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Chapter 8
Tube placement policy, nutritional policy and swallowing exercises
None of the patients received prophylactic tube feeding (23). Feeding tube placement was either advised to patients or deemed necessary for treatment completion in case of excessive weight loss (> 5% of baseline body weight in three months or > 10% in six months), insufficient oral intake (< 50% of recommended daily calories and protein), dehydration or proven aspiration based on videofluoroscopy at baseline or during the course of CRT. For patients who received a feeding tube, bi-weekly consultations were planned to evaluate weight, possible side effects of the enteral nutrition and oral intake. According to Institution’s protocol, all patients were seen by a speech language pathologist and dietitian for clinical check-up and counseling before CRT. All patients were enrolled in a prophylactic swallowing exercise program before treatment (34), and all were advised to take 1.5 g/kg of protein per day and a caloric intake according to the Harris-Benedict 1984 equation with an addition of 30% for disease, up to a BMI of 30 (35).
Data collection
We collected the following variables retrospectively from the medical file: gender, age at diagnosis, comorbidity including the Adult Comorbidity Evaluation-27 (ACE-27) index, tumor site, T and N classification, general tumor (TNM) stage, pretreatment Body Mass Index (BMI), pretreatment weight loss (none, less or more than 10% over the past six months compared to baseline), and pretreatment Functional Oral Intake Scale (FOIS) (scored retrospectively when not available). The FOIS reflects the functional oral intake on a seven-point ordinal scale with a score of 7 indicating a normal diet without restrictions (36). Also, timing of feeding tube placement and duration of dependency were assessed. Prolonged dependency was defined as a tube in situ for more than ninety days after tube placement (nasogastric tube or percutaneous gastrostomy) at any time before or during CRT. This cut-off was chosen based on the consideration that after ninety days, acute local treatment-related toxicities have subsided and ongoing functional impairments can be considered chronic. Socioeconomic status (SES) was assessed by means of status scores according to postal codes with 0 being the mean status score in The Netherlands in 2017 (37). Negative and positive scores indicate SES below and above the mean, respectively.
Measurement of skeletal muscle mass
Skeletal muscle mass was measured on a routinely performed CT scan of the head and neck area using a previously described protocol (see Figure 1). A single CT slice at the level of C3 was selected for skeletal muscle mass measurement. First, the cross-sectional muscle areas (CSMA) of the paravertebral and sternocleidomastoid muscles at the level of the third cervical vertebra (C3) were segmented on the pretreatment head and neck CT scan (38). The total skeletal muscle area at the level of C3 was defined as the CSMA of the paravertebral muscles and the left and right sternocleidomastoid muscles (total CSMA). The total CSMA was then normalized for height in meters, in a similar method compared to research in other cancer types, to calculate the neck skeletal muscle index (39). Lower values of the neck SMI indicate lower skeletal muscle mass. All CT scans were segmented using Worldmatch, an in-house developed radiotherapy planning and image evaluation software tool.