MP18-09: More than meets the eye: Evaluating the effect of novel neoadjuvant androgen signaling inhibition on prostate multiparametric MRI
Friday, May 3, 2024 3:30 PM to 5:30 PM · 2 hr. (US/Central)
302B
Abstract
Information
Full Abstract and Figures
Author Block
Christopher R Koller*, Sahil H Parikh, Kyle C Schuppe, Charles Hesswani, William S Azar, Alexander P Kenigsberg, David G Gelikman, Neil Mendhiratta, Bethesda, MD, Sarah Azari, Northwest, DC, Daniel Nethala, Bethesda, MD, Samuel Gold, Dallas, TX, Sandeep Gurram, Ravi A Madan, Fatima Karzai, Baris Turkbey, Peter A Pinto, Bethesda, MD
Introduction
The role of neoadjuvant novel androgen signaling inhibitors (ASI) in prostate cancer (PCa) is established in the metastatic or castration resistant settings. The effect of neoadjuvant ASI on tumor anatomical characteristics and surgical planning remains an area of interest. Simultaneously, it remains unclear whether urologists should plan their surgery based on initial imaging or imaging after completion of ASI. We aim to determine whether radiologic changes between pre- and post-neoadjuvant therapy are reflective of final pathology.
Methods
In two phase II clinical trials starting in 2015, men with PCa received 6 months of enzalutamide & androgen deprivation therapy (ADT) with or without abiraterone. Multiparametric MRI (mpMRI) was obtained prior to the initiation of ASI and after completion. MRI features pre and post ASI included extraprostatic extension (EPE), seminal vesicle invasion (SVI), prostate volume, number of lesions, and largest tumor lesion diameter. The sensitivity and specificity of these radiologic findings were calculated to predict final pathology adverse features such as EPE & SVI. Paired t-test and X2 test were used to compare patient characteristics.
Results
We identified 41 patients with PCa who underwent radical prostatectomy after ASI. After neoadjuvant therapy, both prostate volume (40 vs 20 mL, p < 0.001) and largest tumor lesion diameter (2.8 vs. 1.4 cm, p < 0.001) significantly decreased in size. The average number of lesions also decreased after neoadjuvant therapy, from 1.7 to 1.1 lesions per patient (p = 0.002). 21 (31%) lesions of out a total of 68 achieved complete radiological response (radiological T0), after neoadjuvant ASI. The mpMRI prior to initiation of ASI was shown to have higher rates of ECE (70% vs 29%, p = 0.002) and similar SVI rates between both groups (32% vs. 15%, p = 0.07). In terms of predicting ECE on final pathology, pre-ASI mpMRI had a sensitivity of 87% and a specificity of 77% while post-ASI mpMRI had a sensitivity of 60% and specificity of 89%. The positive predictive value was 68% and 75% for the pre- and post-ASI mpMRI, respectively.
Conclusions
Neoadjuvant ASI prior to radical prostatectomy leads to radiographic changes of visible lesions on prostate MRI. Post-neoadjuvant MRI demonstrates increased specificity, but lower sensitivity, for ECE compared to pre-treatment MRI, suggesting that post-treatment MRI may not be reliable for ruling out adverse pathology on final prostatectomy and surgical planning should be based on initial mpMRI.
Source Of Funding
N/A
Author Block
Christopher R Koller*, Sahil H Parikh, Kyle C Schuppe, Charles Hesswani, William S Azar, Alexander P Kenigsberg, David G Gelikman, Neil Mendhiratta, Bethesda, MD, Sarah Azari, Northwest, DC, Daniel Nethala, Bethesda, MD, Samuel Gold, Dallas, TX, Sandeep Gurram, Ravi A Madan, Fatima Karzai, Baris Turkbey, Peter A Pinto, Bethesda, MD
Introduction
The role of neoadjuvant novel androgen signaling inhibitors (ASI) in prostate cancer (PCa) is established in the metastatic or castration resistant settings. The effect of neoadjuvant ASI on tumor anatomical characteristics and surgical planning remains an area of interest. Simultaneously, it remains unclear whether urologists should plan their surgery based on initial imaging or imaging after completion of ASI. We aim to determine whether radiologic changes between pre- and post-neoadjuvant therapy are reflective of final pathology.
Methods
In two phase II clinical trials starting in 2015, men with PCa received 6 months of enzalutamide & androgen deprivation therapy (ADT) with or without abiraterone. Multiparametric MRI (mpMRI) was obtained prior to the initiation of ASI and after completion. MRI features pre and post ASI included extraprostatic extension (EPE), seminal vesicle invasion (SVI), prostate volume, number of lesions, and largest tumor lesion diameter. The sensitivity and specificity of these radiologic findings were calculated to predict final pathology adverse features such as EPE & SVI. Paired t-test and X2 test were used to compare patient characteristics.
Results
We identified 41 patients with PCa who underwent radical prostatectomy after ASI. After neoadjuvant therapy, both prostate volume (40 vs 20 mL, p < 0.001) and largest tumor lesion diameter (2.8 vs. 1.4 cm, p < 0.001) significantly decreased in size. The average number of lesions also decreased after neoadjuvant therapy, from 1.7 to 1.1 lesions per patient (p = 0.002). 21 (31%) lesions of out a total of 68 achieved complete radiological response (radiological T0), after neoadjuvant ASI. The mpMRI prior to initiation of ASI was shown to have higher rates of ECE (70% vs 29%, p = 0.002) and similar SVI rates between both groups (32% vs. 15%, p = 0.07). In terms of predicting ECE on final pathology, pre-ASI mpMRI had a sensitivity of 87% and a specificity of 77% while post-ASI mpMRI had a sensitivity of 60% and specificity of 89%. The positive predictive value was 68% and 75% for the pre- and post-ASI mpMRI, respectively.
Conclusions
Neoadjuvant ASI prior to radical prostatectomy leads to radiographic changes of visible lesions on prostate MRI. Post-neoadjuvant MRI demonstrates increased specificity, but lower sensitivity, for ECE compared to pre-treatment MRI, suggesting that post-treatment MRI may not be reliable for ruling out adverse pathology on final prostatectomy and surgical planning should be based on initial mpMRI.
Source Of Funding
N/A
Sessions
MP18: Imaging/Uroradiology I
302B