Dosimetric Factors Associated With Long-Term Dysphagia After Definitive Radiotherapy for Squamous Cell Carcinoma of the Head and Neck
ABSTRACT Intensification of radiotherapy and chemotherapy for head-and-neck cancer may lead to increased rates of dysphagia. Dosimetric predictors of objective findings of long-term dysphagia were sought.
From an institutional database, 83 patients were identified who underwent definitive intensity-modulated radiotherapy for squamous cell carcinoma of the head and neck, after exclusion of those who were treated for a second or recurrent head-and-neck primary lesion, had locoregional recurrence at any time, had less than 12 months of follow-up, or had postoperative radiotherapy. Dosimetric parameters were analyzed relative to three objective endpoints as a surrogate for severe long-term dysphagia: percutaneous endoscopic gastrostomy (PEG) tube dependence at 12 months, aspiration on modified barium swallow, or pharyngoesophageal stricture requiring dilation.
Mean dose greater than 41 Gy and volume receiving 60 Gy (V(60)) greater than 24% to the larynx were significantly associated with PEG tube dependence and aspiration. V(60) greater than 12% to the inferior pharyngeal constrictor was also significantly associated with increased PEG tube dependence and aspiration. V(65) greater than 33% to the superior pharyngeal constrictor or greater than 75% to the middle pharyngeal constrictor was associated with pharyngoesophageal stricture requiring dilation.
Doses to the larynx and pharyngeal constrictors predicted long-term swallowing complications, even when controlled for other clinical factors. The addition of these structures to intensity-modulated radiotherapy optimization may reduce the incidence of dysphagia, although cautious clinical validation is necessary.
- SourceAvailable from: Arjen van der Schaaf
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- "The treatment of these patients with radiotherapy (RT), chemoradiation (CRT) or radiotherapy plus cetuximab (CetRT) may further affect swallowing function, eventually leading to tube feeding dependence. Incidences of tube feeding dependence at 2 years after treatment of up to 51% have been reported     . Ronis et al. showed that at 1 year after treatment, the presence of a feeding tube was the most powerful predictor of quality of life in HNC patients , thus indicating the clinical importance of preventing tube feeding dependence. "
ABSTRACT: Curative radiotherapy/chemo-radiotherapy for head and neck cancer (HNC) may result in severe acute and late side effects, including tube feeding dependence. The purpose of this prospective cohort study was to develop a multivariable normal tissue complication probability (NTCP) model for tube feeding dependence 6 months (TUBEM6) after definitive radiotherapy, radiotherapy plus cetuximab or concurrent chemoradiation based on pre-treatment and treatment characteristics.Radiotherapy and Oncology 10/2014; 113(1). DOI:10.1016/j.radonc.2014.09.013 · 4.86 Impact Factor
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- "We decided to use this publication as a reference as it was the only one dedicated to the description of SWOARs delineation guidelines and because these guidelines were actually used in a subsequent publication that reported on the development of multivariate NTCP-models for different endpoints related to dysphagia . This publication also included an overview of eight other guidelines for delineation of SWOARs that were published between 2000 and 2010        . "
ABSTRACT: Purpose To test the hypothesis that delineation of swallowing organs at risk (SWOARs) based on different guidelines results in differences in dose–volume parameters and subsequent normal tissue complication probability (NTCP) values for dysphagia-related endpoints. Materials and methods Nine different SWOARs were delineated according to five different delineation guidelines in 29 patients. Reference delineation was performed according to the guidelines and NTCP-models of Christianen et al. Concordance Index (CI), dosimetric consequences, as well as differences in the subsequent NTCPs were calculated. Results The median CI of the different delineation guidelines with the reference guidelines was 0.54 for the pharyngeal constrictor muscles, 0.56 for the laryngeal structures and 0.07 for the cricopharyngeal muscle and esophageal inlet muscle. The average difference in mean dose to the SWOARs between the guidelines with the largest difference (maxΔD) was 3.5 ± 3.2 Gy. A mean ΔNTCP of 2.3 ± 2.7% was found. For two patients, ΔNTCP exceeded 10%. Conclusions The majority of the patients showed little differences in NTCPs between the different delineation guidelines. However, large NTCP differences >10% were found in 7% of the patients. For correct use of NTCP models in individual patients, uniform delineation guidelines are of great importance.Radiotherapy and Oncology 04/2014; 111(1). DOI:10.1016/j.radonc.2014.01.019 · 4.86 Impact Factor
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- "Doses to both the GSL and IPC have been associated with late swallowing toxicity [2,11-15]. Mean doses to the GSL and IPC were reduced in the 3Dose plans, although these structures were not constrained in our planning process for either the RTOG or 3Dose plans. Further reductions should theoretically be possible in appropriate patients. "
ABSTRACT: Previous work by our group suggests smaller target volumes may result in equivalent locoregional control for head and neck cancer. We evaluated whether smaller target volumes may also result in improved normal tissue sparing. Ten patients with Stage III-IV head and neck cancer were contoured and planned according to target definitions in RTOG 0522 in a two dose level plan (RTOG), as well as a three dose level plan, using smaller target volumes and an intermediate dose prescription (3Dose). Plans were compared for coverage of targets and sparing of normal tissues The high dose target, elective nodal target, and total volume targeted were significantly smaller in 3Dose plans (p < 0.001). There was no difference in volume receiving 100% of each prescription level in RTOG or 3Dose plans. Mean dose to contralateral parotid, mandible, larynx, and inferior pharyngeal constrictor, and maximum dose to brainstem were significantly lower in 3Dose plans. There was no significant difference in maximum dose to spinal cord or volume of tissue not otherwise specified receiving 70 Gy. Smaller target volumes with the addition of an intermediate dose volume results in improved sparing of most normal tissues.Head & Neck Oncology 08/2011; 3(1):34. DOI:10.1186/1758-3284-3-34 · 3.14 Impact Factor