Whole-Body MRI Found Superior to Bone Scan for Prognosis in Patients with Metastatic Prostate Cancer

The management of patients with advanced prostate cancer at time of diagnosis has changed considerably in recent years due to the development of multiple effective treatments.¹ Although metastatic prostate cancer has a 5-year survival rate of approximately 30%, earlier detection, more accurate local staging, identifying oligometastatic disease, and treatment response assessment with more precise imaging may help to improve management and clinical outcomes in patients with metastatic prostate cancer.¹ Treatment-naïve prostate cancer is sensitive to hormonal treatment with therapy consisting of combination treatment including androgen-deprivation therapy.¹ Optimal treatment for patients with advanced prostate cancer is dependent upon many life-prolonging therapies, with imaging contributing to tumor understanding by determining the extent and location of tumors, guiding biopsy sampling, demonstrating treatment response, and detecting treatment failure.¹

Iwamura and colleagues recently released results of a study that compared the prognostic significance of quantitative whole-body magnetic resonance imaging (MRI) and bone scan in patients with metastatic hormone-naïve prostate cancer. The results were published in the September 2021 edition of The Journal of Urology. The intent was to determine any associations between clinical factors, including calculated tumor volume and castration-resistant prostate cancer-free survival (CRPC-FS). The trial enrolled 22 participants with a median age of 73 years (range, 69-82 years) who had metastatic hormone-naïve prostate cancer and underwent whole-body MRI and bone scan at baseline.² All participants were treated with first-line gonadotropin-releasing hormone-antagonist monotherapy. The Attractive BD-Score^® was used to calculate total diffusion volume, and the BONENAVI diagnosis system was used to calculate the bone scan index (BSI). The median total diffusion volume at baseline was 104.2 mL, and the median BSI at baseline was 0.44%. The median follow-up period for this study was 17 months (range, 12-26 months).²

When Kaplan-Meier analysis was performed, participants with high total diffusion volume had a significantly worse CRPC-FS rate (89%) compared with participants with a low total diffusion volume, who had a CRPC-FS rate of 23%. There was no significant difference in CRPC-FS rates between high and low BSI groups.² Further evaluation with multivariate analysis demonstrated that high total diffusion volume was an independent risk factor for CRPC-FS, but high BSI had no association with CRPC-FS.

References

1. Perez-Lopez R, Tunariu N, Padhani AR, et al. Imaging diagnosis and follow-up of advanced prostate cancer: clinical perspectives and state of the art. Radiology. 2019;292:273-286.
2. Iwamura H, Ito J, Hatakeyama S, et al. MP11-16 comparison of quantitative whole-body MRI and bone scan for the prognosis of patients with metastatic hormone-naïve prostate cancer: a prospective study. J Urol. 2021;206:185.