Assessment of the Radiation Exposure of Surgeons and Patients During a Lumbar Microdiskectomy and a Cervical Microdiskectomy: A French Prospective Multicenter Study

Assessment of organ doses, peak skin doses and effective doses in patients undergoing anterior cervical discectomy and fusion utilising VirtualDose-IR software

In this study, the effect of patient- and procedure-related parameters on organ doses (ODs), peak skin dose (PSD) and effective dose (E) during anterior cervical discectomy and fusion (ACDF) was evaluated. Patient- and procedure-related parameters, as well as fluoroscopy time, kerma-area product (KAP), cumulative air-kerma (Kair) and incident Kair, were analysed for 50 ACDF procedures performed with a mobile C-arm. These parameters were inserted in VirtualDose-IR software implementing sex-specific and body mass index (BMI)-adjustable anthropomorphic phantoms to calculate OD, PSD and E. The BMI, gender and type of implants did not significantly affect KAP, incident Kair, PSD and E. However, the type of fusion significantly affected the E. The single fusions in C5/C6 resulted in significantly higher KAP, incident Kair and E than C4/C5 levels, while those performed in C6/C7 resulted in significantly higher E and PSD than C4/C5 levels. The thyroid, oesophagus and salivary glands received the largest doses in all groups studied. The BMI did not significantly affect ODs. The salivary glands absorbed significantly higher doses in males than females, while the extrathoracic region's dose significantly increased for multi- than single-level fusions. The fusions in C6/C7 resulted in significantly higher oesophagus and thyroid doses than C3/C4 and C4/C5 levels, as well as fusions performed in C5/C6 compared with C4/C5 levels. The data presented here could be used by the neurosurgeons as a comparator for future studies in optimising radiation protection during ACDF procedures in the operating theatre by keeping the ODs, PSD and E as low as reasonably practicable.

Robot-assisted percutaneous vertebroplasty for osteoporotic vertebral compression fracture treatment and risk factor screening for postoperative refracture

Osteoporotic vertebral compression fracture (OVCF) is a serious complication of osteoporosis, and percutaneous vertebroplasty (PVP) is a major therapeutic method for OVCF. This study aimed to evaluate the clinical efficacy and postoperative complications of robot-assisted targeted PVP for the treatment of OVCF. The data from 202 OVCF patients were analyzed in this study, including 72 cases received traditional PVP (PVP group), 68 cases received robot-assisted PVP (R-PVP group), and 62 cases underwent robot-assisted PVP combined with targeted plugging (R-PVP + TP group). The fluoroscopic exposure conditions, operative duration, lengths of stay, postoperative bone cement leakage, refracture, Visual Analog Scale (VAS) score, and Oswestry Disability Index (ODI) score were obtained and compared between the three groups. The Kaplan-Meier method and logistic regression model were adopted to screen the risk factors related with postoperative refracture. R-PVP and R-PVP + TP group had significantly reduced fluoroscopic frequency and radiation dose, and reduced cement leakage compared with PVP group. R-PVP + TP not only showed more obvious advantages in these aspects, but also had a lower probability of postoperative refracture. In addition, BMD, fracture vertebral distribution, cement leakage, and surgery methods were independent related with refracture. All the results demonstrated robot assistance could improve the application of PVP in the treatment of OVCF, and robot-assisted PVP combined with targeted plugging showed significantly reduced fluoroscopic exposure, bone cement leakage, and rate of postoperative refracture. BMD, fracture vertebral distribution, cement leakage, and operation methods were identified as four risk factors for the onset of refracture after PVP.

