Patient Radiation Dose Research Articles

Radiation dose of prostatic artery embolization for benign prostatic hyperplasia: A protocol for systematic review.

Increasing evidence supports the efficacy and safety of prostatic artery embolization (PAE) in the treatment of benign prostatic hyperplasia. However, PAE relies on ionizing radiation, which has not been studied systematically so far. Therefore, the potential associated risks remain largely unknown and are subject to intense debate. We performed a protocol for systematic review and meta-analysis to evaluate the clinical benefits of different radiation doses in patients with benign prostatic hyperplasia undergoing PAE. A comprehensive search of several databases from 1966 to October 2022 was conducted. The databases include Ovid Medline In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Ovid PsycINFO, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and PubMed. Risk of bias of the included studies was assessed by the "Risk of Bias Assessment Tool" of the Cochrane Handbook for randomized controlled trials. All data were analyzed using the Comprehensive Meta-Analysis software package (Biostat, Engelwood, NJ). The results will be submitted to a peer-reviewed journal once completed. This review will provide reliable evidence for extensive application of PAE for benign prostatic hyperplasia and determine the most rational radiation dose for these patients.

Patient and provider radiation exposure during fluoroscopy guided chemical and thermal neurolysis of genicular nerves: A prospective cohort comparison study

PurposeTo evaluate the differences in radiation dosimetry, fluoroscopy time and procedure time between fluoroscopy-guided chemical and thermal genicular neurolysis techniques. MethodsThis single-site, open label observational cohort was done at an urban, tertiary medical center pain clinic. Board certified pain medicine physicians with at least 5 years of experience with genicular neurolysis procedures performed or supervised all interventions. Clinical characteristics and procedural details were collected at each procedure. Patients underwent chemical neurolysis using phenol or cooled radiofrequency neurolysis. Radiation dosimetry was the primary outcome and was compared between the between chemical and radiofrequency neurolysis groups. ResultsThirty-one subjects (15 had chemical and 16 had radiofrequency neurolysis procedures) underwent a total of 43 interventions. Twelve underwent bilateral procedures. Radiation dosimetry per procedure was 1.66 (0.89 to 2.45) Gy-cm2 for chemical and 1.76 (1.08 to 2.28) Gy-cm2 for radiofrequency neurolysis, adjusted mean difference −0.092 (−0.60 to 1.114, P ​= ​0.864) Gy-cm2. Procedure times were shorter for chemical compared to radiofrequency neurolysis procedures, difference 9.2 (95% CI 6.8 to 11.6, P ​< ​0.001) minutes; but no between treatment group differences in fluoroscopy time or interventionalist radiation exposure were observed. Higher BMI and advanced Kellgren-Lawrence grades were associated with increased patient radiation dosimetry. ConclusionsWe found that patient radiation dose, fluoroscopy time, and interventionalist radiation exposure were not different between chemical and radiofrequency neurolysis. Genicular neurolysis was more rapidly performed using chemical as compared to radiofrequency neurolysis. BMI and Kellgren-Lawrence grade, but not procedural factors were associated with greater absorbed radiation doses.

EFFECT OF PELVIC LEAD SHIELD ON ORGAN DOSES IN POSTERO-ANTERIOR CHEST RADIOGRAPHY.

Lead shields are commonly used in X-ray imaging to protect radiosensitive organs and to minimise patient's radiation dose. However, they might also complicate or interfere with the examination, and even decrease the diagnostic value if they are positioned incorrectly. In this study, the radiation dose effect of waist half-apron lead shield was examined via Monte Carlo simulations of postero-anterior (PA) chest radiography examinations using a female anthropomorphic phantom. Relevant organs for dose determination were lungs, breasts, liver, kidneys and uterus. The organ dose reductions varied depending on shield position and organ but were negligible for properly positioned shields. The shield that had the largest effective dose reduction (9%) was partly positioned inside the field of view, which should not be done in practice. Dose reduction was practically 0% for properly positioned shields. Therefore, the use of lead shield in the pelvic region during chest PA examinations should be discontinued.

