1. Imaging modalities in prostate cancer
Bahjat moussa PGY4 urology
Dr Georges Assaf Moderator

2. PET in PC patients Role of functional imaging The aim of this review
not well established yet
The aim of this review
to offer an overview about the main applications of choline PET in PC patients

3. Detection of intra-prostatic cancer

4. The only potential application of PET/CT
Use of choline PET/CT for initial diagnosis and local staging of prostate cancer
not recommended as a first line screening method
The only potential application of PET/CT
increase the detection rate of cancer on repeated TRUS-guided biopsies
in patients in which at least 2 inconclusive TRUS-guided biopsy have been already performed

5. Staging

6. The use of choline PET/CT for preoperative LN staging
showed very contradictory results
However good specificity and PPV
limited to patients with very high risk for LN positive status according to nomograms

7. At the present time
routine clinical use of choline PET/CT cannot be recommended in staging patients with PC

8. A negative Choline PET/CT
is not sufficient to rule out a lymph-adenectomy
PET could be useful to exclude from surgery
patients with high surgical risk in which the presence of LN lesions were assessed by PET (high PPV)

9. PET/CT showed
sensitivity 60%
a much better specificity 97%

10. Restaging

11. Imaging should be able to find the site of recurrence
distinguish between local failure and distant metastasis

12. significantly high detection rate
Detection of LN and distant recurrence in PC patients with biochemical recurrence
significantly high detection rate
relationship between detection rate and Trigger PSA values
a relationship between detection rate and PSA kinetics
a crucial role as first diagnostic procedure in patients who demonstrate a fast growing PSA kinetics and low Trigger PSA

13. In case of slow growing PSA kinetics
sensitivity of PET does not seems to be so high
questionable if a PET/CT should be performed as first imaging procedure

14. In case of local relapse
TRUS and/or pelvic endorectal MR remain the first procedures
choline PET/CT could have only a complementary role to exclude the presence of distant metastasis, before a local RT salvage treatment

16. Conclusion Use of choline PET/CT for initial diagnosis and staging
is not recommended as a first-line method
Most important application of choline PET/CT
restaging of the disease in case of biochemical relapse for the detection of LN and distant recurrence

17. Conclusion Choline PET/CT
could play a crucial role as first diagnostic procedure in PC patients who show a fast growing PSA kinetics

20. The diagnostic evidence is stronger in restaging than in staging settings

21. Proper patient selection
PSA level
PSA doubling time
initial tumor stage
is the key to avoiding FN results up front

23. The use of choline PET/CT scanning
May accurately provide the localisation of the site of prostate recurrence in a single step
Choline PET/CT’s detection rate of recurrences rises together with the increase in PSA serum value

24. According to the current available data
the routine use of choline PET/CT scanning cannot be commonly recommended for PSA values <1 ng/ml

25. Independent predictors of positive choline PET/CT
PSA DT
previous biochemical failure
locally advanced tumour
pathologic lymph node disease at initial staging

26. Can choline positron emission tomography/computed tomography help individualise treatment decisions?

27. Confirmatory data are still needed
Choline PET/CT imaging has recently been proposed to allow new opportunities for individualised treatment on recurrent lesions after radical treatment for PCa

28. Patients with local recurrence after RP
best treated by salvage RT when the PSA serum level is <0.5 ng/ml
Choline PET/CT scanning is not commonly useful in this scenario
low detection rate for PSA serum values <1 ng/ml

29. Choline PET/CT scanning, providing whole-body information on Pca spread
may be useful in selecting patients to be referred to local treatment
by distinguishing those patients with local recurrences from those who present with distant metastases

30. Salvage lymphadenectomy
Choline PET/CT scanning
very useful for indicating the presence of lymph nodal involvement
in patients who present with a progressive PSA increase after radical treatment
it provides a basis for further treatment decisions

31. Role of MRI

32. According to the guidelines
PSA increase over a threshold of 0.2 ng/ml later than 6 to 12 months after radical prostatectomy
suggests treatment failure with a high risk of local recurrence
increase within a shorter period
correlates with distant metastasis
For EBRT; biochemical failure
increasing PSA level after a nadir level

