The role of FDG PET/CT in the evaluation of treatment response in a case of calcified ovarian metastases

Document Type: Case report

Authors

1 Research Center for Nuclear Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran

2 Department of Nuclear Medicine, Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran

Abstract

Evaluation of calcified metastatic lesions by conventional imaging can be challenging. Ovarian cancer metastases can present with calcification which might increase in size and number following therapy. It is not entirely clear whether these calcifications are associated with tumor response or disease progression. Calcified lesions which do not change in size or configuration are particularly problematic when assessed by RECIST criteria. Positron emission tomography (PET)/computed tomography (CT) is of particular value as it demonstrates the metabolic activity of the calcified lesions, in addition, it might reveal metastases in unexpected sites. We report a case of serous papillary ovarian cancer with extensive abdomino-pelvic calcified metastases referred for evaluation of therapy response. Despite being reported as stable disease on CT evaluation, we observed increased metabolic activity in the calcified lesions both on CT-attenuation corrected and non-attenuation corrected images, which was indicative of inadequate response to therapy. PET/CT is an ideal modality in follow-up of patients with ovarian cancer presenting with calcified metastatic tumoral deposits.

Keywords


  1. Pandit-Taskar N, Mahajan S, Ma W. Diagnostic Applications of Nuclear Medicine: Ovarian Cancer.In: Strauss HW, Mariani G, Volterrani D, Larson SM. Nuclear Oncology: Pathophysiology and Clinical Applications. 2nd ed: Springer Science & Business Media; 2017. p. 1022.
  2. Ganeshan D, Bhosale P, Wei W, Ramalingam P, Mudasiru-Dawodu E, Gershenson D, et al. Increase in post-therapy tumor calcification on CT scan is not an indicator of response to therapy in low-grade serous ovarian cancer. Abdom Radiol (NY). 2016; 41(8):1589-95.
  3. Zhou Y, Zhang J, Pu D, Bi F, Chen Y, Liu J, et al. Tumor calcification as a prognostic factor in cetuximab plus chemotherapy-treated patients with metastatic colorectal cancer. Anticancer Drugs. 2019; 30(2):195.
  4. Drago PC, Badalament RA, Lucas J, Drago JR. Bladder wall calcification after intravesical mitomycin C treatment of superficial bladder cancer. J Urol. 1989; 142(4):1071-2.
  5. Burkill G, Allen S, A'hern R, Gore M, King D. Significance of tumour calcification in ovarian carcinoma. Br J Radiol. 2009; 82(980):640-4.
  6. Kunieda K, Okuhira M, Nakano T, Nakatani S, Tateiwa J, Hiramatsu A, et al. Diffuse calcification in gastric cancer. J Int Med Res. 1990; 18(6):506-14.
  7. Wong L, Peh W. Clinics in diagnostic imaging (22). Calcified peritoneal carcinomatosis. Singapore Med J. 1997; 38(2):88-91.
  8. Agarwal A, Yeh BM, Breiman RS, Qayyum A, Coakley FV. Peritoneal calcification: causes and distinguishing features on CT. AJR Am J Roentgenol. 2004; 182(2):441-5.
  9. Lin EC, Alavi A. PET and PET/CT: a clinical guide. 3rd ed: Thieme; 2019.
  10. Hu S-L, Zhou Z-R, Zhang Y-J. Calcified metastases from ovarian carcinoma highlighted by F-18 FDG PET/CT: report of two cases. Abdom Imaging. 2012; 37(4):675-9.
  11. Nikaki A, Alexopoulos A, Vlachou F, Filippi V, Andreou I, Rapti V, et al. Hypermetabolic Calcified Lymph Nodes on 18Fludeoxyglucose-Positron Emission Tomography/Computed Tomography in a Case of Treated Ovarian Cancer Recurrence: Residual Disease or Benign Formation? Mol Imaging Radionucl Ther. 2016; 25(2):91.