Chancen und Grenzen der stereotaktisch fraktionierten Hochpräzisionsbestrahlung beim nichtkleinzelligen Lungenkarzinom im Stadium I/II

BackgroundFractionated stereotactic body radiotherapy (SBRT) can achieve excellent tumor control with good toxicity profiles and maintained quality of life through non-invasive application of ablative radiation dose in patients with early stage non-small-cell lung cancer (ES-NSCLC).Materials and methodsThe current standard and challenges of SBRT for patients with ES-NSCLC are presented. Recommendations from guidelines and literature are also discussed.ResultsFor inoperable patients, SBRT is considered the standard of care and is superior to conventionally fractionated RT and radiofrequency ablation (RFA) in survival data. For operable patients, resection remains the standard, even if studies show good local control rates, toxicity profiles, and quality of life for SBRT. Only risk-adapted fractionation schemes should be used in patients with central ES-NSCLC; in patients with interstitial lung disease (ILD), increased risk of toxicity must be weighed against the indication. Another challenge is to improve systemic control and survival, which is addressed by combining SBRT with checkpoint inhibitors.ConclusionsThe innovative technique of extracranial SBRT has undergone exorbitant developments in recent years and represents an established treatment alternative to surgery and RFA that is already recommended for inoperable patients with ES-NSCLC and is to be considered for operable patients. Challenges in the use of SBRT are treatment of centrally localized tumors, patients suffering from pulmonary diseases and the combination of SBRT with systemic therapy, which is the subject of current studies.

Oncology-specific radiation dose and image noise reference levels in adult abdominal-pelvic CT

ObjectivesTo provide our oncology-specific adult abdominal-pelvic CT reference levels for image noise and radiation dose from a high-volume, oncologic, tertiary referral center. MethodsThe portal venous phase abdomen-pelvis acquisition was assessed for image noise and radiation dose in 13,320 contrast-enhanced CT examinations. Patient size (effective diameter) and radiation dose (CTDIvol) were recorded using a commercial software system, and image noise (Global Noise metric) was quantified using a custom processing system. The reference level and range for dose and noise were calculated for the full dataset, and for examinations grouped by CT scanner model. Dose and noise reference levels were also calculated for exams grouped by five different patient size categories. ResultsThe noise reference level was 11.25 HU with a reference range of 10.25–12.25 HU. The dose reference level at a median effective diameter of 30.7 cm was 26.7 mGy with a reference range of 19.6–37.0 mGy. Dose increased with patient size; however, image noise remained approximately constant within the noise reference range. The doses were 2.1–2.5 times than the doses in the ACR DIR registry for corresponding patient sizes. The image noise was 0.63–0.75 times the previously published reference level in abdominal-pelvic CT examinations. ConclusionsOur oncology-specific abdominal-pelvic CT dose reference levels are higher than in the ACR dose index registry and our oncology-specific image noise reference levels are lower than previously proposed image noise reference levels. Advances in knowledgeThis study reports reference image noise and radiation dose levels appropriate for the indication of abdomen-pelvis CT examination for cancer diagnosis and staging. The difference in these reference levels from non-oncology-specific CT examinations highlight a need for indication-specific, dose index and image quality reference registries.

Assessing the impact of binaural and non-binaural auditory beat intervention to pain and compression in mammography

IntroductionPain and discomfort has a negative impact on a patient's overall experience and may impact on subsequent re-attendance to mammography. Pain during mammography remains a significant issue. Assessment of interventions to reduce levels of pain associated with mammography are essential to increase attendance to breast services and improve user experience. MethodsParticipants (n = 60) were invited to take part in the study at one hospital Trust within the UK. Postal invitations were sent 2 weeks prior to appointment to patients older than 40 years with previous mammography attendance at the same Trust to allow for comparison of previous and current pain scores/compression values. Patients were randomised into 3 groups: Binaural music (BM), non-binaural music (NBM) and standard care (C). A numerical rating scale (NRS) was used to rate pain. ResultsPatient tolerance is increased by the application of both the non-binaural and binaural music. Binaural music was most effective in improving patient tolerance (p = 0.02). When applied compression increased some patients recorded less pain, which may have implications to image quality and radiation dose for patients. Binaural music reduces the perception of mammographic pain within this data set. Conclusion5 min exposure to binaural music improves patient experience and tolerance for mammography which could be utilised to improve attendance rates in screening and symptomatic services. Implications for practiceThere is an indication for further research looking at application prior and during interventional biopsies. Music intervention can be offered to patients in the severe pain category who refuse mammography. It is acknowledged from these findings that the introduction of BM and NBM prior to mammography would be a low risk, cost effective intervention within the hospital setting.

