A number of for-profit medical clinics have been heavily advertising total-body ultrafast computed tomography (CT) scanning as a screening test. However, no medical professional organization has recommended the use of ultrafast whole-body CT as a screening test. In addition, there are no published clinical trials examining the safety and effectiveness of whole-body ultrafast CT scanning.
The American College of Radiology Board of Chancellors issued the following position statement on full-body CT screening:
“The American College of Radiology (ACR), at this time, does not believe there is sufficient scientific evidence to justify recommending total body computed tomographic (CT) screening for patients with no symptoms or a family history suggesting disease. To date there is no evidence that total body CT screening is cost effective or is effective in prolonging life. In addition, the ACR is concerned that this procedure will lead to the discovery of numerous findings that will not ultimately affect patients’ health, but will result in increased patient anxiety, unnecessary follow-up examinations and treatments and wasted expense. ACR will continue to monitor scientific studies concerning this procedure. The benefits and risks of this method of screening have not been assessed in adequate clinical trials. In addition, these screening tests may unnecessarily expose patients to harmful levels of radiation.”
A technology assessment conducted by the Institute for Clinical Systems Improvement (2003) reached the following conclusions:
- Whole-body CT should not be considered as a screening tool at this time. Whole-body CT screening is not specific enough or tailored appropriately to detect coronary artery calcification, lung cancer, or colon polyps or masses.
- The CT screening procedure is safe except for the risk of radiation exposure and minor side effects that have been reported. There are potentially hazardous risks associated with false positive and false negative findings and associated follow-up procedures.
- No evidence exists to evaluate the effectiveness of whole-body CT as a screening test for patients with no symptoms or a family history suggesting disease (Conclusion Grade: Grade Not Assignable). There is concern that this procedure may lead to the discovery of numerous findings that will not ultimately affect a patient’s health, but will result in increased patient anxiety, unnecessary follow-up examinations and treatments, and wasted expense.
Routine full-body CT screening may increase risk of cancer mortality. Brenner and Elliston (2004) estimated that the lifetime risk of cancer death increases after just 1 CT scan and grows with each successive scan. For example, a single full-body CT scan in a 45-year old results in a 1 in 1,250, or 0.08 %, increased chance of dying from cancer. This risk jumps to 1 in 50, or 1.9 %, for an adult who begins having scans at 45 and has 1 each year for 30 years. This study also found that radiation-induced lung cancer was the main form of cancer associated with CT scans.
Furtado et al (2005) retrospectively determined the frequency and spectrum of findings and recommendations reported with whole-body CT screening at a community screening center. The radiological reports of 1,192 consecutive patients who underwent whole-body CT screening of the chest, abdomen, and pelvis at an outpatient imaging center from January to June 2000 were reviewed. Scans were obtained with electron-beam CT without oral or intravenous contrast material. Reported imaging findings and recommendations were retrospectively tabulated and assigned scores. Descriptive statistics were used (means, standard deviations, and percentages); comparisons between subgroups were performed with univariate analysis of variance and chi(2) or Fisher exact tests. Screening was performed in 1,192 patients (mean age of 54 years). Sixty-five % (774/1,192) were men and 35 % (418/1,192) were women; 903 (76 %) of 1,192 patients were self-referred, and 1,030 (86 %) of 1,192 subjects had at least 1 abnormal finding described in the whole-body CT screening report. There were a total of 3,361 findings, with a mean of 2.8 per patient. Findings were described most frequently in the spine (1,065/3,361; 32 %), abdominal blood vessels (561/3,361; 17 %), lungs (461/3,361; 14 %), kidneys (353/3,361; 11 %), and liver (183/3,361); 5 %). A total of 445 (37 %) patients received at least 1 recommendation for further evaluation. The most common recommendations were for additional imaging of the lungs or the kidneys. The authors concluded that with whole-body CT screening, findings were detected in a large number of subjects, and most findings were benign by description and required no further evaluation; 37 % of patients had findings that elicited recommendations for additional evaluation, but further research is needed to determine the clinical importance of these findings and the effect on patient care.
Sierink et al (2012) evaluated the value of immediate total-body CT during the primary survey of injured patients compared with conventional radiographic imaging supplemented with selective CT. A systematic search of the literature was performed in MEDLINE, Embase, Web of Science and Cochrane Library databases. Reports were eligible if they contained original data comparing immediate total-body CT with conventional imaging supplemented with selective CT in injured patients. The main outcomes of interest were overall mortality and time in the emergency room (ER). A total of 4 studies were included describing a total of 5,470 patients; 1 study provided 4,621 patients (84.5 %). All 4 studies were non-randomized cohort studies with retrospective data collection. Mortality was reported in 3 studies. Absolute mortality rates differed substantially between studies, but within studies mortality rates were comparable between immediate total-body CT and conventional imaging strategies (pooled odds ratio 0.91, 95 % confidence interval: 0.79 to 1.05). Time in the ER was described in 3 studies, and in 2 was significantly shorter in patients who underwent immediate total-body CT: 70 versus 104 mins (p = 0.025) and 47 versus 82 mins (p < 0.001) respectively. The authors concluded that this review showed differences in time in the ER in favor of immediate total-body CT during the primary trauma survey compared with conventional radiographic imaging supplemented with selective CT. There were no differences in mortality. They stated that the substantial reduction in time in the ER is a promising feature of immediate total-body CT; but well-designed and larger randomized studies are needed to see how this will translate into clinical outcomes.
Gentile et al (2013) stated that total body computed tomography (TB-CT) scan is not mandatory in the diagnostic/staging algorithm of chronic lymphocytic leukemia (CLL). These researchers determined the value and prognostic significance of TB-CT scan in early stage CLL patients. Baseline TB-CT scan was performed in 240 Binet stage A CLL patients (179 Rai low- and 61 Rai intermediate-risk) included in a prospective multi-center observational study (clinicaltrial.gov ID:NCT00917549). The cohort included 69 clinical monoclonal B lymphocytosis (cMBLs). Patients were re-staged considering only radiological data. Following TB-CT scans, 20 % of cases re-classified as radiologic Binet (r-Binet) stage B. r-Binet B patients showed a higher incidence of unfavorable cytogenetic abnormalities (p = 0.027), as well as a shorter PFS (p = 0.001). At multi-variate analysis, r-Binet stage [HR = 2.48; p = 0.004] and IGHV mutational status [HR = 3.01; p = 0.002] retained an independent predictive value for PFS. Among 179 Rai low-risk cases, 100 were redefined as r-Rai intermediate-risk based upon TB-CT scan data, showing a higher rate of cases with higher ZAP-70 (p = 0.033) and CD38 expression (p = 0.029) and β2-microglobulin levels (p < 0.0001), as well as a shorter PFS than those with r-Rai low-risk (p = 0.008). r-Rai stage [HR = 2.78; p = 0.046] and IGHV mutational status [HR = 4.25; p = 0.009] retained a significant predictive value for PFS at multi-variate analysis. Forty-two percent of cMBL patients were reclassified as r-small lymphocytic lymphomas (r-SLLs) by TB-CT scan. The authors concluded that TB-CT scan appeared to provide relevant information in early stage CLL related to the potential and the timing of patients to progress towards the more advanced disease stages.