Influence of water bolus temperature on measured skin surface and intradermal temperatures.

Temperature measurements utilizing thermometry probes placed on the skin surface are often used clinically to assess temperatures for the purposes of power control and evaluating treatment efficacy. There is a question, however, as to what extent applicator temperature-controlled liquid coupling boluses can create temperature gradients which can cause significant differences between measurements taken by sensors placed on the skin surface and the actual temperature of the tissue beneath. To address this question, experiments were conducted with human subjects instrumented with surface and shallowly implanted temperature sensors.

Automated mechanical thermometry probe mapping systems for hyperthermia.

In order to better assess temperature distribution patterns in patients, tissue equivalent phantoms, and experimental animals, mechanical devices and automated control systems for positioning temperature probes in implanted catheters and catheters laid on the skin surface have been developed. They employ stepper motor actuated roller and idler wheel drives to move the probes. Two devices incorporate positive positioners in addition to the drive rollers in order to obtain higher positioning accuracy where significant probe to catheter friction is present.

Body conformable 915 MHz microstrip array applicators for large surface area hyperthermia.

The optimal treatment with hyperthermia of superficially located tumors which involve large surface areas requires applicators which can physically conform to body contours, and locally alter their power deposition patterns to adjust for nonuniform temperature caused by tissue inhomogeneities and blood flow variations. A series of 915 MHz microstrip array applicators satisfying these criteria have been developed and clinically tested. Clinical and engineering design tradeoffs for practical devices are discussed.

Hyperthermia and radiation therapy of local-regional recurrent breast cancer: prognostic factors for response and local control of diffuse or nodular tumors.

Over the past decade, hyperthermia has been extensively studied as an adjuvant to radiation therapy in the management of local-regional metastases from adenocarcinoma of the breast. A retrospective review of our experience from July 1982 to January 1990 identified 241 fields in 89 patients which satisfied the following criteria: biopsy confirmation of recurrent or metastatic adenocarcinoma of the breast; involvement of the chest wall and/or regional lymph nodes with diffuse or nodular metastases; treatment which included radiation therapy and externally administered hyperthermia during which mechanically-mapped and/or multipoint normal tissue and intratumoral temperatures were monitored; and at least one follow-up evaluation at 3 weeks or more after completion of treatment. The majority of fields were in patients who had extensive prior treatment including radiation therapy (68%), chemotherapy (86%), and hormonal therapy (58%).

Interstitial 192Ir flexible catheter radiofrequency hyperthermia treatments of head and neck and recurrent pelvic carcinomas.

Since September 1983, five patients with head and neck cancers and five patients with pelvic or perineal recurrences of colorectal neoplasms received 192Ir interstitial implants through flexible afterloading catheters that were modified to allow RF hyperthermia treatments of the tumor within 1 hr pre- and post-brachytherapy. Local control in the implant volume was obtained in three of the patients with head and neck cancers (base tongue--2/4; floor of mouth--1/1) with follow-up of 9 to 42 months. Two patients had local recurrences after disease-free periods of 8 and 24 months.