Pitfalls with MRI Evaluation of Prostate Cancer Detection

Okamura, Takehiko; Umemoto, Yukihiro; Yamashita, Kota; Suzuki, Shugo; Shirai, Tomoyuki; Hashimoto, Yoshihiro; Kohri, Kenjiro

doi:10.1159/000096332

Cited by 15 publications

(1 citation statement)

References 38 publications

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“…The clinical significance of the contralateral local failures after US-IMRT in patients with low-risk and low-volume disease is debatable, given that such patients typically have excellent clinical outcomes, even without radical therapy, under current active surveillance protocols [19]. Nevertheless, the contralateral failures in our study, despite MRI screening and enrollment of only low risk patients, underscore the multifocal nature of prostate cancer and highlight the limitations of MRI to reliably identify patients with unifocal disease who may be appropriate candidates for focal prostate cancer therapies, a topic of ongoing debate in the prostate cancer community [20-22]. …”

Section: Discussionmentioning

confidence: 95%

Randomized phase II trial of urethral sparing intensity modulated radiation therapy in low-risk prostate cancer: implications for focal therapy

et al. 2012

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BackgroundLow-risk prostate cancer (PCa) patients have excellent outcomes, with treatment modality often selected by perceived effects on quality of life. Acute urinary symptoms are common during external beam radiotherapy (EBRT), while chronic symptoms have been linked to urethral dose. Since most low-risk PCa occurs in the peripheral zone (PZ), we hypothesized that EBRT using urethral sparing intensity modulated radiation therapy (US-IMRT) could improve urinary health-related quality of life (HRQOL) while maintaining high rates of PCa control.MethodsPatients with National Comprehensive Cancer Network (NCCN) defined low-risk PCa with no visible lesion within 5 mm of the prostatic urethra on MRI were randomized to US-IMRT or standard (S-) IMRT. Prescription dose was 75.6 Gy in 41 fractions to the PZ + 3–5 mm for US-IMRT and to the prostate + 3 mm for S-IMRT. For US-IMRT, mean proximal and distal urethral doses were limited to 65 Gy and 74 Gy, respectively. HRQOL was assessed using the Expanded Prostate Cancer Index (EPIC) Quality of Life questionnaire. The primary endpoint was change in urinary HRQOL at 3 months.ResultsFrom June 2004 to November 2006, 16 patients were randomized, after which a futility analysis concluded that continued accrual was unlikely to demonstrate a difference in the primary endpoint. Mean change in EPIC urinary HRQOL at 3 months was −0.5 ± 11.2 in the US-IMRT arm and +3.9 ± 15.3 in the S-IMRT arm (p = 0.52). Median PSA nadir was higher in the US-IMRT arm (1.46 vs. 0.78, p = 0.05). At 4.7 years median follow-up, three US-IMRT and no S-IMRT patients experienced PSA failure (p = 0.06; HR 8.8, 95% CI 0.9–86). Two out of 3 patients with PSA failure had biopsy-proven local failure, both located contralateral to the original site of disease.ConclusionsCompared with S-IMRT, US-IMRT failed to improve urinary HRQOL and resulted in higher PSA nadir and inferior biochemical control. The high rate of PSA failure and contralateral local failures in US-IMRT patients, despite careful selection of MRI-screened low-risk patients, serve as a cautionary tale for focal PCa treatments.

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Section: Discussionmentioning

confidence: 95%

Randomized phase II trial of urethral sparing intensity modulated radiation therapy in low-risk prostate cancer: implications for focal therapy

et al. 2012

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Magnetic Resonance Spectroscopy of Prostate Cancer

Kurhanewicz

Vigneron

2016

eMagRes

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High spectral and spatial resolution MRI of age‐related changes in murine prostate

Foxley

Fan

Jansen

et al. 2008

Magnetic Resonance in Med

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The purpose of this work was to evaluate high resolution echo-planar spectroscopic magnetic resonance imaging of normal and pre-cancerous prostatic changes in a transgenic mouse line. Simian virus large T-antigen transgenic male mice (n = 7, age = 34 ± 3.7 weeks) with prostatic hyperplasia and intraepithelial neoplasia (PIN) were studied. High spectral and spatial resolution (HiSS) MRI of the water proton signal was compared to the FID integral image and conventional gradient echo and spin echo imaging. Water peak-height images of the prostate produced from HiSS datasets showed improved contrast-to-noise ratio (p < 0.03), and greater morphological detail (p < 0.004) based on texture analysis. Despite the high spectral resolution of the HiSS datasets, signal-to-noise ratio compared favorably with that of the FID integral and conventional images. Lobular features in HiSS images of older mice were consistent with hyperplasia seen on histology. A partially deuterated water-filled catheter was inserted in the mouse rectum for susceptibility matching between the colon interior and exterior to minimize image artifacts. These preliminary results suggest that HiSS MRI provides detailed morphology of the murine prostate and can detect early changes associated with the development of cancer. HiSS MRI of patients may have similar advantages.

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Pitfalls with MRI Evaluation of Prostate Cancer Detection

Cited by 15 publications

References 38 publications

Randomized phase II trial of urethral sparing intensity modulated radiation therapy in low-risk prostate cancer: implications for focal therapy

Randomized phase II trial of urethral sparing intensity modulated radiation therapy in low-risk prostate cancer: implications for focal therapy

Magnetic Resonance Spectroscopy of Prostate Cancer

High spectral and spatial resolution MRI of age‐related changes in murine prostate

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