{"doi":"10.2967/jnumed.121.262793","title":"Biodistribution and Radiation Dosimetry of Intraperitoneally Administered <sup>124</sup>I-Omburtamab in Patients with Desmoplastic Small Round Cell Tumors","abstract":"The aim of this study was to assess the pharmacokinetics, biodistribution, and radiation dosimetry of <sup>124</sup>I-omburtamab administered intraperitoneally in patients with desmoplastic small round cell tumor (DSRCT). <b>Methods:</b> Eligible patients diagnosed with DSRCT with peritoneal involvement were enrolled in a phase I trial of intraperitoneal radioimmunotherapy with <sup>131</sup>I-omburtamab (NCT01099644). After thyroid blockade and prior to radioimmunotherapy, patients received ~74 MBq <sup>124</sup>I-omburtamab intraperitoneally. Five serial PET/CT scans were performed up to 144 h post-injection. Multiple blood samples were obtained up to 120 h post-injection. Organ absorbed doses were calculated with OLINDA/EXM. <b>Results:</b> Thirty-one patients were studied. Blood pharmacokinetics exhibited a biphasic pattern consisting of an initial rising phase with a median half-time (± standard deviation) of 23±15 h and a subsequent falling phase with a median half-time of 56±34 h. Peritoneal distribution was heterogenous but diffuse in most patients. Self-dose to the peritoneal cavity was 0.58±0.19 mGy/MBq. Systemic distribution and activity noted in major organs was low. The median absorbed doses were 0.72±0.23 mGy/MBq for liver, 0.48±0.17 mGy/MBq for spleen, and 0.57±0.12 mGy/MBq for kidneys. The mean effective dose was 0.31±0.10 mSv/MBq. Whole-body and peritoneal cavity biological half-times were 45±9 h and 24±5 h, respectively. <b>Conclusion:</b> PET/CT imaging with intraperitoneally administered <sup>124</sup>I-omburtamab enables assessment of intraperitoneal distribution and estimation of absorbed dose to peritoneal space and normal organs prior to therapy.","journal":"Journal of Nuclear Medicine","year":2021,"id":207963,"datarank":0.24141568686511508,"base_score":1.6094379124341003,"endowment":1.6094379124341003,"self_citation_contribution":0.24141568686511508,"citation_network_contribution":0.0,"self_endowment_contribution":0.24141568686511508,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9632,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":106451,"name":"Shakeel Modak","orcid":"0000-0002-7280-1726","position":1,"is_corresponding":false},{"id":345009,"name":"Pat Zanzonico","orcid":"0000-0002-7334-2752","position":2,"is_corresponding":false},{"id":308731,"name":"Jorge A. Carrasquillo","orcid":"0000-0002-8513-5734","position":3,"is_corresponding":false},{"id":424346,"name":"Steven M. Larson","orcid":"0000-0002-6111-7507","position":4,"is_corresponding":false},{"id":255807,"name":"John L. Humm","orcid":"0000-0003-4245-5591","position":5,"is_corresponding":false},{"id":438334,"name":"Neeta Pandit‐Taskar","orcid":"0000-0003-1551-2036","position":6,"is_corresponding":false},{"id":255788,"name":"Milan Grkovski","orcid":"0000-0001-7228-9497","position":0,"is_corresponding":true}],"reference_count":27,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-18T23:51:53.662668Z","pmid":"34857661","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":[]}