Raymond Oyen

The contribution of magnetic resonance imaging to the three-dimensional treatment planning of localized prostate cancer.

PURPOSE To investigate whether the use of transaxial and coronal MR imaging improves the ability to localize the apex of the prostate and the anterior part of the rectum compared to the use of transaxial CT alone, and whether the incorporation of MR could improve the coverage of the prostate by the radiotherapy field and change the volume of rectum irradiated. METHODS AND MATERIALS Ten consecutive patients with localized prostate carcinoma underwent a CT and an axial and coronal MR scan in treatment position. The CT and MR images were mathematically aligned, and three observers were asked to contour independently the prostate and the rectum on CT and on MR. The interobserver variability of the prostatic apex location and of the delineation of the anterior rectal wall were assessed for each image modality. A dosimetry study was performed to evaluate the dose to the rectum when MR was used in addition to CT to localize the pelvic organs. RESULTS The interobserver variation of the prostatic apex location was largest on CT ranging from 0.54 to 1.07 cm, and smallest on coronal MR ranging from 0.17 to 0.25 cm. The interobserver variation of the delineation of the anterior rectum on MR was small and constant along the whole length of the prostate (0.09+/-0.02 cm), while for CT it was comparable to that for the MR delineation at the base of the prostate, but it increased gradually towards the apex, where the variation reached 0.39 cm. The volume of MR rectum receiving more than 80% of the prescribed dose was on average reduced by 23.8+/-11.2% from the CT to the MR treatment plan. CONCLUSION It can be concluded that the additional use of axial and coronal MR scans, in designing the treatment plan for localized prostate carcinoma, improves substantially the localization accuracy of the prostatic apex and the anterior aspect of the rectum, resulting in a better coverage of the prostate and a potential to reduce the volume of the rectum irradiated to a high dose.

Neoadjuvant Hormonal Therapy Before Radical Prostatectomy Decreases the Number of Positive Surgical Margins in Stage T2 Prostate Cancer: Interim Results of a Prospective Randomized Trial

PURPOSE We investigated the effect of neoadjuvant treatment before radical prostatectomy for clinically localized prostate cancer. MATERIALS AND METHODS A total of 130 patients with stages T2b and T3 prostate cancer was randomized in a multicenter study: 62 underwent immediate radical prostatectomy and 65 received 560 mg. estramustine phosphate daily for 6 weeks preoperatively. RESULTS For clinical stage T2b tumors the neoadjuvant treatment resulted in a significant decrease in positive surgical margins compared to the nonpretreated group. This difference was not found for clinical stage T3 tumors. The impact on progression and survival still must be analyzed. CONCLUSIONS Neoadjuvant treatment can be beneficial for clinical stage T2 prostate cancer. Optimal treatment for stage T3 tumors remains controversial.

FDG-PET for preoperative staging of bladder cancer

PurposeThe presence of lymph node involvement (N) and distant metastasis (M) in patients with invasive bladder carcinoma is a major determinant of survival and, therefore, a pivotal element in the therapeutic management. The aim of this prospective study was to evaluate the use of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in this indication.MethodsWhole-body FDG-PET and computed tomography (CT) were performed in 55 patients with non-metastatic invasive bladder cancer for preoperative staging. Correlative imaging of PET with CT was performed, leading to a PET(CT) result. The imaging results were compared with the gold standard, consisting of histopathology (lymphadenectomy, guided biopsy) or clinical follow-up for 12 months, and related to overall survival using the Kaplan-Meier method.ResultsThe gold standard was available in 40 patients and indicated NM-positive disease in 15 patients (12 N lesions, 8 M lesions), and NM-negative disease in 25 patients. For the diagnosis of NM-positive disease, the sensitivity, specificity and accuracy of PET(CT) were 60%, 88% and 78%, respectively. Diagnostic discordances between PET(CT) and CT alone were found in 9/40 patients, among whom PET was correct in six (15%): three with true-positive and one with true-negative distant metastases, and two with true-negative lymph nodes. Median survival time of patients in whom PET(CT) indicated NM-positive disease was 13.5 months, compared with 32.0 months in the patients with a NM-negative PET(CT) (p=0.003).ConclusionAddition of metabolism-based information provided by FDG-PET to CT in the preoperative staging of invasive bladder carcinoma yields a high diagnostic and prognostic accuracy.

