Neuroendocrine Differentiation of Prostate Cancer Metastases Evidenced "in Vivo" by 68Ga-DOTANOC PET/CT: Two Cases

Abstract

Prostate cancer is the second most commonly diagnosed neoplasm in men. This neoplasm has usually excellent prognosis, mostly consequent to the early diagnosis and the effective hormonal therapy. However, significant percentages of patients treated with total androgen blockade therapy, escape to treatment and evolve toward a more aggressive type of cancer. This clinical entity, named castration-resistant prostate cancer, has few and less effective therapeutic opportunities. Therefore, any additional information concerning possible biological targets to therapy is welcome. Here we describe two cases in which ⁶⁸Ga-DOTANOC PET/CT evidenced the somatostatin receptor overexpression by prostate metastases. The presence of these receptors may support with a more strong evidence the possibility to administer somatostatin analogs as an adjuvant therapy.

Keywords: Castration-resistant prostate cancer; Positron emission tomography; Somatostatin receptors.

Figure 1

⁶⁸Ga-DOTANOC transaxial PET/CT (left CT attenuation correction, middle fused PET/CT, right PET only) showing increased uptake of the radiopharmaceutical in the left sovra-acetabular region corresponding to a mixed (predominantly lytic) skeletal metastasis (arrows).

Figure 2

Same patient and acquisition parameters of Fig. 1. ⁶⁸Ga-DOTANOC transaxial PET/CT (left CT attenuation correction, middle fused PET/CT, right PET only) showing increased uptake corresponding to lymphangitic carcinomatosis of the right lung (arrows).

Figure 3

⁶⁸Ga-DOTANOC transaxial PET/CT at the level of left humeral head showing increased uptake of the radiopharmaceutical in a mixed metastasis (pointers).

Figure 4

Same patient and acquisition parameters of Fig. 3. ⁶⁸Ga-DOTANOC transaxial PET/CT at the level of fourth lumbar vertebra showing increased uptake of the radiopharmaceutical in a mixed metastasis.