title: Prediction model to predict critical weight loss in patients with head and neck cancer during (chemo)radiotherapy.
abstract: OBJECTIVE
  Patients with head and neck cancer (HNC) frequently encounter weight loss with multiple negative outcomes as a consequence. Adequate treatment is best achieved by early identification of patients at risk for critical weight loss. The objective of this study was to detect predictive factors for critical weight loss in patients with HNC receiving (chemo)radiotherapy ((C)RT).
  
  
  METHODS
  In this cohort study, 910 patients with HNC were included receiving RT (±surgery/concurrent chemotherapy) with curative intent. Body weight was measured at the start and end of (C)RT. Logistic regression and classification and regression tree (CART) analyses were used to analyse predictive factors for critical weight loss (defined as >5%) during (C)RT. Possible predictors included gender, age, WHO performance status, tumour location, TNM classification, treatment modality, RT technique (three-dimensional conformal RT (3D-RT) vs intensity-modulated RT (IMRT)), total dose on the primary tumour and RT on the elective or macroscopic lymph nodes.
  
  
  RESULTS
  At the end of (C)RT, mean weight loss was 5.1±4.9%. Fifty percent of patients had critical weight loss during (C)RT. The main predictors for critical weight loss during (C)RT by both logistic and CART analyses were RT on the lymph nodes, higher RT dose on the primary tumour, receiving 3D-RT instead of IMRT, and younger age.
  
  
  CONCLUSIONS
  Critical weight loss during (C)RT was prevalent in half of HNC patients. To predict critical weight loss, a practical prediction tree for adequate nutritional advice was developed, including the risk factors RT to the neck, higher RT dose, 3D-RT, and younger age.
authors.affiliation: Department of Nutrition and Dietetics, Internal Medicine, VU University Medical Center Amsterdam, PO Box 7057, 1007 MB Amsterdam, The Netherlands; Faculty of Health, Nutrition and Sport, The Hague University of Applied Sciences, Joh. Westerdijkplein 75, 2521EN The Hague, The Netherlands. Electronic address: j.langius@vumc.nl.
authors.forename: Jacqueline A E
authors.initials: JA
authors.lastname: Langius
authors.affiliation: Department of Health Science, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
authors.forename: Jos
authors.initials: J
authors.lastname: Twisk
authors.affiliation: Department of Nutrition and Dietetics, Internal Medicine, VU University Medical Center Amsterdam, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
authors.forename: Martine
authors.initials: M
authors.lastname: Kampman
authors.affiliation: Department of Radiation Oncology, VU University Medical Center Amsterdam, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
authors.forename: Patricia
authors.initials: P
authors.lastname: Doornaert
authors.affiliation: Department of Internal Medicine, VU University Medical Center Amsterdam, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
authors.forename: Mark H H
authors.initials: MH
authors.lastname: Kramer
authors.affiliation: Department of Nutrition and Dietetics, Internal Medicine, VU University Medical Center Amsterdam, PO Box 7057, 1007 MB Amsterdam, The Netherlands; Department of Nutrition and Dietetics, Amsterdam University of Applied Sciences, Dr. Meurerlaan 8, 1067 SM Amsterdam, The Netherlands.
authors.forename: Peter J M
authors.initials: PJ
authors.lastname: Weijs
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center Amsterdam, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
authors.forename: C René
authors.initials: CR
authors.lastname: Leemans
mesh_terms: D000368:Aged; D000465:Algorithms; D003131:Combined Modality Therapy / Q000009:adverse effects*; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy* / Q000628:therapy; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*
keywords: Chemoradiotherapy; Head and neck cancer; Malnutrition; Nutrition; Oral cancer; Radiation; Weight loss