Long-term follow-up results of endorectal balloon-assisted helical tomotherapy for localized prostate cancer patients in the high-risk group of gastrointestinal adverse events.

Endorectal balloon (ERB) has been shown to reduce rectal radiation dose and late gastrointestinal toxicities in patients with prostate cancer. However, the usefulness of ERBs for patients with prostate cancer whose rectal shape or size is suboptimal has not been investigated. The purpose of this study was to present the long-term follow-up results of ERB-assisted helical tomotherapy for localized prostate cancer patients whose initial radiation treatment planning (RTP) was unacceptable due to suboptimal rectal shape or size. Of 541 consecutive patients with localized prostate cancer, 10 were included in this study whose RTPs without ERBs did not meet dose constraints due to: 1) Intestinal intrusion, 2) Small rectum; or 3) Unstable rectal shape. We re-planned using ERBs and delivered 76 Gy in 38 fractions, and evaluated the long-term usefulness and safety of ERB-assisted helical tomotherapy. At a median follow-up of 109 months, there were no local recurrences of prostate cancer. The overall, cause-specific, and progression-free survivals at 10 years were 90.0%, 100%, and 83%, respectively. Adverse events of grade 3 or higher were not observed during or after ERB-assisted helical tomotherapy. When intestinal intrusion, a small rectum, or an unstable rectal shape is an obstacle for administering helical tomotherapy, ERBs might be the solution.

Dedicated CCTA Followed by High-Pitch Scanning versus TRO-CT for Contrast Media and Radiation Dose Reduction: A Retrospective Study.

We aimed to compare dedicated coronary computed tomography angiography (CCTA) followed by high-pitch scanning and triple-rule-out computed tomography angiography (TRO-CTA) in terms of radiation dose, contrast media (CM) use, and image quality. Patients with acute chest pain were retrospectively enrolled and assigned to group A (n = 55; scanned with dedicated CCTA followed by high-pitch scanning) or group B (n = 45; with TRO-CTA). Patient characteristics, radiation dose, CM use, and quantitative parameters (CT value, image noise, signal-to-noise ratio, contrast-to-noise ratio, and image quality score) of pulmonary arteries (PAs), thoracic aortae (TAs), and coronary arteries (CAs) were compared. The total effective dose was significantly lower in group A (6.25 ± 2.94 mSv) than B (8.93 ± 4.08 mSv; p < 0.001). CM volume was significantly lower in group A (75.7 ± 8.9 mL) than B (95.0 ± 0 mL; p < 0.001). PA and TA image quality were significantly better in group B, whereas that of CA was significantly better in group A. Qualitative image scores of PA and TA scans rated by radiologists were similar, whereas that of CA scans was significantly higher in group A than B (p < 0.001). Dedicated CCTA followed by high-pitch scanning demonstrated lower radiation doses and CM volume without debasing qualities of PA, TA, and CA scans than did TRO-CTA.

A Novel Laser Angle Selection System for Computed Tomography-Guided Percutaneous Transthoracic Needle Biopsies.

Purpose: To evaluate a novel laser angle selection system (LASS) for improving the efficiency of a computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB). Methods: Thirty-eight patients referred for CT-guided PTNB were randomly separated into a LASS-assisted puncture group (18 patients) or conventional freehand control group (20 patients). The puncture time, number of control CT scans, and patients' radiation dose were compared for each group. Results: The lesion size, target-to-pleural distance, planned puncture depth, and angle of the two groups were not significantly different. LASS-assisted PTNB significantly reduced the number of control scans (1.7 ± 0.8 vs 3.5 ± 1.5, P < .001) and the mean operation time (12.0 ± 4.3min vs 28.8 ± 13.3min, P < .001) compared with the conventional method. The corresponding room time (27.1 ± 6.6min vs 44.1 ± 14.4min, P < .001) and total radiation dose (7.9 ± 1.0mSv vs 10.1 ± 1.7mSv, P < .001) of each procedure also decreased significantly. Fifty-six percent (10/18) of the operations hit the target on the first needle pass when using LASS compared with 10% (2/20) using the conventional method. Conclusions: Compared with a conventional method, this novel laser angle simulator improves puncture efficiency with fewer needle readjustments and reduces patient radiation dose.

