title: Radiation therapy planning for early-stage Hodgkin lymphoma: experience of the International Lymphoma Radiation Oncology Group.
abstract: OBJECTIVE
  Early-stage Hodgkin lymphoma (HL) is a rare disease, and the location of lymphoma varies considerably between patients. Here, we evaluate the variability of radiation therapy (RT) plans among 5 International Lymphoma Radiation Oncology Group (ILROG) centers with regard to beam arrangements, planning parameters, and estimated doses to the critical organs at risk (OARs).
  
  
  METHODS
  Ten patients with stage I-II classic HL with masses of different sizes and locations were selected. On the basis of the clinical information, 5 ILROG centers were asked to create RT plans to a prescribed dose of 30.6 Gy. A postchemotherapy computed tomography scan with precontoured clinical target volume (CTV) and OARs was provided for each patient. The treatment technique and planning methods were chosen according to each center's best practice in 2013.
  
  
  RESULTS
  Seven patients had mediastinal disease, 2 had axillary disease, and 1 had disease in the neck only. The median age at diagnosis was 34 years (range, 21-74 years), and 5 patients were male. Of the resulting 50 treatment plans, 15 were planned with volumetric modulated arc therapy (1-4 arcs), 16 with intensity modulated RT (3-9 fields), and 19 with 3-dimensional conformal RT (2-4 fields). The variations in CTV-to-planning target volume margins (5-15 mm), maximum tolerated dose (31.4-40 Gy), and plan conformity (conformity index 0-3.6) were significant. However, estimated doses to OARs were comparable between centers for each patient.
  
  
  CONCLUSIONS
  RT planning for HL is challenging because of the heterogeneity in size and location of disease and, additionally, to the variation in choice of treatment techniques and field arrangements. Adopting ILROG guidelines and implementing universal dose objectives could further standardize treatment techniques and contribute to lowering the dose to the surrounding OARs.
authors: Departments of Clinical Oncology and Hematology, Rigshospitalet, University of Copenhagen, Denmark. Electronic address: dra.maraldo@gmail.com.
authors: Maja V
authors: MV
authors: Maraldo
authors: Department of Radiation Oncology, MD Anderson Cancer Center, Texas.
authors: Bouthaina S
authors: BS
authors: Dabaja
authors: Department of Oncology, University of Torino School of Medicine, Torino, Italy.
authors: Andrea R
authors: AR
authors: Filippi
authors: Department of Oncology, Christie Hospital, Manchester, United Kingdom.
authors: Tim
authors: T
authors: Illidge
authors: Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
authors: Richard
authors: R
authors: Tsang
authors: Department of Oncology, University of Torino School of Medicine, Torino, Italy.
authors: Umberto
authors: U
authors: Ricardi
authors: Departments of Clinical Oncology and Hematology, Rigshospitalet, University of Copenhagen, Denmark.
authors: Peter M
authors: PM
authors: Petersen
authors: Departments of Clinical Oncology and Hematology, Rigshospitalet, University of Copenhagen, Denmark.
authors: Deborah A
authors: DA
authors: Schut
authors: Department of Radiation Oncology, MD Anderson Cancer Center, Texas.
authors: John
authors: J
authors: Garcia
authors: Department of Oncology, Christie Hospital, Manchester, United Kingdom.
authors: Jayne
authors: J
authors: Headley
authors: Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
authors: Amy
authors: A
authors: Parent
authors: Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
authors: Benoit
authors: B
authors: Guibord
authors: Department of Oncology, University of Torino School of Medicine, Torino, Italy.
authors: Riccardo
authors: R
authors: Ragona
authors: Departments of Clinical Oncology and Hematology, Rigshospitalet, University of Copenhagen, Denmark.
authors: Lena
authors: L
authors: Specht
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001940:Breast / Q000528:radiation effects; D002173:Cancer Care Facilities / Q000592:standards; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D006321:Heart / Q000000981:diagnostic imaging / Q000528:radiation effects; D006689:Hodgkin Disease / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000528:radiation effects; D008297:Male; D008479:Mediastinal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D008875:Middle Aged; D058958:Organs at Risk / Q000000981:diagnostic imaging / Q000528:radiation effects*; D018787:Radiation Oncology / Q000592:standards*; D011859:Radiography; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000528:radiation effects; D055815:Young Adult