As low as reasonably achievable: Methods for reducing radiation exposure during the management of renal and ureteral stones

Does KUB play a role in the diagnosis of bladder bowel dysfunction?

INTRODUCTION

Kidney ureter bladder radiography (KUB) is widely used for the evaluation of constipation in children with bladder and bowel dysfunction (BBD); however, there is varying evidence to support its routine diagnostic use. One drawback to KUB is radiation exposure. The dangers of radiation in children are well-documented, and per As Low As Reasonably Achievable, non-beneficial radiation should be avoided. This risk is especially high in children who undergo repeated imaging in the follow up of constipation treatment.

OBJECTIVE

We sought to assess the utility of KUB in diagnosing children with BBD by comparing it to four diagnostic tests and/or validated instruments: the Dysfunctional Voiding Symptom Score (DVSS), Rome IV criteria, rectal diameter on ultrasound (RD), and the Bristol Stool Form Score (BSFS).

STUDY DESIGN

We prospectively enrolled a cohort of patients presenting to an academic pediatric urology practice with symptoms of BBD. Severity of stool burden on KUB (mild, moderate, or severe), RD on ultrasound (≥3.4 cm), DVSS, Rome IV, and BSFS were obtained for each patient. All imaging was interpreted by a pediatric radiologist and pediatric urologist. Primary outcomes were the association between the four diagnostic tests and KUB stool burden. Bivariate analysis of all individual variables versus KUB was performed, as well as multivariate regressions to determine if multiple measures were predictive of KUB stool burden when combined.

RESULTS

Between October 2020 and May 2022, 50 patients were enrolled. All children were under the age of 18, with a median age of 8 years (IQR 3-13). 38 % were male. Median BMI-for-age-percentile was 80.8 (IQR 50.3-98.3). When comparing individual variables to KUB in bivariate analyses, it was found that RD on ultrasound is predictive of significant stool burden on KUB (p = 0.03). No other individual variables were predictive. In the multivariate analyses, no combination of tests was found to be predictive of KUB.

DISCUSSION

We compared the effectiveness of four commonly used diagnostic tests in children with BBD to validate the use of KUB. In conclusion, our results support the use of RD on ultrasound as a non-radiating alternative to KUB to assess stool burden. Data also suggest that KUB for fecal load does not correlate with urinary (DVSS) or bowel (Rome IV, BSFS) symptoms in BBD, and that symptoms scores should still be used independently for diagnosis and monitoring of treatment response.

CONCLUSION

In conclusion, KUB has a limited role in the diagnosis of BBD.

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

X-ray therapy safety and awareness education for medical trainees and attending physicians

INTRODUCTION

Medical imaging involving ionizing radiation is common in the clinical setting. Little is known about the level of radiation safety training for medical trainees and attending physicians. We sought to identify the level of radiation safety knowledge and training at the undergraduate, postgraduate, and attending physician level.

METHODS

A 29-question survey was sent by email to two sites in Canada. We pooled the results of medical students, residents, and attending physicians. The primary outcome was to describe the amount of radiation safety training among these groups. The secondary outcomes were to describe the frequency of radiation exposure, level of radiation knowledge, and preferred training method for radiation safety.

RESULTS

Of 115 surveys that were properly completed, 31 (26.9%) medical students, 17 (14.7%) residents, and 67 (58.3%) attending physicians responded. A greater number of medical students (41.9%) reported they had zero hours of training time for radiation safety compared to attending physicians (14.9%) (p<0.05). A higher number of attending physicians (47.8%) and residents (64.7%) participated in patient care involving fluoroscopy daily or at least several times per week compared to medical students (3.2%) (p<0.001). Attending physicians had the greatest number of correct responses to radiation safety questions. Online courses and workshops were the preferred training methods.

CONCLUSIONS

Radiation safety training is an important component of medical education for medical trainees and attending physicians. Current radiation safety training requirements and procedures at various levels of medical training in Canada should be addressed. Implementing radiation safety education may improve adherence to the radiation safety principles.

