Medicina (Jun 2021)

To Enhance or Not to Enhance? The Role of Contrast Medium <sup>18</sup>F-FDG PET/CT in Recurrent Ovarian Carcinomas

  • Michela Massollo,
  • Francesco Fiz,
  • Gianluca Bottoni,
  • Martina Ugolini,
  • Francesco Paparo,
  • Cristina Puppo,
  • Nicoletta Provinciali,
  • Massimiliano Iacozzi,
  • Vania Altrinetti,
  • Angelina Cistaro,
  • Manlio Cabria,
  • Andrea DeCensi,
  • Giorgio Treglia,
  • Arnoldo Piccardo

DOI
https://doi.org/10.3390/medicina57060561
Journal volume & issue
Vol. 57, no. 6
p. 561

Abstract

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Background and Objectives: 18F-fluorodeoxyglucose (FDG) positron emission tomography/X-ray computed tomography (PET/CT) represents the mainstay diagnostic procedure for suspected ovarian cancer (OC) recurrence. PET/CT can be integrated with contrast medium and in various diagnostic settings; however, the effective benefit of this procedure is still debated. We aimed to compare the diagnostic capabilities of low-dose and contrast-enhanced PET/CT (PET/ldCT and PET/ceCT) in patients with suspected ovarian cancer relapse. Materials and Methods: 122 OC patients underwent both PET/ldCT and PET/ceCT. Two groups of nuclear medicine physicians and radiologists scored the findings as positive or negative. Clinical/radiological follow-up was used as ground truth. Sensitivity, specificity, negative/positive predictive value, and accuracy were calculated at the patient and the lesion level. Results: A total of 455 and 474 lesions were identified at PET/ldCT and PET/ceCT, respectively. At the lesion level, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were not significantly different between PET/ldCT and PET/ceCT (98%, 93.3%, 97.4%, 94.9%, and 96.9% for PET/ldCT; 99%, 95.5%, 98.3%, 97%, and 98% for PET/ceCT, p = ns). At the patient level, no significant differences in these parameters were identified (e.g., p = 0.22 and p = 0.35 for accuracy, in the peritoneum and lymph nodes, respectively). Smaller peritoneal/lymph node lesions close to physiological FDG uptake sources were found in the cases of misidentification by PET/ldCT. PET/ceCT prompted a change in clinical management in four cases (3.2%) compared to PET/ldCT. Conclusions: PET/ceCT does not perform better than PET/ldCT but can occasionally clarify doubtful peritoneal findings on PET/ldCT. To avoid unnecessary dose to the patient, PET/ceCT should be excluded in selected cases.

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