Use of Positron Emission Tomography for Pregnancy-Associated Cancer Assessment: A Review

Abstract

Background. Positron emission tomography (PET) has proven clinical utility both in the initial and relapse staging phase, but this technique is controversial during pregnancy. The objective of this review is to provide a compendium of available information on the use of PET during pregnancy. Materials and methods. A systematic literature review was conducted from 1 January 2004 until 20 May 2021. A total of 4 small series and 9 case reports consisting of 25 cases were selected. Results. During the first trimester, the fetus is most sensitive to ionization damage, so lower doses are recommended (2.6E-02 mGy/MBq). Fetal-effective doses are higher in this period and the average fetal dose (4.06 ± 3.22 mGy) remains significantly below the threshold for deterministic effects. During the second and third trimesters, recommended doses are higher (1.4E-02 mGy/MBq at 6 months, and 6.9E-03 mGy/MBq at 9 months of gestation). 18F-FDG activity was distributed to the whole fetus with a prevalence of myocardial tissue in seven cases. The use of special precautions, such as PET-magnetic resonance (MR) and urinary bladder catheterization, reduces the amount of radioactive tracer. Breastfeeding interruption is not recommended. Conclusions. 18F-FDG PET is not contraindicated in pregnancy, but multidisciplinary discussion is necessary and strict precautions are recommended.

Emerging Role of FAPI PET Imaging for the Assessment of Benign Bone and Joint Diseases

“…The most common tracer used to perform such a diagnostic procedure is 18 F-fluorodeoxyglucose ([ 18 F]FDG), which has the ability to reveal hypermetabolic lesions based on their increased glycolytic metabolism. As a consequence, [ 18 F]FDG PET/CT has proven its role to assess neoplastic disease both in staging and restaging settings [ 1 , 2 , 3 , 4 , 5 ]. However, its usefulness for the evaluation of inflammatory and infectious diseases has also emerged, in particular in the last decade [ 6 , 7 , 8 , 9 ].…”

Effects of ionizing radiation exposure during pregnancy

“…Parpinel et al, [ 24 ] reviewed several small studies that estimated dose to the conceptus for 18F-2-fluoro-2-deoxy-D-glucose (FDG) PET. Their pooled results are given in Table 4 .…”

Contrast Agents during Pregnancy: Pros and Cons When Really Needed

“…The 18F-FDG that is not involved in glucose metabolism in any tissue is then excreted in the urine, so some authors have suggested recurring bladder catheterization in order to maintain an empty bladder and to minimize its concentration in one of the anatomical sites which is closest to the fetus. It is important to assess and verify that the pregnant patient is normoglycemic when undergoing PET imaging with 18F-FDG Injection [ 46 ].…”

“…As for other radiological exams, low doses are recommended during the first trimester of pregnancy, due to the major fetal sensitivity to ionizing radiation [ 46 ].…”