Would renal cell carcinoma (RCC) be visible on a dotatate (PET) scan?

Detection of Renal Cell Carcinoma on DOTATATE PET Scan

Renal cell carcinoma (RCC) can show uptake on DOTATATE PET scans, particularly clear cell RCC, which may demonstrate intense uptake that can mimic neuroendocrine tumors.

Imaging Characteristics of RCC on Different PET Modalities

DOTATATE PET Scan and RCC

• Clear cell RCC has been documented to show significant uptake on 68Ga-DOTATATE PET scans 1, 2, 3
• In a study of patients with recurrent RCC, DOTATATE-PET/CT demonstrated a patient-based sensitivity of 88% and lesion-based sensitivity of 87% 1
• This uptake occurs because some RCCs express somatostatin receptors, which are the targets for DOTATATE tracers 3

Comparison with FDG-PET

• When comparing DOTATATE-PET/CT with FDG-PET/CT in patients with RCC:
  • DOTATATE showed higher lesion-based sensitivity (74%) compared to FDG (59%) 1
  • Eight lesions were detected only by DOTATATE, while four lesions from papillary RCC were detected only by FDG 1
  • This suggests complementary roles for these two imaging modalities

Clinical Applications and Guidelines

Current Guideline Recommendations

• Standard imaging for RCC diagnosis and staging includes contrast-enhanced CT of chest, abdomen, and pelvis 4
• FDG-PET is not recommended as a standard investigation for diagnosis and staging of clear cell RCC 4
• The European Association of Urology (2022) notes that "PET is increasingly being used in papillary RCC, but PET is currently not a standard investigation in patients with clear-cell RCC" 4

Potential Diagnostic Pitfalls

• DOTATATE uptake is not specific for neuroendocrine tumors and can lead to misdiagnosis 2, 3
• Clear cell RCC metastases can mimic neuroendocrine tumors on DOTATATE PET scans 2
• In patients with a history of RCC, DOTATATE-avid lesions should prompt consideration of RCC metastasis in the differential diagnosis 3

Clinical Implications

Diagnostic Considerations

• In patients with known or suspected RCC, DOTATATE PET may be useful for detecting recurrent disease, particularly for clear cell RCC 1
• For patients with pancreatic masses and history of RCC, intense DOTATATE uptake should not automatically lead to a diagnosis of neuroendocrine tumor 3
• Histopathological confirmation remains essential for definitive diagnosis

Treatment Planning

• According to surgical radioguidance guidelines, RCC has been documented to be detectable with beta probes using various tracers including 68Ga-PSMA-11 and 124I-cG250 4
• This suggests potential applications for DOTATATE imaging in surgical planning for selected RCC cases

Conclusion

While not currently recommended as a first-line imaging modality for RCC in clinical guidelines, DOTATATE PET scans can detect RCC, particularly the clear cell subtype. This characteristic should be considered when interpreting DOTATATE PET scans, especially in patients with a history of RCC, to avoid misdiagnosis of RCC as neuroendocrine tumors.