Value of image fusion in the staging of prostatic carcinoma.
OBJECTIVE
We assessed the value of image fusion in the staging of prostatic cancer in a series of 32 patients who underwent preoperative evaluation with transrectal colour-Doppler ultrasonography (TRUS) and magnetic resonance imaging (MRI).


METHODS
Colour-Doppler TRUS exams were performed using a 7.5-MHz biplanar probe. MRI exams were done with a scanner operating at 1.5 Tesla (T) using an endorectal coil. All patients underwent radical prostatectomy within 2 weeks from the imaging assessment. Whole-mount sections were prepared from the surgical specimens and were subsequently digitised by using a high-resolution scanner. The Digital Imaging and Communications in Medicine (DICOM) TRUS and MR images as well as the digitised pathological images were transferred to a graphic workstation to perform image fusion.


RESULTS
Image fusion was technically possible in 25/32 cases in which axial TRUS images were available. The following fusion images were obtained: TRUS + pathological sections; MRI + pathological sections; TRUS + MRI + pathological sections. The final pathological staging concerning the T status was: four pT2b, fourteen pT2c, three pT3a and four pT3b. The three types of image fusion led to the following results: TRUS + pathological sections, correct staging in 20/25 cases (accuracy 80%); MRI + pathological sections, correct staging in 22/25 cases (accuracy 88%); TRUS + MRI + pathological sections, correct staging in 23/25 cases (accuracy 92%).


CONCLUSIONS
Our study suggests that by using image fusion between colour-Doppler TRUS and endorectal MRI, it is possible to improve the accuracy of pathological staging in patients who are candidates for radical prostatectomy.
Selli
C
C
Division of Urology, Department of Surgery, Pisa University Hospitals, Pisa, Italy.
Caramella
D
D
Giusti
S
S
Conti
A
A
Tognetti
A
A
Mogorovich
A
A
De Maria
M
M
Bartolozzi
C
C
D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000473:pathology*; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016612:Paraffin Embedding; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000032:analysis; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D012669:Seminal Vesicles / Q000473:pathology; D012680:Sensitivity and Specificity; D016707:Tissue Fixation; D018615:Ultrasonography, Doppler, Color / Q000379:methods*
D017430:Prostate-Specific Antigen