Physiological changes to the swallowing mechanism following (Chemo)radiotherapy for head and neck cancer: a systematic review

Emerging research suggests that preventative swallowing rehabilitation, undertaken before or during (chemo)radiotherapy ([C]RT), can significantly improve early swallowing outcomes for head and neck cancer (HNC) patients. However, these treatment protocols are highly variable. Determining specific physiological swallowing parameters that are most likely to be impacted post-(C)RT would assist in refining clear targets for preventative rehabilitation. Therefore, this systematic review (1) examined the frequency and prevalence of physiological swallowing deficits observed post-(C)RT for HNC, and (2) determined the patterns of prevalence of these key physiological deficits over time post-treatment. Online databases were searched for relevant papers published between January 1998 and March 2013. A total of 153 papers were identified and appraised for methodological quality and suitability based on exclusionary criteria. Ultimately, 19 publications met the study’s inclusion criteria. Collation of reported prevalence of physiological swallowing deficits revealed reduced laryngeal excursion, base-of-tongue (BOT) dysfunction, reduced pharyngeal contraction, and impaired epiglottic movement as most frequently reported. BOT dysfunction and impaired epiglottic movement showed a collective prevalence of over 75 % in the majority of patient cohorts, whilst reduced laryngeal elevation and pharyngeal contraction had a prevalence of over 50 %. Subanalysis suggested a trend that the prevalence of these key deficits is dynamic although persistent over time. These findings can be used by clinicians to inform preventative intervention and support the use of specific, evidence-based therapy tasks explicitly selected to target the highly prevalent deficits post-(C)RT for HNC

Reduction of the dose to the elective neck in head and neck squamous cell carcinoma, a randomized clinical trial using intensity modulated radiotherapy (IMRT). Dosimetrical analysis and effect on acute toxicity

Background and purpose A randomized trial was initiated to investigate whether a reduction of the dose to the elective nodal sites and the swallowing apparatus delivered by IMRT would result in a reduction of acute and late side effects without compromising tumor control. The aim of this paper is to report on dosimetrical analysis and acute toxicity. Materials & methods Two-hundred patients were randomized. In the standard arm, elective nodal volumes (PTV elect) were irradiated up to an equivalent dose of 50 Gy. In the experimental arm an equivalent dose of 40 Gy was prescribed to the PTV elect. The dose to the swallowing apparatus was kept as low as possible without compromising therapeutic PTV (PTVther) coverage. Results No significant difference was seen between both arms concerning PTV ther coverage. The median D95 of the PTVelect was significantly lower in the experimental arm (39.5 vs 49.8 Gy; p < 0.001). Concerning the organs at risk, the dose to swallowing structures and spinal cord was significantly reduced. There was no significant difference in acute toxicity. Three months after radiotherapy there was significantly less grade ≥3 dysphagia in the experimental arm (2% vs 11%; p = 0.03). With a median follow-up of 6 months no significant differences were observed in locoregional control, disease free survival or overall survival. Conclusions Using IMRT we were able to significantly reduce the dose to the PTVelect and several organs at risk without compromising PTVther coverage. This resulted in a significant reduction of severe dysphagia 3 months after radiotherapy. Further follow-up is necessary to investigate whether these observations translate into a benefit on late treatment related dysphagia without affecting treatment outcome. © 2013 Elsevier Ireland Ltd. All rights reserved

Late term tolerance in head neck cancer patients irradiated in the IMRT era

BACKGROUND: The aim was to quantify severe transient and persisting late term effects in our single institution head neck cancer (HNC) cohort treated with curatively intended intensity modulated radiation therapy (IMRT). Hypothesis was if a 2-year follow up (FU) is sufficient to estimate the long term tolerance in HNC irradiated in the IMRT era. METHODS: Between 01/2002-8/2012, 707/1211 (58%) consecutively treated IMRT patients met the inclusion criteria of a FU time >12 months and loco-regional disease control (LRC). 45% presented with loco-regionally advanced disease; 55% were referred for curative definitive IMRT (66Gy-72Gy in 30--35 fractions), 45% underwent postoperative IMRT (60-66Gy in 30--33 fractions). Systemic concomitant therapy was administered in 85%. Highly consistent treatment procedures were performed with respect to contouring processes, dose constraints, radiation schedules, and the use of systemic therapy. Grade 3/4 late term effects were prospectively assessed and analyzed with respect to subgroups at particular risk for specific late effects. RESULTS: Mean/median FU of the cohort was 41/35 months (15--124). 13% of the patients (92/707) experienced any grade 3/4 late effects (101 events in 92/707 patients), 81% in the first 12 months after radiation. 4% of all developed persisting late grade 3/4 effects (25 events in 25/707 patients). CONCLUSIONS: IMRT led to a high late term tolerance in loco-regionally disease free HNC patients. The onset of any G3/4 effects showed a plateau at 2 years. The question of the cervical vessel tolerance in disease free long time survivors is still open and currently under evaluation at our institution