Review of the radiation exposure during screening of surgically implanted central venous access devices

Age-specific Dose Catalog for Diagnostic Fluoroscopy and Fluoroscopically Guided Interventional Procedures from a Pediatric Hospital

Background Fluoroscopy is an imaging modality associated with a wide range of dose levels, characterized using a variety of dose metrics, including effective dose. However, for clinical procedures, effective dose is a seldom-used and unregulated metric in the United States, and thus, it is not extensively studied in radiology despite potentially large clinical implications for patients, especially children and infants. Purpose To formulate and report a dose catalog across all diagnostic and interventional radiology (IR) fluoroscopy examination or procedure types at a specialized tertiary care pediatric hospital. Materials and Methods In this retrospective study, dose metrics taken from radiation dose structured reports of fluoroscopy between October 2014 and March 2023 were analyzed. The reports included fluoroscopy across 18 diagnostic examination types and 24 IR procedure types. The National Cancer Institute dosimetry system for Radiography and Fluoroscopy Monte Carlo software was used to estimate age-specific effective dose from dose-area product (DAP). The DAP-to-effective dose conversion factors were estimated per IR procedure type and diagnostic fluoroscopy examination type based on age. Results A total of 11 536 individual diagnostic fluoroscopy examinations (18 types) and 8017 individual IR procedures (24 types) were analyzed. Median effective dose values per diagnostic fluoroscopy examination type ranged from 0.0010 to 0.44 mSv (mean, 0.0808 mSv ± 0.0998 [SD]). Calculated DAP-to-effective dose conversion factors ranged from 0.04 to 2.48 mSv/Gy · cm2 (mean, 0.758 mSv/Gy · cm2 ± 0.614) across all diagnostic fluoroscopy examination types. Median effective dose values per IR procedure type ranged from 0.0007 to 3.90 mSv (mean, 0.6757 mSv ± 0.8989). Calculated DAP-to-effective dose conversion factors ranged from 0.001 to 0.87 mSv/Gy · cm2 (mean, 0.210 mSv/Gy · cm2 ± 0.235) across all IR procedure types. Conclusion A pediatric fluoroscopy dose catalog was created, including age-specific effective dose, using a repeatable robust method based on accurate clinical data. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Borrego and Balter in this issue.

Local reference and achievable dose levels for vascular and enterostomy access procedures in pediatric interventional radiology

BACKGROUND

Knowledge of radiation quantities delivered in routine practice is an essential responsibility of a pediatric interventional radiology department.

OBJECTIVE

To review radiation indices in frequently performed vascular and enterostomy access procedures at a quaternary pediatric hospital to formulate dosimetric reference levels and achievable levels.

MATERIALS AND METHODS

A retrospective review of patient demographics, procedure information and quantitative dose metrics over a 2-year period was performed. Dosimetric details for common procedures (central line insertions, gastrostomy/gastrojejunostomy insertions and maintenance) were evaluated, correlated with demographic data and stratified across five weight groups (0-5 kg, 5-15 kg, 15-30 kg, 30-50 kg, 50-80 kg). Achievable (50th percentile) and reference (75th percentile) levels with confidence intervals were established for each procedure.

RESULTS

Within the evaluation period, 3,165 studies satisfied the inclusion criteria. Five were classified as device insertions (peripherally inserted central catheter, n=1,145; port-a-catheter, n=321; central venous line, n=285; gastrostomy-tube [G-tube], n=262, and gastrojejunostomy-tube [GJ-tube], n=66), and two were classified as maintenance procedures (G-tube, n=358, and GJ-tube, n=728, checks, exchanges and reinsertions). Representative reference and achievable levels were calculated for each procedure category and weight group.

CONCLUSION

This work highlights the creation of local reference and achievable levels for common pediatric interventional procedures. These data establish a dosimetric reference to understand the quantity of radiation routinely applied, allowing for improved relative radiation risk assessment and enriched communication to interventionalists, health care providers, parents and patients.

