The use of advanced imaging in guiding the further investigation and treatment of primary prostate cancer

Abstract

In the era of precision medicine, oncological imaging techniques are advancing at a rapid pace, particularly molecular imaging with promising new targets for prostate cancer (PC) such as gastrin releasing peptide receptors (GRPR) along the established and indispensable prostate specific membrane antigen (PSMA). As PC is characterized by heterogenous tumor biology ranging from indolent to aggressive disease, distinguishing clinically significant tumors from indolent disease is critical. Multiparametric MRI- and PET-targeted prostate biopsies mitigate the shortcomings and risks of standard systematic template biopsy by identifying more significant cancers.Focal treatment for localized disease is a minimally invasive approach that targets the index tumor - the lesion of the highest grade - while sparing the surrounding healthy tissue. Real-time MRI-guidance and thermal control with MR-thermometry, improves treatment accuracy and results in lower rates of functional side effects. PET imaging could be an useful tool to assess response to treatment compared to invasive prostate biopsies.In this comprehensive review, we focus on the image-guided detection and treatment of localized primary prostate cancer, its current status and future perspectives.

Keywords: 68 Ga-PSMA; 68 Ga-RM2; Image-guided; PET; Prostate Cancer; mpMRI.

Fig. 1.

48-year-old man presents with PSA 11.30 ng/mL and PSA density 0.31 ng/mL² for targeted prostate biopsy: mpMRI A shows a PI-RADS 4 lesion in the right lateral base whereas ⁶⁸ Ga-PSMA11 axial PET B, axial fused PET/MRI C, and maximum intensity projection (MIP) D reveal a larger tumor volume. Subsequent PET-targeted biopsy resulted in a Gleason score 4 + 3 prostate cancer

Fig. 2.

62-year-old man with PSA 7.0 ng/mL and PSA density 0.24 ng/mL². MRI shows a PI-RADS 4 lesion in the right lateral base with color coded needle tracks from biopsy; green-benign, yellow-Gleason score 3 + 3, red-Gleason score 3 + 4 or higher A, and target tumor volume B. ⁶⁸ Ga-PSMA11 C and ⁶⁸ Ga-RM2 D axial PET, axial fused PET/MRI, and MIP show congruent focal uptake in the right prostate lesion. The lesion was treated with HIFU; resolution on both ⁶⁸ Ga-PSMA11 and ⁶⁸ Ga-RM2 PET/MRI was seen 6 months after treatment

Fig. 3.

78-year-old man presents with PSA 15.90 ng/mL and PSA density 0.14 ng/mL² for PET-targeted HIFU of a PI-RADS 5 lesion in the right posterior apex. Pre-therapy ⁶⁸ Ga-PSMA11 A and ⁶⁸ Ga-RM2 C axial PET, axial fused PET/MRI, MRI, and MIP images show concordant focal uptake in the right posterior prostate (red arrows). After HIFU, ⁶⁸ Ga-PSMA11 B and ⁶⁸ Ga-RM2 D axial PET, axial fused PET/MRI, MRI, and MIP show structural changes with urine pooling in the treated area (blue arrows) but no pathologic uptake. Biopsy confirmed no evidence of PC in the treated area