Knowledge, attitude, and practice of lead aprons among dental practitioners and specialists

In dentistry, radiographs are often used to diagnose and assess problems relating to oral conditions as well as for better treatment planning. Even though the radiation risk offered by X-rays is minimal, the absorption of this lower level radiation in the individual for a long time challenges a health concern. The aim of the study was to assess the knowledge, attitude and practice of lead aprons among dental practitioners and specialists in Tamil Nadu. A cross-sectional survey was performed around 100 dentists in Tamil Nadu, India, by framing standard questionnaires and collecting responses by online survey forms such as "Google Forms." The statistical study was undertaken with SPSS version 22 and the Chi-square test was selected to determine the correlation. This study showed that lead aprons were regularly used by 63% of participants during radiation exposure. Thirty percent of participants were aware of radiation protection protocol but neglected to use lead aprons routinely (P = 0.113). About 91% of participants gave more preference for thyroid gland to protect it from dental radiation rather than other head-and-neck organs and 82% of them were using thyroid collars for patients during exposure (P = 0.671). Our survey shows that the usage of lead aprons is practiced strictly by dental practitioners under <5 years of clinical experience. However, dental practitioners and specialists were aware of radiation protective aprons but often neglected to use them in practice.

Ergonomics and Surgeon Comfort During Flexible Ureteroscopy

The technological advancements of flexible ureteroscopy (FURS) and its accessories have resulted in broadening its indications to include the management of complex renal stones, with long operative time. The surgeon's understanding about the ergonomics of the ureteroscopes and their cognizance of the operation theatre layout helps to improve their performance, including the surgical outcomes. This paper will describe the ergonomics that are involved in conducting FURS which in turn will aid in developing a more conducive surgical environment for the surgeon during the procedure, based on scientific literature review and expert opinions in high-volume centres. Proper surgeon position, well-arranged operation theatre layout, monitor and pedal position, anaesthesia type, and surgical team are important factors to decrease musculoskeletal strains for surgeons and increase work efficiency. Different types of flexible ureteroscope have different characters and knowing these special characters leads to better ergonomics during surgery. Robotic-assisted FURS have shown good safety and ergonomics in clinical application.

Very low-dose computerized tomography for confirmation of urinary stone presence

PURPOSE

To determine whether a modified non-contrast very low-dose computed tomography (VLD-CT) protocol is applicable for confirmation of known urolithiasis.

METHODS AND MATERIALS

Consecutive adult patients with a CT scan showing urinary tract stone(s) between 6/2017-12/2018 were included. They were referred to a modified VLD-CT protocol if stone presence was equivocal or if stone location needed reassessment before an endourological interventional procedure. The scanned area was limited to the level of initial stone location caudally. Data on patients' demographics andbody mass index, were collected. The scanned length and radiation dose were calculated. Images were reviewed by two radiologists who assessed stone size and location. Follow-up reference standard included stone passage, surgical removal, and other imaging and clinical information.

RESULTS

Sixty-three patients [63 stones, mean BMI 28.7 (range 19-41.9)] were included. VLD-CTs revealed 31 stones in 31 patients, with a mean stone length of 5.5 mm. Fifteen stones remained at the same location, and 16 had migrated, of which two appeared in the bladder. Thirty-two stones were not observed on VLD-CT. The mean span scanned on the VLD-CT was 274 mm (± 80). The average radiation exposure was 1.47 mGy (range 1.09-3.3), and the absorbed dose was 0.77 mSv (range 0.39-1.43), compared to 10.24 mGy (range 1.75-28.9) and 7.87 mSv (range 1.44-18.5) in the previous scan. The mean radiation dose reduction between scans was 89%. On follow-up, all VLD-CT findings were confirmed.

CONCLUSION

A modified imaging protocol is applicable for confirmation of stone presence and location by utilizing very low-dose radiation exposure.

Underestimation of fluoroscopic exposure among orthopedic residents

OBJECTIVES

Concerns about radiation exposure for health care workers have increased in the last decade, along with the increased use of fluoroscopic imaging for surgical procedures. Recent literature suggests that surgeons with the least experience have higher exposure during surgery, and their perception of exposure may be lower. The purpose of this study was to examine the accuracy of orthopedic resident trainees' estimates of their exposure during fluoroscopy cases.

MATERIALS AND METHODS

Orthopedic resident trainees were surveyed after participation in various fluoroscopic orthopedic surgeries and asked to estimate the number of fluoroscopy exposures used. Their answers were compared against the actual number of exposures retrieved from the fluoroscopy machine. The perceived number of exposures was then compared to the actual number taken for junior residents in training year 1, 2, or 3 versus senior residents in training year 4 or 5.

