Tumor lesion diameter on diffusion weighted magnetic resonance imaging could help predict insignificant prostate cancer in patients eligible for active surveillance: preliminary analysis.

PURPOSE We analyzed the pathological outcomes of candidates for active surveillance according to tumor lesion diameter on diffusion weighted magnetic resonance imaging. MATERIALS AND METHODS We retrospectively analyzed 188 candidates for active surveillance who had undergone diffusion weighted magnetic resonance imaging before radical prostatectomy between 2006 and 2012. We measured the diameter of the suspicious tumor lesion on diffusion weighted magnetic resonance imaging and stratified the cohort into 2 groups. Group 1 included patients with normal magnetic resonance imaging or a suspicious tumor lesion smaller than 1 cm and group 2 included patients with a suspicious tumor lesion larger than 1 cm. We compared pathological outcomes including insignificant prostate cancer in each group and analyzed whether different tumor diameters resulted in a change in insignificant prostate cancer rates. RESULTS Group 1 consisted of 115 (61.2%) patients and group 2 included 73 (38.8%) patients. In group 1 magnetic resonance imaging was normal in 72 patients. Mean ± SD diameter of suspicious tumor lesions was 12.0 ± 5.58 mm. Tumor volume was significantly different between the groups (0.73 ± 0.86 vs 1.09 ± 1.07 cm(3), p = 0.018), as was the rate of insignificant prostate cancer (48.7% vs 24.7%, p = 0.001). The rate of insignificant prostate cancer decreased as tumor diameter increased over 1 cm. On multivariate logistic regression analysis the diameter of suspicious tumor lesions was an important predictor of insignificant prostate cancer (OR 0.319, p = 0.014). CONCLUSIONS Our analysis demonstrates that the simple measurement of the diameter of suspicious tumor lesions on diffusion weighted magnetic resonance imaging could improve the prediction of insignificant prostate cancer in candidates for active surveillance.

[1]  A. Evans,et al.  ‘Prostatic evasive anterior tumours’: the role of magnetic resonance imaging , 2010, BJU international.

[2]  T. Metens,et al.  What is the optimal b value in diffusion-weighted MR imaging to depict prostate cancer at 3T? , 2012, European Radiology.

[3]  J. Epstein,et al.  Letters to the Editor/Errata Re: Radical Prostatectomy Findings in Patients in Whom Active Surveillance of Prostate Cancer Fails , 2010 .

[4]  Neil Fleshner,et al.  Impact of multiparametric endorectal coil prostate magnetic resonance imaging on disease reclassification among active surveillance candidates: a prospective cohort study. , 2012, The Journal of urology.

[5]  Cher Heng Tan,et al.  Diffusion-weighted MRI in the detection of prostate cancer: meta-analysis. , 2012, AJR. American journal of roentgenology.

[6]  D. Dearnaley,et al.  A study of diffusion-weighted magnetic resonance imaging in men with untreated localised prostate cancer on active surveillance. , 2009, European urology.

[7]  P. Walsh,et al.  Pathologic and clinical findings to predict tumor extent of nonpalpable (stage T1c) prostate cancer. , 1994, JAMA.

[8]  Y. Choi,et al.  Comparison of pathological outcomes of active surveillance candidates who underwent radical prostatectomy using contemporary protocols at a high-volume Korean center. , 2012, Japanese journal of clinical oncology.

[9]  Alexandre Mamedov,et al.  Clinical results of long-term follow-up of a large, active surveillance cohort with localized prostate cancer. , 2010, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[10]  Thomas Hambrock,et al.  Relationship between apparent diffusion coefficients at 3.0-T MR imaging and Gleason grade in peripheral zone prostate cancer. , 2011, Radiology.

[11]  Baris Turkbey,et al.  Correlation of magnetic resonance imaging tumor volume with histopathology. , 2012, The Journal of urology.

[12]  K. Nakagawa,et al.  Maximum tumor diameter is a simple and valuable index associated with the local extent of disease in clinically localized prostate cancer , 2006, International journal of urology : official journal of the Japanese Urological Association.

[13]  Beom Jin Park,et al.  Detectability of low and intermediate or high risk prostate cancer with combined T2-weighted and diffusion-weighted MRI , 2012, European Radiology.

[14]  Kazuro Sugimura,et al.  Prostate cancer detection with 3 T MRI: Comparison of diffusion‐weighted imaging and dynamic contrast‐enhanced MRI in combination with T2‐weighted imaging , 2010, Journal of magnetic resonance imaging : JMRI.

[15]  Yousef Mazaheri,et al.  Diffusion-weighted endorectal MR imaging at 3 T for prostate cancer: tumor detection and assessment of aggressiveness. , 2011, Radiology.

[16]  N M deSouza,et al.  Diffusion-weighted magnetic resonance imaging: a potential non-invasive marker of tumour aggressiveness in localized prostate cancer. , 2008, Clinical radiology.

[17]  Masoom A Haider,et al.  Combined T2-weighted and diffusion-weighted MRI for localization of prostate cancer. , 2007, AJR. American journal of roentgenology.

[18]  M. Jordá,et al.  Pathologic prostate cancer characteristics in patients eligible for active surveillance: a head-to-head comparison of contemporary protocols. , 2012, European urology.

[19]  Jason A Koutcher,et al.  Prostate tumor volume measurement with combined T2-weighted imaging and diffusion-weighted MR: correlation with pathologic tumor volume. , 2009, Radiology.

[20]  Alan W Partin,et al.  Active Surveillance Program for Prostate Cancer: An Update of the Johns Hopkins Experience , 2011 .