title: Radiotherapy of Langerhans' Cell Histiocytosis : Results and Implications of a National Patterns-of-Care Study.
abstract: OBJECTIVE
  This patterns-of-care study was performed to define the current clinical experience with radiotherapy of Langerhans' cell histiocytosis in adults in Germany and to define open questions resulting from this study.
  
  
  METHODS
  A standardized questionnaire was sent to 198 German radiotherapy institutions. Data about patient characteristics, stage of disease, practice and fractionation of radiotherapy, outcome of therapy, etc. were systematically evaluated. 123 of 198 institutions answered the complete questionnaire (62.1%).
  
  
  RESULTS
  Only 23 of the 123 institutions (18.7%) reported experience with radiotherapy of Langerhans' cell histiocytosis of adults. 18 institutions with 98 patients were evaluable. The majority of patients (72 of 98) was treated on a linear accelerator. The median single dose of radiotherapy was 2 Gy, while the median total dose was 24 Gy. 81 of 89 evaluable patients (91%) reached a local control of the treated lesion(s), 69 of those had a complete remission. Eight of 89 patients (9%) developed an in-field recurrence. 87.8% of patients experienced no acute and 97% of patients no late side effects of radiotherapy.
  
  
  CONCLUSIONS
  Clinical experience with radiotherapy of Langerhans' cell histiocytosis in adults in Germany is still very limited. Nevertheless, the clinical results-with high remission and local control rates-confirm the effectiveness of radiotherapy in the multidisciplinary treatment of this disease. Due to the small number of patients in this study despite higher incidence rates, the knowledge of this disease has to be multiplied in Germany. Future patients should be systematically included into a prospective radiotherapy registry.
authors.affiliation: Department of Radiotherapy and Radiation Oncology, Alfried Krupp Krankenhaus, Alfried-Krupp-Strasse 21, 45117 Essen, Germany. thomas.olschewski@uni-duisburg-essen.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Olschewski
authors.forename: Michael Heinrich
authors.initials: MH
authors.lastname: Seegenschmiedt
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003037:Cobalt Radioisotopes / Q000627:therapeutic use; D019583:Dose Fractionation, Radiation; D004583:Electrons / Q000627:therapeutic use; D005858:Germany; D019538:Health Care Surveys; D006646:Histiocytosis, Langerhans-Cell / Q000532:radiotherapy*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D010315:Particle Accelerators; D017785:Photons / Q000627:therapeutic use; D011867:Radioisotope Teletherapy; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012008:Recurrence; D012074:Remission Induction; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D003037:Cobalt Radioisotopes