Sparing the Hippocampus in Prophylactic Cranial Irradiation Using Three Different Linear Accelerators: A Comparative Study.

Autor:	Giakoumettis G; Medical Physics and Digital Innovation Laboratory, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, GRC., Gkantaifi A; Radiation Oncology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, GRC.; Radiation Oncology, Theagenio Cancer Hospital of Thessaloniki, Thessaloniki, GRC., Giakoumettis D; Neurosurgery, Agios Savvas, General Anticancer-Oncological Hospital of Athens, Athens, GRC., Papanastasiou E; Medical Physics and Digital Innovation Laboratory, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, GRC., Plataniotis G; Radiation Oncology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, GRC., Misailidou D; Radiation Oncology, Interbalkan European Medical Center of Thessaloniki, Thessaloniki, GRC., Kouskouras K; Radiology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, GRC., Bamidis PD; Medicine, Aristotle University of Thessaloniki, Thessaloniki, GRC., Siountas A; Medical Physics and Digital Innovation Laboratory, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, GRC.
Jazyk:	angličtina
Zdroj:	Cureus [Cureus] 2024 Jun 25; Vol. 16 (6), pp. e63137. Date of Electronic Publication: 2024 Jun 25 (Print Publication: 2024).
DOI:	10.7759/cureus.63137
Abstrakt:	Hippocampus protection, as an organ at risk in brain radiotherapy, might protect patients' quality of life. Prophylactic cranial irradiation (PCI) has been used traditionally in small cell lung cancer (SCLC) patients as it increases survival. This study aimed to discover the contributing parameters for a successful PCI with simultaneous protection of the hippocampus by using three different treatment machines. For this purpose, treatment plans were generated for 45 SCLC patients using three half-arcs in three linear accelerators (LINACs; Elekta Infinity, Synergy, and Axesse; Elekta Ltd, Stockholm, Sweden) with different radiation field sizes and multileaf collimator (MLC) leaf thickness characteristics. The prescribed dose was 25 Gy in 10 fractions. Thresholds for the hippocampus were calculated based on the Radiation Therapy Oncology Group 0933 dose constraints. The planning and treatment system templates were common to all three LINACs. Plan evaluation was based on the dosimetric target coverage by the 95% isodose, the maximum dose of the plan, the conformity index (CI), the degree of plan modulation (MOD), and the patient-specific quality assurance (QA) pass rate. The mean target coverage was highest for Infinity (97.3%), followed by Axesse (96.6%) and Synergy (95.5%). The mean maximum dose was higher for Synergy (27.5 Gy), followed by Infinity (27.0 Gy) and Axesse (26.9 Gy). Axesse plans had the highest CI (0.93), followed by Infinity (0.91) and Synergy (0.88). Plan MOD was lower for Synergy (2.88) compared with Infinity (3.07) and Axesse (3.69). Finally, patient-specific QA was successful in all Infinity plans, in all but one Synergy plan, and in 17/45 Axesse plans, as was expected from the field size in that treatment unit. Based on overall performance, the most favorable combination of target coverage, hippocampus sparing, and plan deliverability was obtained with the LINAC, which has the largest field opening and thinnest MLC leaves. Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. School of Medicine of Aristotle University of Thessaloniki issued approval 7149/28-6-2019. Patients who were eligible received written informed consent to store their anonymized data and publish the study results. If the patient could not give written informed consent (e.g., due to aphasia or altered consciousness state), it was asked for from the patient's legal representative. In the event that the patient withdraws their permission, the data will not be used. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work. (Copyright © 2024, Giakoumettis et al.)
Databáze:	MEDLINE
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