Whole body MRI (WB-MRI) assessment of metastatic spread in prostate cancer: Therapeutic perspectives on targeted management of oligometastatic disease.

To determine the proportion of prostate cancer (PCa) patients with oligometastatic disease (≤3 synchronous lesions) using whole body magnetic resonance imaging with diffusion-weighted imaging (WB-MRI/DWI). To determine the proportion of patients with nodal disease confined within currently accepted target areas for extended lymph node dissection (eLND) and pelvic external beam radiation therapy (EBRT). Two radiologists reviewed WB-MRI/DWI studies in 96 consecutive newly diagnosed metastatic PCa patients; 46 patients with newly diagnosed castration naive PCa (mHNPC) and 50 patients with first appearance of metastasis during monitoring for non-metastatic castration resistant PCa (M0 to mCRPC). The distribution of metastatic deposits was assessed and the proportions of patients with oligometastatic disease and with LN metastases located within eLND and EBRT targets were determined. Twenty-eight percent of mHNPC and 50% of mCPRC entered the metastatic disease with ≤3 sites. Bone metastases (BM) were identified in 68.8% patients; 71.7% of mHNPC and 66% mCRPC patients. Most commonly involved areas were iliac bones and lumbar spine. Enlarged lymph nodes (LN) were detected in 68.7% of patients; 69.6% of mHNPC and 68.0% of mCRPC. Most commonly involved areas were para-aortic, inter-aortico-cava, and external iliac areas. BM and LN were detected concomitantly in 41% of mHNPC and 34% of mCRPC. Visceral metastases were detected in 6.7%. Metastatic disease was confined to LN located within the accepted boundaries of eLND or pelvic EBRT target areas in only ≤25% and ≤30% of patients, respectively. Non-invasive mapping of metastatic landing sites in PCa using WB-MRI/DWI shows that 28% of the mHNPC patients, and 52% of the mCRPC can be classified as oligometastatic, thus challenging the concept of metastatic targeted therapy. More than two thirds of metastatic patients have LN located outside the usually recommended targets of eLND and pelvic EBRT. Prophylactic or salvage treatments of these sole areas in patients with high-risk prostate cancer may not prevent the emergence of subsequent metastases. Prostate 76:1024-1033, 2016. © 2016 Wiley Periodicals, Inc.

Larbi A ，Dallaudière B ，Pasoglou V ，Padhani A ，Michoux N ，Vande Berg BC ，Tombal B ，Lecouvet FE ... -  《-》

Pattern of metastatic deposit in recurrent prostate cancer: a whole-body MRI-based assessment of lesion distribution and effect of primary treatment.

Pasoglou V ，Michoux N ，Van Damme J ，Van Nieuwenhove S ，Halut M ，Triqueneaux P ，Tombal B ，Lecouvet FE ... -  《-》

Topography of lymph node metastases in prostate cancer patients undergoing radical prostatectomy and extended lymphadenectomy: results of a combined molecular and histopathologic mapping study.

To determine the anatomic extent of pelvic lymph node dissection (PLND) in prostate cancer (PCa) patients at the time of radical prostatectomy (RP), knowledge about the topography of lymph node (LN) metastases is required. Because small-volume LN metastases may be missed by standard histopathologic examination, we performed an anatomic mapping study combining molecular and histopathologic LN examination in PCa patients treated with RP and extended PLND (ePLND). A total of 52 patients with intermediate- (n=15) and high-risk (n=37) PCa underwent RP and ePLND without neoadjuvant treatment. ePLND included dissection of the obturator fossa and the external, internal, and common iliac vessels. LNs ≥3 mm in diameter were analysed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) for prostate-specific antigen (PSA) expression and by standard histopathology. Topography of positive LNs was determined descriptively. Of 1469 dissected LNs (median: 27 LNs per patient), 1186 LNs were ≥3 mm. Molecular LN analysis was positive in 127 LNs of 27 patients (52%) including 32 LNs of 12 patients (23%) with histopathologic positive LNs. Molecular examination was negative in 3 of 35 histopathologic positive LNs (9%). Combining both molecular and histopathologic findings, positive LNs were located in the standard PLND field defined by obturator fossa and external iliac vessels in 71%, along the internal iliac vessels in 16%, and along the common iliac vessels in 13%. Of LN-positive patients, 63% had LN metastases outside the standard PLND field. The internal iliac field was involved in 48% and the common iliac field in 37% of node-positive patients. Notably, internal and common iliac vessels were the only positive regions in 7% and 11% of node-positive patients, respectively. A limitation is the small number of patients included. These findings underline the enhanced sensitivity of qRT-PCR in comparison with standard histopathology for detection of small-volume LN metastases in PCa patients. Our results support an ePLND including the common iliac vessels, at least up to the ureteral crossing, to optimise nodal staging and to remove LNs potentially harbouring metastases.

