Lung shunt fraction calculation using 99mTc-MAA SPECT/CT imaging for 90Y microsphere selective internal radiation therapy of liver tumors

Abstract Background 99mTc-macroaggregated albumin (99mTc-MAA) scintigraphy is utilized in treatment planning for Yttrium-90 (90Y) Selective Internal Radiation Therapy (SIRT) of liver tumors to evaluate hepatopulmonary shunting by calculating the lung shunt fraction (LSF). The purpose of this study was to evaluate if LSF calculation using SPECT/CT instead of planar gamma camera imaging is more accurate and if this can potentially lead to more effective treatment planning of hepatic lesions while avoiding excessive pulmonary irradiation. Results LSF calculation was obtained using two different methodologies in 85 cases from consecutive patients intended to receive 90Y SIRT. The first method was based on planar gamma camera imaging in the anterior and posterior views with geometric mean calculation of the LSF from regions of interest of the liver and lungs. The second method was based on segmentation of the liver and lungs from SPECT/CT images of the thorax and abdomen. The differences in planar imaging versus SPECT/CT derived LSF values along with the estimated absorbed lung mean dose (LMD) were evaluated. The LSF values were higher in planar imaging versus SPECT/CT in 81/85 cases, with a mean value of 8.5% vs. 4.6% respectively; the difference was statistically significant using a paired t-test (alpha = 0.05). In those patients who received SIRT, the estimated absorbed LMD calculated with planar imaging was significantly higher than with SPECT/CT (t-test, P < 0.005). Repeated phantom experiments using an anthropomorphic torso phantom with variable 99mTc activity concentrations for the liver and lungs were performed with the standard patient protocol, demonstrated improved accuracy of the LSF calculation based on SPECT/CT than planar imaging (mean overestimated value of 6% vs. 26%). Conclusions This study demonstrates that LSF calculation using planar imaging can be significantly overestimated while calculation using SPECT/CT imaging and appropriate segmentation tools can be more accurate. Minimizing the errors in obtaining the LSF can lead to more effective 90Y SIRT treatment planning for hepatic tumors while ensuring the lung dose will not exceed the standard acceptable safety thresholds.

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Lung Shunt Fraction Calculation Using 99mTc-MAA SPECT/CT Imaging for 90Y Microsphere Selective Internal Radiation Therapy of Liver Tumors

10.21203/rs.3.rs-542791/v1 ◽

2021 ◽

Author(s):

Michalis Georgiou ◽

Russ A Kuker ◽

Matthew Studenski ◽

Preeti P Ahlman ◽

Megan Witte ◽

...

Keyword(s):

Radiation Therapy ◽

Treatment Planning ◽

Gamma Camera ◽

Liver Tumors ◽

T Test ◽

Selective Internal Radiation Therapy ◽

Shunt Fraction ◽

Planar Imaging ◽

Internal Radiation ◽

Lung Shunt

Abstract Background99m Tc-macroaggregated albumin ( 99m Tc-MAA) scintigraphy is utilized in treatment planning for Yttrium-90 ( 90 Y) Selective Internal Radiation Therapy (SIRT) of liver tumors to evaluate hepatopulmonary shunting by calculating the lung shunt fraction (LSF). The purpose of this study was to evaluate if LSF calculation using SPECT/CT instead of planar gamma camera imaging is more accurate and if this can potentially lead to more effective treatment planning while avoiding excessive pulmonary irradiation. ResultsLSF calculation was obtained using two different methodologies in 85 cases from consecutive patients intended to receive 90Y SIRT. The first method was based on planar gamma camera imaging in the anterior and posterior views with geometric mean calculation of the LSF from regions of interest of the liver and lungs. The second method was based on segmentation of the liver and lungs from SPECT/CT images of the thorax and abdomen. The differences in planar imaging versus SPECT/CT derived LSF values along with the estimated absorbed lung mean dose (LMD) were evaluated. The LSF values were higher in planar imaging versus SPECT/CT in 81/85 cases, with a mean value of 8.5% vs. 4.6% respectively; the difference was statistically significant using a paired t-test (alpha = 0.05). In those patients who received SIRT, the estimated absorbed LMD calculated with planar imaging was significantly higher than with SPECT/CT (t-test, P<0.005). Repeated phantom experiments using an anthropomorphic torso phantom with variable 99m- Tc activity concentrations for the liver and lungs were performed with the standard patient protocol, demonstrated improved accuracy of the LSF calculation based on SPECT/CT than planar imaging (mean overestimated value of 6% vs. 26%).ConclusionsThis study demonstrates that LSF calculation using planar imaging can be significantly overestimated while calculation using SPECT/CT imaging and appropriate segmentation tools can be more accurate. A lower calculated LSF could allow for a higher dose prescription which can potentially lead to more effective treatments for hepatic tumors.

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Serious hepatic complications of selective internal radiation therapy with yttrium-90 microsphere radioembolization for unresectable liver tumors

Asia-Pacific Journal of Clinical Oncology ◽

10.1111/ajco.12229 ◽

2014 ◽

Vol 10 (3) ◽

pp. 266-272 ◽

Cited By ~ 6

Author(s):

James C Kuo ◽

Andrea Tazbirkova ◽

Robert Allen ◽

Suzanne Kosmider ◽

Peter Gibbs ◽

...

