Taylor & Francis Group
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Dosimetric comparison of five different techniques for craniospinal irradiation across 15 European centers: analysis on behalf of the SIOP-E-BTG (radiotherapy working group)

Version 2 2022-04-09, 12:40
Version 1 2018-04-26, 17:07
posted on 2022-04-09, 12:40 authored by Enrica Seravalli, Mirjam Bosman, Yasmin Lassen-Ramshad, Anne Vestergaard, Foppe Oldenburger, Jorrit Visser, Efi Koutsouveli, Chryssa Paraskevopoulou, Gail Horan, Thankamma Ajithkumar, Beate Timmermann, Carolina-Sofia Fuentes, Gillian Whitfield, Thomas Marchant, Laetitia Padovani, Eloise Garnier, Lorenza Gandola, Silvia Meroni, Bianca A. W. Hoeben, Martijn Kusters, Claire Alapetite, Sandra Losa, Farid Goudjil, Henriette Magelssen, Morten Egeberg Evensen, Frank Saran, Gregory Smyth, Barbara Rombi, Roberto Righetto, Rolf-Dieter Kortmann, Geert O. Janssens

Conventional techniques (3D-CRT) for craniospinal irradiation (CSI) are still widely used. Modern techniques (IMRT, VMAT, TomoTherapy®, proton pencil beam scanning [PBS]) are applied in a limited number of centers. For a 14-year-old patient, we aimed to compare dose distributions of five CSI techniques applied across Europe and generated according to the participating institute protocols, therefore representing daily practice.

A multicenter (n = 15) dosimetric analysis of five different techniques for CSI (3D-CRT, IMRT, VMAT, TomoTherapy®, PBS; 3 centers per technique) was performed using the same patient data, set of delineations and dose prescription (36.0/1.8 Gy). Different treatment plans were optimized based on the same planning target volume margin. All participating institutes returned their best treatment plan applicable in clinic.

The modern radiotherapy techniques investigated resulted in superior conformity/homogeneity-indices (CI/HI), particularly in the spinal part of the target (CI: 3D-CRT:0.3 vs. modern:0.6; HI: 3D-CRT:0.2 vs. modern:0.1), and demonstrated a decreased dose to the thyroid, heart, esophagus and pancreas. Dose reductions of >10.0 Gy were observed with PBS compared to modern photon techniques for parotid glands, thyroid and pancreas. Following this technique, a wide range in dosimetry among centers using the same technique was observed (e.g., thyroid mean dose: VMAT: 5.6–24.6 Gy; PBS: 0.3–10.1 Gy).

The investigated modern radiotherapy techniques demonstrate superior dosimetric results compared to 3D-CRT. The lowest mean dose for organs at risk is obtained with proton therapy. However, for a large number of organs ranges in mean doses were wide and overlapping between techniques making it difficult to recommend one radiotherapy technique over another.