Somatostatin receptor expression in Merkel cell carcinoma as target for molecular imaging

BMC Cancer. 2014 Apr 17:14:268. doi: 10.1186/1471-2407-14-268.


Background: Merkel cell carcinoma (MCC) is a rare cutaneous neoplasm with increasing incidence, aggressive behavior and poor prognosis. Somatostatin receptors (SSTR) are expressed in MCC and represent a potential target for both imaging and treatment.

Methods: To non-invasively assess SSTR expression in MCC using PET and the radiotracers [68Ga]DOTA-D-Phe1-Tyr3-octreotide (DOTATOC) or -octreotate (DOTATATE) as surrogate for tumor burden. In 24 patients with histologically proven MCC SSTR-PET was performed and compared to results of computed tomography (CT).

Results: SSTR-PET detected primary and metastatic MCC lesions. On a patient-based analysis, sensitivity of SSTR-PET was 73% for nodal metastases, 100% for bone, and 67% for soft-tissue metastases, respectively. Notably, brain metastases were initially detected by SSTR-PET in 2 patients, whereas liver and lung metastases were diagnosed exclusively by CT. SSTR-PET showed concordance to CT results in 20 out of 24 patients. Four patients (17%) were up-staged due to SSTR-PET and patient management was changed in 3 patients (13%).

Conclusion: SSTR-PET showed high sensitivity for imaging bone, soft tissue and brain metastases, and particularly in combination with CT had a significant impact on clinical stage and patient management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brain Neoplasms / diagnostic imaging*
  • Brain Neoplasms / pathology
  • Brain Neoplasms / secondary
  • Carcinoma, Merkel Cell / diagnostic imaging
  • Carcinoma, Merkel Cell / genetics*
  • Carcinoma, Merkel Cell / pathology
  • Carcinoma, Merkel Cell / therapy
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Male
  • Middle Aged
  • Molecular Imaging*
  • Octreotide / analogs & derivatives
  • Positron-Emission Tomography / methods
  • Radiopharmaceuticals
  • Receptors, Somatostatin / biosynthesis*
  • Receptors, Somatostatin / therapeutic use
  • Somatostatin / metabolism
  • Tomography, X-Ray Computed


  • Radiopharmaceuticals
  • Receptors, Somatostatin
  • Somatostatin
  • Octreotide
  • Edotreotide