Radiation Dose Exposure to Patients During Transcatheter Patent Ductus Arteriosus Closure via the Arterial Route

Objective This study aims to evaluate the radiation dose for transcatheter patent ductus arteriosus (PDA) viathe arterial route and compare it with previously published benchmarks. Background Exposure to radiation in the catheterization lab can cause skin injury and cancer in the long run, especially in pediatric patients with complex heart conditions, which necessitate serial catheterizations. Therefore, measuring the patient radiation dose and establishing a benchmark for each cardiac interventional procedure is essential. Material and methods In this prospective study, 34 patients with transcatheter patent ductus arteriosus closure via an arterial route were included. Patients who had silent PDAs, no left heart dilatation and PDA size of less than 2mm had PDA closed via an arterial route. All the study group patients received an Amplatzer duct occluder II-additional size device (St. Jude Medical Corp, St. Paul, MN) using biplane flat-panel fluoroscopy equipment adjusted in accordance with the pediatric parameters. Patients' dose area product, air kerma and fluoroscopytime were recorded in the catheterization lab and finally compared with internationally published reference data. Results Of 73 patients who had transcatheter patent ductus arteriosus closure between April 2021 to December 2021, 34patients who had a PDA closure via an arterial route were enrolled. The median age and weight were 11.5 (4-168) months and 10.5 (6-31) kg. Twenty-one (61.8%) were males, and 13 (38.2%) were males. The median radiation dose parameters were as follows: air kerma 11 (3-42) milliGray, dose area product 131 (33-443) microGray per m2, median dose area product indexed to weight 12 (1-48) microGray m2 per kg, fluoroscopy time 2 (2-4) min and frame rate 15 (7.5-15) frames per second. Due to many factors, our radiation dose parameters were less than internationally published reference values for transcatheter PDA closure. Conclusion Patient selection, detailed pre-catheterization echocardiography and procedure planning are essential for accomplishing device closure of PDA with a significant reduction in radiation dose. Hemodynamic assessment in the catheterization lab is unnecessary for most PDA patients. Additionally, a next-generation imaging platform equipped with flat-panel detectors and adjusted for pediatric settings and a fluoro recording option can be used to reduce radiation exposure.

Efficacy of Scalp-Sparing VMAT Approach in Reducing Scalp Radiation Dose for Patients with Glioblastoma

<h3>Purpose/Objective(s)</h3> Radiation therapy is integral to the treatment of glioblastomas. Radiation induced scalp toxicity, however, is common and can negatively impact patients' quality of life. Volumetric modulated radiation therapy (VMAT) can optimize dose to organs at risk. We hypothesize that scalp-sparing VMAT (SSV) can significantly reduce undesirable dose to the scalp without compromising target dose. In this study, we evaluate the dosimetric feasibility and benefit of SSV for patients with newly diagnosed glioblastomas (GBM). <h3>Materials/Methods</h3> This is a retrospective study of GBM patients who received radiation treatment at our institution with conventional VMAT without scalp-sparing optimization. We contoured the scalp for these patients, which was defined as a 5 mm ring structure beneath the skin, above the foramen magnum. We replanned these patients using non-coplanar SSV techniques. Dosimetric data for scalp, target, and critical normal structure were collected and compared. <h3>Results</h3> 20 patients with newly diagnosed GBM were selected for this study. All patients received a total radiation dose of 60 Gy in 30 fractions. 10 patients received 60 Gy in 30 fractions in a single-course. The rest received radiation in a split-course, with 46 Gy in 23 fractions to an initial volume followed by 14 Gy in 7 fractions to a cone-down volume, for a combined dose of 60 Gy in 30 fractions. New VMAT plans were generated after adding scalp as an organ at risk. Median scalp volume was 410 cc (range: 377-443 cc). With SSV, there was no significant reduction in maximum scalp dose. However, SSV significantly reduced mean scalp dose, doses received by 20cc and 30 cc of the scalp, and volumes of the scalp receiving 30 Gy, 40 Gy and 50 Gy. Median reduction in mean scalp dose was 21.4% (range: 5.0–39.9%), from 14.6 Gy to 10.9 Gy. Median reduction in 20 cc scalp dose was 33.9% (range: 2.7–36.9%), from 43.9 Gy to 33.9 Gy, and 30 cc scalp dose was 24.2% (range: 5.3-39.5%), from 36.6 Gy to 28.1 Gy. There were significant reductions in the volumes of scalp receiving 30 Gy, 40 Gy, and 50 Gy as well. There were no significant differences in the doses of target, brainstem, and optic nerves between non-SSV and SSV plans. <h3>Conclusion</h3> Scalp-sparing VMAT is a feasible technique and can significantly reduce scalp radiation dose without compromising target coverage or critical normal structure constraints. This may lead to reduced acute and late radiation toxicity to the scalp. A prospective trial evaluating the clinical benefit of this technique is ongoing (NCT03251027).

