Dosimetric analysis and clinical outcomes in CT-based mould brachytherapy in early oral cancers in patients unfit for surgery

Abstract

PurposeBrachytherapy in the oral cavity is an important alternative to conventional treatment, and provides a high localized dose and short overall treatment time. A rapid fall of dose beyond radioactive source makes it possible for increased tumour control and sparing surrounding tissue, while short overall treatment duration reduces risk of tumour repopulation. Moulds are fabricated to hold the catheters in position as closely as possible to tumour surface to provide adequate dose coverage of tumour volume and increase distance to other normal surrounding structures. Image based planning and dose optimisation help in better defining target volume and dose coverage.Material and methodsA retrospective analysis of patients of early squamous cell carcinomas of lip and buccal mucosa from September 2011 to June 2014 to study response to mould brachytherapy. Double plane moulds were prepared for all lip cancer cases and single plane for buccal mucosa cases. Patients are being followed up till disease recurrence. In this study evaluation was done of the technique used, planning details, response to therapy, and reactions encountered.ResultsNine patients treated by mould therapy were reviewed; seven cases were of lip and two of buccal mucosal cancers. Dose delivered ranged from 12.5-48 Gy in fraction sizes of 2.5-3.5 Gy. Equivalent dose in 2 Gy fractions (EQD2) ranged from 18-64 Gy. Maximum dose to organs at risk (OAR) was 91% of prescribed dose. Local mucositis was only reaction in all cases, which resolved in 3-6 weeks. Median follow-up was 19 months. Eight out of nine patients are in remission at a minimum of 7 months (1 case, rest over 14 months) post therapy and only patient had nodal recurrence at 18 months.ConclusionsMould therapy is an effective treatment method for selected early and superficial squamous cell carcinomas of the oral cavity, although indications are limited.

Squamous Cell and Adenoid Cystic Carcinoma Collision Tumor of the Soft Palate Treated with Surface Mold Brachytherapy

“…External beam radiotherapy may be used to address this. However, in our patient, the tumor was small in size, was located superficially and there was no perineural invasion, so we felt comfortable using brachytherapy [7,8,[15][16][17][18][19]. The patient tolerated the procedure well with only grade two acute mucositis of the soft palate.…”

“…The radiation dose to the normal tissues can be lowered by this method in select cases [15][16][17]. When tumors are technically accessible and superficially-located, surface mold brachytherapy technique may be utilized in oral and oropharyngeal cancers [7,8,18,19].…”

A dosimetric study of electron beam therapy vs. high-dose-rate mould brachytherapy in adjuvant treatment of non-melanoma skin carcinomas of the head and neck region

“…Experiences of using custom mould brachytherapy are also scarce. A few studies have used them for treatment of skin cancers and the results have been promising, compared to other modes of radiation delivery [13,15,22,23,24]. In a few studies, 3D planning based custom mould brachytherapy was used and they showed very good dose distribution with respect to PTV coverage and OAR sparing.…”

High-dose-rate brachytherapy in severe trismus: Making it happen!

“…Brachytherapy has been widely employed as a salvage or definitive modality in recurrent and/or localized early lesions, respectively [ 1 ]. In recent years, with the evolution of new techniques, high-dose-rate brachytherapy (HDR-BT) is usually preferred as it is an outpatient-based procedure, which does not require hospitalization and reduces radiation safety concerns [ 2 , 3 ]. For sites within head and neck region like oral cavity and oropharynx, brachytherapy provides an effective alternative especially when surgery is morbid or not possible [ 4 ].…”

“…For sites within head and neck region like oral cavity and oropharynx, brachytherapy provides an effective alternative especially when surgery is morbid or not possible [ 4 ]. Effective inter-disciplinary approach helps in fabrication of customized radiation-carrier prosthesis, which enables accurate dose delivery with excellent dose distribution [ 2 ].…”