Multicenter evaluation of different target volume delineation concepts in pediatric Hodgkin’s lymphoma: A case study

• Published in: Strahlentherapie und Onkologie 2012-11, Vol.188 (11), p.1025-1030
• Main Authors: Lütgendorf-Caucig, C., Fotina, I., Gallop-Evans, E., Claude, L., Lindh, J., Pelz, T., Knäusl, B., Georg, D., Pötter, R., Dieckmann, K.
• Format: Article
• Language: English
• Subjects: Adolescent; Feasibility Studies; Female; Hodgkin Disease - pathology; Hodgkin Disease - radiotherapy; Humans; Interobserver variability; Involved-node radiotherapy; Involved-node-level radiotherapy; Lymphatic Metastasis - pathology; Lymphatic Metastasis - radiotherapy; Male; Medicine; Medicine & Public Health; Neoplasm Staging; Observer Variation; Oncology; Original Article; Pediatric Hodgkin's lymphoma; Radiotherapy; Radiotherapy Planning, Computer-Assisted - methods; Target volume delineation; Tumor Burden - radiation effects
• ISSN: 0179-7158; 1439-099X; 1439-099X
• DOI: 10.1007/s00066-012-0182-4

Background and purpose In pediatric Hodgkin’s lymphoma (PHL) improvements in imaging and multiagent chemotherapy have allowed for a reduction in target volume. The involved-node (IN) concept is being tested in several treatment regimens for adult Hodgkin’s lymphoma. So far there is no consensus on the definition of the IN. To improve the reproducibility of the IN, we tested a new involved-node-level (INL) concept, using defined anatomical boundaries as basis for target delineation. The aim was to evaluate the feasibility of IN and INL concepts for PHL in terms of interobserver variability. Patients and methods The INL concept was defined for the neck and mediastinum by the PHL Radiotherapy Group based on accepted concepts for solid tumors. Seven radiation oncologists from six European centers contoured neck and mediastinal clinical target volumes (CTVs) of 2 patients according to the IN and the new INL concepts. The median CTVs, coefficient of variation (COV), and general conformity index (CI) were assessed. The intraclass correlation coefficient (ICC) for reliability of delineations was calculated. Results All observers agreed that INL is a feasible and practicable delineation concept resulting in stronger interobserver concordance than the IN (mediastinum CI INL  = 0.39 vs. CI IN  = 0.28, neck left CI INL  = 0.33; CI IN  = 0.18; neck right CI INL  = 0.24, CI IN  = 0.14). The COV showed less dispersion and the ICC indicated higher reliability of contouring for INL (ICC INL  = 0.62, p