ABSTRACT
The authors have developed a new inexpensive precious metal alloy plaque for use in customized iodine-125 plaque therapy. Each plaque is formed from two flat circular gold/palladium foils which are used in dental crown work. Using a simple manual mechanism, the two forms are stamped over a customized acrylic die shaped to the dimensions of the tumor base plus a 2-mm margin. Completed plaques consist of a back wall, a 2-mm side wall, and a 1.5-mm wide lip with holes for suture placement. Advantages include: simple construction from inexpensive components, customized shape, and iodine seeds that are readily visible on plane radiographs.
Subject(s)
Brachytherapy/methods , Choroid Neoplasms/radiotherapy , Melanoma/radiotherapy , Equipment Design , Iodine RadioisotopesABSTRACT
One hundred and six patients with locally advanced cancers of the head and neck were treated with neutrons at the Fermilab Neutron Therapy Facility. Of these, 44 patients were previously untreated, 33 were recurrent following attempted surgery and 29 patients had previously received a full course of radiation therapy with conventional radiation. Results were analyzed to study the influence of stage, previous management, site of origin and tumor histology on local control of the disease. The most significant factor determining the outcome in this series of patients is the histological type. For epidermoid carcinoma, long term local control was achieved in 17/35 patients (49%) in the previously unirradiated group. With non-epidermoid tumors (adenocarcinoma, cylindroma, muco-epidermoid carcinoma), the local control rate was 28/39 (72%). Disease-free survival analysis also shows a survival advantage in non-epidermoid lesions treated with neutrons. It is concluded that neutron beam therapy may probably be the treatment of choice for non-resectable or recurrent non-epidermoid cancers of the head and neck and requires a clinical trial to establish this observation.
Subject(s)
Carcinoma, Squamous Cell/radiotherapy , Head and Neck Neoplasms/radiotherapy , Radiotherapy, High-Energy , Adenocarcinoma/radiotherapy , Carcinoma/radiotherapy , Carcinoma, Adenoid Cystic/radiotherapy , Fast Neutrons/therapeutic use , Head and Neck Neoplasms/mortality , Humans , Neoplasm Recurrence, LocalABSTRACT
Specific capillary blood flow and small-vessel pathology in animal tumors (rhabdomyosarcoma BA-1112) of WAG/Rij rats were examined following local tumor heating to 40-44.5 degrees C. Blood flow in tumors heated to 40-41 degrees C for 40 minutes was reduced initially by about 50%, but returned to near preheating values within 72 hours, consistent with the histopathological observations indicating small-vessel dilation and temporary congestion. The application of hyperthermia greater than 43 degrees C (for 40 minutes) resulted in the virtual elimination of capillary blood flow, consistent with pathological findings of widespread vessel rupture and hemorrhage in this temperature range.