Heck MM ，Retz M ，Bandur M ，Souchay M ，Vitzthum E ，Weirich G ，Mollenhauer M ，Schuster T ，Autenrieth M ，Kübler H ，Maurer T ，Thalgott M ，Herkommer K ，Gschwend JE ，Nawroth R ... -  《-》

Patterns of Lymph Node Failure after Dose-escalated Radiotherapy: Implications for Extended Pelvic Lymph Node Coverage.

Clinical trials evaluating the benefit of pelvic radiotherapy (PRT) in the radiotherapeutic management of patients with higher-risk prostate cancer have limited the superior field border to the S1/S2 or L5/S1 interspace. However, imaging and surgical series have demonstrated a high frequency of prostatic lymph node (LN) drainage beyond these landmarks. To determine the patterns of radiographically defined abdominopelvic LN failures and their potential implications for PRT field design. During 1992-2008, 2694 patients with localized prostate cancer were treated with prostate/seminal vesicle-only radiotherapy without PRT. Some 156 patients had their first failure within the abdominopelvic LNs, of whom 60 had isolated failures within the pelvic LNs. A radiologist reviewed all imaging and mapped each LN failure to a template consisting of 34 abdominopelvic LN stations. The median follow-up was 8.9 yr. Of patients who experienced first recurrence in the pelvic LNs (n=60), the common iliac station was involved in 55% (n=33) of patients, including 10% (n=6) who had isolated common iliac failures. Use of a PRT field superior border of L5/S1 would fully cover only 42% of the first recurrences among these patients. Extending the field to cover the common iliac stations would increase coverage to 93% of recurrences. The presence of T3/T4 disease and omission of androgen-deprivation therapy both independently conferred an approximate fivefold increase in the likelihood of having a common iliac LN failure. Use of imaging as a surrogate for LN involvement is the primary study limitation. Pelvic LN failures frequently occur superior to the commonly used L5/S1 landmark for PRT coverage, and use of ADT may be protective of more superior LN failures. The current RTOG 0924 trial is evaluating the benefit of PRT with extended superior coverage to L4/5 when possible, which, according to our data, should significantly improve the coverage of potential sites of failure. We looked at lymph node recurrence patterns after external beam radiotherapy of the prostate in men who did not have their lymph nodes treated. We found that there was a high incidence of pelvic lymph node recurrences above the internal and external iliac lymph node regions. Therefore, the current field recommendation for pelvic lymph nodes that stops at the superior border of the internal and external iliac vessels provides inadequate coverage of common sites of cancer recurrence, namely the common iliac lymph nodes.

Spratt DE ，Vargas HA ，Zumsteg ZS ，Golia Pernicka JS ，Osborne JR ，Pei X ，Zelefsky MJ ... -  《-》

Can whole-body magnetic resonance imaging with diffusion-weighted imaging replace Tc 99m bone scanning and computed tomography for single-step detection of metastases in patients with high-risk prostate cancer?

Technetium Tc 99m bone scintigraphy (BS) and contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) of the pelvis and abdomen are universally recommended for detecting prostate cancer (PCa) metastases in cancer of all stages. However, this two-step approach has limited sensitivity and specificity. Evaluate the diagnostic accuracy of whole-body MRI (WBMRI) as a one-step screening test for PCa metastases. One hundred consecutive PCa patients at high risk for metastases prospectively underwent WBMRI, CT, and BS completed with targeted x-rays (BS/TXR) in case of equivocal BS. Four independent reviewers reviewed the images. This study compares the diagnostic performance of WBMRI, CT, BS, and BS/TXR in detecting PCa metastases using area under the curve (AUC) receiver operator characteristics. A best valuable comparator (BVC) approach was used to adjudicate final metastatic status in the absence of pathologic evaluation. Based on the BVC, 68 patients had metastases. The sensitivity of BS/TXR and WBMRI for detecting bone metastases was 86% and 98-100%, respectively (p<0.04), and specificity was 98% and 98-100%, respectively. The first and second WBMRI readers respectively identified bone metastases in 7 and 8 of 55 patients with negative BS/TXR. The sensitivity of CT and WBMRI for detecting enlarged lymph nodes was similar, at 77-82% for both; specificity was 95-96% and 96-98%, respectively. The sensitivity of the combination of BS/TXR plus CT and WBMRI for detecting bone metastases and/or enlarged lymph nodes was 84% and 91-94%, respectively (p=0.03-0.10); specificities were 94-97% and 91-96%, respectively. The 95% confidence interval of the difference between the AUC of the worst WBMRI reading and the AUC of any of the BS/TXR plus CT lay within the noninferiority margin of ±10% AUC. WBMRI outperforms BS/TXR in detecting bone metastases and performs as well as CT for enlarged lymph node evaluation. WBMRI can replace the current multimodality metastatic work-up for the concurrent evaluation of bones and lymph nodes in high-risk PCa patients.

Lecouvet FE ，El Mouedden J ，Collette L ，Coche E ，Danse E ，Jamar F ，Machiels JP ，Vande Berg B ，Omoumi P ，Tombal B ... -  《-》