Table 1.

Statements on diagnosis and management of NENs.

	Statement
1. Multidisciplinary discussion	A network among “tumor boards” working on NEN patients is advisable NEN-dedicated multidisciplinary teams should adopt the same main criteria independently of local experience.
2. Initial prognostic characterization	Initial prognostic characterization should be based on clinical information (functioning/non-functioning, performance status, comorbidity), histopathology (differentiation and grading), and morphological and functional imaging. There is no recommended definition of disease at high risk after radical surgery across NEN primary diseases.
3. Watchful waiting	A watchful waiting strategy is generally not recommended in locally advanced/metastatic patients.
4. Follow-up of radically resected NENs	Follow-up should be patient-tailored in patients with NEN after radical surgery and should include a panel of conventional tests, including circulating markers, plus a list of optional instrumental tests, chosen based on the characteristics of the tumor and patient. A patient-tailored long term follow-up strategy is still lacking and needs to be defined. The timing should be modulated on the basis of prognostic parameters, while strongly taking into account safety issues related to potentially invasive exams.
5. Therapeutic strategies	There is poor evidence regarding a specific sequence or integration of various treatments in NENs. The therapeutic strategy with sequence and type of treatments should be decided in a tumor board considering the characteristics of the patient, literature data, and regulatory aspects.
6. Informed consent for RLT	A standard informed consent form for RLT should be used. Informed consent should include specific information about the purpose, mode of execution, risk-benefit balance, and potential for early and late side effects, allowing optimization of communication about the risks, benefits, and possible alternative options, to provide the same level of information within all institutions.
7. Dosimetry of RLT (for therapy)	Dosimetry evaluation should be recommended to prevent potential risks to bone marrow and kidney function to provide data to clinicians, especially in patients with long survival expectancy.
8. Management of patients with comorbidities	Comorbidities not representing an absolute contraindication to RLT (i.e., severe hypertension, brittle diabetes, functioning tumors, concomitant meningioma, etc.) should require specific protocols.
9. Management of therapy with SSA during RLT	SSA therapy should be continued during the entire course of RLT. Dosage may be adjusted in case of functioning tumors.
10. Evaluation of response (morphological vs. functional and clinical) after RLT	Assessment of tumor response after RLT should carefully consider both morphological and functional imaging. However, the timing of imaging should be correlated with characteristics of the individual tumor.
11. Follow-up after RLT	Follow-up should be patient-tailored and include morphological (CT and/or MRI) and/or functional (PET/CT with radiolabeled somatostatin analogs and/or FDG) imaging and biomarkers, chosen based on the characteristics of the tumor. The timing should be modulated based on prognostic parameters, while strongly considering safety issues. It is suggested to intercalate morphological and functional imaging to reduce the patient’s irradiation dose given the very long follow-up.
12. Off-label use of RLT	Alternative schedules, means of administration, indications other than approved, and rechallenge should be limited to specific clinical studies.
13. Approach to patients with bone metastases	Bone involvement with appropriate imaging techniques must be carefully assessed in patients with a metastatic NEN to identify those at risk of skeletal-related events.
14. Role of PROs in management	Patient-reported outcomes (PROs) should be considered as a critical endpoint of benefit. Thus, guidelines should consider PROs, pointing out that their lack may have a bearing on the ultimate recommendation.