Results

All 10 invited experts completed the questionnaire and participated in the consensus meeting. Consensus was defined a priori as agreement by at least 70% of panelists. Overall agreement was high, and consensus (≥ 70% agreement) was achieved for all proposed statements. However, the degree of agreement was not uniform across items. Several statements reached consensus with lower proportions of “strongly agree” responses, indicating areas of residual clinical uncertainty rather than uncontested standards of care. The complete set of statements and their corresponding levels of agreement are summarized in Table 1, which reports detailed agreement percentages for each item and provides a structured framework for the clinical use of PRRT in neuroendocrine tumors.

In the patient selection domain, the panel agreed on the need to confirm somatostatin receptor expression by functional imaging, recognized the complementary prognostic (rather than exclusionary) role of [18F]-FDG-PET/CT in selected cases, and highlighted the influence of clinical and pathological features, such as tumor grade and primary site.

For treatment administration, the experts endorsed standard dosing, the use of renal protection, and close monitoring for hematological toxicity, particularly in high-risk patients. The role of multidisciplinary tumor boards was also emphasized as a key element in individualizing therapeutic decisions.

In the response assessment domain, agreement was reached on the use of an integrated approach combining morphological criteria (RECIST), functional imaging, and biochemical markers when appropriate. The level of agreement across statements in this domain varied, underscoring the complexity of response evaluation after PRRT.

Finally, in the follow-up domain, the panel supported consensus on the type and periodicity of imaging after PRRT, together with long-term surveillance strategies to detect late toxicities and monitor disease progression. As reflected in Table 1, agreement levels also differed across follow-up-related statements, highlighting areas where clinical practice remains heterogeneous despite shared principles.

In the response assessment domain, agreement was reached on the use of an integrated approach combining morphological criteria (RECIST), functional imaging, and biochemical markers when appropriate. The level of agreement across statements in this domain varied, underscoring the complexity of response evaluation after PRRT and the absence of a single standardized approach in routine practice.

Finally, in the follow-up domain, the panel supported consensus on the type and periodicity of imaging after PRRT, together with long-term surveillance strategies to detect late toxicities and monitor disease progression. As reflected in Table 1, agreement levels also differed across follow-up-related statements, highlighting areas where clinical practice remains heterogeneous despite shared principles.