Keyword(s):

Radiation Therapy ◽

Liver Tumors ◽

Selective Internal Radiation Therapy ◽

Internal Radiation ◽

Selective Internal Radiation ◽

Internal Radiation Therapy ◽

Yttrium 90

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Serum proinflammatory cytokine response in patients with advanced liver tumors following selective internal radiation therapy (SIRT) with 90Yttrium microspheres

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/s0360-3016(00)01420-6 ◽

2001 ◽

Vol 49 (4) ◽

pp. 1015-1021 ◽

Cited By ~ 22

Author(s):

J.Kesara Wickremesekera ◽

Wangxue Chen ◽

Rebecca J Cannan ◽

Richard S Stubbs

Keyword(s):

Radiation Therapy ◽

Proinflammatory Cytokine ◽

Liver Tumors ◽

Cytokine Response ◽

Selective Internal Radiation Therapy ◽

Internal Radiation ◽

Selective Internal Radiation ◽

Internal Radiation Therapy

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Effects of Yttrium-90 selective internal radiation therapy on non-conventional liver tumors

World Journal of Gastroenterology ◽

10.3748/wjg.v21.i27.8271 ◽

2015 ◽

Vol 21 (27) ◽

pp. 8271 ◽

Cited By ~ 24

Author(s):

Andrew Kuei

Keyword(s):

Radiation Therapy ◽

Liver Tumors ◽

Selective Internal Radiation Therapy ◽

Internal Radiation ◽

Selective Internal Radiation ◽

Internal Radiation Therapy ◽

Yttrium 90

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Effect of selective internal radiation therapy (SIRT) in patients with unresectable primary or metastatic liver tumors on microsomal liver function by means of 13C-methacetin breath test (MBT)

10.1055/s-0038-1677123 ◽

2019 ◽

Author(s):

O Goetze ◽

SH Lee ◽

M Kircher ◽

A Buck ◽

R Kickuth ◽

...

Keyword(s):

Radiation Therapy ◽

Liver Function ◽

Breath Test ◽

Liver Tumors ◽

Selective Internal Radiation Therapy ◽

Internal Radiation ◽

Selective Internal Radiation ◽

Microsomal Liver ◽

Metastatic Liver Tumors ◽

Metastatic Liver

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Effect of transarterial chemoembolization prior to selective internal radiation therapy on yttrium-90 microsphere delivery in hepatocellular carcinoma patients.

Journal of Clinical Oncology ◽

10.1200/jco.2016.34.4_suppl.458 ◽

2016 ◽

Vol 34 (4_suppl) ◽

pp. 458-458

Author(s):

Mu-Han Lin ◽

Babak Saboury ◽

Homan Mohammadi ◽

Fred M Moeslein ◽

Michael David Chuong

Keyword(s):

Hepatocellular Carcinoma ◽

Radiation Therapy ◽

Transarterial Chemoembolization ◽

Liver Tumors ◽

Normal Liver ◽

Pet Scan ◽

Average Dose ◽

Selective Internal Radiation Therapy ◽

Internal Radiation ◽

Yttrium 90

458 Background: Transarterial chemoembolization (TACE) and selective internal radiation therapy (SIRT) are commonly used for treatment of liver tumors. The use of TACE, which is macroembolic, prior to SIRT may cause hemodynamic changes in tumor vasculature that impair yttrium-90 (90Y) microsphere delivery to the targeted lesions. This work aims to quantify dosimetric tumor coverage using positron emission tomography (PET) dosimetry after SIRT alone compared to TACE followed by SIRT. Methods: A total of 40 consecutive hepatocellular carcinoma (HCC) SIRT patients who had a post-SIRT PET scan were evaluated. Yttrium-90 PET scan was performed within 2 hours after completion of SIRT. 3D dose distribution of each patient was then reconstructed from the PET images. To quantify the quality of SIRT microsphere delivery, we evaluated the selectivity index (SI) defined as the ratio of the average dose inside the treated lesion(s) and the average dose of the normal liver. The SI values of patients were compared based on whether TACE was previously used. Results: Thirty patients had complete data for analysis. The average dose for a total of 125 targeted lesions was 106 Gy (range 0 Gy – 495 Gy). The average SI of the entire patient group was 3.0, indicating that the targeted lesion dose was three times higher than normal liver dose. The average SI was 1.7 for the 13 patients who had prior TACE and 3.8 for the 17 patients who did not have prior TACE (p = 0.01). Nearly 80% of the patients with prior TACE demonstrated poor 90Ymicrosphere delivery (SI < 2) while none demonstrated excellent microsphere delivery (SI > 4). On the other hand, the incidence of SI < 2 and SI > 4 among patients with no prior TACE was 24% and 40%, respectively. Conclusions: 3D dose evaluation using post-SIRT PET suggests that 90Y microsphere delivery to liver tumors is impaired among patients who received prior TACE compared to those who receive SIRT alone. These data warrant evaluation of clinical outcomes in SIRT patients based on prior use of TACE and may provide a rationale for the use of SIRT prior to TACE.

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