Radiation exposure and mortality risk from CT and PET imaging of patients with malignant lymphoma

Abstract

ObjectiveTo quantify radiation exposure and mortality risk from computed tomography (CT) and positron emission tomography (PET) imaging with 18F-fluorodeoxyglucose (18F-FDG) in patients with malignant lymphoma (Hodgkin’s disease [HD] or non-Hodgkin’s lymphoma [NHL]).MethodsFirst, organ doses were assessed for a typical diagnostic work-up in children with HD and adults with NHL. Subsequently, life tables were constructed for assessment of radiation risks, also taking into account the disease-related mortality.ResultsIn children with HD, cumulative effective dose from medical imaging ranged from 66 mSv (newborn) to 113 mSv (15 years old). In adults with NHL the cumulative effective dose from medical imaging was 97 mSv. Average fractions of radiation-induced deaths for children with HD [without correction for disease-related mortality in brackets] were 0.4% [0.6%] for boys and 0.7% [1.1%] for girls, and for adults with NHL 0.07% [0.28%] for men and 0.09% [0.37%] for women.ConclusionTaking into account the disease-related reduction in life expectancy of patients with malignant lymphoma results in a higher overall mortality but substantial lower incidence of radiation induced deaths. The modest radiation risk that results from imaging with CT and 18F-FDG PET can be considered as justified, but imaging should be performed with care, especially in children.Key PointsSurvival of malignant lymphoma has improved dramatically over the past decades.PET and CT currently play important roles for malignant lymphoma patients.The potential hazard of ionising radiation has become an increasingly important issue.When assessing radiation risks, disease-related reduction in life expectancy should be considered.CT and18F-FDG PET create a modest radiation-induced mortality risk.

Value of18F-FDG PET and PET/CT for Evaluation of Pediatric Malignancies

“…Several recent studies have demonstrated that routine follow-up by 18 F-FDG PET/CT and other imaging techniques may be overused for routine surveillance of patients with HL, contributing to increased cost and radiation exposure without a clear survival benefit (6,50,58). More data are needed to determine which patient group will benefit from which surveillance test for how long and at which frequency.…”

“…Several studies have demonstrated improved sensitivities and specificities for 18 F-FDG PET/CT compared with all collective standard staging procedures, specifically for patients with lymphomas, sarcomas, and head and neck cancers (1)(2)(3)(4). However, exposure of children to radiation through 18 F-FDG PET/CT is of concern to the pediatric imaging community (5,6), and various low-dose approaches are being pursued (7)(8)(9). A thorough understanding of the state of knowledge is needed to preserve the advantages of current 18 F-FDG PET/CT staging tests and create new imaging tests without compromises.…”

PET/MRI: Applications in Clinical Imaging

“…With the recommendation of frequent PET/CT however, there is significant accumulation of radiation over time, which raises concerns specifically in young patient populations [65]. The expected benefit of PET/MRI in this regard appears obvious in that radiation exposure can be limited to the dose generated by the radioactive tracer.…”

Pediatric nuclear medicine and pediatric radiology

“…In some countries nuclear medicine is an independent specialty, and in other countries radiologists are in charge of nuclear medicine tests. Physicians-in-training in radiology and in nuclear medicine have to receive multimodality training [8][9][10][11][12]. And continuing education in both specialties is vital to ensure that senior specialists are well-versed in the latest techniques.…”

“…The most typical example is abdominal CT, which has a higher dose than the most frequent nuclear medicine studies. Another example is that two-thirds of the radiation dose from PET/CT is from the CT component [12][13][14]. In the latter case it is possible to perform a diagnostic CT scan during the PET/CT examination rather than a separate diagnostic CT scan.…”