Somatostatin receptor PET response assessment framework for patients with neuroendocrine tumours (V1.0): a modified Delphi consensus from the European Neuroendocrine Tumor Society (endorsed by EANM and NANETS)

Deroose CM, Leupe H, Hicks RJ, Virgolini I, Braat AJ, Mittra ES, Albert NL, Bailey DL, Bodei L, Chan DL, Dekervel J, Denecke T, Dromain C, Falconi M, Fournier L, Grozinsky-Glasberg S, Hofland J, Hope TA, Karfis I, Kos-Kudła B, Koumarianou A, Lamarca A, Litière S, Pavel ME, Stroobants S, Strosberg J, Sundin A, Taïeb D, Trikalinos N, Unterrainer M, Verslype C, Vijayvergia N, Wild D, Kjaer A, Ambrosini V, Prasad V (2026)

Publication Type: Journal article, Review article

Publication year: 2026

Journal

Book Volume: 27

Pages Range: e392-e402

Journal Issue: 8

DOI: 10.1016/S1470-2045(26)00145-2

Abstract

Somatostatin receptor PET imaging is integral to the management of patients with neuroendocrine tumours (NETs), yet standardised criteria for therapy response assessment with the use of this modality are not available. This Policy Review reports the development of the European Neuroendocrine Tumor Society somatostatin receptor PET response assessment framework, established through a structured modified Delphi process coordinated by the European Neuroendocrine Tumor Society. 34 international experts from nuclear medicine, radiology, oncology, endocrinology, surgery, and related disciplines participated in four iterative rounds evaluating 76 statements, with consensus defined as at least 75% agreement. The framework proposes response categorisation based primarily on volumetric changes in somatostatin receptor-expressing target lesions, complemented by assessment of new lesions, rather than reliance on standardised uptake value-based metrics. Partial response is defined by at least 40% reduction in target lesion volume without new lesions, whereas progressive disease is defined by at least 40% volume increase of target lesions or the emergence of new lesions. Complete response requires absence of pathological tracer uptake, and a category of unconfirmed progressive disease is introduced for equivocal cases warranting short-interval reassessment. Although not yet validated against survival outcomes, this expert-derived framework (SSTR-PeRForm) provides a pragmatic foundation for harmonising somatostatin receptor PET-based response assessment in clinical trials and routine practice and represents a key step towards outcome-based validation.

Authors with CRIS profile

Involved external institutions

Rigshospitalet Denmark (DK) University of Bologna / Università di Bologna Italy (IT) Washington University in St. Louis United States (USA) (US) Medizinische Universität Innsbruck Austria (AT) University Medical Centre Utrecht (UMC Utrecht) Netherlands (NL) Oregon Health and Science University (OSHU) United States (USA) (US) Klinikum der Universität München (LMU Klinikum) Germany (DE) Royal North Shore Hospital (RNSH) Australia (AU) Memorial Sloan Kettering Cancer Center United States (USA) (US) University of Sydney (USYD) Australia (AU) University Hospital Leuven (UZ) / Universitaire ziekenhuizen Leuven Belgium (BE) Universitätsklinikum Leipzig Germany (DE) Lausanne University Hospital / Centre hospitalier universitaire vaudois (CHUV) Switzerland (CH) Università Vita-Salute San Raffaele (UniSR) Italy (IT) Université Paris Cité France (FR) Hôpital de la Timone France (FR) Erasmus University Medical Center (MC) Netherlands (NL) University of California San Francisco (UCSF) United States (USA) (US) Brussels University Hospital (H.U.B) / Hôpital Universitaire de Bruxelles Belgium (BE) European Neuroendocrine Tumor Society e.V. (ENETS) Germany (DE) Attikon Hospital / Πανεπιστημιακού Γενικού Νοσοκομείου "Αττικόν" Greece (GR) Hospital Universitario Fundación Jiménez Díaz Spain (ES) European Organisation for Research and Treatment of Cancer (EORTC) Belgium (BE) Hospital Network Antwerp / Ziekenhuis Netwerk Antwerpen (ZNA) Belgium (BE) H. Lee Moffitt Cancer Center & Research Institute United States (USA) (US) Uppsala University Sweden (SE) Alvin J. Siteman Cancer Center United States (USA) (US) Fox Chase Cancer Center United States (USA) (US) Universitätsspital Basel Switzerland (CH) The University of Melbourne Australia (AU)

How to cite

APA:

Deroose, C.M., Leupe, H., Hicks, R.J., Virgolini, I., Braat, A.J., Mittra, E.S.,... Prasad, V. (2026). Somatostatin receptor PET response assessment framework for patients with neuroendocrine tumours (V1.0): a modified Delphi consensus from the European Neuroendocrine Tumor Society (endorsed by EANM and NANETS). Lancet Oncology, 27(8), e392-e402. https://doi.org/10.1016/S1470-2045(26)00145-2

MLA:

Deroose, Christophe M., et al. "Somatostatin receptor PET response assessment framework for patients with neuroendocrine tumours (V1.0): a modified Delphi consensus from the European Neuroendocrine Tumor Society (endorsed by EANM and NANETS)." Lancet Oncology 27.8 (2026): e392-e402.

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