) developed long-term complications. Thermal damage was associated with IHT treatments exceeding maximum average temperatures of > or = 44 degrees C and maximum peak temperatures of > or = 45 degrees C.

Interstitial thermal radiation therapy: five-year experience with head and neck tumors.

Sixty-two patients with 24 primary advanced, six persistent, 28 locally recurrent, and four metastatic tumors of the head and neck were treated with combined interstitial low-dose iridium-192 radiation therapy, interstitial 915-MHz microwave hyperthermia (IHT), and external-beam radiation therapy. Diagnoses were squamous cell carcinoma in 56, adenocarcinoma in three, and soft-tissue sarcoma in three lesions. IHT was applied immediately before Ir-192 was placed and after its removal for 45-60 minutes at 41 degrees C-44 degrees C. At 3 months, complete remission had occurred in 39 lesions; partial remission, in 18; and no change or progressive disease, in five. At 12-month follow-up, local control was achieved in 29 of 50 patients; seven other patients had slow ongoing tumor regression with an unclear residual mass at computed tomography or magnetic resonance imaging. Lesion type, tumor volume, total radiation dose, and thermal parameters with "good quality of heating" at high minimum tumor temperature were identified as statistically significant (P less than .05) prognostic factors influencing initial and long-term tumor response. There was no prognostic factor for acute or late thermal damage.