PET/CT-Based Dosimetry in 90Y-Microsphere Selective Internal Radiation Therapy. Issue 23 (June 2015)

• Record Type: Journal Article
• Authors: Song, Yoo Sung; Paeng, Jin Chul; Kim, Hyo-Cheol; Chung, Jin Wook; Cheon, Gi Jeong; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook; Zakko., Saad
• Is Part Of: Medicine. Volume 94:Issue 23(2015)
• Publication Date: 2015-06
• Subjects: Medicine -- Periodicals; Medicine -- Periodicals; Médecine -- Périodiques; Geneeskunde; Medicine; Periodicals; Periodicals; 610.5
• DOI: 10.1097/MD.0000000000000945
• Languages: English
• ISSNs: 0025-7974

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Abstract</title> <p> <sup>90</sup>Y PET/CT can be acquired after <sup>90</sup>Y-microsphere selective radiation internal therapy (SIRT) to describe radioactivity distribution. We performed dosimetry using <sup>90</sup>Y-microsphere PET/CT data to evaluate treatment efficacy and appropriateness of activity planning from <sup>99m</sup>Tc-MAA scan and SPECT/CT.</p> <p>Twenty-three patients with liver malignancy were included in the study. <sup>99m</sup>Tc-MAA was injected during planning angiography and whole body <sup>99m</sup>Tc-MAA scan and liver SPECT/CT were acquired. After SIRT using <sup>90</sup>Y-resin microsphere, <sup>90</sup>Y-microsphere PET/CT was acquired. A partition model (PM) using 4 compartments (tumor, intarget normal liver, out-target normal liver, and lung) was adopted, and absorbed dose to each compartment was calculated based on measurements from <sup>99m</sup>Tc-MAA SPECT/CT and <sup>90</sup>Y-microsphere PET/CT, respectively, to be compared with each other. Progression-free survival (PFS) was evaluated in terms of tumor absorbed doses calculated by <sup>99m</sup>Tc-MAA SPECT/CT and <sup>90</sup>Y-microsphere PET/CT results.</p> <p>Lung shunt fraction was overestimated on <sup>99m</sup>Tc-MAA scan compared with <sup>90</sup>Y-microsphere PET/CT (0.060 ± 0.037 vs. 0.018 ± 0.026, <italic>P</italic> < 0.01). Tumor absorbed dose exhibited a close correlation between the results from <sup>99m</sup>Tc-MAA SPECT/CT and <sup>90</sup>Y-microsphere PET/CT (<italic>r</italic> = 0.64, <italic>P</italic> < 0.01), although the result from <sup>99m</sup>Tc-MAA SPECT/CT was significantly lower than that from <sup>90</sup>Y-microsphere PET/CT (135.4 ± 64.2 Gy vs. 185.0 ± 87.8 Gy, <italic>P</italic> < 0.01). Absorbed dose to in-target normal liver was overestimated on <sup>99m</sup>Tc-MAA SPECT/CT compared with PET/CT (62.6 ± 38.2 Gy vs. 45.2 ± 32.0 Gy, <italic>P</italic> = 0.02). Absorbed dose to out-target normal liver did not differ between <sup>99m</sup>Tc-MAA SPECT/CT and <sup>90</sup>Y-microsphere PET/CT (<italic>P</italic> = 0.49). Patients with tumor absorbed dose >200 Gy on <sup>90</sup>Y-microsphere PET/CT had longer PFS than those with tumor absorbed dose ⩽200 Gy (286 ± 56 days vs. 92 ± 20 days, <italic>P</italic> = 0.046). Tumor absorbed dose calculated by <sup>99m</sup>Tc-MAA SPECT/CT was not a significant predictor for PFS.</p> <p>Activity planning based on <sup>99m</sup>Tc-MAA scan and SPECT/CT can be effectively used as a conservative method. Post-SIRT dosimetry based on <sup>90</sup>Y-microsphere PET/CT is an effective method to predict treatment efficacy.</p> </sec> </abstract>