Preoperative Magnetic Resonance (MR) Imaging of Prostate Cancer

Background:

During the last two decades, Magnetic Resonance Imaging (MRI) of the prostate has evolved to become a promising tool in preoperative evaluation of prostate cancer. Several studies have evaluated the radiological and histopathological correlation. However, the sensitivity and specificity in regard to staging have shown wide ranges and poor reproducibility. These discrepancies can be explained by difference in patient selection, MRI methods, and criteria used for diagnosis. More studies are therefore needed to evaluate the clinical impact of preoperative MRI in patients with prostate cancer.

Aims of the study:

To evaluate 1) detection rate of tumor 1-3 (tumor 1 = index tumor), size of tumor 1-3, possible extraprostatic extension and predict presence of Gleason grade 4 and 5 tumor, 2) the influence of preoperative MRI on the surgical decision process with respect to the operative procedure for removal of the gland and pelvic lymph node dissection, and 3) the impact of preoperative MRI on the rate of positive surgical margins and functional results.

Material and method:

A prospective study including 400 consecutive patients referred to robot assisted laparoscopic prostatectomy randomised to preoperative MRI (intervention group) and no MRI (control group). The prostatectomy specimens will be histopathologically examined, and TNM classification will be performed according to 2002 AJCC standard.

Inclusion criteria

• All patients suitable for surgery.
• Positive biopsy (Gleason grade >3).
• Informed consent.

Exclusion criteria

• Patients who do not sign the consent paper for any reason or do not accept the study premises.
• Patents who want to withdraw for any reason during the study.
• Patients with contraindications to MRI (pacemaker, claustrophobia etc) and/or surgery.
• Patients who have undergone a high quality MRI examination of the prostate at another radiological center. In this situation the MR examination is evaluated together with the surgeon but the patient is not included in the study. (In case of a low quality examinations, we will disregard the findings, and include the patient).
• If the surgeon finds it unacceptable to perform RALP without MRI, because of various reasons (eg. patient demand, too high risk etc) the patient will not be included in the study.
• If preoperative MRI reveals extensive tumor invasion into adjacent organ (T4) or skeletal metastases (M1), as these cancer stadiums do not benefit from RALP.