{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T13:26:46Z","timestamp":1783690006056,"version":"3.55.0"},"reference-count":41,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,9,5]],"date-time":"2025-09-05T00:00:00Z","timestamp":1757030400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"philanthropic research funding from the BC Cancer Foundation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Current Oncology"],"abstract":"<jats:p>Neuroendocrine tumors of unknown primary (CUP-NET) present a diagnostic challenge when conventional imaging fails to localize the primary tumor. This study aimed to evaluate the diagnostic value of concurrent [68Ga]Ga-DOTA-TOC and [18F]FDG PET\/CT imaging in localizing primary tumors in patients with histologically confirmed CUP-NET. Thirty-four patients underwent both imaging modalities as part of a prospective imaging protocol after negative conventional imaging or [111In]In-octreotide scintigraphy. Primary tumor detection rates were assessed, and imaging characteristics compared between the two modalities. The overall localization rate was 58.9% (20\/34). Of these, 90% (18\/20) of primary tumors were identified solely by [68Ga]Ga-DOTA-TOC PET\/CT, with the remaining two visualized by both modalities. [18F]FDG PET\/CT did not independently localize any primary tumors. Identified primaries were limited to grade 1 (60%) or grade 2 (40%) tumors, predominantly in the small intestine (95%). Among localized cases, 45% (9\/20) underwent surgical resection and 15% (3\/20) became eligible for peptide receptor radionuclide therapy. [68Ga]Ga-DOTA-TOC PET\/CT demonstrated superior detection of metastatic lesions compared to [18F]FDG PET\/CT (97.1% vs. 70.6%, p = 0.006). No significant survival differences were observed between patients with localized versus non-localized primaries. These findings support the value of [68Ga]Ga-DOTA-TOC PET\/CT for identifying primary tumors in CUP-NET. Further research is warranted to explore the role of [18F]FDG PET\/CT in high-grade NETs.<\/jats:p>","DOI":"10.3390\/curroncol32090497","type":"journal-article","created":{"date-parts":[[2025,9,5]],"date-time":"2025-09-05T12:18:18Z","timestamp":1757074698000},"page":"497","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Dual PET Imaging with [68Ga]Ga-DOTA-TOC and [18F]FDG to Localize Neuroendocrine Tumors of Unknown Origin"],"prefix":"10.3390","volume":"32","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-6428-3401","authenticated-orcid":false,"given":"Ali","family":"Zaidi","sequence":"first","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pavithraa","family":"Ravi","sequence":"additional","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-8635-0305","authenticated-orcid":false,"given":"Ingrid","family":"Bloise","sequence":"additional","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Harsini","sequence":"additional","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2806-9184","authenticated-orcid":false,"given":"Heather C.","family":"Stuart","sequence":"additional","affiliation":[{"name":"Vancouver General Hospital, Vancouver, BC V5Z 1N1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hagen F.","family":"Kennecke","sequence":"additional","affiliation":[{"name":"Department of Medicine, Oregon Health & Science University, Portland, OR 97239, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ian","family":"Alberts","sequence":"additional","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7995-3581","authenticated-orcid":false,"given":"Fran\u00e7ois","family":"B\u00e9nard","sequence":"additional","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Don","family":"Wilson","sequence":"additional","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrick","family":"Martineau","sequence":"additional","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8189-2132","authenticated-orcid":false,"given":"Jonathan M.","family":"Loree","sequence":"additional","affiliation":[{"name":"BC Cancer, Vancouver, BC V5Z 4E6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1428","DOI":"10.1016\/S0140-6736(11)61178-1","article-title":"Cancer of Unknown Primary Site","volume":"379","author":"Pavlidis","year":"2012","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1159\/000443167","article-title":"ENETS Consensus Guidelines Update for the Management of Distant Metastatic Disease of Intestinal, Pancreatic, Bronchial Neuroendocrine Neoplasms (NEN) and NEN of Unknown Primary Site","volume":"103","author":"Pavel","year":"2016","journal-title":"Neuroendocrinology"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"876","DOI":"10.1159\/000511812","article-title":"A Real-World, Population-Based Study for the Incidence and Outcomes of Neuroendocrine Neoplasms of Unknown Primary","volume":"111","year":"2021","journal-title":"Neuroendocrinology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1007\/s00423-011-0741-7","article-title":"Surgical Treatment of Gastrointestinal Neuroendocrine Tumors","volume":"396","author":"Fendrich","year":"2011","journal-title":"Langenbeck\u2019s Arch. 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