Radiation absorbed dose distribution in a patient treated with yttrium‐90 microspheres for hepatocellular carcinoma

Sarfaraz, Mehrdad; Kennedy, Andrew S.; Lodge, Martin A.; Li, X. Allen; Wu, X; Yu, C

doi:10.1118/1.1781332

Cited by 83 publications

(64 citation statements)

References 14 publications

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“…Point kernels can also be integrated over a cubic volume to provide dose voxel kernels similar to the voxel S factors. 42 Sarfaraz et al 43 present an image-based 3D dosimetry for 90 Y microspheres. The bremsstrahlung SPECT imaging does not have adequate resolution for dose distribution calculation.…”

Section: Ivc Image-based Dosimetrymentioning

confidence: 99%

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for ⁹⁰Y microsphere brachytherapy in the treatment of hepatic malignancies

Dezarn¹,

et al. 2011

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Yttrium-90 microsphere brachytherapy of the liver exploits the distinctive features of the liver anatomy to treat liver malignancies with beta radiation and is gaining more wide spread clinical use. This report provides a general overview of microsphere liver brachytherapy and assists the treatment team in creating local treatment practices to provide safe and efficient patient treatment. Suggestions for future improvements are incorporated with the basic rationale for the therapy and currently used procedures. Imaging modalities utilized and their respective quality assurance are discussed. General as well as vendor specific delivery procedures are reviewed. The current dosimetry models are reviewed and suggestions for dosimetry advancement are made. Beta activity standards are reviewed and vendor implementation strategies are discussed. Radioactive material licensing and radiation safety are discussed given the unique requirements of microsphere brachytherapy. A general, team-based quality assurance program is reviewed to provide guidance for the creation of the local procedures. Finally, recommendations are given on how to deliver the current state of the art treatments and directions for future improvements in the therapy.

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Section: Ivc Image-based Dosimetrymentioning

confidence: 99%

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for ⁹⁰Y microsphere brachytherapy in the treatment of hepatic malignancies

Dezarn¹,

et al. 2011

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“…16 An optimal treatment planning should include 3D voxelbased dosimetry, accounting for nonuniform absorbed dose distributions when studying dose-effect correlations. 9,[17][18][19][20][21][22][23] Image-based 3D dosimetry can be performed in several ways: direct Monte Carlo (MC) simulation, which is considered the gold standard; 9,[24][25][26][27][28][29][30] convolution calculations by voxel S-values, reliable in nearly uniform density tissue; 19,[31][32][33][34][35][36] local energy deposition method. 18,20,[36][37][38][39] Activity distribution quantification by SPECT is the major concern, due to physical and clinical degrading factors of the images.…”

Section: Introductionmentioning

confidence: 99%

Impact of SPECT corrections on 3D‐dosimetry for liver transarterial radioembolization using the patient relative calibration methodology

et al. 2016

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Purpose: Many centers aim to plan liver transarterial radioembolization (TARE) with dosimetry, even without CT-based attenuation correction (AC), or with unoptimized scatter correction (SC) methods. This work investigates the impact of presence vs absence of such corrections, and limited spatial resolution, on 3D dosimetry for TARE. Methods: Three voxelized phantoms were derived from CT images of real patients with different body sizes. Simulations of 99m Tc-SPECT projections were performed with the SIMIND code, assuming three activity distributions in the liver: uniform, inside a "liver's segment," or distributing multiple uptaking nodules ("nonuniform liver"), with a tumoral liver/healthy parenchyma ratio of 5:1. Projection data were reconstructed by a commercial workstation, with OSEM protocol not specifically optimized for dosimetry (spatial resolution of 12.6 mm), with/without SC (optimized, or with parameters predefined by the manufacturer; dual energy window), and with/without AC. Activity in voxels was calculated by a relative calibration, assuming identical microspheres and 99m Tc-SPECT counts spatial distribution. 3D dose distributions were calculated by convolution with lesions and healthy parenchyma from different reconstructions were compared with those obtained from the reference biodistribution (the "gold standard," GS), assessing differences for D95%, D70%, and D50% (i.e., minimum value of the absorbed dose to a percentage of the irradiated volume). γ tool analysis with tolerance of 3%/13 mm was used to evaluate the agreement between GS and simulated cases. The influence of deep-breathing was studied, blurring the reference biodistributions with a 3D anisotropic gaussian kernel, and performing the simulations once again. Results: Differences of the dosimetric indicators were noticeable in some cases, always negative for lesions and distributed around zero for parenchyma. Application of AC and SC reduced systematically the differences for lesions by 5%-14% for a liver segment, and by 7%-12% for a nonuniform liver. For parenchyma, the data trend was less clear, but the overall range of variability passed from −10%/40% for a liver segment, and −10%/20% for a nonuniform liver, to −13%/6% in both cases. Applying AC, SC with preset parameters gave similar results to optimized SC, as confirmed by γ tool analysis. Moreover, γ analysis confirmed that solely AC and SC are not sufficient to obtain accurate 3D dose distribution. With breathing, the accuracy worsened severely for all dosimetric indicators, above all for lesions: with AC and optimized SC, −38%/−13% in liver's segment, −61%/−40% in the nonuniform liver. For parenchyma, D50% resulted always less sensitive to breathing and sub-optimal correction methods (difference overall range: −7%/13%). Conclusions: Reconstruction protocol optimization, AC, SC, PVE and respiratory motion corrections should be implemented to obtain the best possible dosimetric accuracy. On the other side, thanks to the relative calibration, D50% inaccuracy for the healthy paren...