Observation and Management of Patient Radiation Dose in CT

Purpose: The aim was to observe and manage the patient radiation dose in CT Methodology: A retrospective study of observation and management of patient radiation dose in CT was conducted for 5 months. During this period patient radiation dose was observed. CTDI and DLP were calculated. Patients were divided in three age groups (0-15 yrs, 16-55 yrs, 56-85 yrs) on the basis of pre-reproductive, reproductive &amp; post-reproductive age. All the age groups were compared on the basis of dose received. Radiation dose was also compared in different body parts. Result: A study was conducted in the department of radiology at SGT hospital for observation and management of the patient radiation dose in CT. Total 84 patients were taken in this study. Out of which 50 (59.5%) were males and 34 (40.4%) were females. In the age group of 0-15 yrs DLP was high in abdomen 772.47 mGy.cm and low in chest 234.22 mGy.cm. In the age group of 16-55 yrs DLP was high in head (809.51 mGy.cm) and low in neck (380.27 mGy.cm) and in the age group of 56-85 yrs DLP was high in head (923.63 mGy.cm) and low in chest (477.51 mGy.cm). Among all the age groups head dose was high in the age group of 56-85 yrs, neck dose was high in the age group of 56-85 yrs, chest dose was high in the age group of 16-55 yrs and abdomen dose was high in the age group of 56-85 yrs. The overall radiation dose was high in the age group of 56-85 yrs (37%) and less in the age group of 0-15 yrs (30%). It was observed that radiographers uses lead apron to cover the area of patient which is outside the ROI to protect the patient from unnecessary radiation dose. They always keep in mind that the centering of patient should be correct. They also avoid repeated exposure to the patient. Conclusion: In this study, it was found that in head, neck and abdomen dose was high in the age group of 56-85 yrs and chest dose was high in the age group of 16-55 yrs. The overall radiation dose was high in the age group of 56-85 yrs which was 37% and lowest radiation dose was in the age group of 0-15 yrs which was 30%. It was observed that radiographers uses radiation protection devices to cover the area of patient which is not needed to be examine, to protect the patient from unnecessary radiation dose. They do the proper centering of patient. They also avoid repeated exposure to the patients. It is suggested to give less radiation dose to the patient. Keywords: observation, management, patient, radiation, dose, computed, tomography

