The Association Between [68Ga]PSMA PET/CT Response and Biochemical Progression in Patients with High-Risk Prostate Cancer Receiving Neoadjuvant Therapy

Mengxia Chen; Yao Fu; Shan Peng; Shiming Zang; Shuyue Ai; Junlong Zhuang; Feng Wang; Xuefeng Qiu; Hongqian Guo

doi:10.2967/jnumed.122.265368

The Association Between [⁶⁸Ga]PSMA PET/CT Response and Biochemical Progression in Patients with High-Risk Prostate Cancer Receiving Neoadjuvant Therapy

J Nucl Med. 2023 Oct;64(10):1550-1555. doi: 10.2967/jnumed.122.265368. Epub 2023 Jul 20.

Authors

Mengxia Chen^{1

2}, Yao Fu³, Shan Peng³, Shiming Zang⁴, Shuyue Ai⁴, Junlong Zhuang^{1

2}, Feng Wang⁴, Xuefeng Qiu^{5

2}, Hongqian Guo^{5

2}

Affiliations

¹ Department of Urology, Affiliated Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China.
² Institute of Urology, Nanjing University, Nanjing, China.
³ Department of Pathology, Affiliated Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China; and.
⁴ Department of Nuclear Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, China.
⁵ Department of Urology, Affiliated Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China; dr.ghq@nju.edu.cn xuefeng_qiu@nju.edu.cn.

PMID: 37474268
DOI: 10.2967/jnumed.122.265368

Abstract

Our previous study found that the prostate-specific membrane antigen (PSMA) PET/CT response of primary prostate cancer (PCa) to neoadjuvant therapy can predict the pathologic response. This study was designed to investigate the association between [⁶⁸Ga]PSMA PET/CT changes and biochemical progression-free survival (bPFS) in high-risk patients who underwent neoadjuvant therapy before radical prostatectomy (RP). Methods: Seventy-five patients with high-risk PCa in 2 phase II clinical trials who received neoadjuvant therapy before RP were included. The patients received androgen deprivation therapy plus docetaxel (n = 33) or androgen deprivation therapy plus abiraterone (n = 42) as neoadjuvant treatment. All patients had serial [⁶⁸Ga]PSMA PET/CT scans before and after neoadjuvant therapy. Age, initial prostate-specific antigen level, nadir prostate-specific antigen level before RP, tumor grade at biopsy, treatment regimen, clinical T stage, PET imaging features, pathologic N stage, and pathologic response on final pathology were included for univariate and multivariate Cox regression analyses to identify independent predictors of bPFS. Results: With a median follow-up of 30 mo, 18 patients (24%) experienced biochemical progression. Multivariate Cox regression analyses revealed that only SUV_max derived from posttreatment [⁶⁸Ga]PSMA PET/CT and pathologic response on final pathology were independent factors for the prediction of bPFS, with hazard ratios of 1.02 (95% CI, 1.00-1.04; P = 0.02) and 0.12 (95% CI, 0.02-0.98; P = 0.048), respectively. Kaplan-Meier analysis revealed that patients with a favorable [⁶⁸Ga]PSMA PET/CT response (posttreatment SUV_max < 8.5) or a favorable pathologic response (pathologic complete response or minimal residual disease) had a significantly lower rate of 3-y biochemical progression. Conclusion: Our results indicated that [⁶⁸Ga]PSMA PET/CT response was an independent risk factor for the prediction of bPFS in patients with high-risk PCa receiving neoadjuvant therapy and RP, suggesting [⁶⁸Ga]PSMA PET/CT to be an ideal tool to monitor response to neoadjuvant therapy.

Keywords: [68Ga]PSMA PET/CT; biochemical progression; neoadjuvant therapy; prediction; prostate cancer.

MeSH terms

Androgen Antagonists
Androgens
Gallium Radioisotopes
Humans
Male
Neoadjuvant Therapy
Positron Emission Tomography Computed Tomography / methods
Prostate-Specific Antigen*
Prostatic Neoplasms* / diagnostic imaging
Prostatic Neoplasms* / drug therapy

Substances

Prostate-Specific Antigen
Gallium Radioisotopes
Androgen Antagonists
Androgens