Peptide Receptor Radionuclide Therapy With 177Lu-Dotatate Associated With Metronomic Capecitabine In Patients Affected By Aggressive Gastro-Etero-Pancreatic Neuroendocrine Tumors

Inclusion Criteria:

* Histopathologic diagnosis of inoperable or metastatic gastro-entero-pancreatic neuroendocrine neoplasia.
* Conserved hematological, liver and renal parameters: haemoglobin \>= 10 g/dL, absolute neutrophil count (ANC) \>= 1.5 x 109 /L, platelets \>= 100 x 109 /L, bilirubin ≤1.5 X UNL (upper normal limit), ALT \<2.5 X UNL (\< 5 X UNL in presence of liver metastases), creatinine \< 2 mg/dL.
* Age more than 18 years.
* Patients with documented disease will be admitted to therapeutic phase only if the diagnostic receptor imaging (OctreoScan) demonstrate a significant uptake in the tumor (grade 2 or 3, according to a preset scoring, where grade 1= equal to normal liver, grade2 = higher than normal liver, grade 3= higher than kidneys and spleen), that may allow delivering a low absorbed dose to normal organs and a high dose to the tumor.
* Patients with documented disease will be admitted to therapeutic phase only if the 18FDG PET/CT is positive with a SUV \> 2.5 at least in one documented lesion.
* Disease must be measurable by means of conventional imaging (CT or MRI).
* Before treatment clinical history data will be collected, physical examination will be performed and diagnostic and laboratory data will be examined.
* Patients must not receive other treatments (e.g. chemo- or radiotherapy) from one month before to two months after the completion of 177Lu-DOTATATE cycles.
* Patients must be naive from previous radionuclide treatments with radiopeptides (e.g. 111Inpentetreotide, 90Y-DOTATOC) or other radiopharmaceuticals (e.s. 131I-MIBG, 131I).

Exclusion Criteria:

* Pregnancy/breastfeeding (a pregnancy test not older than 7 days is mandatory).
* Assessed bone marrow invasion \> 25%.
* Other concomitant neoplasm (excluding in situ basaliomas and radically treated cervical cancers).
* ECOG score higher than 2.
* Expectancy of life shorter than 6 months.
* Patients with psycho-physical conditions that are not suitable for entering this clinical study and fulfilling its requirements.