RESULTS

Nineteen residents were surveyed, 13 of which were junior residents and six of which were senior residents. Of the 13 junior-level residents, total estimation was 441 exposures, versus 1411 actual exposures, an underestimation of over 69%. The six senior residents totaled 457 estimated exposures, compared to 645 actual exposures, for an underestimation of just under 30%.

CONCLUSIONS

In this survey study at a single institution, junior-level residents greatly underestimated radiation exposure compared to senior-level residents. Trainees should be aware that they grossly underestimate their exposure levels during procedures, and residency programs should emphasize fluoroscopic training early.

Running water sound technique in contrast-based voiding cystourethrogram: A case-control study

BACKGROUND

An intervention that can reduce the patient void time during a voiding cystourethrogram (VCUG) procedure can reduce the total radiation dose to the patient. This is because a delay in voiding leads to a high number of intermittent screenings to monitor if voiding occurs. This study assessed the impact of running-water sound (RWS) upon patients' voiding parameters and fluoroscopy screening times during VCUG examinations among children and adults.

MATERIALS AND METHODS

A case-control study involving 252 patients was undertaken which consisted two groups (control and test) of adults and children. The test groups underwent VCUG with RWS technique while the control groups underwent the procedure normally. T-test was used to compare the study parameters between the two groups and a p-value less than 0.05 was interpreted as significant.

RESULTS

The mean screening times (s) for children who underwent VCUG with and without RWS were 17.15 ± 2.5s and 30.61 ± 5.1s respectively (p = 0.0024). For adults, the RWS technique recorded a mean screening time of 37.36 ± 4.4s while the non-RWS procedures recorded 49.80 ± 5.2s (p = 0.001). The participants who received RWS intervention also felt the urge to void earlier than those who received no RWS intervention. The differences were also statistically significant for both children and adults.

CONCLUSION

The study being one of the first in this subject area indicates that the application of RWS technique induces early urge of iodinated-contrast voiding, and reduces voiding and fluoroscopy screening times during VCUG among children and adults. This simple technique can potentially enhance current practice.

Urolithiasis: Comparison of diagnostic performance of digital tomosynthesis and ultrasound. Which one to choose and when?

OBJECTIVE

To assess the diagnostic performance of digital tomosynthesis (DT) in detecting urolithiasis and compare it with ultrasonography (USG), keeping standard volumetric multi-detector computed tomography (MDCT) as the reference.

MATERIALS AND METHODS

This prospective analytical study was approved by our institutional ethical committee. A total of 66 patients were enrolled who had either clinical suspicion of urolithiasis or history of recurrent urolithiasis. All patients underwent DT, USG and MDCT within 24 h. In all these three investigations, the calculi were categorised according to their location and size by two radiologists. Sensitivity, specificity, positive and negative predictive values of DT and USG were calculated with MDCT as a reference standard.

RESULTS

Our study comprised of 66 patients (36 males and 30 females with age range of 19-73 years). A total of 121 calculi were assessed with 52 calculi <5 mm in size, 32 calculi measuring 5-10 mm and 37 calculi >10 mm. Kappa test of agreement was used to assess the interobserver agreement for all observations. The measurement of agreement kappa value was 1. The overall sensitivity of DT and USG in detecting urolithaisis was 50% (p value <0.001) and 50.4% (p value 0.005) respectively. No statistically significant difference was noted between USG and DT in detecting urolithiasis. The sensitivity of DT and USG in detecting renal calculi was 47.1% and 50.9% respectively and the sensitivity of DT and USG in detecting ureteric calculi was 74.9% and 39.2% respectively. We observed statistically significant difference between USG and DT in detecting ureteric calculi.

CONCLUSION

In our study, there was no statistically significant difference noted between USG and DT in diagnosis of urolithiasis. DT performed significantly better than USG in detecting ureteric calculi with a higher sensitivity. Hence, we are tempted to opine that DT may be preferred over USG for initial evaluation of patients with suspected ureteric calculi. However considering the strength of ultrasound in demonstrating associated signs as hydroureteronephosis, we are still of the opinion, that both DT and USG should be used as complementary techniques in resolving these common clinical screnarios.

Virtual stone clinic – the future of stone management?

Objectives:

Increasing demands on the urology outpatient department at Brighton and Sussex University Hospitals (BSUH) have posed a significant challenge on the provision of a timely service for patients with stone disease. This study aimed to evaluate the patient outcomes and waiting times achieved with a newly implemented virtual stone clinic (VSC).

