Surface applicators for high dose rate brachytherapy in AIDS-related Kaposi's sarcoma.
Int J Radiat Oncol Biol Phys
; 39(3): 769-74, 1997 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-9336161
ABSTRACT
PURPOSE:
The development of commercially available surface applicators using high dose rate remote afterloading devices has enabled radiotherapy centers to treat selected superficial lesions using a remote afterloading brachytherapy unit. The dosimetric parameters of these applicators, the clinical implementation of this technique, and a review of the initial patient treatment regimes are presented. METHODS AND MATERIALS A set of six fixed-diameter (1, 2, and 3 cm), tungsten/steel surface applicators is available for use with a single stepping-source (Ir-192, 370 GBq) high dose rate afterloader. The source can be positioned either in a parallel or perpendicular orientation to the treatment plane at the center of a conical aperture that sits at an SSD of approximately 15 mm and is used with a 1-mm thick removable plastic cap. The surface dose rates, percent depth dose, and off-axis ratios were measured. A custom-built, ceiling-mounted immobilization device secures the applicator on the surface of the patient's lesion during treatment.RESULTS:
Between November 1994, and September 1996, 16 AIDS-related Kaposi's sarcoma patients having a total of 120 lesions have been treated with palliative intent. Treatment sites were distributed between the head and neck, extremity, and torso. Doses ranged from 8 to 20 Gy, with a median dose of 10 Gy delivered in a single fraction. Treatments were well tolerated with minimal skin reaction, except for patients with lesions treated to 20 Gy who developed moderate/severe desquamation.CONCLUSION:
Radiotherapy centers equipped with a high dose rate remote afterloading unit may treat small selected surface lesions with commercially available surface applicators. These surface applicators must be used with a protective cap to eliminate electron contamination. The optimal surface dose appears to be either 10 or 15 Gy depending upon the height of the lesion.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sarcoma de Kaposi
/
Neoplasias Cutâneas
/
Braquiterapia
/
Síndrome da Imunodeficiência Adquirida
Tipo de estudo:
Etiology_studies
Limite:
Adult
/
Humans
/
Male
/
Middle aged
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article