33. Transrectal ultrasound-guided biopsy
The current reference standard for the detection of local recurrence in patients with biochemical failure
Invasive
may fail to depict some tumours because only a small fraction of the gland is sampled

34. Computed tomography
Not widely used for the detection of local recurrence
low accuracy in the differentiation of local recurrence from postsurgical scarring

35. MRI
MRI can accurately detect local recurrences after EBRT and radical prostatectomy
DCE MRI is particularly accurate
The addition of 1H-MRSI to DCE MRI
significantly improve the diagnostic accuracy of local prostate cancer recurrence

36. MRI
usually used for local staging in intermediate and high risk patient groups
useful in low risk patients as well
sensitivity and specificity 75% and 95% respectively

37. Functional MRI techniques
diffusion-weighted magnetic resonance (DW-MR)
dynamic contrast-enhanced (DCE-MR)
MR spectroscopy

38. Conventional MRI
only able to diagnose metastatic lymph nodes bigger than 10 mm
A newly invented MRI technique lymphotropic superparamagnetic nanoparticles
detect occult lymph node metastasis smaller than 10 mm
100% sensitivity and 95.7% specificity

39. MR Spectroscopy
Measures the level of specific metabolites in the prostate gland
Combination of choline and creatine is measured in MRS
The other metabolite that MRS measures is citrate
accumulate in peripheral zone
high in normal prostate tissue but decreases in malignant tissues

40. MR Spectroscopy The ratio of Cho+Cr/Ci Higher ratio
used for evaluation of prostate cancer
Higher ratio
in favor of higher risk of malignancy
more than 0.75 is considered as significant and is consistent with prostate cancer

41. MR Spectroscopy
More accurate in detecting prostate cancers with high grade of malignancy
in low grade cancers its accuracy is limited

42. Dynamic Contrast Study
Works based on neo angiogenesis in tumor cells
Angiogenesis rate is high
newly made vessels have low integrity in their wall
more permeable than normal vessels

43. Dynamic Contrast Study
Gadolinium contrast agent is injected
then serial 3D T1- weighted images are obtained
Fast leakage of contrast agent from leaky tumoral vasculature
early enhancement of tumoral tissue in T1 - weighted MRI
early wash out of contrast agent are seen in prostate cancer

44. Diffusion Weighted Imaging
Works based on water molecules movements
Water molecules movement decrease in a high cellular environment
so diffusion become lower
Sensitivity and specificity of DWI when added to T2-Weighted MRI for detecting prostate cancer is about 84% and 87% respectively

45. MRI Ability to Detection Bony Metastasis
The most sensitive and specific technique in detecting bony metastasis

46. Whole-body DW imaging The most newly MRI technique
Very helpful in detection of prostate cancer and its metastasis as well as post cancer therapy fallow up

47. Local Staging of Prostate Cancer
High resolution MR images
especially with the use of endorectal coil
can show with high accuracy
whether the tumor is confined to prostate gland or there is extra capsular extension

48. The gold standard approach for:
Diagnosis
Staging and management of prostate cancer
Is using 1.5 T MR machines with both endorectal and pelvic phased-array coils

49. Evaluation of Local Recurrence After Treatment
MR spectroscopy detects recurrence after radical prostatectomy
84% and 88% sensitivity and specificity respectively
DWMRI
capable to detect cancer recurrence after radical prostatectomy in patients that conventional MRI has missed recurrence

50. In combination with T2-Weighted MRI
DW-MR imaging alone shows low sensitivity in cancer recurrence detection after radiotherapy (25%)
In combination with T2-Weighted MRI
sensitivity increases to 62%
Specificity in both condition is acceptable (92% vs 97%)

51. High resolution Multiparametric MR imaging
includes:
regular T1 weighted and T2 weighted images
dynamic contrast-enhanced MRI
diffusion weighted imaging
MR spectroscopy

52. High resolution Multiparametric MR imaging
Obtained in 1.5 T MR machines with simultaneous use of pelvic and endorectal coils
best imaging modality in prostate cancer
useful for
detection and local staging of prostate cancer
follow-up of patients after radical prostatectomy or radiation therapy
detection of skeletal metastasis
targeting biopsies in patients highly suspicious of prostate cancer but with previous negative TRUS guided biopsies

53. References