Clinical Investigations Pulsed dose rate brachytherapy as the boost in combination with external beam irradiation in base of tongue cancer. Long-term results from a uniform clinical series

Abstract

PurposeTo evaluate long time outcome with regard to local tumour control, side effects and quality of life of combined pulsed dose rate (PDR) boost and hyperfractionated accelerated external beam radiotherapy (EBRT) for primary base of tongue (BOT) cancers.Material and methodsBetween 1994 and 2007, the number of 83 patients were treated with primary T1-T4 BOT cancers. Seven patients (8%) were T1-2N0 (AJCC stage I-II) and 76 (92%) patients were T1-2N+ or T3-4N0-2 (AJCC stage III-IV). The mean estimated primary tumour volume was 15.4 (1-75) cm3. EBRT was given with 1.7 Gy bid to 40.8 Gy to primary tumour and bilateral neck lymph nodes in 2.5 weeks. PDR boost of 35 Gy and a neck dissection in clinical node positive case was performed 2-3 weeks later. The patients were followed for a median of 54 (2-168) months.ResultsThe 2-, 5- and 10-years rates of actuarial local control were 91%, 89% and 85%, overall survival 85%, 65% and 44%, disease free survival 86%, 80% and 76%, respectively. The regional control rate was 95%. Six patients (7%) developed distant metastases. A dosimetric analysis showed a mean of 100% isodose volume of 58.2 (16.7-134) cm3. In a review of late complications 11 cases of minor (13%) and 5 of major soft tissue necroses (6%), as well as 6 cases of osteoradionecroses (7%) were found. The patients median subjective SOMA/LENT scoring at last follow up was as follow: grade 0 for pain and trismus, grade 1 for dysphagia and taste alteration, and grade 2 for xerostomia. Global visual-analogue-scale (VAS) scoring of quality of life was 8.ConclusionLocal and regional tumour control rate was excellent in this treatment protocol. The data shows the PDR boost as at least as effective as published continuous low dose rate (CLDR) results.

GEC-ESTRO ACROP recommendations for head & neck brachytherapy in squamous cell carcinomas: 1st update – Improvement by cross sectional imaging based treatment planning and stepping source technology

“…It has also been postulated that pulsing every second or third hour would be equivalent [12]. Long term clinical outcome data with PDR 24 pulses per day and 12 pulses per day are now available [13][14][15][16]. In contrast, when moving from LDR to HDR the total treatment dose has to be reduced depending on the dose per fraction.…”

The efficacy of iodine-125 interstitial brachytherapy for the treatment of locally advanced adenoid cystic carcinoma of the base of tongue: a non-surgical approach

“…Brachytherapy is increasingly accepted as an alternative treatment for inoperable head and neck malignant neoplasms. High-dose brachytherapy and iridium-192 ( 192 Ir) IBT were used for tongue squamous cell carcinoma [28][29][30]. To the best of our knowledge, no research on brachytherapy or 125 I was reported in ACC of the BOT.…”