177Lu-PP-F11N in Combination With Sacubitril for Receptor Targeted Therapy and Imaging of Metastatic Thyroid Cancer

Inclusion Criteria:

* Advanced MTC with elevated levels of calcitonin (\> 100 pg/ml) and/or calcitonin-doubling time \< 24 months before or after total thyroidectomy
* 68Ga-DOTATOC PET/CT not older than 12 weeks
* Age \> 18 years
* Informed consent

Exclusion Criteria:

* Medication with Vandetanib 3 weeks before the study and during the study
* Renal failure (calculated glomerular filtration rate (GFR) \< 60 ml/min per 1.73 m2 body surface).
* Bone marrow failure (thrombocytes \< 70 000/μl, leucocytes \< 2 500/μl, hemoglobin \< 8 g/dl).
* Pregnancy and breast feeding
* Known, serious side reaction in the case of a former application of pentagastrin
* Active, second malignancy oder remission after second malignancy \< 5 years
* Age over 64 years
* Systolic bood pressure \< 112 mmHg at the time of screening
* Simultaneous medication with angiotensin converting enzyme (ACE)-inhibitors, or withdrawal for less than 36 h prior to the medication with Entresto or simultaneous medication with AT-II-receptor blockers
* Known intolerance to Sacubitril or Valsartan
* Known angioedema in anamnesis in the context of a medication with an ACE-inhibitor or an AT-II-receptor blocker