You are here

Article Text

Article menu
Download PDFPDF
Cervical Cancer
Comparison of Tumor Volume Between PET and MRI in Cervical Cancer With Hybrid PET/MR
  1. Shaomin Zhang, PhD*,
  2. Jun Xin, MD, PhD*,†,
  3. Qiyong Guo, MD, PhD*,
  4. Jietao Ma, MD‡,
  5. Quanmei Ma, MD* and
  6. Hongzan Sun, MD, PhD*,†
  1. *Departments of Radiology,
  2. †Nuclear Medicine, and
  3. ‡Oncology, Shengjing Hospital of China Medical University, Shenyang, China.
  1. Address correspondence and reprint requests to Qiyong Guo, MD, PhD, Department of Radiology, Shengjing Hospital of China Medical University, Shenyang 110004, China. E-mail: Guoqiyongcmu{at}gmail.com

Abstract

Objective This study aimed to compare the tumor volume between magnetic resonance imaging–defined gross tumor volume (MR-GTV) and positron emission tomography–defined GTV (PET-GTV) in cervical cancer with hybrid PET/MR.

Materials and Methods Twenty-seven patients with cervical cancer underwent PET/MR pelvic examination before radiotherapy. The MR-GTV was manually outlined on T2-weighted MR images. The PET-GTV was autocontoured on PET images using a 40% maximum standardized uptake value threshold. Results were analyzed by Pearson analysis, Bland-Altman plot, and 1-way analysis of variance.

Results Magnetic resonance imaging–GTV significantly correlated with PET-GTV (r2 = 0.797, P < 0.001). The Bland-Altman plot showed a bad agreement between MR-GTV and PET-GTV. The PET-GTV underestimated the MR-GTV in 23 of 27 tumors. Patients were divided into the following 3 groups according to MR-GTV: less than 14 mL (n = 6), 14 to 62 mL (n = 12), and 62 mL or more (n = 9). The mean (SD) MR-GTV, PET-GTV, ratio, and overlap between MR-GTV and PET-GTV for the less than 14 mL cohort were 9.6 (2.6) mL, 16.7 (10.1) mL, 0.77 (0.40), and 0.47 (0.20), respectively. The PET-GTV overestimated MR-GTV in 4 of the 6 lesions by a mean (SD) of 11.1 (9.4) mL. Among the 14 to 62 mL cohort, the mean (SD) MR-GTV, PET-GTV, ratio, and overlap were 38.6 (14.5) mL, 24.9 (8.6 mL), 1.54 (0.25), and 0.87 (0.08), respectively. The PET-GTV underestimated MR-GTV for 12 tumors by a mean (SD) of 13.7 (8.4) mL. In the 62 mL or more cohort, the mean (SD) MR-GTV, PET-GTV, ratio, and overlap were 85.9 (25.8) mL, 54.3 (14.1) mL, 1.61 (0.35), and 0.87 (0.09), respectively. The PET-GTV underestimated MR-GTV 9 tumors by a mean (SD) of 31.6 (19.5) mL. The ratio and overlap differences were statistically significant among groups (F = 14.619, P < 0.001; F = 25.134, P < 0.001).

Conclusions Tumor volume discrepancies were observed between MR-GTV and PET-GTV for cervical cancer. With an increasing tumor volume, there was an increase in the difference between MR-GTV and PET-GTV. In addition, larger tumors had a higher degree of overlap compared with small tumors.

  • Cervical cancer
  • PET/MR
  • MR-GTV
  • PET-GTV

https://doi.org/10.1097/IGC.0000000000000097

Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    Footnotes

    • The authors declare no conflicts of interest.