{"doi":"10.1002/mp.17175","title":"Quantitative evaluation of <sup>90</sup>Y‐PET/CT and <sup>90</sup>Y‐SPECT/CT‐based dosimetry following Yttrium‐90 radioembolization","abstract":"Abstract Background Following yttrium‐90 radioembolization ( 90 Y‐RE), 90 Y‐PET/CT and 90 Y‐SPECT/CT imaging provide the means to calculate the voxelized absorbed dose distribution. Given the widespread use of the two imaging modalities and lack of well‐established standardized dosimetry protocols for 90 Y‐RE, there is a clinical need to systematically investigate and evaluate differences in the performance of voxel‐based dosimetry between 90 Y‐PET/CT and 90 Y‐SPECT/CT. Purpose To quantitatively analyze and compare 90 Y‐PET/CT and 90 Y‐SPECT/CT‐based dosimetry following 90 Y‐RE. Methods 90 Y‐PET/CT and 90 Y‐SPECT/CT imaging was acquired for 35 patients following 90 Y‐RE with TheraSphere for the treatment of unresectable hepatocellular carcinoma. Dosimetry was performed using the local deposition method with known activity and the mean dose ( D mean ) was calculated for perfused liver volumes (PV), tumors (T), and perfused normal livers (NL). Additionally, the absorbed dose to x% of the volume ( D x , x [5%, 10%, …, 90%, 95%]) and the volume receiving y Gy ( V y , y [10 Gy, 20 Gy, …, 190 Gy, 200 Gy]) were calculated for T and NL, respectively. Dose metrics were compared using linear regression, Bland‐Altman analysis, and statistical testing. Results Both 90 Y‐SPECT/CT and 90 Y‐PET/CT‐based tumor D mean were strongly correlated ( R 2 ≥ 0.90) with D x , excluding metrics on the extrema. Intra‐modality comparisons of various D x and V y metrics yielded statistically significant differences (ANOVA, p &lt; 0.001) for both 90 Y‐PET/CT and 90 Y‐SPECT/CT. Based on statistical testing, only D x metrics separated by greater than 20%–30% coverage, and only V y metrics separated by greater than 40–70 Gy, reported significant differences. For PV, there was a strong correlation ( R 2 ≥ 0.99) between D mean derived separately from 90 Y‐PET/CT and 90 Y‐SPECT/CT imaging. The strength of the correlation was slightly reduced for T and NL with R 2 = 0.91 and R 2 = 0.95, respectively. For PV, the mean bias ± standard error (SE) and 95% limits of agreement (LOA) between D mean from the two modalities was effectively zero with ‐0.8 ± 0.4% (± 2.5%). For T and NL, the mean bias ± SE (± LOA) was ‐14.5 ± 3.7% (± 24%) and 9.4 ± 4.7% (± 27%), respectively. Conclusion The strong correlation between D mean and D x suggests information from multiple dose metrics (e.g., D 70 and D mean ) is largely redundant when establishing dose‐response relationships in 90 Y‐RE. D mean is highly correlated between 90 Y‐PET/CT and 90 Y‐SPECT/CT‐based dosimetry, for all liver VOIs. Relative to 90 Y‐SPECT/CT, 90 Y‐PET/CT, on average, yielded higher D mean to tumors (14%) and lower D mean to perfused normal livers (9%). Absorbed dose differences for perfused liver volumes between 90 Y‐SPECT/CT and 90 Y‐PET/CT were negligible.","journal":"Medical Physics","year":2024,"id":455895,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":6,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9542,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1124157,"name":"Éric Henry","orcid":"0000-0001-5247-9939","position":1,"is_corresponding":false},{"id":971276,"name":"Benjamín López","orcid":"0000-0003-0886-9010","position":2,"is_corresponding":false},{"id":648307,"name":"Armeen Mahvash","orcid":"0000-0003-0416-4566","position":3,"is_corresponding":false},{"id":403950,"name":"S. Cheenu Kappadath","orcid":"0000-0003-4643-7745","position":0,"is_corresponding":true}],"reference_count":42,"raw_metadata":null,"created_at":"2026-07-19T02:03:22.974789Z","pmid":"38781554","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}