Peptide Receptor Radionuclide Therapy in the Treatment of Advanced, Non-resectable and/or Symptomatic Tumors With SSTR Overexpression

Inclusion Criteria:

* Adults ≥18 years old, male or female, with histologically proven, well-differentiated G1/2 GEP-NET, BPCs, PPGLs or NET (cancer with unknown primary - CUP), with Ki-67 \<20%, in selected cases patients with NETG3 will be included if there will be reported well/moderate morphological appearance but Ki-67\>20% but less then Ki\<30%; and there will be high expression of somatostatin receptor seen in functional imaging utilized functional imaging 99mTc HYNICTOC or 68Ga DOTATATE or 68Ga DOTATOC.
* The presence of high expression of somatostatin receptors demonstrated on Somatostatin Receptor Imaging using 99mTc HYNICTOC (SPECT) or 68Ga DOTATATE or 68Ga DOTATOC (PET) scans, et least as uptake in not involved liver, Krenning \>2
* Non-resectable, advanced determined by an appropriately specialized surgeon or deemed not suitable for liver directed therapies where liver is the only site of disease;
* Performance status (PS) based on ECOG 0-2;
* Unresectable, advanced/metastatic progressive disease evaluated as clinical, biochemical, bad control symptoms of tumour hypersecretion or disease progression seen in imaging structural or functional.
* Adequate renal function (measured creatinine clearance \> 30 ml/min by DTPA or eGFR),
* Adequate bone marrow function (Hb\>8 g/d/L, WBC\>2.0 x109L, ACN\>1.5 x109L and PLT\>80 x 103/L);
* Adequate liver function (serum total bilirubin ≤ 1.5 x ULN, and Alanine aminotransferase (ALAT), Aspartate aminotransferase (ASPAT), Alkaline phosphatase (ALP) ≤ 2.5 x ULN (≤ 5 x ULN for patients with liver metastases)). INR ≤ 1.5 (or on a stable dose of LMW heparin for \>2 weeks at time of enrollment);
* Life expectancy of at least 6 months;
* The tumor parameters that can be measured objectively as the size to be assessed in radiological studies on the basis of the RECIST 1.0;
* In the absence of the ability to measure tumor size based on RECIST criteria, they have tumor parameters that can be measured objectively as tumor markers determined in the blood or urine CgA, 5HIAA.
* Study treatment both planned and able to start within 28 days of inclusion;
* Willing and able to comply with all study requirements, including treatment, timing and/or nature of required assessments;
* Signed, written informed consent.

Exclusion Criteria:

* • Primary non-NETs;

  * Cytotoxic chemotherapy e.g. CAPTEM, or any other type of chemotherapy recorded 6 weeks before enrollment into the study;
  * Any type of biotherapy using somatostatin analogues or any targeted therapy within the last four weeks;
  * Pre-existing locoregional treatment such as radiomebolization (SIR-spheres) or HDR brachytherapy under CT control, performed in the last 6 months;
  * Major surgery/surgical therapy for any cause within two months before start of PRRT;
  * Surgical therapy of loco-regional metastases within the last three months prior to inclusion;
  * Uncontrolled metastases to the central nervous system, in the case of surgical and / or radiotherapeutic treatment, patients should remain on a stable dose of steroids for at least 2 weeks before enrollment, without deterioration of the general state associated with the presence of metastatic disease in the CNS;
  * Poorly controlled concurrent medical illness. E.g. unstable diabetes with glycosylated hemoglobin (HbA1c\> 9.0), the optimal glycaemic control should be achieved before starting trial therapy);
  * Symptomatic heart failure NYHA class III or IV, congestive cardiac failure, myocardial infarction in the last 6 months, serious uncontrolled cardiac arrhythmia, unstable angina, or other serious cardiac problems;
  * Active uncontrolled infection, including Hepatitis and Hepatitis, HIV, in the case of HCV and HBV infection, the patient can be included in the study confirming the suppression of viral replication and the patient remains on the correct therapeutic dose of antiviral drugs;
  * Pregnant patients (a negative pregnancy test is required);
  * Women of childbearing age must present a negative pregnancy test at the beginning of the study and must use double barrier to contraception. Women of childbearing age are defined as menopausal if they remain menstrual for at least 1 year, or surgical sterilization or removal of the uterus before the start of the study;
  * Breast-feeding female patients;
  * Patients in a mental state who can't understand the nature, extent and possible consequences of participating in the study associated with radioisotope treatment, or there is evidence of a lack of cooperation by the patient;
  * Exclusive clinical and laboratory findings that may compromise the patient's safety or reduce the chances of obtaining satisfactory data to achieve the goal (s) of the study;
  * Presence of any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule, including alcohol dependence or drug abuse;
  * The patient may be included in the maintenance treatment if the patient's clinical condition is stable.