{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T14:26:54Z","timestamp":1787668014550,"version":"build-2736575974"},"reference-count":22,"publisher":"Springer Science and Business Media LLC","issue":"9","license":[{"start":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T00:00:00Z","timestamp":1779062400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T00:00:00Z","timestamp":1779062400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100007642","name":"Universit\u00e0 degli Studi di Roma Tor Vergata","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100007642","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Ann Nucl Med"],"published-print":{"date-parts":[[2026,9]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To assess whether simple paired semiquantitative somatostatin receptor (SSTR) PET metrics identify treatment-related changes after 177Lu-DOTATATE in patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) and to explore their relationship with single-lesion size measured on contrast-enhanced CT in an exploratory paired target-lesion framework.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We retrospectively evaluated 29 consecutive patients with GEP-NENs who completed four cycles of 177Lu-DOTATATE and underwent baseline and post-treatment 68Ga-DOTA-peptide PET\/CT. Median age at treatment initiation was 64.5 years, 18\/29 patients were male, 15 had a pancreatic primary, 13 an intestinal primary, and 1 a pancreatic\/duodenal primary of uncertain origin. Most tumors were grade 2 (17\/29), and liver metastases were present in 26\/29 patients. For each patient, semiquantitative measurements were extracted from the target lesion recorded in the institutional database at baseline and post-treatment assessment. SUVmax, SUVmean, target lesion size, Krenning score, tumor-to-liver ratio, and tumor-to-blood ratio were compared between baseline and post-treatment imaging. Exploratory molecular response was defined as a reduction of at least 30% in semiquantitative PET parameters, whereas exploratory morphologic change was defined as a reduction of at least 20% in lesion size measured on contrast-enhanced CT. Baseline PET\/CT was typically performed within 4\u20136 weeks before PRRT initiation, and post-treatment PET\/CT approximately 3 months after PRRT completion according to institutional routine practice.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Median target lesion SUVmax decreased from 52.22 to 29.73 (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.0007), and median SUVmean decreased from 11.44 to 7.25 (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.023). Median target lesion size changed from 2.80 to 2.49\u00a0cm and was not significantly different (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.168). Tumor-to-liver ratio decreased from 9.38 to 5.31 (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001), and tumor-to-blood ratio from 45.96 to 22.57 (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001). Krenning score showed a modest but significant shift despite an unchanged median value of 4 (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.0049). Using predefined exploratory thresholds, molecular response based on tumor-to-blood ratio was observed in 20\/29 patients, whereas exploratory contrast-enhanced CT-based size reduction was observed in 9\/29; 14 of 20 patients with molecular response showed no concomitant size reduction. Among 24 patients with evaluable final imaging response, a tumor-to-blood ratio reduction of at least 30% was observed in 10\/11 patients with complete or partial response and in 7\/13 with stable or progressive disease.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>In this exploratory paired target-lesion analysis, semiquantitative SSTR PET metrics showed significant treatment-related changes after 177Lu-DOTATATE, whereas paired single-lesion size changes on contrast-enhanced CT were modest. These findings support the presence of molecular\u2013morphologic discordance after PRRT and suggest that normalized PET-derived metrics deserve further investigation as practical tools for post-treatment assessment in GEP-NENs.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s12149-026-02231-y","type":"journal-article","created":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T11:24:07Z","timestamp":1779103447000},"page":"1111-1120","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Semiquantitative SSTR PET metrics show molecular\u2013morphologic discordance after 177Lu-DOTATATE in gastroenteropancreatic neuroendocrine neoplasms: an exploratory paired target-lesion analysis"],"prefix":"10.1007","volume":"40","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8017-8858","authenticated-orcid":false,"given":"Agostino","family":"Chiaravalloti","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martina","family":"Egidi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio","family":"D\u2019Agostini","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luca","family":"Filippi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elizabeth Katherine Anna","family":"Triumbari","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oreste","family":"Bagni","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Orazio","family":"Schillaci","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,5,18]]},"reference":[{"issue":"24","key":"2231_CR1","doi-asserted-by":"publisher","first-page":"2818","DOI":"10.1200\/jco.22.00176","volume":"40","author":"TA Hope","year":"2022","unstructured":"Hope TA, Pavel M, Bergsland EK. 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