{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T19:48:59Z","timestamp":1789501739077,"version":"build-2803163510"},"reference-count":44,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T00:00:00Z","timestamp":1780617600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Cancer Institute"},{"DOI":"10.13039\/100018110","name":"Dendreon","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100018110","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>Immunotherapy has shown limited efficacy in metastatic castration-resistant prostate cancer (mCRPC), highlighting the need for noninvasive tools to monitor treatment-related biological changes. This case series evaluated exploratory metabolic imaging correlates using [18F]-FDG PET\/CT in mCRPC patients enrolled in a Cancer Immunotherapy Trials Network (CITN) trial of sipuleucel-T (sip-T) with or without recombinant interleukin-7 (IL-7). Among 54 enrolled patients (NCT01881867), three underwent serial [18F]-FDG PET\/CT imaging at baseline and following sip-T therapy. Imaging assessed tumor metabolic activity and potential immune-related metabolic changes, based on the premise that immune processes may influence FDG uptake. Patient 1, treated with sip-T alone, demonstrated progressive sternal metastasis with stable SUVmax and marked increases in metabolic tumor volume (MTV: 10.1\u201334.5) and total lesion glycolysis (TLG: 43.4\u2013145.8), consistent with poor prognosis. Patient 2 showed minimal tumor avidity but transient increases in splenic SUVmax and SUVmean following sip-T, which may reflect treatment-related or immune-associated metabolic activity. Patient 3, treated with sip-T plus IL-7, demonstrated a 33% reduction in SUVmax, stable disease on follow-up imaging, decreased PSA levels, and metabolic changes consistent with treatment response in this individual case. These findings were observed in a single patient and are considered exploratory and hypothesis-generating only. [18F]-FDG PET\/CT imaging may provide exploratory insights into metabolic changes in tumors and immune-related organs in mCRPC. Metabolic changes in tumors and immune organs may provide insights into treatment-associated biological effects. Larger studies are warranted to validate these findings.<\/jats:p>","DOI":"10.3390\/ijms27115129","type":"journal-article","created":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T17:18:16Z","timestamp":1780679896000},"page":"5129","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Exploratory FDG PET\/CT Imaging in mCRPC Patients Treated with Sipuleucel-T \u00b1 IL-7: A Phase II Trial Subanalysis"],"prefix":"10.3390","volume":"27","author":[{"given":"Sandeep Surendra","family":"Panikar","sequence":"first","affiliation":[{"name":"Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA"},{"name":"Alvin J. 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Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO 63110, USA"},{"name":"Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2437-1239","authenticated-orcid":false,"given":"Daniel L. J.","family":"Thorek","sequence":"additional","affiliation":[{"name":"Alvin J. Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO 63110, USA"},{"name":"Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA"},{"name":"Department of Biomedical Engineering, Washington University, St. Louis, MO 63130-4899, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7306-2590","authenticated-orcid":false,"given":"Richard","family":"Wahl","sequence":"additional","affiliation":[{"name":"Alvin J. Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO 63110, USA"},{"name":"Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA"},{"name":"Department of Biomedical Engineering, Washington University, St. Louis, MO 63130-4899, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Russell K.","family":"Pachynski","sequence":"additional","affiliation":[{"name":"Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA"},{"name":"Alvin J. Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO 63110, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,5]]},"reference":[{"key":"ref_1","unstructured":"National Cancer Institute (2024). Cancer Stat Facts: Prostate Cancer."},{"key":"ref_2","unstructured":"American Cancer Society (2024). 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