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“…Despite positive results from published studies,6, 7 the reported doses assume that the activity distribution within the treatment volume is uniform. Quantitative patient‐specific 90 Y dosimetry has been studied using bremsstrahlung single photon emission computed tomography (SPECT)/computed tomography (CT) 8, 9, 10, 11 and positron emission tomography (PET)/CT 12, 13, 14, 15, 16. However, such dosimetric studies have utilized research software that is not readily available to the medical community and have not illustrated scenarios where voxel‐based dosimetry could be used to predict treatment response.…”

Section: Introductionmentioning

confidence: 99%

SPECT/CT image‐based dosimetry for Yttrium‐90 radionuclide therapy: Application to treatment response

Potrebko

Shridhar

Biagioli

et al. 2018

J Applied Clin Med Phys

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This work demonstrates the efficacy of voxel‐based 90Y microsphere dosimetry utilizing post‐therapy SPECT/CT imaging and applies it to the prediction of treatment response for the management of patients with hepatocellular carcinoma (HCC). A 90Y microsphere dosimetry navigator (RapidSphere) within a commercial platform (Velocity, Varian Medical Systems) was demonstrated for three microsphere cases that were imaged using optimized bremsstrahlung SPECT/CT. For each case, the 90Y SPECT/CT was registered to follow‐up diagnostic MR/CT using deformable image registration. The voxel‐based dose distribution was computed using the local deposition method with known injected activity. The system allowed the visualization of the isodose distributions on any of the registered image datasets and the calculation of dose‐volume histograms (DVHs). The dosimetric analysis illustrated high local doses that are characteristic of blood‐flow directed brachytherapy. In the first case, the HCC mass demonstrated a complete response to treatment indicated by a necrotic region in follow‐up MR imaging. This result was dosimetrically predicted since the gross tumor volume (GTV) was well covered by the prescription isodose volume (V150 Gy = 85%). The second case illustrated a partial response to treatment which was characterized by incomplete necrosis of an HCC mass and a remaining area of solid enhancement in follow‐up MR imaging. This result was predicted by dosimetric analysis because the GTV demonstrated incomplete coverage by the prescription isodose volume (V470 Gy = 18%). The third case demonstrated extrahepatic activity. The dosimetry indicated that the prescription (125 Gy) isodose region extended outside of the liver into the duodenum (178 Gy maximum dose). This was predictive of toxicity as the patient later developed a duodenal ulcer. The ability to predict outcomes and complications using deformable image registration, calculated isodose distributions, and DVHs, points to the clinical utility of patient‐specific dose calculations for 90Y radioembolization treatment planning.

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Radiation absorbed dose distribution in a patient treated with yttrium‐90 microspheres for hepatocellular carcinoma

Cited by 83 publications

References 14 publications

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for ⁹⁰Y microsphere brachytherapy in the treatment of hepatic malignancies

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for ⁹⁰Y microsphere brachytherapy in the treatment of hepatic malignancies

Impact of SPECT corrections on 3D‐dosimetry for liver transarterial radioembolization using the patient relative calibration methodology

SPECT/CT image‐based dosimetry for Yttrium‐90 radionuclide therapy: Application to treatment response

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Radiation absorbed dose distribution in a patient treated with yttrium‐90 microspheres for hepatocellular carcinoma

Cited by 83 publications

References 14 publications

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for 90Y microsphere brachytherapy in the treatment of hepatic malignancies

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for 90Y microsphere brachytherapy in the treatment of hepatic malignancies

Impact of SPECT corrections on 3D‐dosimetry for liver transarterial radioembolization using the patient relative calibration methodology

SPECT/CT image‐based dosimetry for Yttrium‐90 radionuclide therapy: Application to treatment response

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Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for ⁹⁰Y microsphere brachytherapy in the treatment of hepatic malignancies

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for ⁹⁰Y microsphere brachytherapy in the treatment of hepatic malignancies