CT Scans and Cancer Risks: A Systematic Review and Dose-response Meta-analysis.

BACKGROUND: There is still uncertainty on whether ionizing radiation from CT scans can increase the risks of cancer. This study aimed to identify the association of cumulative ionizing radiation from CT scans with pertaining cancer risks in adults. METHODS: Five databases were searched from their inception to November 15, 2020. Observational studies reporting cancer risks from CT scans in adults were included. The main outcome included quantified cancer risks as cancer case numbers in exposed/unexposed adult participants with unified converted measures to odds ratio (OR) for relative risk, hazard ratio. Global background radiation (2.4 mSv per year) was used as control for lifetime attribution risk (LAR), with the same period from incubation after exposure until survival to 100 years. RESULTS: 25 studies were included with a sum of 111,649,943 participants (mean age: 45.37 years, 83.4% women), comprising 2,049,943 actual participants from 6 studies with an average follow-up period as 30.1 years (range, 5 to 80 years); 109,600,000 participants from 19 studies using LAR. The cancer risks for adults following CT scans were inordinately increased (LAR adults, OR, 10.00 [95% CI, 5.87 to 17.05]; actual adults, OR, 1.17 [95%CI, 0.89 to 1.55]; combined, OR, 5.89 [95%CI, 3.46 to 10.35]). Moreover, cancer risks elevated with increase of radiation dose (OR, 33.31 [95% CI, 21.33 to 52.02]), and multiple CT scan sites (OR, 14.08 [95% CI, 6.60 to 30.05]). The risk of solid malignancy was higher than leukemia. Notably, there were no significant differences for age, gender, country, continent, study quality and studying time phrases. CONCLUSIONS: Based on 111.6 million adult participants from 3 continents (Asia, Europe and America), this meta-analysis identifies an inordinately increase in cancer risks from CT scans for adults. Moreover, the cancer risks were positively correlated with radiation dose and CT sites. The meta-analysis highlights the awareness of potential cancer risks of CT scans as well as more reasonable methodology to quantify cancer risks in terms of life expectancy as 100 years for LAR. PROSPERO TRIAL REGISTRATION NUMBER: CRD42019133487.

Epidemiology of Lumbar Degenerative Phenotypes of Children and Adolescents: A Large-Scale Imaging Study.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: Recently, there has been a rise in children and adolescents developing low back pain and/or sciatica. Degenerative lumbar spine MRI phenotypes can occur in this population but reports have been sporadic and the true incidence of such spine changes remains debatable. As such, the study aimed to address the epidemiology of MRI phenotypes of the lumbar spine in this young population. METHODS: 597 children and adolescents with lumbar MRIs were included in the study. T1- and T2-weighted lumbar images from L1/2 to L5/S1 were analyzed in axial and sagittal planes. Global phenotype assessment was performed of each level and based on established nomenclature protocols. RESULTS: The cohort consisted of 57.3% (342) boys and 42.7% (255) girls, with a mean age of 10.75 ± 5.25 years (range: 0 to 18 years). The prevalence of imaging findings of lumbar disc degeneration (LDD) and lumbar disc herniation (LDH) were 2.2% (95% CI: 0.93-3.43) and 5.8% (95%CI: 2.58-8.99), respectively. There was significant difference between each disc segment from L1/2 to L5/S1 for both LDD and LDH. Schmorl's nodes were noted in 16 cases (2.7%, youngest case as 15 years), with 11 boys (68.8%) and most frequent segment as L3/4. Modic changes and high-intensity zones were absent in this cohort. CONCLUSIONS: LDD can emerge as early as the first decade of life with Schmorl's nodes, without additional specific phenotypes, including Modic changes and high-intensity zones. The study provides valuable information of a unique age group that is often under-represented but equally important as adults.

Decompression Using Minimally Invasive Surgery for Lumbar Spinal Stenosis Associated with Degenerative Spondylolisthesis: A Review.

Lumbar spinal stenosis (LSS), which often occurs concurrently with degenerative spondylolisthesis (DS), is a common disease in the elderly population, affecting the quality of life of aged people significantly. Notwithstanding the frequently good effect of conservative therapy on LSS, a minority of the patients ultimately require surgery. Surgery for LSS aims to decompress the narrowed spinal canals with preservation of spinal stability. Traditional open surgery, either pure decompression or decompression with fusion, was considered effective for the treatment of LSS with or without DS. However, the long-term clinical outcomes of traditional open surgery are still unclear. Moreover, the disadvantages of conventional open surgery are extensive, examples including tissue injuries or secondary instability, with limited outcomes and significant reoperation rates. With the development and improvement of surgical tools, various minimally invasive spine surgery (MISS) methods, including indirect decompression techniques of interspinous process devices (IPDs) and direct decompression techniques such as microscopic spine surgery or endoscopic spine surgery (ESS), have been updated with enhancement. IPDs, such as Superion devices, were reported to behave with comparable physical function, disability, and symptoms outcomes to laminectomy decompression. As an emerging technique of MISS, ESS has beneficial hallmarks including minimal tissue injuries, reduced complication rates, and shortened recovery periods, thus gaining popularity in recent years. ESS can be classified in terms of endoscopic hallmarks and approaches. Predictably, with the continuous development and gradual maturity, MISS is expected to replace traditional open surgery widely in the surgical treatment of LSS associated with DS in the future.