PARTIAL NEPHRECTOMY FOR RENAL CELL CARCINOMA CAN ACHIEVE LONG-TERM TUMOR CONTROL

PURPOSE Partial nephrectomy is becoming more widely accepted as alternative treatment for small renal cell carcinoma. To analyze its value in tumor control and its complication rate a retrospective study was done. MATERIALS AND METHODS A total of 76 patients underwent kidney sparing surgery, which was required in 25 and in the presence of a normal contralateral kidney in 51. Tumor size varied between 0.9 and 15 cm. Simple enucleation was done in 4 and partial nephrectomy in all other cases. The patients were followed every 3 months during year 1, every 4 months during years 2 and 3, and every 6 months during years 4 and 5 postoperatively. Mean followup is 75 months. RESULTS Eight patients had postoperative complications, most often hemorrhage. None of the patients had local recurrence, although in 3 systemic disease developed. CONCLUSIONS Nephron sparing surgery is more challenging than radical nephrectomy and, therefore, can be more complicated. The selection of suitable candidates is the key to success. Many patients can benefit from nephron sparing surgery for small easily resectable renal cell carcinoma even in presence of a normal contralateral kidney. Randomized trials are needed to establish the definitive role of this approach in kidney cancer treatment.

Mapping of Pelvic Lymph Node Metastases in Prostate Cancer

BACKGROUND Opinions about the optimal lymph node dissection (LND) template in prostate cancer differ. Drainage and dissemination patterns are not necessarily identical. OBJECTIVE To present a precise overview of the lymphatic drainage pattern and to correlate those findings with dissemination patterns. We also investigated the relationship between the number of positive lymph nodes (LN+) and resected lymph nodes (LNs) per region. DESIGN, SETTING, AND PARTICIPANTS Seventy-four patients with localized prostate adenocarcinoma were prospectively enrolled. Patients did not show suspect LNs on computed tomography scan and had an LN involvement risk of ≥ 10% but ≤ 35% (Partin tables) or a cT3 tumor. INTERVENTION After intraprostatic technetium-99m nanocolloid injection, patients underwent planar scintigraphy and single-photon emission computed tomography imaging. Then surgery was performed, starting with a sentinel node (SN) procedure and a superextended lymphadenectomy followed by radical prostatectomy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Distribution of scintigraphically detected SNs and removed SNs per region were registered. The number of LN+, as well as the percentage LN+ of the total number of removed LNs per region, was demonstrated in combining data of all patients. The impact of the extent of LND on N-staging and on the number of LN+ removed was calculated. RESULTS AND LIMITATIONS A total of 470 SNs were scintigraphically detected (median: 6; interquartile range [IQR]: 3-9), of which 371 SNs were removed (median: 4; IQR: 2.25-6). In total, 91 LN+ (median: 2; IQR: 1-3) were found in 34 of 74 patients. The predominant site for LN+ was the internal iliac region. An extended LND (eLND) would have correctly staged 32 of 34 patients but would have adequately removed all LN+ in only 26 of 34 patients. When adding the presacral region, these numbers increased to 33 of 34 and 30 of 34 patients, respectively. CONCLUSIONS Standard eLND would have correctly staged the majority of LN+ patients, but 13% of the LN+ would have been missed. Adding the presacral LNs to the template should be considered to obtain a minimal template with maximal gain. NOTE: This manuscript was invited based on the 2011 European Association of Urology meeting in Vienna.

Pelvic floor descent in females: comparative study of colpocystodefecography and dynamic fast MR imaging.

The purpose of this study was to compare fast dynamic magnetic resonance imaging (MRI) with colpocystodefecography (CCD) in the evaluation of pelvic floor descent in women. Thirty‐five women with clinical evidence of pelvic floor descent were studied. A fast single‐shot MR sequence was performed in the supine position during pelvic floor relaxation and during maximal pelvic strain. On the same day, a dynamic CCD was performed with the patient seated on a stool‐chair. The degree of descent of the bladder, vagina, and anorectal junction was evaluated as the vertical distance between the pubococcygeal line and the bladder base, the vaginal vault, and the anorectal junction, respectively. A bulge of more than 3 cm measured as the distance between the extended line of the anterior border of the anal canal and the tip of the rectocele was interpreted as a rectocele. MRI was compared with CCD during maximal pelvic strain (CCD I) and during voiding and defecation (CCD II). CCD was considered as the gold standard. Compared with clinical examination, CCD I showed a larger number of involved compartments, except for the middle compartment. CCD II was superior to clinical examination in all cases. In comparison with CCD I and especially CCD II, MRI had a lower sensitivity, especially for the anterior and middle compartment. Even four enteroceles seen on CCD II were not detected by MRI. When CCD I and CCD II were compared, a cystocele, a vaginal vault prolapse, an enterocele, and a rectocele were more readily seen on CCD II than with CCD I. When compared with CCD, supine dynamic MRI is unreliable, especially in the anterior and middle compartment. Even in the detection of enteroceles CCD was superior to MRI. In general, the best results with MRI can be expected for evaluation of the rectum.J. Magn. Reson. Imaging 1999;9:373–377.

