The predictive role of ADC values in prostate cancer patients treated with carbon-ion radiotherapy: initial clinical experience at Shanghai Proton and Heavy Ion Center (SPHIC)

Wei-Xiang Qi; Qing Zhang; Ping Li; Xiao-Meng Zhang; Guang-Yuan Zhang; Bin Wu; Jiade J Lu; Guo-Liang Jiang; Shen Fu

doi:10.1007/s00432-016-2142-3

The predictive role of ADC values in prostate cancer patients treated with carbon-ion radiotherapy: initial clinical experience at Shanghai Proton and Heavy Ion Center (SPHIC)

J Cancer Res Clin Oncol. 2016 Jun;142(6):1361-7. doi: 10.1007/s00432-016-2142-3. Epub 2016 Mar 23.

Authors

Wei-Xiang Qi¹, Qing Zhang¹, Ping Li¹, Xiao-Meng Zhang², Guang-Yuan Zhang³, Bin Wu³, Jiade J Lu¹, Guo-Liang Jiang¹, Shen Fu⁴

Affiliations

¹ Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, No. 4365 Kang Xin Road, Shanghai, 201318, China.
² Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, No. 4365 Kang Xin road, Shanghai, 201321, Shanghai, China.
³ Department of Radiology, Shanghai Proton and Heavy Ion Center, No. 4365 Kang Xin Road, Shanghai, 201318, China.
⁴ Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, No. 4365 Kang Xin road, Shanghai, 201321, Shanghai, China. fushen2014@sina.com.

PMID: 27008005
DOI: 10.1007/s00432-016-2142-3

Abstract

Objective: The aim of our study was to investigate the predictive role of apparent diffusion coefficient (ADC) values in evaluating for therapeutic changes from carbon-ion radiotherapy (CIRT) in prostate cancer patients.

Materials and methods: Thirty-one patients with prostate cancer treated with CIRT were enrolled in this retrospective study. Diffusion-weighted imaging (DWI) at 3-T was performed before and after CIRT. Before and after treatment, ADC values were measured in the tumors and in the benign tissues of the prostate, and serum prostate-specific antigen (PSA) levels were also assessed. We divided the patients into two groups: PSA response (PSA declines ≥50 %) and non-PSA response group (PSA declines <50 %).

Results: After CIRT treatment, the mean ADC value of the tumors (1.23 × 10(-3)mm(2)/s) was significantly increased as compared with the pretreatment value (1.07 × 10(-3)mm(2)/s) (p < 0.001), whereas the ADC values of the benign tissues after treatment did not significantly increase compared with the pretreatment values (p = 0.235). The mean PSA level was significantly reduced from 2.027 ng/mL before treatment to 0.822 ng/mL, respectively, after treatment (p = 0.0063). The mean of ADC changes in PSA response group before and after CIRT was significantly higher than that in non-PSA response group (∆ADC value: 0.217 vs 0.097 × 10(-3)mm(2)/s, p = 0.0229), and the rate of patients with PSA response was higher in the high ∆ADC group (∆ADC ≥ 0.10) than in the low ∆ADC group (∆ADC < 0.10) (72.7 and 33.3 %, respectively), but marginally significant (p = 0.056). Additionally, the baseline tumor ADC values revealed a negative correlation with changes in PSA levels after treatment (correlation coefficient, ρ = -0.524; p = 0.0025).

Conclusion: Our preliminary results suggest that ADC vales measurement may be a useful imaging biomarker for prediction and early assessment of therapeutic response of prostate cancer to CIRT.

Keywords: Carbon-ion radiotherapy; Diffusion-weighted MRI; Prostate cancer; Prostate-specific antigen.

MeSH terms

Aged
Aged, 80 and over
China
Humans
Magnetic Resonance Imaging
Male
Middle Aged
Prostatic Neoplasms / radiotherapy*
Radiotherapy / methods
Retrospective Studies