Advanced patient-specific hyperthermia treatment planning

Abstract

Hyperthermia treatment planning (HTP) is valuable to optimize tumor heating during thermal therapy delivery. Yet, clinical hyperthermia treatment plans lack quantitative accuracy due to uncertainties in tissue properties and modeling, and report tumor absorbed power and temperature distributions which cannot be linked directly to treatment outcome. Over the last decade, considerable progress has been made to address these inaccuracies and therefore improve the reliability of hyperthermia treatment planning. Patient-specific electrical tissue conductivity derived from MR measurements has been introduced to accurately model the power deposition in the patient. Thermodynamic fluid modeling has been developed to account for the convective heat transport in fluids such as urine in the bladder. Moreover, discrete vasculature trees have been included in thermal models to account for the impact of thermally significant large blood vessels. Computationally efficient optimization strategies based on SAR and temperature distributions have been established to calculate the phase-amplitude settings that provide the best tumor thermal dose while avoiding hot spots in normal tissue. Finally, biological modeling has been developed to quantify the hyperthermic radiosensitization effect in terms of equivalent radiation dose of the combined radiotherapy and hyperthermia treatment. In this paper, we review the present status of these developments and illustrate the most relevant advanced elements within a single treatment planning example of a cervical cancer patient. The resulting advanced HTP workflow paves the way for a clinically feasible and more reliable patient-specific hyperthermia treatment planning.

Whither Magnetic Hyperthermia? A Tentative Roadmap

“…Treatment planning-which reproduces the dose needed to destroy the tumors preserving as much healthy tissue as possible-for many hyperthermia modalities have benefitted from the developments made in radiotherapy [175][176][177][178][179]. In the particular case of magnetic hyperthermia, so far, there is only one commercially available system for the purpose developed by MagForce, the NanoPlan ® (formerly known as HyperPlan ® ) [180].…”

EPTlib: An Open-Source Extensible Collection of Electric Properties Tomography Techniques

“…Electric properties tomography (EPT) is a MRI-based quantitative imaging technique which reconstructs the distribution of the electric properties (EPs), conductivity σ and relative permittivity ε r , of the biological tissues at the Larmor frequency of the used MRI scanner [4][5][6][7]. The benefit of a reliable EPT is twofold: on the one hand, EPT can be used as a diagnostic tool, since the electric conductivity of the biological tissues acts as a physical biomarker for some pathologies [8,9]; on the other hand, the knowledge of the actual distribution of the EPs would allow planning electromagnetic-based therapies, like oncological hyperthermia, specifically for each patient [10,11]. A plethora of different techniques implementing EPT has been proposed in the literature [7].…”

Quantification of thermal dose in moderate clinical hyperthermia with radiotherapy: a relook using temperature–time area under the curve (AUC)

“…The recent progress in the development of patient-specific hyperthermia treatment planning systems could help optimize tumor heating and provide guidance for HT treatments during their execution [53]. Incorporating AUC !…”