Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, California.
UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California.
Cancer. 2021 Aug 1;127(15):2693-2704. doi: 10.1002/cncr.33554. Epub 2021 Apr 12.
Optimal treatment selection for localized renal tumors is challenging because of their variable biologic behavior and limitations in the preoperative assessment of tumor aggressiveness. The authors investigated the emerging hyperpolarized (HP) C magnetic resonance imaging (MRI) technique to noninvasively assess tumor lactate production, which is strongly associated with tumor aggressiveness.
Eleven patients with renal tumors underwent HP C pyruvate MRI before surgical resection. Tumor C pyruvate and C lactate images were acquired dynamically. Five patients underwent 2 scans on the same day to assess the intrapatient reproducibility of HP C pyruvate MRI. Tumor metabolic data were compared with histopathology findings.
Eight patients had tumors with a sufficient metabolite signal-to-noise ratio for analysis; an insufficient tumor signal-to-noise ratio was noted in 2 patients, likely caused by poor tumor perfusion and, in 1 patient, because of technical errors. Of the 8 patients, 3 had high-grade clear cell renal cell carcinoma (ccRCC), 3 had low-grade ccRCC, and 2 had chromophobe RCC. There was a trend toward a higher lactate-to-pyruvate ratio in high-grade ccRCCs compared with low-grade ccRCCs. Both chromophobe RCCs had relatively high lactate-to-pyruvate ratios. Good reproducibility was noted across the 5 patients who underwent 2 HP C pyruvate MRI scans on the same day.
The current results demonstrate the feasibility of HP C pyruvate MRI for investigating the metabolic phenotype of localized renal tumors. The initial data indicate good reproducibility of metabolite measurements. In addition, the metabolic data indicate a trend toward differentiating low-grade and high-grade ccRCCs, the most common subtype of renal cancer.
Renal tumors are frequently discovered incidentally because of the increased use of medical imaging, but it is challenging to identify which aggressive tumors should be treated. A new metabolic imaging technique was applied to noninvasively predict renal tumor aggressiveness. The imaging results were compared with tumor samples taken during surgery and showed a trend toward differentiating between low-grade and high-grade clear cell renal cell carcinomas, which are the most common type of renal cancers.
由于局部肾肿瘤的生物学行为存在差异，且术前评估肿瘤侵袭性存在局限性，因此治疗方案的选择颇具挑战。本研究旨在探讨新兴的超极化（HP） 13 C磁共振（MR）成像技术，以无创方式评估与肿瘤侵袭性密切相关的乳酸生成。
11 例肾肿瘤患者在手术切除前接受 HP 13 C丙酮酸 MR 检查。动态采集肿瘤 13 C 丙酮酸和 13 C 乳酸图像。其中 5 例患者在同一天接受 2 次扫描，以评估 HP 13 C 丙酮酸 MR 检查的患者内可重复性。比较肿瘤代谢数据与组织病理学检查结果。
8 例患者的肿瘤有足够的代谢物信噪比进行分析；2 例患者因肿瘤灌注不良或 1 例患者因技术误差而导致肿瘤信噪比不足。8 例患者中，3 例为高级别透明细胞肾细胞癌（ccRCC），3 例为低级别 ccRCC，2 例为嫌色细胞 RCC。高级别 ccRCC 的乳酸/丙酮酸比值较低级别 ccRCC 有升高趋势。2 例嫌色细胞 RCC 的乳酸/丙酮酸比值相对较高。5 例同一天接受 2 次 HP 13 C 丙酮酸 MR 检查的患者中，可重复性较好。
目前的结果表明，HP 13 C 丙酮酸 MR 检查用于研究局部肾肿瘤的代谢表型是可行的。代谢物测量的初步数据表明具有良好的可重复性。此外，代谢数据表明其具有区分低级别和高级别 ccRCC 的趋势，而 ccRCC 是最常见的肾癌亚型。
