Helical CT versus intermittent CT fluoroscopic guidance for musculoskeletal needle biopsies: impact on radiation exposure, procedure time, diagnostic yield, and adverse events

Comparison of patient radiation exposure and procedure time between CT-fluoroscopy and spiral CT for lumbar epidural steroid injections

OBJECTIVE

To compare patient radiation exposure and procedure time for lumbar epidural steroid injections (ESIs) performed under CT-fluoroscopy (CTF) vs spiral CT-guidance.

MATERIALS AND METHODS

A retrospective cohort study of 767 consecutive lumbar ESIs performed between 2015-2023 using CTF vs spiral CT-guidance was conducted. Patient characteristics (age, sex, weight), procedural characteristics (injection level, type of ESI, trainee participation), and outcomes (patient radiation exposure, procedure time, pain relief, complications) were compared. Student's t and chi-squared tests were performed for statistical analysis.

RESULTS

There were 240 CTF and 527 spiral CT-guided lumbar ESIs. There were no significant differences in patient demographics between groups. Radiation exposure for the CTF group was 37.2 ± 50.5 mGy ∙ cm, compared to 251.1 ± 178.6 mGy ∙ cm in the spiral CT group (p < 0.001). Procedure times were shorter in the CTF group (20.1 ± 6.1 vs 29.6 ± 12.9 min, p < 0.001). There was no significant difference in immediate post-procedure pain reduction in CTF vs spiral CT groups (p = 0.12). There were no intrathecal puncture complications in the CTF group and four in the spiral CT group. Subgroup analysis of attending-only and trainee-performed lumbar ESIs comparing CTF vs spiral-CT groups showed similar results as the primary analysis, with significant reductions in patient radiation (attending: 31.6 ± 40.7 vs 144.4 ± 97.4 mGy ∙ cm; trainee: 40.7 ± 55.5 vs 264.5 ± 182.0 mGy ∙ cm; both p < 0.001) and procedural time (attending: 18.3 ± 4.2 vs 24.4 ± 7.4 min; trainee: 21.2 ± 6.8 vs 30.2 ± 12.4; both p < 0.001).

CONCLUSION

Image-guided lumbar ESIs using CTF were associated with less patient radiation exposure and shorter procedure times without differences in pain relief when compared with spiral CT technique in our practice.

Image-Guided Musculoskeletal Interventional Radiology in the Personalised Management of Musculoskeletal Tumours

Musculoskeletal image-guided interventional radiology plays a key role in diagnosing and treating a range of conditions. Recent advances have yielded a wide variety of procedures that can be applied selectively and enable the personalisation of patient care. This review aims to outline the indications, applications, and techniques of subspecialist musculoskeletal oncology interventional procedures that were used at our tertiary referral centre with a focus on how these may be used to personalise patient management. The applications of a range of diagnostic and therapeutic image-guided interventional procedures including different methods of bone and soft tissue sampling, ablation, and augmentation procedures across different types of patients and pathologies are reviewed. To supplement the reviewed literature, we included our own experience and radiology images retrospectively collected from our Picture Archiving and Communication System (PACS). We demonstrate how the range of musculoskeletal image-guided interventions provide flexibility in the diagnosis and management of different tumours across different patient populations. This study provides the musculoskeletal interventional radiologist with insight into how to appropriately utlilise different techniques to optimise the diagnosis, treatment and palliation of tumours.

Real-time measurement of radiation exposure in interventional radiologists during CT-guided intrathecal injections of nusinersen

PURPOSE

Some patients with spinal muscular atrophy and scoliosis require CT guidance during injections of nusinersen. The radiation applied to the operator in such procedures becomes an important issue in terms of staff health and safety. The aim of the study was to assess the operator's radiation exposure during CT-guided nusinersen injections in patients with spinal muscular atrophy and scoliosis.

METHODS

Consecutive 40 CT-guided nusinersen injections were analyzed in terms of operator's radiation exposure measured in real time.

RESULTS

The median radiation dose measured under the physician's lead apron and patient dose in terms of DLP was 0.20 µSv and 31.90 mGy*cm respectively. The radiation doses were significantly higher (p = 0.047) in patients with spinal instrumentation.

CONCLUSION

The results show that CT-guided nusinersen injection is a relatively safe procedure in terms of operator's radiation exposure. This can allow for interventional radiologists to perform more procedures without exceeding their annual dose limit.

CT in musculoskeletal imaging: still helpful and for what?

Computed tomography (CT) is a common modality employed for musculoskeletal imaging. Conventional CT techniques are useful for the assessment of trauma in detection, characterization and surgical planning of complex fractures. CT arthrography can depict internal derangement lesions and impact medical decision making of orthopedic providers. In oncology, CT can have a role in the characterization of bone tumors and may elucidate soft tissue mineralization patterns. Several advances in CT technology have led to a variety of acquisition techniques with distinct clinical applications. These include four-dimensional CT, which allows examination of joints during motion; cone-beam CT, which allows examination during physiological weight-bearing conditions; dual-energy CT, which allows material decomposition useful in musculoskeletal deposition disorders (e.g., gout) and bone marrow edema detection; and photon-counting CT, which provides increased spatial resolution, decreased radiation, and material decomposition compared to standard multi-detector CT systems due to its ability to directly translate X-ray photon energies into electrical signals. Advanced acquisition techniques provide higher spatial resolution scans capable of enhanced bony microarchitecture and bone mineral density assessment. Together, these CT acquisition techniques will continue to play a substantial role in the practices of orthopedics, rheumatology, metabolic bone, oncology, and interventional radiology.

