Correlation between dose to the pharyngeal constrictors and patient quality of life and late dysphagia following chemo-IMRT for head and neck cancer

Dysphagia after definitive radiotherapy for head and neck cancer. Correlation of dose-volume parameters of the pharyngeal constrictor muscles

BACKGROUND

Dysphagia is a complication of head and neck cancer patients undergoing radiotherapy (RT). We analysed frequency and severity of swallowing dysfunction and correlated these findings with dose-volume histograms (DVHs) of the pharyngeal constrictor muscles.

METHODS

A total of 50 patients treated by radical RT were enrolled. DVHs of constrictor muscles were correlated with acute and late dysphagia and with the items of three quality of life questionnaires.

RESULTS

Mean dose to superior and middle constrictor muscles (SCM, MCM), partial volume of SCM and MCM receiving a dose ≥ 50 Gy dose to the whole constrictor muscles ≥ 60 Gy and tumour location were associated to late dysphagia at univariate analysis. Mean dose to the MCM was the only statistically significant predictor of late dysphagia at the multivariable analysis.

CONCLUSION

The study shows a significant relationship between long-term dysphagia and mean doses to SCM, MCM, whole constrictor muscles, and oropharyngeal tumour. This finding suggests a potential advantage in reducing the RT dose to swallowing structures to avoid severe dysphagia.

Treatment of hypopharyngeal carcinoma with primary chemoradiotherapy: functional morbidity

PURPOSE OF REVIEW

This review aims at unravelling the medical literature which has reported on the treatment of 'larynx preserving' chemoradiotherapy strategies and separating the treatment sites, larynx and hypopharynx, from each other and reporting on the adverse effects and functional outcomes of patients with hypopharyngeal cancer.

RECENT FINDINGS

The literature reports on the treatment of advanced laryngeal and hypopharyngeal cancer with chemoradiotherapy together as a 'common cancer site'. Although the chemotherapeutic drugs affect the tumour and the normal tissues similarly in both the larynx and hypopharynx, their effects on the patient groups are different, mainly affecting swallow, airway protection mechanisms and voice/speech to a greater or lesser extent. Pretreatment symptoms and function should be documented subjectively and objectively prior to commencing nonsurgical treatment. Hypopharyngeal cancer should be reported separately, and preferably stratified into the three subsites, according to the T stage of disease rather than TNM stage. Equipment for such testing and the process for such documentation are available in most clinical areas, worldwide.

SUMMARY

Future analysis relies on the conscientious monitoring of adverse effects of all treatment modalities and an assessment of function as well as quality of life impact on the patient. Thus, the specialty can make informed decisions on the most appropriate and most suitable mode of treatment for individual patients based upon their tumour, their preoperative organ function, their likely future organ function and the likelihood of cure.

Clinical evaluation of intensity-modulated radiotherapy for head and neck cancers

Radiotherapy and surgery are the principal curative modalities in treatment of head and neck cancer. Conventional two-dimensional and three-dimensional conformal radiotherapy result in significant side effects and altered quality of life. Intensity-modulated radiotherapy (IMRT) can spare the normal tissues, while delivering a curative dose to the tumour-bearing tissues. This article reviews the current role of IMRT in head and neck cancer from the point of view of normal tissue sparing, and also reviews the current published literature by individual head and neck cancer subsites. In addition, we briefly discuss the role of image guidance in head and neck IMRT, and future directions in this area.

Emerging understanding of dosimetric factors impacting on dysphagia and nutrition following radiotherapy for oropharyngeal cancer

BACKGROUND

Research has reported relationships between 3-dimensional (3D) radiation dose to head and neck structures and consequential swallowing/nutritional outcomes. However, this evidence is preliminary. The current study aimed to identify which reported dose constraints identified functional impairment at 6 months posttreatment.

METHODS

Dose constraints with reported relationships to swallowing and nutrition were identified through a systematic literature review. Dose-volume histograms for 12 patients with T1-T3 oropharyngeal cancer treated with 3D conformal radiotherapy determined dosages delivered to specific structures. Doses were examined in relation to published dose constraints and the swallowing and nutritional outcomes at 6 months posttreatment.

RESULTS

In all, 66% of the reported mean, maximum, and partial doses to 8 structures correctly identified swallowing and nutrition outcomes at 6 months.

CONCLUSION

The relationships observed between known dosimetric constraints and functional outcomes highlight the potential for dosimetric data to assist in prognosis and treatment. Systematic research is required to refine dosimetric parameters and the impact on functional outcomes.

Predictive modelling for swallowing dysfunction after primary (chemo)radiation: results of a prospective observational study

BACKGROUND AND PURPOSE

The purpose of this large multicentre prospective cohort study was to identify which dose volume histogram parameters and pre-treatment factors are most important to predict physician-rated and patient-rated radiation-induced swallowing dysfunction (RISD) in order to develop predictive models for RISD after curative (chemo) radiotherapy ((CH) RT).

MATERIAL AND METHODS

The study population consisted of 354 consecutive head and neck cancer patients treated with (CH) RT. The primary endpoint was grade 2 or more swallowing dysfunction according to the RTOG/EORTC late radiation morbidity scoring criteria at 6 months after (CH) RT. The secondary endpoints were patient-rated swallowing complaints as assessed with the EORTC QLQ-H&N35 questionnaire. To select the most predictive variables a multivariate logistic regression analysis with bootstrapping was used.

