Craniospinal irradiation using pencil beam Scanning: The PSI experience.
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BORIS DOI
Date of Publication
November 2024
Publication Type
Article
Division/Institute
Contributor
Bolsi, Alessandra | |
De Angelis, Claudio | |
Siewert, Dorota | |
Lomax, Antony J |
Subject(s)
Series
Physica Medica
ISSN or ISBN (if monograph)
1120-1797
Publisher
Elsevier
Language
English
Publisher DOI
PubMed ID
39393158
Description
Introduction
We present the dosimetric evaluation of craniospinal irradiation (CSI) treatments delivered with protons at Paul Scherrer Institute (PSI), with special focus on local recurrences and late toxicity outcome.
Methods
This study included 71 children, adolescents and young adults (c-AYA), who received or intended to receive (3 patients, pts) CSI using PBS-PT at PSI between 2004 and January 2021. The most frequent primary tumours were: medulloblastoma (42 pts), ependymoma (8 pts) and germ cell tumors (6 pts). The patients were treated prone on Gantry1 (G1; 22 pts) up to 2017, and afterwards supine on Gantry2 (G2; 49 pts). Accuracy of prone vs. supine setup was evaluated. Nine patients received CSI for local failure (LF) after a first course of local fractionated radiation therapy (RT). For 59/71 patients (excluding three patients not receiving PBS-PT CSI and nine preirradiated) CSI plans were compared considering gantry and planning technique. Detailed analysis of the full treatment (CSI and boost series) was performed for 8 patients presenting with LFs (4 of them presented also distal failure) and for selected patients presenting with late toxicity (G2 to G4) or asymptomatic radiation-induced radiological findings.
Results
Supine positioning resulted in lower systematic and random errors as compared to prone (0.25 mm and 0.4 mm systematic errors respectively for supine and prone; random errors in PA direction reduced from 1.8 mm for prone to 1.4 mm for supine).
Conclusions
LFs were not correlated with potential dose inaccuracies or lack of robustness and no correlation of toxicities to enhanced LET have been observed.
We present the dosimetric evaluation of craniospinal irradiation (CSI) treatments delivered with protons at Paul Scherrer Institute (PSI), with special focus on local recurrences and late toxicity outcome.
Methods
This study included 71 children, adolescents and young adults (c-AYA), who received or intended to receive (3 patients, pts) CSI using PBS-PT at PSI between 2004 and January 2021. The most frequent primary tumours were: medulloblastoma (42 pts), ependymoma (8 pts) and germ cell tumors (6 pts). The patients were treated prone on Gantry1 (G1; 22 pts) up to 2017, and afterwards supine on Gantry2 (G2; 49 pts). Accuracy of prone vs. supine setup was evaluated. Nine patients received CSI for local failure (LF) after a first course of local fractionated radiation therapy (RT). For 59/71 patients (excluding three patients not receiving PBS-PT CSI and nine preirradiated) CSI plans were compared considering gantry and planning technique. Detailed analysis of the full treatment (CSI and boost series) was performed for 8 patients presenting with LFs (4 of them presented also distal failure) and for selected patients presenting with late toxicity (G2 to G4) or asymptomatic radiation-induced radiological findings.
Results
Supine positioning resulted in lower systematic and random errors as compared to prone (0.25 mm and 0.4 mm systematic errors respectively for supine and prone; random errors in PA direction reduced from 1.8 mm for prone to 1.4 mm for supine).
Conclusions
LFs were not correlated with potential dose inaccuracies or lack of robustness and no correlation of toxicities to enhanced LET have been observed.
File(s)
| File | File Type | Format | Size | License | Publisher/Copright statement | Content | |
|---|---|---|---|---|---|---|---|
| 1-s2.0-S1120179724010743-main.pdf | text | Adobe PDF | 3.92 MB | Attribution (CC BY 4.0) | published |