Potential Application of MR-MR-US Fusion Imaging Navigation with Needle Tail Intelligent Positioning in Guiding Puncture in Percutaneous Transforaminal Endoscopic Discectomy

This study sought to investigate the feasibility of using magnetic resonance-magnetic resonance-ultrasound (MR-MR-US) fusion imaging navigation (FIN) with needle tail intelligent positioning (NTIP) to guide puncture in percutaneous transforaminal endoscopic discectomy (PTED). First, in a pig experiment, we found that puncture errors in lumbar intervertebral foramen (LIF) puncture using magnetic resonance-magnetic resonance-ultrasound (MR-MR-US) FIN with NTIP for experienced and novice operators were 2.00 ± 1.00 and 2.57 ± 0.98 mm, respectively (p = 0.231), suggesting this technique was minimally dependent on experience. Then, two experienced surgeons agreed (inter-observer agreement к=0.801) that the quality of MR-MR fusion images was good or sufficient. Finally, we performed PTED in eight patients using MR-MR-US FIN with NTIP, and no significant complications were reported during LIF puncture. Overall, MR-MR-US FIN with NTIP may be a potential application for guiding puncture in PTED, but more clinical studies with a larger sample size are required to further evaluate the advantages of MR-MR-US FIN with NTIP.

Diagnostic reference levels during fluoroscopically guided interventions using mobile C-arms in operating rooms: A national multicentric survey

PURPOSE

To establish diagnostic reference levels (DRLs) and achievable levels (ALs) for the most common fluoroscopically guided interventions (FGIs) performed in operating rooms using mobile C-arm equipment.

METHODS

A national survey was performed in 57 centers in France. Anonymous data from 6817 patients undergoing FGIs were prospectively collected over a period of 7 months. DRLs (third quartile of the distribution) and ALs (median of the distribution) were determined for each type of intervention in terms of kerma area product (KAP) and fluoroscopy time (FT).

RESULTS

DRLs and ALs were proposed for 31 procedure types related to seven surgical specialties: orthopedics (n = 9), urology (n = 3), vascular (n = 6), cardiology (n = 5), neurosurgery (n = 3), gastrointestinal (n = 3), and multi-specialty (n = 2). DRLs in terms of KAP ranged from 0.1 Gy·cm² for hallux valgus to 78 Gy·cm² for abdominal aortic aneurysm endovascular repair. A factor of 155 was obtained between the FTs for a herniated lumbar disk (0.2 min) and an abdominal aortic aneurysm endovascular repair (31 min). The highest variations were obtained within orthopedic procedures in terms of KAP (ratio 122) and within gastrointestinal procedures in terms of FT (ratio 9). Overall, the FGIs associated with the highest radiation exposure (KAP > 10 Gy·cm²) were found in the cardiology, vascular, and gastrointestinal specialties.

CONCLUSIONS

DRLs and ALs are suggested for a wide range of FGIs performed in operating rooms using a mobile C-arm. We aim at providing a practical optimization tool for medical physicists and surgeons.

Comparison of Radiation Exposure Among 3 Different Endoscopic Diskectomy Techniques for Lumbar Disk Herniation

BACKGROUND

Lumbar disk herniation can be successfully treated by lumbar endoscopic spinal procedures. However, one of the most important disadvantages of the endoscopic methods used is radiation exposure. There are multiple endoscopic spinal procedures and this study aims to compare unilateral biportal endoscopic diskectomy (UBED), percutaneous endoscopic lumbar diskectomy (PELD), and microendoscopic diskectomy (MED) methods in terms of radiation exposure.

METHODS

A total of 75 people were included in this prospective and multicenter study. The demographic characteristics, operating times (minutes), levels of surgery, lumbar disk herniation types, radiation exposures (dose area product [DAP]), and fluoroscopy times (seconds) of the groups were compared.

RESULTS

Mean DAP values were 1.39 Gy·cm² in the UBED group, 2.46 Gy·cm² in the PELD group, and 1.01 Gy·cm² in the MED group. The UBED group had no statistically significant difference with the MED and PELD groups in terms of DAP (P = 0.281 and P = 0.058, respectively), whereas the PELD group had statistically significantly higher DAP values than the MED group (P = 0.016). The maximum mean duration of fluoroscopy usage time was 34.9 seconds in the PELD group, 19.3 seconds in the UBED group, and 4.6 seconds in the MED group. The differences between the groups were significant (P ≤ 0.001).

