2207 Calculated dose distributions of beta-particle sources used for intravascular brachytherapy

Author(s):  
T. Fox ◽  
C. Soares ◽  
I. Crocker ◽  
K. Brooks ◽  
L. Davis
1974 ◽  
Vol 27 (3) ◽  
pp. 289-297 ◽  
Author(s):  
H. H. Hubbell ◽  
Wei-Li Chen ◽  
W. H. Shinpaugh ◽  
T. D. Jones

2020 ◽  
Author(s):  
Briana C. Thompson ◽  
William A. Dezarn

Abstract Background: Transarterial Radioembolization (TARE) effectively treats unresectable primary and metastatic liver tumors through local injection of Yttrium-90 (90Y) beta particle emitting microspheres. These microspheres implant around the tumor, damaging tumorous cells while sparing healthy liver tissue. Current dosimetry models are highly simplistic and based patient characteristics such as body surface area and fail to consider many important factors. There is a large need for an imaged based dosimetry post-TARE which would improve treatment safety and efficacy. Current post-TARE imaging is 90Y bremsstrahlung SPECT/CT and we study the use of these images for post-TARE dosimetry. Methods: Retrospective image review of 10 patients having a Philips HealthcareTM SPECT/CT following TARE SIR-Spheres® implantation. Emission series with attenuation correction were resampled to 3mm resolution and used to create image based dose distributions. Dose distributions and analysis were performed in MIM Software SurePlanTM utilizing SurePlanTM Local Deposition Method (LDM) and our own dose convolution method (WFBH). We sought to implement a patient specific background subtraction technique prior to dose calculation to make these noisy bremsstrahlung SPECT images suitable for post-TARE dosimetry calculations. Results: On average the percentage of mean background counts to maximum count in the image across all patients was 9.4 ± 4.9% with a maximum of 17.6% and minimum of 2.3%. Absolute dose increased and profile line width decreased as background subtraction value increased. The average value of the LDM and WFBH dose methods were statistically the same. As background subtraction value increased, we found the DVH curves to become unrealistic and distorted.Conclusion: Background subtraction on bremsstrahlung SPECT image had a large effect on post-TARE dosimetry. The background contour we defined provides a systematic estimate to the activity background that accounts for the scanner and patient conditions at the time of the image study and is easily implemented using commercially available software. We found using the mean count in the background contour as a constant subtraction across the entire image gave the most realistic dose distributions. Comparison of dosimetry from background subtracted SPECT images to image based dosimetry obtained via 90Y PET images will be the subject of our next analysis.


2009 ◽  
Vol 92 ◽  
pp. S193 ◽  
Author(s):  
A. Karlsson ◽  
C. Behrens ◽  
R. Ottosson ◽  
E. Samsoe ◽  
D. Sjöström

2003 ◽  
Vol 9 (6) ◽  
pp. 501-502
Author(s):  
Heung-Rae Lee ◽  
Claudio Sibata ◽  
Ron Allison ◽  
Wen Chen Hsi ◽  
James CH Chu

2003 ◽  
Vol 30 (7) ◽  
pp. 1628-1636 ◽  
Author(s):  
Ning Yue ◽  
Kenneth B. Roberts ◽  
Steven E. Pfau ◽  
Ravinder Nath

2021 ◽  
Vol 27 (1) ◽  
pp. 1-9
Author(s):  
Krzysztof Buliński ◽  
Tomasz Kuszewski ◽  
Katarzyna Wnuk ◽  
Janusz Braziewicz ◽  
Krzysztof Ślosarek

Abstract Both the measurement of the dose and the measurement of its distribution, like any other measurements, are subject to measurement uncertainties. These uncertainties affect all dose calculations and dose distributions in a patient’s body during treatment planning in radiotherapy. Measurement uncertainty is not a medical physicist’s error, but an inevitable element of their work. Planning the dose distribution in a patient’s body, we often try to reduce it in the volume of critical organs (OaR - Organ at Risk) or increase the minimum dose in the PTV region by a few percent. It is believed that the measurement uncertainty should be taken into account in these calculations at the stage of treatment planning. The paper presents the method of calculating the measurement uncertainty for different physical quantities in radiotherapy as percentage depth dose, profile function and output factor, due to the fact that these quantities have a particular impact on the calculated dose distributions in a patient’s body. The uncertainties that must be taken into account in planning treatment the planned dose per fraction and real in PTV, maybe different up to 4%.


Sign in / Sign up

Export Citation Format

Share Document