High-Dose-Rate Brachytherapy Boost Following External Radiotherapy in a Case of Carcinoma External Ear

Abstract

Squamous cell carcinoma of the external ear is rare and the combination of external beam radiotherapy and brachytherapy has been beneficial for tumors in this location due to the advantage of organ preservation and thereby cosmesis. The incorporation of brachytherapy allows the delivery of doses large enough for the eradication of tumor and the advantage of rapid dose fall off due to brachytherapy minimizes the radiation damage to the nearby organs at risk. Herein we report a case of elderly male with early stage squamous cell carcinoma of external ear treated with a combination of external beam radiation with brachytherapy. An eighty nine year old male reported to our hospital with the complaints of left sided ear ache the presence of some mass in the left external ear. A diagnostic Contrast enhanced Computed Tomography (CECT) scan of head and neck showed a 1.6*1.5*1.4 cm mass lesion (maximum diameter) involving anterior cartilaginous part of left external auditory canal and preauricular soft tissue, thereby staged as T2N0, stage II. Patient was planned for External Beam Radiotherapy (EBRT) using 3D CRT(Conformal Radiotherapy) technique by 6 MV photon beam to a dose of 50 Gy in 25 fractions (2 Gy/#) and following this, a gap of seven days was given and after that four fractions of HDR brachytherapy using Iridium 192 of 3 Gy/# keeping a gap of six hours between two fractions on a single day, Two flexible plastic tubes were used for radiation delivery. The size of the catheter used for radiation delivery was 6 French. Planning CT scan was taken and target volume defined as PTV and a dose of 3 Gy per fraction to a total of 4 fractions was prescribed to the target volume. The spike of intravenous site was used for fixing the plastic tube in the mould. The tumor responded ver well to radiotherapy. Brachytherapy is an effective modality to boost high risk areas without significant damage to the surrounding area. External Beam Radiotherapy in case of early stage carcinoma external auditory canal combined with brachytherapy boost can be considered as a better modality with less severe side effects and better cosmesis.