International Journal of Hematology and Oncology 2019, Vol 29, Num 1 Page(s): 007-013
Langerhans Cell Histiocytosis: Excellent Local Control with Low Dose Radiotherapy

Serra Arun KAMER1, Esra Korkmaz KIRAKLI2, Nazan CETINGUL3, Mehmet KANTAR3, Guray SAYDAM4, Yavuz ANACAK1

1Ege University, Faculty of Medicine, Department of Radiation Oncology, İzmir, TURKEY
2Dr Suat Seren Chest Diseases and Surgery Training Hospital, Department of Radiation Oncology, İzmir, TURKEY
3Ege University, Faculty of Medicine, Department of Pediatric Oncology, İzmir, TURKEY
4Ege University, Faculty of Medicine Department of Hematology, İzmir, TURKEY

Keywords: Langerhans cell histiocytosis, Radiotherapy, Local control
Langerhans cell histiocytosis (LCH) is a rare disorder. Uncontrolled clonal proliferation of langerhans cells leads to a diversity of clinical manifestations. Low dose Radiotherapy (RT) is used mainly for osseous manifestations as a sole treatment or in combination with surgery/chemotherapy/steroids. Altough the mechanism of action of RT is an unresolved issue, it’s usually used in adjuvant/palliative settings, also as first-line local therapy with curative intent in unresectable or resectable cases in case surgery would result in functional compromise. This study is conducted to review indications, dose-fractionation schedules, clinical characteristics and outcomes of LCH patients received local RT mainly for osseous lesions. The medical records of biopsy proven all LCH patients referred to our center and treated with RT between 2000-2016 were evaluated retrospectively. Disease-free survival (DFS), local control and side effects were defined as study end-points. There was 35 patients, 21 of them were children. At presentation 65.7% had single systemsingle bone, 20% had single system-multiple bone, 15% had multisystem disease.Soft tissue extension were detected in 16 children, 4 adults (p= 0.013).Mean radiation dose was 10.8 Gy. Median follow-up from the date of biopsy was 105 months (range= 8-204) in children and 88 (range:31-245) in adults (log rank p:0.029).Complete response rate was 97%. 11 children and 1 adult experienced relapse (p= 0.05), median interval for relapse was 9months in children, 19months in adults. The most common relapse pattern was as single system-multiple bone (58.3%). Local control was 97.1%. Median disease free survival was 85 months. Low dose local RT seems to be effective and safe in multidisciplinary management of LCH.