Dose-Related Analysis in Percutaneous Central Venous Catheters Insertion: Experience of a Pediatric Interventional Radiology Center

Background: There are many techniques for long-term central venous catheter (CVC) placement, but none of them are specific for pediatric patients or focused on the delivered dose of ionizing radiation. Materials and Methods: This retrospective study examined a sample of pediatric patients who received percutaneous long-term CVC positioning in a tertiary care pediatric hospital. Effective dose, dose-area product (DAP) and length of time of exposition during the procedure were determined, using an appropriate technical procedure, exam and program set of the angiograph, and compared with an unpaired t-test analysis. Results: The study included 1410 enrolled patients, with a median age of 10 years (range 0.2–18 years), between 2016 and 2019. In 2016 (318 pts), the mean effective dose was 0.13 mSv and the mean DAP dose was 18.95 µGy/m² In 2017 (353 pts), the mean effective dose was 0.11 mSv and the mean DAP dose was 17.26 µGy/m². In 2018 (351 pts), the mean effective dose was 0.05 mSv and the mean DAP dose was 7.23 µGy/m². In 2019 (388 pts), the mean effective dose was 0.02 mSv and the mean DAP dose was 3.10 µGy/m². Conclusions: Medical and technical expertise led to a remarkable reduction in the radiation dose. Therefore, the authors’ hypothesis is that US- and fluoroscopy-guided percutaneous long-term CVC insertion technique is safer, more cost-effective and lower in terms of radiation exposure if correctly applied, compared to surgical or percutaneous by direct puncture techniques.

Radiation Exposure in Pediatric Interventional Procedures

The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. The expanding applications of interventional procedures coupled with the potential harmful effects of ionizing radiation highlight the need to assess the delivered radiation dose and establish an effective radiation protection program, particularly in the radiosensitive pediatric population. Given the complexity and heterogeneity of interventional procedures as well as the unique characteristics of children, the management of radiation dose is proving to be quite challenging. The aim of the current article is to provide an overview of the radiation exposure in pediatric patients during interventional procedures focusing on the importance of radiation protection in the pediatric population, the reported radiation doses and the techniques of minimizing radiation dose.

A decision tree to guide long term venous access placement in children and adolescents undergoing surgery for renal tumors

BACKGROUND/PURPOSE

While many children with renal tumors require long term venous access (VA) for adjuvant chemotherapy, certainly not all do. This study develops and tests a VA decision tree (DT) to direct the placement of VA in patients with renal tumors.

METHODS

Utilizing data readily available at surgery a VADT was developed. The VADT was tested retrospectively by 2 independent reviewers on a historic cohort. The ability of the VADT to appropriately select which patients would benefit from VA placement was tested.

RESULTS

160 patients underwent renal tumor surgery between 2005 and 2018. 70 (43.8%) patients met study criteria with median age of 45.1 months (range 1.1-224); 73% required VA. Using the VADT, VA placement was "needed" in 67.1% of patients and "deferred" in 32.9%. Interrater reliability was very high (kappa = 0.97, 95% CI 0.91-1, p < 0.001). The sensitivity and specificity of the VADT to correctly decide on VA placement were 0.92 (0.8-0.98) and 1 (0.79-1). Using the VADT, no patient would have undergone unnecessary VA placement. In reality, 4.3% of patients had an unnecessary VA placed which required a subsequent removal.

CONCLUSIONS

These preliminary data support the continued study of this VADT to guide intraoperative decisions regarding VA placement in patients with renal tumors.

LEVEL OF EVIDENCE

III - Study of diagnostic test.

Hickman Central Venous Catheters in Children: Open Versus Percutaneous Technique

BACKGROUND

The ideal technique for insertion of tunneled central venous catheters (CVCs) in children is still debatable. This study aimed to compare the outcomes of open versus percutaneous technique for the insertion of tunneled CVCs.

METHODS

The study included 279 patients who had CVCs insertions from 2010 to 2020. Patients were divided into two groups according to the technique of insertion: group 1 (n = 90) included patients who had the open cutdown method and group 2 (n = 189) included patients who had the percutaneous technique.

RESULTS

There was no difference in age and gender distribution between groups (P = 0.152 and 0.102, respectively). Chemotherapy was the most common indication of insertion (77 [85.56%] vs. 165 [87.30%]); in group 1 vs. 2, P = 0.688). The left external jugular was the most common site of insertion in group 1 (n = 66; 73.33%), and the left subclavian was the most common site in group 2 (n = 77; 40.74%). Complications of insertion were nonsignificantly higher in group 2 (P = 0.170). Nine patients in group 2 required conversion to cutdown technique (4.76%). Complications during removal were nonsignificantly higher in group 2 (P = 0.182), and the most common was bleeding (n = 4; 2.12%). The most common indication for catheter removal was the completion of the treatment (36 [40%] vs. 85 [44.97%] in groups 1 and 2, respectively).