Robotic-assisted PCI – insights from a monocenter registry

Abstract Background Robotics in interventional cardiology is a rapidly evolving technique, which is still in an early phase of development and clinical application. Beside the pivotal studies, there is limited real world data on success rates and safety of this new technology. Purpose To investigate the success rate as well as the safety profile of robotic-assisted percutaneous coronary intervention (R-PCI) and compare it with manual PCI (M-PCI). Methods We report preliminary data of our ongoing, prospective FRiK registry, started in mid 2021. This registry focuses on success rates and safety, radiation dose of patients and personnel, long-term outcome (after 6, 12 and 24 months), as well as on economic aspects and the learning curve of the interventionalists. Moreover, the R-PCI is compared with the M-PCI in these categories. Results So far, 51 patients (age 69 (62–80) years, BMI 28.4 (25.2–32) kg/m2, 74.5% male), received R-PCI. PCI success rate was 100%, with 15% requiring manual assistance (Figure 1). Rate of complications (myocardial infarction after PCI, dissection, stent thrombosis, pericardial effusion, target lesion revascularization and MACE (major adverse cardiovascular events) was 0%. Compared with 41 M-PCI patients (Table 1), treated by the same interventionalists, there was a higher median procedural time (diagnostic and intervention) 106 (82–127) min vs. 71 (54–93) min (p&amp;lt;0.001) and fluoroscopy time 20.3 (14.8–28.5) min vs. 14.8 (10.4–22.4) min (p=0.012) in R-PCI patients. However, there was no significant difference between the dose-area product 4662.4 (3019.4–6399.2) cGy cm2 vs. 4193.9 (2759.9–6254.3) cGy cm2 (p=0.487) and contrast volume use 200 (150–280) ml vs. 180 (145–255) ml (p=0.587). Conclusion Preliminary results of R-PCI showed a high success rate, low rates for need of manual assistance, and a very high safety profile without any complications. The dose-area product and contrast volume use were comparable between R-PCI and M-PCI, whereas R-PCI showed a longer procedural and fluoroscopy time. Future steps will include a larger number of cases and definitions of patient cases with optimal eligibility for R-PCI. Funding Acknowledgement Type of funding sources: None.

The critical components for effective adaptive radiotherapy in patients with unresectable non-small-cell lung cancer: who, when and how.

Adaptive radiotherapy (ART) is a new radiotherapy technology based on image-guided radiation therapy technology, used to avoid radiation overexposure to residual tumors and the surrounding normal tissues. Tumors undergoing the same radiation doses and modes can occur unequal shrinkage due to the variation of response times to radiation doses in different patients. To perform ART effectively, eligible patients with a high probability of benefits from ART need to be identified. Confirming the precise timetable for ART in every patient is another urgent problem to be resolved. Moreover, the outcomes of ART are different depending on the various image guidance used. This review discusses 'who, when and how' as the three key factors involved in the most effective implementation for the management of ART.

Hybrid computational pregnant female phantom construction for radiation dosimetry applications

The number of patients undergoing diagnostic radiology and radiation therapy procedures has increased drastically owing to improvements in cancer diagnosis and treatment, and consequently, patient survival. However, the risk of secondary malignancies owing to radiation exposure remains a matter of concern. We previously published three hybrid computational fetal phantoms, which contained 27 fetal organs, as a starting point for developing the whole hybrid computational pregnant phantom set, which is the final objective of this study. An International Commission on Radiological Protection (ICRP) reference female voxel model was converted to a non-uniform rational B-spline (NURBS) surface model to construct a hybrid computational female phantom as a pregnant mother for each fetal model. Both fetal and maternal organs were matched with the ICRP- 89 reference data. To create a complete standard pregnant computational phantom set at 20, 30, and 35 weeks of pregnancy, the model mother’s reproductive organs were removed, and fetal phantoms with appropriate placental and uterine models were added to the female pelvis using a 3D-modeling software. With the aid of radiological image sets that had originally been used to construct the fetal models, each fetal position and rotation inside the uterus were carefully adjusted to represent the real fetal locations inside the uterus. The major abdominal soft tissue organs below the diaphragm, namely the small intestine, large intestine, liver, gall bladder, stomach, pancreas, uterus, and urinary bladder, were removed from non-pregnant females. The resulting fetal phantom was positioned in the appropriate location, matching the original radiological image sets. An obstetrician-gynecologist reviewed the complete internal anatomy of all fetus phantoms and the pregnant women for accuracy, and suggested changes were implemented as needed. The remaining female anatomical tissues were reshaped and modified to accommodate the location of the fetus inside the uterus. This new series of hybrid computational pregnant phantom models provides realistic anatomical details that can be useful in evaluating fetal radiation doses in pregnant patients undergoing diagnostic imaging or radiotherapy procedures where realistic fetal computational human phantoms are required.

Feasibility analysis of high pitch cervical spine CT in uncooperative patients with acute cervical spine trauma: An initial experience.

