New horizons in prostate cancer imaging

Abstract

Prostate cancer is the most common non-cutaneous malignancy among American men. Imaging has recently become more important in detection of prostate cancer since screening techniques such as digital rectal examination (DRE), prostate specific and transrectal ultrasound guided biopsy have considerable limitations in diagnosis and localization of prostate cancer. In this manuscript, we reviewed conventional, functional and targeted imaging modalities used in diagnosis and local staging of prostate cancer with exquisite images.

Figure 1

Transrectal ultrasound image in the axial plane shows of the peripheral (P) and central (C) zones without evidence of a focal lesion.

Figure 2

Transrectal ultrasound image in axial plane demonstrates a hypoechoic triangular area in the anterior horn of the left peripheral zone that is suspicious for tumor (arrow).

Figure 3

Axial contrast enhanced computed tomography (CT) image of a patient with prostate cancer shows no evidence of tumor within prostate gland (arrow). CT has inherently low contrast resolution for the prostate and surrounding tissues.

Figure 4

Axial contrast enhanced computed tomography images of a patient with prostate cancer (PSA>50ng/ml) shows enlarged prostate gland with an infiltrative tumor lesion (arrows) (a) and distant mediastinal lymph node involvement (arrow) (b) (courtesy of Dr. Musturay Karcaaltincaba, Ankara, Turkey).

Figure 4

Axial contrast enhanced computed tomography images of a patient with prostate cancer (PSA>50ng/ml) shows enlarged prostate gland with an infiltrative tumor lesion (arrows) (a) and distant mediastinal lymph node involvement (arrow) (b) (courtesy of Dr. Musturay Karcaaltincaba, Ankara, Turkey).

Figure 5

Axial T2 weighted images demonstrates a normal peripheral zone (P) which is hyperintense compared to the transitional zone (T), and is separated by a pseudocapsule (arrowheads); additionally the true capsule of the prostate gland is seen as a hypointense rim around the gland (solid arrows) with neurovascular bundles at the posterolateral aspect of the capsule (dashed arrows) (b); normal seminal vesicles (arrows) are seen posterior to base of urinary bladder (UB) (b).

Figure 5

Axial T2 weighted images demonstrates a normal peripheral zone (P) which is hyperintense compared to the transitional zone (T), and is separated by a pseudocapsule (arrowheads); additionally the true capsule of the prostate gland is seen as a hypointense rim around the gland (solid arrows) with neurovascular bundles at the posterolateral aspect of the capsule (dashed arrows) (b); normal seminal vesicles (arrows) are seen posterior to base of urinary bladder (UB) (b).

Figure 6

Axial (a) and sagittal (b) T2 weighted images of a patient with prostate cancer show focal low signal intensity lesion in the left mid peripheral zone (arrows) consistent with prostate cancer.

Figure 6

Axial (a) and sagittal (b) T2 weighted images of a patient with prostate cancer show focal low signal intensity lesion in the left mid peripheral zone (arrows) consistent with prostate cancer.

Figure 7

Axial (a) and coronal (b) T2 weighted images of a patient with prostate cancer shows a tumor in the right mid peripheral zone with extracapsular extension (arrow); additionally a nodular low signal intensity focus invading the pseudocapsule consistent with transitional zone tumor is also seen (arrowheads).

Figure 7

Axial (a) and coronal (b) T2 weighted images of a patient with prostate cancer shows a tumor in the right mid peripheral zone with extracapsular extension (arrow); additionally a nodular low signal intensity focus invading the pseudocapsule consistent with transitional zone tumor is also seen (arrowheads).

Figure 8

Axial (a) and coronal (b) T2 weighted images of a patient with prostate cancer depicts a tumor in the right peripheral zone (asterix). Tumor invades the capsule (arrowhead) and directly extends into the periprostatic space (arrow) (a); moreover tumor invades right obturator internus muscle (arrowhead) (b).

Figure 8

Axial (a) and coronal (b) T2 weighted images of a patient with prostate cancer depicts a tumor in the right peripheral zone (asterix). Tumor invades the capsule (arrowhead) and directly extends into the periprostatic space (arrow) (a); moreover tumor invades right obturator internus muscle (arrowhead) (b).

Figure 9

Axial T2 weighted image of a patient with prostate cancer shows a nodular low signal intensity lesion at the right apex peripheral zone (asterix) with ipsilateral capsular bulge and obliteration of recto-prostatic angle (arrow).

Figure 10

Sagittal T2 weighted image of a patient with prostate cancer demonstrates a big peripheral zone tumor (asterix) which extends superiorly and invades seminal vesicles (arrow).

Figure 11

Axial T1 weighted image (a) of a patient who had TRUS guided sextant biopsy 5 weeks prior to the MRI which shows hyperintense foci consistent with hemorrhage (arrows); numerous low signal intensity foci secondary to hemorrhage mimicking cancers (arrows) are seen on axial T2 weighted image (b).

