Diffusion-Weighted Magnetic Resonance Diagnosis of Local Recurrences of Prostate Cancer after Radical Prostatectomy: Preliminary Evaluation on Twenty-Seven Cases

Abstract

Objectives. To assess the diagnostic performance of diffusion-weighted MR imaging (DWI) in patients affected by prostatic fossa (PF) relapse after radical prostatectomy (RP) for prostatic carcinoma (PC). Methods. Twenty-seven patients showing a nodular lesion in the PF at T2-weighted MR imaging after RP, with diagnosis of PC relapse established by biopsy or PSA determinations, were investigated by DWI. Two readers evaluated the DWI results in consensus and the apparent diffusion coefficient (ADC) of the nodules, separately; a mean value was obtained (ADCm). Results. Relapses did not significantly differ in size in respect of postsurgical benign nodules. The DWI qualitative evaluation showed sensitivity, specificity, accuracy, ppv, and npv values, respectively, of 83.3%, 88.9%, 85.2%, 93.7%, and 72.7% (100%, 87.5%, 95.6%, 93.7%, and 100%, for nodules >6 mm). The intraclass correlation coefficient (ICC) for ADC evaluation between the two readers was 0.852 (95% CI 0.661–0.935; P = 0.0001). The ADCm values for relapses and benign nodules were, respectively, 0.98 ± 0.21 × 10−3 mm2/sec and 1.24 ± 0.32 × 10−3 mm2/sec (P = 0.006). Sensitivity, specificity, accuracy, ppv and npv of ADCm were, respectively, 77.8%, 88.9%, 81.8%, 93.3%, and 66.7% (93.3%, 87.5%, 85.4%, 93.3%, and 87.5% for nodules >6 mm). Conclusions. Diffusion-weighted MR imaging is a promising tool in the management of a hyperintense nodule detected by T2-weighted sequences. This might have a relevant importance in contouring radiotherapy treatment volumes.

Apparent diffusion coefficient in the analysis of prostate cancer: determination of optimal b-value pair to differentiate normal from malignant tissue

“…In our study, for similar combinations (maximum b-values between 500 and 1100 s/mm 2 combined with b = 0 s/mm 2 ), the range of ADC values for PCa was equivalent (1.01-1.32 × 10 − 3 mm 2 /s). However, for both areas of normal glandular tissue (PZ and CG), the range and mean ADC values were lower than those previously reported [8,13,16,17,19].…”

“…Our results demonstrate that PCa and normal tissue ADC values vary substantially with b-value combinations, in agreement with other studies. Previous ADC quantification studies used maximum b-values from 400 to 1000 s/mm 2 combined with b = 0 s/mm 2 , reporting ADC in PCa between 0.71 and 1.87 × 10 − 3 mm 2 /s and 1.03-3.71 × 10 − 3 mm 2 /s in healthy tissue [8,13,16,17,[19][20][21]. In our study, for similar combinations (maximum b-values between 500 and 1100 s/mm 2 combined with b = 0 s/mm 2 ), the range of ADC values for PCa was equivalent (1.01-1.32 × 10 − 3 mm 2 /s).…”

Functional Magnetic Resonance Imaging in the Diagnosis of Locally Recurrent Prostate Cancer: Are All Pulse Sequences Helpful?

“…After reading the full texts of the 93 articles, we excluded 66 because 1) the aim was not to assess the diagnostic value of MRI for identification and characterization of locally recurrent prostate cancer (n = 44), 2) histopathology analysis and/or follow-up clinical analysis and imaging at 6 months post-surgery were not used as the reference standard (n = 2), 3) sufficient date were not reported for constructing 2 × 2 tables (n = 10), or 4) results were reported for combinations of imaging modalities but not for individual modalities (n = 10). Finally, 27 articles ( 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 ) fulfilled all inclusion criteria and were selected for data extraction and data analysis ( Fig. 1 ).…”

“…Study characteristics are shown in Supplementary Table 1 (in the online-only Data Supplement). Of the 27 studies, 15 were published after January 1, 2010 ( 21 22 23 24 25 30 34 37 38 39 40 42 43 44 45 ). The number of patients per study ranged widely from 11 to 176, and the number of sectors ranged from 42 to 318.…”

“…The number of patients per study ranged widely from 11 to 176, and the number of sectors ranged from 42 to 318. Results were analyzed on a per-patient basis in 20 studies ( 22 23 24 25 26 28 29 30 32 33 34 35 36 37 38 39 40 44 45 46 ) and on a per-lesion basis in 10 studies ( 20 21 23 25 26 27 31 41 42 43 ). A pelvic phased-array coil was used in 13 studies, an endorectal coil in two studies, and a combination of the two in 12 studies.…”