RESULTS

At 6 months after (CH) RT the bootstrapping procedure revealed that a model based on the mean dose to the superior pharyngeal constrictor muscle (PCM) and mean dose to the supraglottic larynx was most predictive. For the secondary endpoints different predictive models were found: for problems with swallowing liquids the most predictive factors were the mean dose to the supraglottic larynx and radiation technique (3D-CRT versus IMRT). For problems with swallowing soft food the mean dose to the middle PCM, age (18-65 versus >65 years), tumour site (naso/oropharynx versus other sites) and radiation technique (3D-CRT versus IMRT) were the most predictive factors. For problems with swallowing solid food the most predictive factors were the mean dose to the superior PCM, the mean dose to the supraglottic larynx and age (18-65 versus >65 years). And for choking when swallowing the V60 of the oesophageal inlet muscle and the mean dose to the supraglottic larynx were the most predictive factors.

CONCLUSIONS

Physician-rated and patient-rated RISD in head and neck cancer patients treated with (CH) RT cannot be predicted with univariate relationships between the dose distribution in a single organ at risk and an endpoint. Separate predictive models are needed for different endpoints and factors other than dose volume histogram parameters are important as well.

Delineation of organs at risk involved in swallowing for radiotherapy treatment planning

BACKGROUND AND PURPOSE

Radiotherapy, alone or combined with chemotherapy, is a treatment modality used frequently in head and neck cancer. In order to report, compare and interpret the sequelae of radiation treatment adequately, it is important to delineate organs at risk (OARs) according to well-defined and uniform guidelines. The aim of this paper was to present our institutional Computed Tomography (CT)-based delineation guidelines for organs in the head and neck at risk for radiation-induced swallowing dysfunction (SWOARs).

MATERIAL AND METHODS

After analyses of the human anatomy of the head and neck area and literature review, CT-based guidelines for delineation of the most relevant SWOARs were described by a panel of experts.

RESULTS AND CONCLUSIONS

This paper described institutional guidelines for the delineation of potential SWOARs, accompanied by CT-based illustrations presenting examples of the delineated structures and their corresponding anatomic borders. This paper is essential to ensure adequate interpretation of future reports on the relationship between dose distribution in these SWOARs and different aspects of post-treatment swallowing dysfunction.

Correlating computed tomography perfusion changes in the pharyngeal constrictor muscles during head-and-neck radiotherapy to dysphagia outcome

PURPOSE

To measure changes in perfusion of the pharyngeal constrictor muscles (PCM) using CT perfusion (CTP) imaging during a course of definitive radiotherapy (RT) in head-and-neck cancer (HNC) patients and correlate with dysphagia outcome after RT.

METHODS AND MATERIALS

Fifteen HNC patients underwent CTP imaging of the PCM at baseline and Weeks 2, 4, and 6 during RT and 6 weeks after RT. Blood flow and blood volume were measured in the PCM, and percentage change from baseline scan was determined. A single physician-based assessment of dysphagia was performed every 3 months after RT using the Common Terminology Criteria for Adverse Events, version 3.0 grading system.

RESULTS

With a median follow-up of 28 months (range, 6-44 months), Grade 3 dysphagia was present in 7 of 15 patients, and 8 patients experienced Grade 0-2 dysphagia. The CTP parameters at Week 2 of RT demonstrated an increase in mean PCM blood flow of 161.9% vs. 12.3% (p = 0.007) and an increase in mean PCM blood volume of 96.6% vs. 8.7% (p = 0.039) in patients with 6-month post-RT Grade 3 dysphagia and Grade 0-2 dysphagia, respectively. On multivariate analysis, when adjusting for smoking history, tumor volume, and baseline dysphagia status, an increase in blood flow in the second week of RT was significant for 3- and 6-month Grade 3 dysphagia (p < 0.05).

CONCLUSIONS

Perfusion changes in the PCM during Week 2 of RT in the PCM may predict the severity of dysphagia after HNC RT.

Intensity modulated radiotherapy (IMRT) in the management of locally advanced oropharyngeal squamous cell carcinomata (SCC): disease control and functional outcome using the therapy outcome measure (TOM) score--report from a single U.K. institution

Introduction

This paper evaluates tumour control and toxicity especially in relation to swallowing dysfunction in those patients with locally advanced oropharyngeal squamous cell carcinoma who have undergone either primary chemo-radiation or post-operative parotid sparing IMRT. The TOM scoring system was used to assess dysphagia.

Methods

All patients with locally advanced (stage 3/4) squamous cell oropharyngeal cancer and who required either primary or post-operative RT were identified. Toxicity was recorded prospectively. The TOM score (0-5 where 5 indicates that the patient is able to eat a normal diet and 0-2 varying degrees of enteral feeding dependency), weights and trismus was recorded immediately prior to and following radiotherapy.

Results

24 patients were identified between 1/2003 and 11/2007. Median weight loss during radiotherapy was 9 kg. All but one patient had a gastrostomy (RIG) tube inserted prophylactically. With a mean follow-up of 37.1 months, 62.5% of pts had a TOM score of 5, 12.5% scored 3, 8% scored and 17% scored 0-2.. For those patients whose swallowing function did recover, it took on average 8.7 months. 15% patients experienced trismus secondary to radiotherapy. 2 year overall survival was 92% and disease specific survival 96%.

Conclusion

Excellent disease control with intensified schedules of radiotherapy with IMRT has been achieved in this patient population. Intermediate toxicity is significant but with longer follow-up, dysphagia continues to improve with 75% of patients not requiring any form of enteral or oral supplementation.