Initial clinical evaluation of PET‐based ion beam therapy monitoring under consideration of organ motion

Kurz, Christopher; Bauer, J.; Unholtz, Daniel; Richter, Daniel; Herfarth, Klaus; Debus, Jürgen; Parodi, Katia

doi:10.1118/1.4940356

Cited by 11 publications

(3 citation statements)

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“…Treatment planning for liver targets relies on the delineation of the Gross Tumor Volume (GTV) based on contrast-enhanced CT and/or MR (Magnetic Resonance) imaging. Approximately, 10 mm of target margins are added to the Clinical Target Volume (CTV) according to target motion as detected by contrast-enhanced 4D CT imaging (Habermehl et al 2013, Richter et al 2014, Kurz et al 2016, thus defining the internal target volume (ITV). Following the nongated irradiation with scanned carbon ions beam, each patient in this study underwent off-line 4D PET-CT acquisitions for treatment verification with the PET-CT scanner (Jakoby et al 2011, Gianoli et al 2014a installed at HIT.…”

Section: Patient Datamentioning

confidence: 99%

Clinical evaluation of 4D PET motion compensation strategies for treatment verification in ion beam therapy

et al. 2016

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A clinical trial named PROMETHEUS is currently ongoing for inoperable hepatocellular carcinoma (HCC) at the Heidelberg Ion Beam Therapy Center (HIT, Germany). In this framework, 4D PET-CT datasets are acquired shortly after the therapeutic treatment to compare the irradiation induced PET image with a Monte Carlo PET prediction resulting from the simulation of treatment delivery. The extremely low count statistics of this measured PET image represents a major limitation of this technique, especially in presence of target motion. The purpose of the study is to investigate two different 4D PET motion compensation strategies towards the recovery of the whole count statistics for improved image quality of the 4D PET-CT datasets for PET-based treatment verification. The well-known 4D-MLEM reconstruction algorithm, embedding the motion compensation in the reconstruction process of 4D PET sinograms, was compared to a recently proposed pre-reconstruction motion compensation strategy, which operates in sinogram domain by applying the motion compensation to the 4D PET sinograms. With reference to phantom and patient datasets, advantages and drawbacks of the two 4D PET motion compensation strategies were identified. The 4D-MLEM algorithm was strongly affected by inverse inconsistency of the motion model but demonstrated the capability to mitigate the noise-break-up effects. Conversely, the pre-reconstruction warping showed less sensitivity to inverse inconsistency but also more noise in the reconstructed images. The comparison was performed by relying on quantification of PET activity and ion range difference, typically yielding similar results. The study demonstrated that treatment verification of moving targets could be accomplished by relying on the whole count statistics image quality, as obtained from the application of 4D PET motion compensation strategies. In particular, the pre-reconstruction warping was shown to represent a promising choice when combined with intra-reconstruction smoothing.

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Section: Patient Datamentioning

confidence: 99%

Clinical evaluation of 4D PET motion compensation strategies for treatment verification in ion beam therapy

et al. 2016

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“…There is ongoing research to measure proton treatment beam range and dose distributions in patients. One study measured the radioactive isotopes produced by particle treatment beam with a positron emission tomography (PET) detector [18,19]. However, there were several limitations, such as poor imaging quality, physiological washout, and organ motion issues.…”

Section: ) In Vivo Beam Monitoring and Dosimetrymentioning

confidence: 99%

Proton Therapy Review: Proton Therapy from a Medical

Lee

2020

Progress in Medical Physics

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With hope and concern, the first Korean proton therapy facility was introduced to the National Cancer Center (NCC) in 2007. It added a new chapter to the history of Korean radiation therapy. There have been challenging clinical trials using proton beam therapy, which has seen many impressive results in cancer treatment. Compared to the rapidly increasing number of proton therapy facilities in the world, only one more proton therapy center has been added since 2007 in Korea. The Samsung Medical Center installed a proton therapy facility in 2015. Most radiation oncology practitioners would agree that the physical properties of the proton beam provide a clear advantage in radiation treatment. But the expensive cost of proton therapy facilities is still one of the main reasons that hospitals are reluctant to introduce them in Korea. I herein introduce the history of proton therapy and the cutting edge technology used in proton therapy. In addition, I will cover the role of a medical physicist in proton therapy and the future prospects of proton therapy, based on personal experience in participating in proton therapy programs from the beginning at the NCC.

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“…The main in-vivo treatment monitoring techniques under development are based on the detection of secondary radiation arising as a consequence of nuclear reactions of the treatment beam with the nuclei of the patient’s tissue [ 37 ]. Despite the demonstrations of the clinical feasibility for some of them ([ 40 , 53 ], and references within), the techniques are currently still under development and evaluation, and none of them is clinically widespread yet.…”

Section: Introductionmentioning

confidence: 99%

Helium ion beam imaging for image guided ion radiotherapy

Martišíková¹,

Gehrke²,

Berke³

et al. 2018

Radiat Oncol

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BackgroundIon beam radiotherapy provides potential for increased dose conformation to the target volume. To translate it into a clinical advantage, it is necessary to guarantee a precise alignment of the actual internal patient geometry with the treatment beam. This is in particular challenging for inter- and intrafractional variations, including movement. Ion beams have the potential for a high sensitivity imaging of the patient geometry. However, the research on suitable imaging methods is not conclusive yet. Here we summarize the research activities within the “Clinical research group heavy ion therapy” funded by the DFG (KFO214). Our aim was to develop a method for the visualization of a 1 mm thickness difference with a spatial resolution of about 1 mm at clinically applicable doses.MethodsWe designed and built a dedicated system prototype for ion radiography using exclusively the pixelated semiconductor technology Timepix developed at CERN. Helium ions were chosen as imaging radiation due to their decreased scattering in comparison to protons, and lower damaging potential compared to carbon ions. The data acquisition procedure and a dedicated information processing algorithm were established. The performance of the method was evaluated at the ion beam therapy facility HIT in Germany with geometrical phantoms. The quality of the images was quantified by contrast-to-noise ratio (CNR) and spatial resolution (SR) considering the imaging dose.ResultsUsing the unique method for single ion identification, degradation of the images due to the inherent contamination of the outgoing beam with light secondary fragments (hydrogen) was avoided. We demonstrated experimentally that the developed data processing increases the CNR by 350%. Consideration of the measured ion track directions improved the SR by 150%. Compared to proton radiographs at the same dose, helium radiographs exhibited 50% higher SR (0.56 ± 0.04lp/mm vs. 0.37 ± 0.02lp/mm) at a comparable CNR in the middle of the phantom. The clear visualization of the aimed inhomogeneity at a diagnostic dose level demonstrates a resolution of 0.1 g/cm2 or 0.6% in terms of water-equivalent thickness.ConclusionsWe developed a dedicated method for helium ion radiography, based exclusively on pixelated semiconductor detectors. The achievement of a clinically desired image quality in simple phantoms at diagnostic dose levels was demonstrated experimentally.

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Initial clinical evaluation of PET‐based ion beam therapy monitoring under consideration of organ motion

Abstract: The feasibility of clinical PET-based treatment verification under consideration of organ motion has been shown for the first time. Improvements in noise-robust 4D PET image reconstruction are deemed necessary to enhance the clinical potential.

Cited by 11 publications

References 53 publications

Clinical evaluation of 4D PET motion compensation strategies for treatment verification in ion beam therapy

Clinical evaluation of 4D PET motion compensation strategies for treatment verification in ion beam therapy

Proton Therapy Review: Proton Therapy from a Medical

Helium ion beam imaging for image guided ion radiotherapy

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