Materials and methods:

All new stone referrals received between August 2016 to January 2017 at BSUH were discussed in the VSC. Patients were reviewed within seven days of referral by a multidisciplinary team led by a consultant stone surgeon. A prospectively collected database was generated with primary outcomes including discharge to primary care, need for further diagnostics, re-review at VSC, direct booking for treatment and referral to a traditional outpatient stone clinic. Waiting times between the VSC and previously used outpatient stone clinic were also compared.

Results:

A total of 526 cases were reviewed in the VSC. One-quarter of patients were discharged following initial VSC review with a further two-thirds discharged after re-review. Treatment was offered to 101 patients, primarily in the form of lithotripsy (65%). Eighty-six patients required formal outpatient clinic appointments. Waiting lists for stone appointments were cleared within two months of implementation of the VSC. Outcomes were very favourable, with only three patients requiring emergency admission for management of their stone disease.

Conclusion:

The VSC model provides a clinically and cost-effective method of managing patients with urinary tract stones with significantly reduced waiting times and overall improved patient satisfaction. Level of evidence: Not applicable for this multicentre audit.

Radiation exposure of patient and surgeon in minimally invasive kidney stone surgery

OBJECTIVE

Percutaneous nephrolithotomy (PNL) and retrograde intrarenal surgery (RIRS) are the standard treatments used in the endoscopic treatment of kidney stones depending on the location and the size of the stone. The purpose of the study was to show the radiation exposure difference between the minimally invasive techniques by synchronously measuring the amount of radiation the patients and the surgeon received in each session, which makes our study unique.

MATERIALS AND METHODS

This is a prospective study which included 20 patients who underwent PNL, and 45 patients who underwent RIRS in our clinic between June 2014 and October 2014. The surgeries were assessed by dividing them into three steps: step 1: the access sheath or ureter catheter placement, step 2: lithotripsy and collection of fragments, and step 3: DJ catheter or re-entry tube insertion.

RESULTS

For the PNL and RIRS groups, mean stone sizes were 30mm (range 16-60), and 12mm (range 7-35); mean fluoroscopy times were 337s (range 200-679), and 37s (range 7-351); and total radiation exposures were 142mBq (44.7 to 221), and 4.4mBq (0.2 to 30) respectively. Fluoroscopy times and radiation exposures at each step were found to be higher in the PNL group compared to the RIRS group. When assessed in itself, the fluoroscopy time and radiation exposure were stable in RIRS, and the radiation exposure was the highest in step 1 and the lowest in step 3 in PNL. When assessed for the 19 PNL patients and the 12 RIRS patients who had stone sizes≥2cm, the fluoroscopy time in step 1, and the radiation exposure in steps 1 and 2 were found to be higher in the PNL group than the RIRS group (P<0.001).

CONCLUSION

Although there is need for more prospective randomized studies, RIRS appears to be a viable alternate for PNL because it has short fluoroscopy time and the radiation exposure is low in every step.

LEVEL OF EVIDENCE

4.

Radiation dosing in the investigation and follow-up of urolithiasis: Comparison between historical and contemporary practices

Purpose

Computed tomography (CT) is the gold standard imaging modality for the diagnosis and follow-up of urolithiasis. Before the use of CT, intravenous urography (IVU) was the imaging modality of choice. CT remains contentious because of the cancer risk related to radiation exposure above a threshold level. We aimed to compare the radiation exposure dose to the average patient with urolithiasis in the era of CT with that of IVU.

Materials and Methods

Our hospital medical records database was searched for patients who presented to the Emergency Department over a 1-month period in 1990 with a diagnosis of renal colic. Patients with the same presentation, from the same month, in 2013 were also identified. A total of 14 patients from each year fulfilled the inclusion criteria. The estimated effective radiation exposure dose for each patient was calculated by using data from population-based studies.

Results

The median effective radiation dose per patient in the 1990 group, for initial diagnosis and subsequent follow-up, was 4.05 mSv (interquartile range [IQR], 3.7–4.4 mSv). The corresponding median dose in the 2013 group was 4.2 mSv (IQR, 4.2–4.9 mSv), and there was no evidence of a statistical difference between the groups (p=0.8).

Conclusions

Despite the contentiousness related to the use of serial CT scanning, our study demonstrated that for radiological investigation and follow-up of urolithiasis, the estimated effective radiation exposure dose to each patient is only marginally higher than in the era of IVU, with improvements in length of hospital stay and time to definitive diagnosis.