CONCLUSIONS

Percutaneous and open tunneled central venous catheter insertion are safe in pediatric patients who require long-term venous access. Both techniques have a low complication rate. The choice of each method should be tailored to the condition of each patient.

Simple preoperative radiation safety interventions significantly lower radiation doses during central venous line placement in children

PURPOSE

The purpose of this study was to reduce radiation exposure during pediatric central venous line (CVL) placement by implementing a radiation safety process including a radiation safety briefing and a job-instruction model with a preradiation time-out.

METHODS

We reviewed records of all patients under 21 who underwent CVL placement in the operating room covering 22 months before the intervention through 10 months after 2013-2016. The intervention consisted of a radiation safety briefing by the surgeon to the intraoperative staff before each case and a radiation safety time-out. We measured and analyzed the dose area product (DAP), total radiation time pre- and postintervention, and the use of postprocedural chest radiograph.

RESULTS

100 patients with valid DAP measurements were identified for analysis (59 preintervention, 41 postintervention). Following implementation of the radiation safety process, there was a 79% decrease in median DAP (61.4 vs 13.1 rad*cm², P < 0.001) and a 73% decrease in the median radiation time (28 vs 7.6 s, P < 0.001). Additionally, there was a significant reduction in use of confirmatory CXR (95% vs 15%, P < 0.01).

CONCLUSION

A preoperative radiation safety briefing and a radiation safety time-out supported by a job-instruction model were effective in significantly lowering the absorbed doses of radiation in children undergoing CVL insertion.

TYPE OF STUDY

Case-control study.

LEVEL OF EVIDENCE

Level III.

Radiation burden of pediatric ultrasound-guided percutaneous central venous access devices: A prospective cohort study

Permanent central venous access is essential for the management of many pediatric patients. Knowing the amount of ionizing radiation used during the insertion of these devices is important. Our aim was to identify the radiation used in percutaneous insertion of central venous access devices, and to correlate radiation exposure to patient weight.

METHODS

Data was prospectively collected during a 12-month period from August 2015 to August 2016 on all ultrasound-guided percutaneous central venous access device insertions. An image intensifier was used in all insertions with data on radiation dose and screening time extracted, when available. The total radiation dose was measured in mGym2 and the total radiation time in seconds. A p-value <0.05 was used to denote statistical significance.

RESULTS

A total of 145 central venous access devices were inserted (82 portacaths, 43 double lumen lines, 16 single lumen lines and 4 hemocaths) in 127 patients (Median Age: 5.5years (Range 0-17); Median Weight 21kg (Range 1.9-100)) with 15 patients requiring multiple insertions over the course of the study. Of these, 88 had data captured for total radiation dose and time used and a further 23 had screening time only recorded. Median radiation dose was 0.00599 mGym2 (range 0.000543-0.148) with a median fluoroscopic screening time of 18s (range 2-479). Median dose was higher for children <10kg compared to larger children, 0.00661 mGym2 (range 0.00202-0.0468) versus 0.005715 mGym2 (range 0.000543-0.148) respectively. Left-sided internal jugular vein (IJV) insertions also had a higher median radiation dose of 0.0091 mGym2 (range 0.00142-0.148 mGym2) versus 0.005245 mGym2 (range 0.000543-0.0285 mGym2) for right-sided IJV insertions.

CONCLUSION

The radiation burden to children from percutaneous ultrasound-guided central venous access device insertions is small, in the order of that received during a chest radiograph. Weight<10kg and access of the left IJV are associated with receiving higher doses.

STUDY TYPE

Cohort Study (Level of Evidence: II).

Comparative Study of Complications in CV Catheter Insertion for Pediatric Patients: Real-time Ultrasound-guided Versus Venography-guided Approach

Background

Tunneled central venous catheters (CVC), called Broviac/Hickman catheter, are widely used in the long-term treatment of pediatric patients. Recently, the percutaneous approach for CVC insertion has become dominant as a less invasive intervention. In this study, we reviewed the mechanical and delayed complications according to different procedures of CVC insertion and assessed the risk factors for complications in CVC insertions for pediatric patients.