CONCLUSIONS

The more the level of invasiveness is reduced in spinal surgery, the greater the exposure to radiation. In this study, the groups are listed as PELD > UBED > MED according to the duration and level of radiation exposure.

OPTIMISATION OF PATIENT DOSE AND IMAGE QUALITY IN FLUOROSCOPICALLY GUIDED CERVICAL SPINE SURGERY: A PHANTOM-BASED STUDY

The purpose of the current study was to provide useful data, which may help neurosurgeons to manage the patient dose and image quality in spinal surgery procedures, utilising a phantom and a test object. The kerma area product, cumulative dose (CD) and entrance surface dose (ESD) rate on the phantom and image intensifier were measured, for selectable fields of view (FOVs), fluoroscopy modes, two geometric magnifications and various phantom thicknesses. The images were subjectively evaluated regarding low-contrast detectability and high-contrast resolution. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), high-contrast spatial resolution (HCSR) and figure of merit (FOM) values were also estimated. The ESD rates increased with increasing phantom thickness, when using electronic or geometric magnification, continuous or high-definition fluoroscopy (HDF). The observers' evaluation showed relatively slight changes in image quality when pulsed fluoroscopy was used. SNR, CNR and HCSR values decreased with increasing phantom thicknesses, while remained almost constant when using pulsed fluoroscopy. SNR and HCSR improved in HDF, while the CNR remained almost constant only for the FOVs 23 and 17 cm. By applying electronic magnification, this resulted in improved HCSR. FOM values decreased in HDF, with increasing phantom thickness and using electronic magnification. For the 'thinnest' patients, CD may overestimate skin dose by 25% than the actual values. Geometric magnification resulted in improved FOM, especially for low-dose fluoroscopy and FOV 23 cm. The knowledge of the increments in dose values, image quality and FOM indices concerning phantom thickness may help neurosurgeons to optimise spinal surgery procedures by selecting the appropriate operational parameters, which could contribute toward the establishment of a radiation protection culture.

Surgeon's and patient's radiation exposure during percutaneous thoraco-lumbar pedicle screw fixation: A prospective multicenter study of 100 cases

HYPOTHESIS

Percutaneous pedicle screw fixations (PPSF) are increasingly used in spine surgery, minimizing morbidity through less muscle breakdown but at the cost of intraoperative fluoroscopic guidance that generates high radiation exposure. Few studies have been conducted to measure them accurately.

MATERIAL AND METHODS

The objective of our study is to quantify, during a PPSF carried out in different experimented centers respecting current radiation protection recommendations, this irradiation at the level of the surgeon and the patient. We have prospectively included 100 FPVP procedures for which we have collected radiation doses from the main operator. For each procedure, the doses of whole-body radiation, lens and extremities were measured.

RESULTS

Our results show a mean whole body, extremity and lens exposure dose per procedure reaching 1.7±2.8μSv, 204.7±260.9μSv and 30.5±25.9μSv, respectively. According to these values, the exposure of the surgeon's extremities and lens will exceed the annual limit allowed by the International Commission on Radiological Protection (ICRP) after 2440 and 4840 procedures respectively.

CONCLUSION

Recent European guidelines will reduce the maximum annual exposure dose from 150 to 20mSv. The number of surgical procedures to not reach the eye threshold, according to our results, should not exceed 645 procedures per year. Pending the democratization of neuronavigation systems, the use of conventional fluoroscopy exposes the eyes in the first place. Therefore they must be protected by leaded glasses.

LEVEL OF PROOF

IV, case series.

Radiation exposure to the surgeon during minimally invasive spine procedures is directly estimated by patient dose

PURPOSE

Radiation exposure is a necessary component of minimally invasive spine procedures to augment limited visualization of anatomy. The surgeon's exposure to ionizing radiation is not easily recognizable without a digital dosimeter-something few surgeons have access to. The aim of this study was to identify an easy alternative method that uses the available radiation dose data from the C-arm to accurately predict physician exposure.