Imaging Guidelines during Percutaneous Liver Ablation to Optimize Outcomes and Patient Safety

Image-guided ablation procedures have become a mainstay in cancer therapy. Typically performed from a percutaneous approach, thermal-based ablation procedures rely heavily on imaging guidance both prior to and during the procedure itself. Advances in imaging as they relate to ablation procedures are as important to successful treatments as advancements in the ablation technology itself. Imaging as it relates to procedural planning, targeting and monitoring, and assessment of procedural endpoint is the focus of this article.

Novel Prostate Biopsy Technique Using Imaging Fusion in a Patient With Absent Rectum

INTRODUCTION

A 70-year-old male with prior total colectomy for ulcerative colitis was referred for elevated prostate specific antigen (PSA) (8.01) with PIRADS 4 lesion on magnetic resonance imaging (MRI). Described is a novel technique using pre-operative multi-parametric prostate MRI and intraoperative computed tomography (CT) 3D/3D fusion for systematic and targeted prostate biopsy in a patient lacking a rectum.

TECHNICAL CONSIDERATIONS

Under general anesthesia, an ultra-low-dose (ULD) cone beam CT was performed in supine position using a robotic-armed fluoroscopy system (Artis Zeego Care+Clear, Siemens). 3D/3D auto-registration of the femoral heads and prostate from the MRI and ULD CT was performed. The prostate edges and two areas of concern were marked. Then, reduced-dose fluoroscopy-guided prostate biopsy was performed transperineally using triangulation technique. 27 prostate biopsy cores were obtained. Grade group 5 (Gleason 4+5=9) prostate cancer was identified in two cores from the targeted lesion and one core from the prostate base. The remaining twenty-four biopsies were negative for malignancy. Surgical time was 81 minutes. PSMA scan demonstrated no metastasis or lymphadenopathy. Robotic-assisted laparoscopic radical prostatectomy was performed without complications. Final pathology demonstrated T3a, grade group 5 prostate adenocarcinoma involving 10% of the prostate volume with negative surgical margins.

CONCLUSION

This is the initial report of fluoroscopy-guided prostate biopsy using imaging fusion techniques in a patient without a rectum. This technique allowed precise identification of localized, very high-risk prostate cancer with over three times the number of cores, and much lower radiation dose, than typical CT-guided biopsies. Our technique could provide a new paradigm in targeted prostate biopsy.

Patient Dose Estimation in Computed Tomography-Guided Biopsy Procedures

This study establishes typical Diagnostic Reference Levels (DRL) values and assesses patient doses in computed tomography (CT)-guided biopsy procedures. The Effective Dose (ED), Entrance Skin Dose (ESD), and Size-Specific Dose Estimate (SSDE) were calculated using the relevant literature-derived conversion factors. A retrospective analysis of 226 CT-guided biopsies across five categories (Iliac bone, liver, lung, mediastinum, and para-aortic lymph nodes) was conducted. Typical DRL values were computed as median distributions, following guidelines from the International Commission on Radiological Protection (ICRP) Publication 135. DRLs for helical mode CT acquisitions were set at 9.7 mGy for Iliac bone, 8.9 mGy for liver, 8.8 mGy for lung, 7.9 mGy for mediastinal mass, and 9 mGy for para-aortic lymph nodes biopsies. In contrast, DRLs for biopsy acquisitions were 7.3 mGy, 7.7 mGy, 5.6 mGy, 5.6 mGy, and 7.4 mGy, respectively. Median SSDE values varied from 7.6 mGy to 10 mGy for biopsy acquisitions and from 11.3 mGy to 12.6 mGy for helical scans. Median ED values ranged from 1.6 mSv to 5.7 mSv for biopsy scans and from 3.9 mSv to 9.3 mSv for helical scans. The study highlights the significance of using DRLs for optimizing CT-guided biopsy procedures, revealing notable variations in radiation exposure between helical scans covering entire anatomical regions and localized biopsy acquisitions.

Importance and potential of simulation training in interventional radiology

BACKGROUND

Simulation training is a common method in many medical disciplines and is used to teach content knowledge, manual skills, and team skills without potential patient danger.

METHODS

Simulation models and methods in interventional radiology are explained. Strengths and weaknesses of both simulators for non-vascular and vascular radiological interventions are highlighted and necessary future developments are addressed.

RESULTS

Both custom-made and commercially available phantoms are available for non-vascular interventions. Interventions are performed under ultrasound guidance, with computed tomography assistance, or using mixed-reality methods. The wear and tear of physical phantoms can be countered with in-house production of 3D-printed models. Vascular interventions can be trained on silicone models or hightech simulators. Increasingly, patient-specific anatomies are replicated and simulated pre-intervention. The level of evidence of all procedures is low.

CONCLUSION

Numerous simulation methods are available in interventional radiology. Training on silicone models and hightech simulators for vascular interventions has the potential to reduce procedural time. This is associated with reduced radiation dose for both patient and physician, which can also contribute to improved patient outcome, at least in endovascular stroke treatment. Although a higher level of evidence should be achieved, simulation training should already be integrated into the guidelines of the professional societies and accordingly into the curricula of the radiology departments.

KEY POINTS

· There are numerous simulation methods for nonvascular and vascular radiologic interventions.. · Puncture models can be purchased commercially or made using 3D printing.. · Silicone models and hightech simulators allow patient-specific training.. · Simulation training reduces intervention time, benefiting both the patient and the physician.. · A higher level of evidence is possible via proof of reduced procedural times..

CITATION FORMAT

· Kreiser K, Sollmann N, Renz M. Importance and potential of simulation training in interventional radiology. Fortschr Röntgenstr 2023; 195: 883 - 889.