Methods

A total of 159 pediatric patients (85 males and 74 females) were included in this study. Primary reasons for indication of CVC settlement were hemato-oncologic disorders (66 cases, 42%), malignant solid tumors (30, 19%) and other benign diseases (63, 40%). CVC insertion was performed with surgical venous cut-down (CD) in 51 patients (32%), with real-time ultrasound-guided puncture (RTUS) in 57 (36%), and venography-guided puncture (VG) in 49 (31%).

Results

CD was dominantly selected and the frequency of venipuncture increased respective to the increased age of patients. RTUS was dominantly selected for one to four year old patients and VG was dominant in 5 to 15 year old patients. Some types of mechanical complication were observed in 4 of 159 (2.5%) and some delayed types were observed in 66 of 159 cases (42%). No mechanical complications occurred in cases with CD and RTUS; on the other hand, 3 (6%) of 49 insertions with VG were observed. However, we could not show any significant risk factors for the mechanical complications. In the meantime, delayed complications and premature removal were significantly observed in patients under 5 years old.

Conclusion

RTUS is superior to our conventional VG considering less frequent mechanical complications. High frequent delayed complication and premature removal should be considered, especially for patients under 5 years old.

Radiology Trainee vs Faculty Radiologist Fluoroscopy Time for Imaging-Guided Procedures: A Retrospective Study of 17,966 Reports Over a 5.5-Year Period

To evaluate differences in fluoroscopy time (FT) for common vascular access and gastrointestinal procedures performed by radiology trainees vs faculty radiologists. Report information was extracted for all 17,966 index fluoroscopy services performed by trainees or faculty, or both from 2 university hospitals over 66 months. Various vascular access procedures (eg, peripherally inserted central catheters [PICCs] and ports) and gastrointestinal fluoroscopy procedures (eg, upper gastrointestinal and contrast enema studies) were specifically targeted. Statistical analysis was performed. FT was recorded in 17,549 of 17,966 reports (98%) The 1393 procedures performed by nonphysician providers or transitional year interns were excluded. Residents, fellows, and faculty were primary operators in 5066, 6489, and 4601 procedures, respectively. Average FT (in seconds) for resident and fellow services, respectively, was less than that of faculty only for PICCs (75 and 101 vs 148, P < 0.01). For all other procedures, average FT of trainee services was greater than that for faculty. This was statistically significant (P < 0.05) for fellows vs faculty port placement (121 vs 87), resident vs faculty small bowel series (130 vs 96), and both resident and fellow vs faculty esophagram procedures (143 and 183 vs 126 ). FT for residents was significantly less than that for fellows only for PICCs (75 vs 101, P < 0.01). For most, but not all, fluoroscopy procedures commonly performed by radiology trainees, FT is greater than that for procedures performed by faculty radiologists. Better awareness and understanding of such differences may aid training programs in developing benchmarks, protocols, and focused teaching in the safe use of fluoroscopy for patients and operators.

Tunneled central venous catheters in children with malignant and chronic diseases: A comparison of open vs. percutaneous implantation

PURPOSE

Tunneled central venous catheters (tCVCs) are routinely used for long-term venous access in children with cancer and chronic diseases. They may be inserted by surgical venous cut-down or percutaneously. The aim of this study was to compare the operative times and intraoperative complications of both techniques.

METHODS

This study compared group A (surgical venous cut-down, years 2002-2006) with group B (percutaneous, years 2008-2012). Patient characteristics, operative times, and intraoperative complications were obtained from surgical reports. (IRB review and approval, number 6/15). Both Hickman/Broviac and Portacath catheters were included.

RESULTS

343 patients in group A and 321 patients in group B were studied. Ages at implantation and underlying diagnoses were similar. Operative time was significantly shorter in group B. Only 60% of primarily dissected veins were suitable for surgical implantation, whereas successful vessel puncture was possible in 96% (87% on the first attempt, 9% on the second). Bleeding occurred in 2% of patients in group A, and pneumothorax occurred in 1.8% of patients in group B. Early catheter dislodgement was similar in both groups.

CONCLUSION

Percutaneous tCVC implantation is safe, less invasive, and faster than surgical implantation. Both techniques are feasible, and complication rates are low.

LEVEL OF EVIDENCE

Level III.