Correlation of immunohistopathological expression of somatostatin receptor 2 with standardised uptake values in 68Ga-DOTATOC PET/CT

Eur J Nucl Med Mol Imaging. 2009 Jan;36(1):48-52. doi: 10.1007/s00259-008-0944-5. Epub 2008 Sep 20.


Purpose: In clinical routine somatostatin analogue positron emission tomography/computed tomography (PET/CT) such as (68)Ga-DOTA-Tyr-octreotide (DOTATOC)-PET/CT could substitute conventional (111)In-Octreotide scintigraphy. Immunohistochemistry (IHC) for somatostatin receptor 2 (SSTR2) might be a tool to predict positivity of (68)Ga-DOTATOC in patients where initial staging was not performed, e.g., in incidental findings. We therefore compared a score of SSTR2-IHC with the in vivo standard uptake value (SUV) of preoperative or prebiopsy (68)Ga-DOTATOC PET/CT.

Materials and methods: In 18 patients, (68)Ga-DOTATOC PET/CT scans were quantified with SUV calculations and correlated to a cell membrane-based SSTR2-IHC score (ranging from 0 to 3).

Results: Negative IHC scores were consistent with SUV values below 10. Furthermore, all score 2 and 3 specimens corresponded with high SUV values (above 15).

Conclusion: SSTR2-IHC scores correlated well with SUV values and we propose to use SSTR2 immunohistochemistry in patients missing a preoperative PET scan to indicate (68)Ga-DOTATOC-PET/CT as method for restaging and follow-up in individual patients.

MeSH terms

  • Adult
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Male
  • Neuroendocrine Tumors / diagnostic imaging
  • Neuroendocrine Tumors / genetics
  • Neuroendocrine Tumors / metabolism
  • Octreotide / analogs & derivatives*
  • Octreotide / chemistry
  • Octreotide / metabolism
  • Organometallic Compounds / chemistry
  • Organometallic Compounds / metabolism*
  • Positron-Emission Tomography
  • Receptors, Somatostatin / immunology*
  • Receptors, Somatostatin / metabolism*
  • Retrospective Studies
  • Thymoma / diagnostic imaging
  • Thymoma / genetics
  • Thymoma / metabolism
  • Tomography, X-Ray Computed


  • Organometallic Compounds
  • Receptors, Somatostatin
  • somatostatin receptor 2
  • Octreotide