title: A clinical concept for interfractional adaptive radiation therapy in the treatment of head and neck cancer.
abstract: OBJECTIVE
  To present an approach to fast, interfractional adaptive RT in intensity-modulated radiation therapy (IMRT) of head and neck tumors in clinical routine. Ensuring adequate patient position throughout treatment proves challenging in high-precision RT despite elaborate immobilization. Because of weight loss, treatment plans must be adapted to account for requiring supportive therapy incl. feeding tube or parenteral nutrition without treatment breaks.
  
  
  METHODS
  In-room CT position checks are used to create adapted IMRT treatment plans by stereotactic correlation to the initial setup, and volumes are adapted to the new geometry. New IMRT treatment plans are prospectively created on the basis of position control scans using the initial optimization parameters in KonRad without requiring complete reoptimization and thus facilitating quick replanning in daily routine. Patients treated for squamous cell head and neck cancer (SCCHN) in 2006-2007 were evaluated as to necessity/number of replannings, weight loss, dose, and plan parameters.
  
  
  RESULTS
  Seventy-two patients with SCCHN received IMRT to the primary site and lymph nodes (median dose 70.4 Gy). All patients received concomitant chemotherapy requiring supportive therapy by feeding tube or parenteral nutrition. Median weight loss was 7.8 kg, median volume loss was approximately 7%. Fifteen of 72 patients required adaptation of their treatment plans at least once. Target coverage was improved by up to 10.7% (median dose). The increase of dose to spared parotid without replanning was 11.7%. Replanning including outlining and optimization was feasible within 2 hours for each patient, and treatment could be continued without any interruptions.
  
  
  CONCLUSIONS
  To preserve high-quality dose application, treatment plans must be adapted to anatomical changes. Replanning based on position control scans therefore presents a practical approach in clinical routine. In the absence of clinically usable online correction methods, this approach allows significant improvement of target volume coverage and continuous parotid sparing without treatment delays.
authors.affiliation: Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany. Alexandra.Jensen@med.uniheidelberg.de
authors.forename: Alexandra D
authors.initials: AD
authors.lastname: Jensen
authors.forename: Simeon
authors.initials: S
authors.lastname: Nill
authors.forename: Peter E
authors.initials: PE
authors.lastname: Huber
authors.forename: Rolf
authors.initials: R
authors.lastname: Bendl
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
authors.forename: Marc W
authors.initials: MW
authors.lastname: Münter
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D016190:Carboplatin / Q000008:administration & dosage; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D000068818:Cetuximab; D059248:Chemoradiotherapy / Q000379:methods; D002945:Cisplatin / Q000008:administration & dosage; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007103:Immobilization / Q000379:methods; D059351:Organ Sparing Treatments / Q000379:methods; D058958:Organs at Risk / Q000000981:diagnostic imaging; D010288:Parenteral Nutrition / Q000295:instrumentation; D010306:Parotid Gland; D056888:Patient Positioning / Q000379:methods; D011859:Radiography; D016499:Radioimmunotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D015431:Weight Loss
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D016190:Carboplatin; D000068818:Cetuximab; D002945:Cisplatin