Cervical computed tomography (CT) often suffers from examination failure in uncooperative patients with acute cervical spinal trauma. Therefore, this study aimed to evaluate the feasibility of using high-pitch cervical CT (HP-CT) in such populations. A total of 95 patients with acute neck/head-neck trauma who underwent HP-CT (n = 29) or standard cervical CT (SD-CT, n = 66) from October 2020 to June 2021 were included in this study. Differences in patient characteristics between the HP-CT group and the SD-CT group were firstly compared. Then, the objective image quality based on the mean score of the signal-to-noise ratio (SNR)/contrast noise ratio (CNR) was evaluated, while double-blind five-point scoring was adopted for the subjective evaluation. Finally, radiation doses in HP-CT and SD-CT were compared. Furthermore, the Student t test and/or Mann–Whitney U test were performed to analyze differences in patient characteristics, image quality, and radiation dose between the two regimes. A total of 17 cases of cervical spine fractures were found in 95 patients, including 6 cases in the HP-CT group and 11 cases in the SD-CT group. The average age of patients who received HP-CT was higher than that of those who received SD-CT, and the scan time using HP-CT was shorter than that SD-CT. The differences were statistically significant (both, P < .05). In addition, there was no significant difference between HP-CT and SD-CT in terms of sex, body mass index, field of view (FOV), and scan length (all P > .05). The SNR/CNR at the middle and upper neck was not significantly different between HP-CT and SD-CT (all P > .05). However, the SNR/CNR at the lower neck in HP-CT was lower than that in SD-CT (all P < .05). There was no significant difference in the subjective scores between HP-CT and SD-CT images in both the soft tissue and bone window (P = .129 and 0.649, respectively). The radiation dose in HP-CT was lower than that in SD-CT (all P < .05). With a scan time reduction of 73%, radiation dose reduction of 10%, and similar image quality, high-pitch cervical CT was of feasibility to evaluate cervical spine injury in uncooperative patients with acute cervical spine trauma.

Computed Tomography Intraoperative Navigation in Spinal Surgery: Assessment of Patient Radiation Exposure in Current Practices.

Patient radiation exposure associated with the use of computed tomography (CT) navigation during spinal surgeries was widely compared with other intraoperative imaging techniques. The aim of this study is to explore the use of navigation with regard to current spinal surgery practices and the technical limitations of such imaging systems. Dosimetric data from 101 patients who underwent intraoperative, CT-navigated spine surgery were retrospectively collected. The study population was divided into 3 groups according to the primary surgical indication. The number of CT image acquisitions per patient, the field length, and the time of exposure per acquisition during a single surgery were compared as well as the radiation dose emitted to patients. Dose-length products (DLP) per acquisition were 678.52, 656.8, and 649.36 mGy·cm with no significant difference for spinal deformity (SD), degenerative disease (DD), and vertebral fracture (VF) procedures, respectively. Analyzing the number of CT image acquisitions per patient revealed that repeated intraoperative scans were often performed for patients who were suffering from an SD due to technical limitations of the navigation. As a consequence, the cumulative dose was higher in the SD group (DLP total = 1175 mGy·cm) than in the DD (DLP total = 762.74 mGy·cm) and VF (DLP total = 649.36 mGy·cm) groups. CT navigation is an efficient intraoperative imaging technique that reduces the rate of surgical complications, but its technical limitations lead to an increased risk of patient radiation exposure, especially for complex surgeries where multiple scanning acquisitions are needed. To avoid patient's overexposure, spine surgeons should minimize the number of intraoperative acquisitions while considering the complexity of the surgery and the limitations of the guidance system. The use of dual guidance systems has also to be considered according to the benefit-risk balance between patient's outcomes and radiation dose exposure.

Percutaneous thoraco-lumbar-sacral pedicle screw placement accuracy results from a multi-center, prospective clinical study using a skin marker-based optical navigation system

