Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Division of Biostatistics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
J Magn Reson Imaging. 2017 Sep;46(3):850-860. doi: 10.1002/jmri.25635. Epub 2017 Feb 2.
To investigate parametric changes in the apparent diffusion coefficient (ADC) at multiple timepoints during and after completion of primary proton and carbon ion irradiation of prostate cancer (PCa) as compared with normal-appearing prostate parenchyma.
In all, 92 patients with histologically confirmed PCa received either proton or carbon ion hypofractionated radiotherapy (RT). All were prospectively evaluated with diffusion-weighted magnetic resonance imaging (DWI-MRI) at five timepoints: baseline, day 10 during therapy and 6 weeks, 6 months, and 18 months after treatment. Linear mixed models (LMM) were used to evaluate the effects of radiation, antihormonal therapy, time, and type of particle irradiation on manual ADC measurements. ADC differences related to prostate-specific antigen (PSA) relapse according to PSA thresholds and to Vancouver rules and Phoenix criteria were examined using LMM and unpaired Student's t-test.
A measurable and continuous increase of tumor ADC measurements from baseline (1.194 × 10 mm /s) during (1.350 × 10 mm /s, day 10, P = 0.006) and after treatment (1.355/1.430/1.490 × 10 mm /s, week 6 / month 6 / month 18, P = 0.001/<0.001/<0.001) was found. ADC values of normal-appearing control tissue remained unchanged. Androgen deprivation (P ≥ 0.320), different PSA thresholds (P = 0.634), and PSA relapse criteria according to Vancouver rules (P ≥ 0.776) had no effect. A weak association between 18-month measurements and Phoenix criteria (P = 0.046) was found.
ADC parametric changes were distinct in tumor tissue, highlighting the ability of diffusion MRI to evaluate different aspects of the microscopic pathophysiology. Although promising, their use as noninvasive imaging biomarkers requires further validation.
1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:850-860.
研究原发性质子和碳离子照射前列腺癌（PCa）期间和之后，表观扩散系数（ADC）在多个时间点的参数变化，并与正常前列腺实质进行比较。
共 92 例经组织学证实的 PCa 患者接受质子或碳离子超分割放疗（RT）。所有患者均前瞻性地在五个时间点（基线、治疗期间的第 10 天以及治疗后 6 周、6 个月和 18 个月）进行弥散加权磁共振成像（DWI-MRI）检查。线性混合模型（LMM）用于评估放射、抗激素治疗、时间以及粒子照射类型对手动 ADC 测量的影响。使用 LMM 和配对学生 t 检验，根据 PSA 复发的 PSA 阈值和温哥华规则及凤凰标准，检查与 ADC 差异相关的指标。
肿瘤 ADC 测量值从基线（1.194×10mm/s）开始，在治疗期间（1.350×10mm/s，第 10 天，P=0.006）和治疗后（1.355/1.430/1.490×10mm/s，第 6 周/第 6 个月/第 18 个月，P=0.001/<0.001/<0.001）呈持续升高趋势。正常前列腺实质的 ADC 值保持不变。去势治疗（P≥0.320）、不同的 PSA 阈值（P=0.634）以及温哥华规则的 PSA 复发标准（P≥0.776）无影响。在第 18 个月测量值和凤凰标准之间发现了微弱的关联（P=0.046）。
肿瘤组织的 ADC 参数变化明显，突出了扩散 MRI 评估微观病理生理学不同方面的能力。尽管有希望，但它们作为非侵入性成像生物标志物的使用需要进一步验证。
1 技术功效：阶段 1 J. MAGN. RESON. IMAGING 2017;46:850-860.
