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Abstract Background Concomitant chemo-radiotherapy (CCRT) has become an indispensable organ, but not always function preserving treatment modality for advanced head and neck cancer. To prevent/limit the functional side effects of CCRT, special exercise programs are increasingly explored. This study presents cost-effectiveness analyses of a preventive (swallowing) exercise program (PREP) compared to usual care (UC) from a health care perspective. Methods A Markov decision model of PREP versus UC was developed for CCRT in advanced head and neck cancer. Main outcome variables were tube dependency at one-year and number of post-CCRT hospital admission days. Primary outcome was costs per quality adjusted life years (cost/QALY), with an incremental cost-effectiveness ratio (ICER) as outcome parameter. The Expected Value of Perfect Information (EVPI) was calculated to obtain the value of further research. Results PREP resulted in less tube dependency (3% and 25%, respectively), and in fewer hospital admission days than UC (3.2 and 4.5 days respectively). Total costs for UC amounted to €41,986 and for PREP to €42,271. Quality adjusted life years for UC amounted to 0.68 and for PREP to 0.77. Based on costs per QALY, PREP has a higher probability of being cost-effective as long as the willingness to pay threshold for 1 additional QALY is at least €3,200/QALY. At the prevailing threshold of €20,000/QALY the probability for PREP being cost-effective compared to UC was 83%. The EVPI demonstrated potential value in undertaking additional research to reduce the existing decision uncertainty. Conclusions Based on current evidence, PREP for CCRT in advanced head and neck cancer has the higher probability of being cost-effective when compared to UC. Moreover, the majority of sensitivity analyses produced ICERs that are well below the prevailing willingness to pay threshold for an additional QALY (range from dominance till €45,906/QALY).

Abstract Purpose To determine the variation in target delineation of nasopharyngeal carcinoma and the impact of measures to minimize this variation. Materials and methods For ten nasopharyngeal cancer patients, ten observers each delineated the Clinical Target Volume (CTV) and the CTV elective. After 3D analysis of the delineated volumes, a second delineation was performed. This implied improved delineation instructions, a combined delineation on CT and co-registered MRI, forced use of sagittal reconstructions, and an on-line anatomical atlas. Results Both for the CTV and the CTV elective delineations, the 3D SD decreased from Phase 1 to Phase 2, from 4.4 to 3.3 mm for the CTV and from 5.9 to 4.9 mm for the elective. There was an increase agreement, where the observers intended to delineate the same structure, from 36 to 64 surface % (p = 0.003) for the CTV and from 17 to 59% (p = 0.004) for the elective. The largest variations were at the caudal border of the delineations but these were smaller when an observer utilized the sagittal window. Hence, the use of sagittal side windows was enforced in the second phase and resulted in a decreased standard deviation for this area from 7.7 to 3.3 mm (p = 0.001) for the CTV and 7.9 to 5.6 mm (p = 0.03) for the CTV elective. Discussion Attempts to decrease the variation need to be tailored to the specific causes of the variation. Use of delineation instructions multimodality imaging, the use of sagittal windows and an on-line atlas result in a higher agreement on the intended target.