Prospective Evaluation of 11C-Choline Positron Emission Tomography/Computed Tomography and Diffusion-Weighted Magnetic Resonance Imaging for the Nodal Staging of Prostate Cancer with a High Risk of Lymph Node Metastases

BACKGROUND Contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging for lymph node (LN) staging of prostate cancer (PCa) are largely inadequate. OBJECTIVE Our aim was to assess prospectively the sensitivity, specificity, and positive and negative predictive values for the LN staging by (11)C-choline positron emission tomography (PET)-CT and MR diffusion-weighted imaging (DWI) of the pelvis before retropubic radical prostatectomy (RRP) with extended pelvic LN dissection (PLND). DESIGN, SETTING, AND PARTICIPANTS From February 2008 to August 2009, 36 patients with histologically proven PCa and no pelvic LN involvement on contrast-enhanced CT with a risk ≥ 10% but ≤ 35% at LN metastasis according to the Partin tables were enrolled in this study. INTERVENTION Patients preoperatively underwent (11)C-choline PET-CT and DWI. Subsequently all patients underwent a wide RRP and an extended PLND. MEASUREMENTS Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for LN status of (11)C-choline PET-CT and DWI were calculated with the final histopathology of the LNs as comparator. RESULTS AND LIMITATIONS Seventeen patients (47%) had a pN1 stage, and 38 positive LNs were identified. On a LN region-based analysis, sensitivity, specificity, PPV, NPV, and the number of correctly recognised cases at (11)C-choline PET-CT were 9.4%, 99.7%, 75.0%, 91.0%, and 7.9%, respectively, and at DWI these numbers were 18.8%, 97.6%, 46.2%, 91.7%, and 15.8%, respectively. Twelve LN regions containing macrometastases, of which 2 had capsular penetration, were not detected by (11)C-choline PET-CT; 11 LNs, of which 2 had capsular penetration, were not detected by DWI. This is a small study with 36 patients, but we intend to recruit more patients. CONCLUSIONS From this prospective histopathology-based evaluation of (11)C-choline PET-CT and DWI for LN staging in high-risk PCa patients, it is concluded that these techniques cannot be recommended at present to detect occult LN metastases before initial treatment.

A phase II trial with rosiglitazone in liposarcoma patients

Agents of the thiazolidinedione drug family can terminally differentiate human liposarcoma cells in vitro by activating genes responsible for lipocyte differentiation. One study has shown clinical activity of troglitazone treatment in liposarcoma patients. We sought to find further evidence for this result. In all, 12 patients with a liposarcoma received rosiglitazone 4 mg b.d. They were followed clinically and with repeated biopsies for histological and biological studies. At the molecular level the mRNA translation of three genes that are induced by this treatment (peroxisome proliferator-activated receptor γ (PPARγ), adipsin and fatty acid binding protein) was determined. Nine patients were eligible for evaluation. One patient had to stop treatment due to hepatotoxicity. The mean time to progression was 6 months (2 – 16 months), with one patient still on treatment. We did not see any significant change in histologic appearance of the liposarcomas by the treatment. The level of gene expression changed significantly in two patients, but this did not result in a clinical response. Based on this study, rosiglitazone is not effective as an antitumoral drug in the treatment of liposarcomas. Increased PPARγ activity does not correlate with the clinical evolution.

Multiparametric MRI for prostate cancer localization in correlation to whole-mount histopathology

To prospectively evaluate multiparametric magnetic resonance imaging (MRI) for accurate localization of intraprostatic tumor nodules, with whole‐mount histopathology as the gold standard.

Neoadjuvant hormonal therapy before radical prostatectomy decreases the number of positive surgical margins in stage T2 prostate cancer: interim results of a prospective randomized trial. The Belgian Uro-Oncological Study Group.

Purpose We investigated the effect of neoadjuvant treatment before radical prostatectomy for clinically localized prostate cancer. Materials and methods A total of 130 patients with stages T2b and T3 prostate cancer was randomized in a multicenter study: 62 underwent immediate radical prostatectomy and 65 received 560 mg. estramustine phosphate daily for 6 weeks preoperatively. Results For clinical stage T2b tumors the neoadjuvant treatment resulted in a significant decrease in positive surgical margins compared to the nonpretreated group. This difference was not found for clinical stage T3 tumors. The impact on progression and survival still must be analyzed. Conclusions Neoadjuvant treatment can be beneficial for clinical stage T2 prostate cancer. Optimal treatment for stage T3 tumors remains controversial.