Fractionated high dose rate brachytherapy moulds--a precise treatment for carcinoma of the pinna.

Abstract

The aim of this paper is to describe a fractionated high dose rate brachytherapy procedure for the treatment of small superficial cancers of the pinna and to report the outcome in a small series of patients. Thirteen patients with superficial cancers of the pinna, not invading cartilage, have been treated and in the majority of cases the tumour thickness was determined by a transdermal ultrasound measurement. For the single-plane moulds the prescribed surface dose was 45 Gy in eight fractions over 5 days and the moulds were constructed such that the full thickness of the disease, as determined by the ultrasound measurement, would lie within the 80% isodose surface. One case was treated with a sandwich mould and in this case the dose was reduced to 42.5 Gy. The treatment machine was a high dose rate microselectron, which contains a single stepping iridium source. The radiation reactions were of moderate severity, but were limited to the high dose volume. In all cases there was complete tumour resolution and rapid healing occurred leaving a barely perceptible scar. There were no recurrences over a minimum follow-up time of 18 months and there were no late radiation complications in this period. The treatment of superficial carcinoma of the pinna by means of HDR moulds is a safe and reliable technique. In this small series of patients there was total tumour control with excellent cosmesis.