The hot-to-cold spot quotient for SAR-based treatment planning in deep microwave hyperthermia
Artikel i vetenskaplig tidskrift, 2022

BACKGROUND: A necessary precondition for a successful microwave hyperthermia (HT) treatment delivered by phased arrays is the ability of the HT applicator to selectively raise the temperature of the entire tumor volume. SAR-based treatment plan (HTP) optimization methods exploit the correlation between specific absorption rate (SAR) and temperature increase in order to determine the set of steering parameters for optimal focusing, while allowing for lower model complexity. Several cost functions have been suggested in the past for this optimization problem. However, their correlation with high and homogeneous tumor temperatures remains sub-optimal in many cases. Previously, we proposed the hot-to-cold spot quotient (HCQ) as a novel cost function for SAR-based HTP optimization and showed its potential to address these issues. MATERIALS AND METHODS: In this work, we validate the HCQ on a standard ESHO patient repository within single and multi-frequency contexts. We verify its correlation with clinical SAR and temperature indexes, and compare it to HTPs obtained using a commonly accepted cost-function for SAR-based HTP (hot-spot to target quotient, HTQ). RESULTS AND DISCUSSION: The results show that low HCQ values produce better SAR (TC50, TC75) and temperature metrics (T50, T90) than HTQ in most patient models and frequency settings. For the deep-seated tumors, the correlation between the clinical indicators and 1/HCQ is more favorable than the correlation exhibited by 1/HTQ. CONCLUSION: The validation confirms the ability of HCQ to promote target coverage and hot-spot suppression in SAR-based HTP optimization, resulting in higher SAR and temperature indexes for deep-seated tumors.

Hyperthermia

cost function

control systems engineering/treatment optimization

SAR

temperature

radiofrequency/microwave

treatment planning

computational modeling

Författare

Massimiliano Zanoli

Chalmers, Elektroteknik, Signalbehandling och medicinsk teknik

Hana Dobsicek Trefna

Chalmers, Elektroteknik, Signalbehandling och medicinsk teknik

International Journal of Hyperthermia

0265-6736 (ISSN) 1464-5157 (eISSN)

Vol. 39 1 1421-1439

Fokuserad mikrovågs hypertermi: för minskade långsiktiga effekter av strålning av barn med hjärntumörer

Vetenskapsrådet (VR) (2021-04935), 2022-01-01 -- 2025-12-31.

Ämneskategorier

Biomedicinsk laboratorievetenskap/teknologi

Signalbehandling

Radiologi och bildbehandling

DOI

10.1080/02656736.2022.2136411

PubMed

36396127

Mer information

Senast uppdaterat

2023-10-26