METHODS

The senior surgeon wore a digital dosimeter during all minimally invasive spine fusion procedures performed over a 12-month period. Patient demographics, procedure information, and radiation exposure throughout the procedure were recorded.

RESULTS

Fifty-five minimally invasive spine fusions utilizing 330 percutaneous screws were included. Average radiation dose was 0.46 Rad/screw to the patient. Average radiation exposure to the surgeon was 1.06 ± 0.71 μSv/screw, with a strong positive correlation (r = 0.77) to patient dose. The coefficient of determination (r²) was 0.5928, meaning almost two-thirds of the variability in radiation exposure to the surgeon is explained by radiation exposure to the patient.

CONCLUSIONS

Intra-operative radiation exposure to the patient, which is easily identifiable as a continuously updated fluoroscopic monitor, is a reliable predictor of radiation exposure to the surgeon during percutaneous screw placement in minimally invasive spinal fusion surgery and therefore can provide an estimate of exposure without the use of a dosimeter. With this, a surgeon can better understand the magnitude of their exposure on a case-by-case basis rather than on a quarterly basis, or more likely, not at all. These slides can be retrieved under Electronic Supplementary Material.

MEASUREMENT OF RADIATION DOSES TO THE EYE LENS DURING ORTHOPEDIC SURGERY USING AN C-ARM X-RAY SYSTEM

The present study aimed to determine doses delivered to the eye lenses of surgeons while using the inverted-C-arm technique and the protective effect of leaded spectacles during orthopedic surgery. The kerma in air was measured at five positions on leaded glasses positioned near the eye lens and on the neck using small optically stimulated luminescence (OSL) dosemeters. The lens equivalent dose was also measured at the neck using an OSL dosemeter. The maximum equivalent dose to the eye lens and the maximum kerma were 0.8 mSv/month and 0.66 mGy/month, respectively. The leaded glasses reduced the exposure by ~60%. Even if the surgeons are exposed to the maximum dose of X-ray radiation for 5 years, the equivalent doses to the eye lens will not exceed the present limit recommended by the ICRP.

Significant reduction of fluoroscopy repetition with lumbar localization system in minimally invasive spine surgery: A prospective study

The conventional location methods for minimally invasive spinal surgery (MISS) were mainly based on repeated fluoroscopy in a trial-and-error manner preoperatively and intraoperatively. Localization system mainly consisted of preoperative applied radiopaque frame and intraoperative guiding device, which has the potential to minimize fluoroscopy repetition in MISS. The study aimed to evaluate the efficacy of a novel lumbar localization system in reducing radiation exposure to patients.Included patients underwent minimally invasive transforaminal lumbar interbody fusion (MISTLIF) or percutaneous transforaminal endoscopic discectomy (PTED). Patients treated with novel localization system were regarded as Group A, and patients treated without novel localization system were regarded as Group B.For PTED, The estimated effective dose was 0.41 ± 0.13 mSv in Group A and 0.57 ± 0.14 mSv in Group B (P < .001); the fluoroscopy exposure time of PTED was 22.18 ± 7.30 seconds in Group A and 30.53 ± 7.56 seconds in Group B (P < .001); The estimated cancer risk of radiation exposure was 22.68 ± 7.38 (10) in Group A and 31.20 ± 7.96 (10) in Group B (P < .001). For MISTLIF, the estimated effective dose was 0.45 ± 0.09 mSv in Group A and 0.58 ± 0.09 mSv in Group B (P < .001); The fluoroscopy exposure time was 25.41 ± 5.52 seconds in Group A and 32.82 ± 5.03 seconds in Group B (P < .001); The estimated cancer risk was 24.90 ± 5.15 (10) in Group A and 31.96 ± 5.04 (10) in Group B (P < .001). There were also significant differences in localization time and operation time between the 2 groups either for MISTLIF or PTED.The lumbar localization system could be a potential protection strategy for minimizing radiation hazards.