Figure 11

Axial T1 weighted image (a) of a patient who had TRUS guided sextant biopsy 5 weeks prior to the MRI which shows hyperintense foci consistent with hemorrhage (arrows); numerous low signal intensity foci secondary to hemorrhage mimicking cancers (arrows) are seen on axial T2 weighted image (b).

Figure 12

Axial T2 weighted image of a patient with prostate cancer shows low signal intensity focus suspicious for tumor in the left peripheral zone (arrow) (a); Ktrans and Kep analysis of the corresponding slice performed with a two compartment kinetic model localizes the lesion to the left peripheral zone (arrows) (upper row). Comparison of the gadopentetate dimeglumine concentration versus time curves of the normal (right) and tumor (left) sites demonstrate that wash-in and wash-out processes were more rapid in the tumor (lower row).

Figure 12

Axial T2 weighted image of a patient with prostate cancer shows low signal intensity focus suspicious for tumor in the left peripheral zone (arrow) (a); Ktrans and Kep analysis of the corresponding slice performed with a two compartment kinetic model localizes the lesion to the left peripheral zone (arrows) (upper row). Comparison of the gadopentetate dimeglumine concentration versus time curves of the normal (right) and tumor (left) sites demonstrate that wash-in and wash-out processes were more rapid in the tumor (lower row).

Figure 13

Flow chart shows Krebs cycle and citrate metabolism in normal prostate gland cell. In tumor cells zinc is missing, which leads to re-activation of aconitase that converts citrate to cis-aconitate, ultimately citrate is metabolized in the Krebs cycle instead of being stored, which results in depletion of citrate detected on MR spectroscopy.

Figure 14

MR spectroscopy image and corresponding voxels demonstrate increased choline and diminished citrate peaks representing tumor (T) (voxels with asterix) at right peripheral zone (a); whereas normal side (N) at left peripheral zone contains normal voxels with normal choline and citrate peaks (b).

Figure 14

MR spectroscopy image and corresponding voxels demonstrate increased choline and diminished citrate peaks representing tumor (T) (voxels with asterix) at right peripheral zone (a); whereas normal side (N) at left peripheral zone contains normal voxels with normal choline and citrate peaks (b).

Figure 15

Axial T2 weighted MR images of a patient with prostate cancer demonstrates bilateral low signal intensity foci suspicious for tumor (arrows) (a), suspicious lesions for cancer appear as bright and dark on corresponding raw diffusion weighted (b) and apparent diffusion coefficient (ADC) maps (c), respectively (arrows).

Figure 15

Axial T2 weighted MR images of a patient with prostate cancer demonstrates bilateral low signal intensity foci suspicious for tumor (arrows) (a), suspicious lesions for cancer appear as bright and dark on corresponding raw diffusion weighted (b) and apparent diffusion coefficient (ADC) maps (c), respectively (arrows).

Figure 15

Axial T2 weighted MR images of a patient with prostate cancer demonstrates bilateral low signal intensity foci suspicious for tumor (arrows) (a), suspicious lesions for cancer appear as bright and dark on corresponding raw diffusion weighted (b) and apparent diffusion coefficient (ADC) maps (c), respectively (arrows).

Figure 16

65 year-old male with stage IV prostate cancer undergoing chemotherapy. Pre-treatment ¹⁸F-FDG PET images (a) demonstrate multiple metabolic avid lesions throughout the skeleton. Post-treatment PET images (b) demonstrate interval resolution of the ¹⁸F-FDG avid lesions. Pre-treatment and post-treatment bone scans (c and d) demonstrate little interval change (Courtesy of Dr. Steven M. Larson, Memorial Sloan-Kettering Cancer Center).

Figure 17

64 year-old male with non-Hodgkins lymphoma. An incidental focus of increased ¹⁸F-FDG uptake in the prostate prompted a biopsy which demonstrated infiltrating adenocarcinoma, gleason 7, stage T3a (courtesy Dr. Annemi Klopper, Cape PET-CT Centre, South Africa).

Figure 18

Transaxial CT (a), PET (b), and fused (c) ¹⁸F-FACBC PET/CT images in a patient with rising PSA status post radiation therapy. A focus of increased radiotracer uptake in the periphery of the right prostate gland helped guide biopsy. Transaxial CT (d), ¹¹¹In capromab SPECT (e), and fused SPECT/CT (f) images demonstrate no abnormal foci of radiotracer uptake. The patient was treated locally with cryotherapy (courtesy of Dr. David Schuster, Emory University).

Figure 19

Coronal PET (a), Transaxial PET (b), Transaxial CT (c), and fused PET/CT (d) ¹⁸F-FDHT images in a patient with metastatic prostate cancer demonstrated several foci of increased radiotracer uptake in the skeleton (courtesy of Dr. Heiko Schoder, Memorial Sloan-Kettering Cancer Center).