Potential Therapeutic Improvements in Prostate Cancer Treatment Using Pencil Beam Scanning Proton Therapy with LET Optimization and Disease-Specific RBE Models

Overview

Journal Cancers (Basel)

Publisher MDPI

Specialty Oncology

Date 2024 Feb 24

PMID 38398171

Authors

Michael Vieceli

Jiyeon Park

Wen Chien Hsi

Mo Saki

Nancy P Mendenhall

Perry Johnson

Mark Artz

Affiliations

Soon will be listed here.

Abstract

Purpose: To demonstrate the feasibility of improving prostate cancer patient outcomes with PBS proton LET optimization.

Methods: SFO, IPT-SIB, and LET-optimized plans were created for 12 patients, and generalized-tissue and disease-specific LET-dependent RBE models were applied. The mean LET in several structures was determined and used to calculate mean RBEs. LET- and dose-volume histograms (LVHs/DVHs) are shown. TODRs were defined based on clinical dose goals and compared between plans. The impact of robust perturbations on LET, TODRs, and DVH spread was evaluated.

Results: LET optimization achieved statistically significant increased target volume LET of ~4 keV/µm compared to SFO and IPT-SIB LET of ~2 keV/µm while mitigating OAR LET increases. A disease-specific RBE model predicted target volume RBEs > 1.5 for LET-optimized plans, up to 18% higher than for SFO plans. LET-optimized target LVHs/DVHs showed a large increase not present in OARs. All RBE models showed a statistically significant increase in TODRs from SFO to IPT-SIB to LET-optimized plans. RBE = 1.1 does not accurately represent TODRs when using LET optimization. Robust evaluations demonstrated a trade-off between increased mean target LET and decreased DVH spread.

Conclusion: The demonstration of improved TODRs provided via LET optimization shows potential for improved patient outcomes.

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