Analysis of recurrences in patients with Head and Neck Squamous Cell Carcinoma treated with Intensity Modulated Radiation Therapy

Heemstra- de Haan, I (2013) Analysis of recurrences in patients with Head and Neck Squamous Cell Carcinoma treated with Intensity Modulated Radiation Therapy. thesis, Medicine.

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Abstract

Purpose: The introduction of Intensity Modulated Radiation Therapy (IMRT) in treating head and neck squamous cell carcinoma (HNSCC) might have an influence on the location of loco- regional recurrences (LRR). The aim of this study was to analyse loco- regional recurrence patterns in patients treated with primary IMRT for HNSCC. Methods and Materials: Between July 2007 and February 2012, 190 patients (M/F 73.7%: 26.3%) with HNSCC were treated with primary IMRT at the University Medical Centre Groningen. Median follow- up was 21.3 months (range: 1.8- 54.7). Primary tumour sites included: oral cavity (6.3%), oropharynx (41.6%), nasopharynx (4.2%), hypopharynx (13.7%) and larynx (34.2%). In almost 79% of the cases, disease had progressed to a stage III/IV cancer. If indicated, concurrent treatment consisted of chemotherapy (35.8%) or concurrent cetuximab (13.7%). The delivered radiation dose in local tumours was 70 Gy (boost) except in one patient. Regional metastasis received 70 Gy (boost), elective neck levels received 54.25 Gy. In case of LRR, the recurrent volume was delineated on the recurrent CT- scan (CT-R) and then co- registered deformably on the initial CT- scan used for treatment planning (CT-P) and the corresponding dose- distribution. Analysing location of recurrences correlated to the 95%-isodose was carried out using the volume- overlap method, in which overlap percentages between the recurrence and the 95%-isodose of the original dose- distribution are calculated and classified in- field, marginal or out- field. Marginal recurrences were further reviewed in terms of dosimetry and centre of mass (COM). Results: LRR occurred in 51 patients (26.8%) of whom 3 were excluded from this study. In the remaining 48 patients, 41 local recurrences (LR) and 45 regional recurrences (RR) developed of which 15 developed in the elective volume. Seven patients who developed LR or RR also were diagnosed with distant metastasis. Of all LR, 34 (82.9%) were in- field and 7 (17.1%) were marginal and of all RR, 40 (88.9%) were located in- field and 5 (11.9%) were marginal. No out- field recurrences were found. The COM of all 12 marginal recurrences was calculated, and based on this method 11 of them were located in- field. The dose received at the COM in the one out- field recurrence (boost volume) was 65.88 Gy. Two- and three year overall survival was 65% en 58%, respectively and loco- regional recurrence free survival in all patients was 72% and 68%, respectively. Conclusion: The initial dose delivery in recurrent tumour volumes has been adequate and the used IMRT technique is effective and sufficient in the primary treatment of HNSCC.

Item Type:	Thesis (Thesis)
Supervisor name:	Bijl, Dr. H.P. and Steenbakkers, Dr. R.J.H.M.
Faculty:	Medical Sciences
Date Deposited:	25 Jun 2020 10:42
Last Modified:	25 Jun 2020 10:42
URI:	https://umcg.studenttheses.ub.rug.nl/id/eprint/364

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