Study designProspective multi-center study.ObjectiveThe study aimed to evaluate the accuracy of pedicle screw placement using a skin marker-based optical surgical navigation system for minimal invasive thoraco-lumbar-sacral pedicle screw placement.MethodsThe study was performed in a hybrid Operating Room with a video camera-based navigation system integrated in the imaging hardware. The patient was tracked with non-invasive skin markers while the instrument tracking was via an on-shaft optical marker pattern. The screw placement accuracy assessment was performed by three independent reviewers, using the Gertzbein grading. The screw placement time as well as the staff and patient radiation doses was also measured.ResultsIn total, 211 screws in 39 patients were analyzed for screw placement accuracy. Of these 32.7% were in the thoracic region, 59.7% were in the lumbar region, and 7.6% were in the sacral region. An overall accuracy of 98.1% was achieved. No screws were deemed severely misplaced (Gertzbein grading 3). The average time for screw placement was 6 min and 25 secs (± 3 min 33 secs). The average operator radiation dose per subject was 40.3 µSv. The mean patient effective dose (ED) was 11.94 mSv.ConclusionSkin marker-based ON can be used to achieve very accurate thoracolumbarsacral pedicle screw placements.

The effect of ionizing radiation through cardiac stereotactic body radiation therapy on myocardial tissue for refractory ventricular arrhythmias: A review.

Cardiac stereotactic body radiation therapy (cSBRT) is a non-invasive treatment modality that has been recently reported as an effective treatment for ventricular arrhythmias refractory to medical therapy and catheter ablation. The approach leverages tools developed and refined in radiation oncology, where experience has been accumulated in the treatment of a wide variety of malignant conditions. However, important differences exist between rapidly dividing malignant tumor cells and fully differentiated myocytes in pathologically remodeled ventricular myocardium, which represent the respective radiation targets. Despite its initial success, little is known about the radiobiology of the anti-arrhythmic effect cSBRT. Pre-clinical data indicates a late fibrotic effect of that appears between 3 and 4 months following cSBRT, which may result in conduction slowing and block. However, there is clear clinical evidence of an anti-arrhythmic effect of cSBRT that precedes the appearance of radiation induced fibrosis for which the mechanism is unclear. In addition, the data to date suggests that even the late anti-arrhythmic effect of cSBRT is not fully attributable to radiation.-induced fibrosis. Pre-clinical data has identified upregulation of proteins expected to result in both increased cell-to-cell coupling and excitability in the early post cSBRT period and demonstrated an associated increase in myocardial conduction velocity. These observations indicate a complex response to radiotherapy and highlight the lack of clarity regarding the different stages of the anti-arrhythmic mechanism of cSBRT. It may be speculated that in the future cSBRT therapy could be planned to deliver both early and late radiation effects titrated to optimize the combined anti-arrhythmic efficacy of the treatment. In addition to these outstanding mechanistic questions, the optimal patient selection, radiation modality, radiation dose and treatment planning strategy are currently being investigated. In this review, we consider the structural and functional effect of radiation on myocardium and the possible anti-arrhythmic mechanisms of cSBRT. Review of the published data highlights the exciting prospects for the development of knowledge and understanding in this area in which so many outstanding questions exist.

Fluoroscopy screening time and radiation dose during complete supine percutaneous nephrolithotomy.

Fluoroscopy-guided percutaneous nephrolithotomy (PCNL) is procedure of choice for treatment of large urinary tract calculi. This study aimed to investigate the affecting factors on fluoroscopy screening time (FST) and radiation dose (RD) of patients undergoing complete supine percutaneous nephrolithotomy (csPCNL). Analytic cross-sectional study was performed on 355 patients who underwent csPCNL. The correlation between the FST and RD and patients' demographics, stone characteristics, preoperative, intraoperative and postoperative parameters were assessed. Multivariate regression analysis was used to explore various parameters which affect FST and RD. Of all 355 patients, 191 (54.65%) were male and 161 were (45.35%) female with mean age of 48.29 ± 12.38 (16-82) years. BMI was 27.61 ± 4.53 (16.61-39.00) kg/m2. The mean operative time was 45.87 ± 18.29min with mean FST of 101.72 ± 62.00s. BMI, operative time, success rate, complications, stone number, and tract number had a significant relationship with FST and RD (P < 0.05). On multivariate analysis, BMI, tract number and success rate were found to be independent predictors for FST and RD. Age, gender, operation side, GFR, target calyx, lithotripsy history, stone opacity, size and site, stone configuration and distribution, and hydronephrosis did not have any correlation with FST and RD (P > 0.05). BMI, success rate and tract number can be significant predictor for FST and RD during csPCNL. Identifying the affecting factors on FST and RD can help the surgeon to minimize the danger of radiation exposure by predicting and preoperative planning.