A Study of Patient's Dose Control Using an Area Exposure Product Meter

Sakamoto, Hajime; Nakamura, Osamu; Yuge, Makoto; Sano, Yoshitomo; Akiyama, Saburou; Araki, Tsutomu

doi:10.6009/jjrt.kj00001357329

Cited by 17 publications

(2 citation statements)

References 6 publications

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“…Data including age, gender, weight, body mass index (BMI), primary diagnosis, levels fused, cumulative fluoroscopic time, cumulative area dose product (DAP) and cumulative air kerma ( AK ) (obtained from the DAP monitor system originally installed on the fluoroscope), operating time, extra time required for this procedure, and complications related to screw placement were extracted from each patient’s medical record. To facilitate comparisons with other studies, the entrance skin dose (ESD) for each patient was calculated from the DAP and AK values using the following formula [ 27 , 28 , 29 ].

…”

Section: Methodsmentioning

confidence: 99%

Reduction in Radiation Exposure in Minimally Invasive Pedicle Screw Placement Using a Tubular Retractor: A Pilot Study

Oki¹,

Lefor

Nakamura³

et al. 2022

Tomography

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Background and Objectives: Percutaneous pedicle screw (PPS) placement is a minimally invasive spinal procedure that has been rapidly adopted over the last decade. However, PPS placement has elicited fear of increased radiation exposure from some surgeons, medical staff, and patients. This is because PPS placement is performed using a K-wire, and the operator must perform K-wire insertion into the pedicle under fluoroscopy. In order to prevent erroneous insertion, there are many occasions when direct insertion is required during radiation exposure, and the amount of radiation exposure to hands and fingers in particular increases. Although these problems are being addressed by navigation systems, these systems are still expensive and not widely available. Attempts have been made to address this situation using instrumentation commonly used in spinal surgery. First, it was considered to visualize anatomical bone markers using a tubular retractor and a microscope. In addition, the use of a self-drilling pin was adopted to locate the pedicle in a narrower field of view. Based on these considerations, a minimally invasive and highly accurate pedicle screw placement technique was developed while avoiding direct radiation exposure. This study evaluated radiation exposure and accuracy of pedicle screw placement using this new procedure in one-level, minimally invasive, transforaminal lumbar interbody fusion (MIS-TLIF). Materials and Methods: Data were collected retrospectively to review pedicle screw placement in single-level MIS TLIFs using a tubular retractor under a microscope. The total fluoroscopy time, radiation dose, and screw placement accuracy were reviewed. Extension of operating time was also evaluated. Results: Twenty-four patients underwent single-level MIS TLIFs, with placement of 96 pedicle screws. There were 15 females and 9 males, with an average age of 64.8 years and a mean body mass index of 25.5 kg/m2. The mean operating time was 201.8 min. The mean fluoroscopic time was 26.8 s. The mean radiation dose of the area dose product was 0.0706 mGy∗m2. The mean radiation dose of air kerma was 6.0 mGy. The mean radiation dose of the entrance skin dose was 11.31 mGy. Postoperative computed tomography scans demonstrated 93 pedicle screws confined to the pedicle (97%) and three pedicle screw breaches (3.2%; two lateral, one medial). A patient with screw deviation of the medial pedicle wall developed right-foot numbness necessitating reoperation. There were no complications after reoperation. The average added time with this combined procedure was 39 min (range 16–69 min) per patient. Conclusions: This novel pedicle screw insertion technique compares favorably with other reports in terms of radiation exposure reduction and accuracy and is also useful from the viewpoint of avoiding direct radiation exposure to hands and fingers. It is economical because it uses existing spinal surgical instrumentation.

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…”

Section: Methodsmentioning

confidence: 99%

Reduction in Radiation Exposure in Minimally Invasive Pedicle Screw Placement Using a Tubular Retractor: A Pilot Study

Oki¹,

Lefor

Nakamura³

et al. 2022

Tomography

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“…2) However, neuroendovascular procedures frequently involve long fluoroscopic time, high-dose fluoroscopic mode, and greater numbers of exposure sessions, which increase radiation dosage for patients and operators, resulting in radiation injuries. [3][4][5][6][7] We previously reported that patient skin doses from neuroendovascular procedures are higher than those from abdominal and cardiac IR. 8) Specialized skills are required to safely perform neuroendovascular procedures, leading the radiation risk to increase to some particular operators.…”

Section: Introductionmentioning

confidence: 99%

Monitoring and Protection against Radiation Dose to Eyes of Operators Performing Neuroendovascular Procedures: A Nationwide Study in Japan

Sakamoto

Moritake

Sun

et al. 2022

JNET

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Objective: To meet the new standard of the annual dose limit for the eye lens recommended by the International Commission on Radiation Protection, radiation doses of neuroendovascular procedures in Japanese institutions were investigated.Methods: Radiation doses to operators involved in 304 neuroendovascular procedures at 30 Japanese institutions were prospectively surveyed. The institutions recruited at an annual meeting of the Japanese Society for Neuroendovascular Therapy participated voluntarily. A maximum of 10 wireless dosimeters were attached to the radiation protection (RP) goggles, the ceiling-mounted RP shielding screen, and the operators' forehead and neck over the protective clothing.Doses recorded inside the goggles were defined as eye lens doses for operators who wore RP goggles, while doses to the forehead were defined as eye lens doses for those who did not. The shielding effect rates of the protection devices were calculated, and statistical analysis was performed for the comparison of radiation doses.Results: From 296 analyzed cases, mean eye lens radiation doses per procedure were 0.088 mGy for the left eye and 0.041 mGy for the right eye. For the left eye, that dose without RP equipment was 0.176 mGy and that with RP goggles plus an RP shielding screen was 0.034 mGy. Four parameters, including left eye dose, air kerma at the patient entrance reference point, fluoroscopic time, and the total number of frames, were assessed for five types of neurovascular procedures. Of them, transarterial embolization for dural arteriovenous fistula was associated with the highest eye lens dose at 0.138 mGy. The shielding effect rates of protection goggles were 60% for the left and 55% for the right RP goggle. The mean doses to the inner and outer surfaces of the RP shielding screen were 0.831 mGy and 0.040 mGy, respectively, amounting to a shielding effect rate of 95%. Conclusion:To meet the new standard, both RP goggles and RP shielding screens are strongly recommended to be used effectively. Without proper use of radiological protection devices, the number of neuroendovascular procedures that one operator performs per year will be limited under the new guideline.

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A new reference point for patient dose estimation in neurovascular interventional radiology

Kawasaki

Imazeki

Hasegawa

et al. 2013

Radiol Phys Technol

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In interventional radiology, dose estimation using the interventional reference point (IRP) is a practical method for obtaining the real-time skin dose of a patient. However, the IRP is defined in terms of adult cardiovascular radiology and is not suitable for dosimetry of the head. In the present study, we defined a new reference point (neuro-IRP) for neuro-interventional procedures. The neuro-IRP was located on the central ray of the X-ray beam, 9 cm from the isocenter, toward the focal spot. To verify whether the neuro-IRP was accurate in dose estimation, we compared calculated doses at the neuro-IRP and actual measured doses at the surface of the head phantom for various directions of the X-ray projection. The resulting calculated doses were fairly consistent with actual measured doses, with the error in this estimation within approximately 15%. These data suggest that dose estimation using the neuro-IRP for the head is valid.

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A Study of Patient's Dose Control Using an Area Exposure Product Meter

Cited by 17 publications

References 6 publications

Reduction in Radiation Exposure in Minimally Invasive Pedicle Screw Placement Using a Tubular Retractor: A Pilot Study

Reduction in Radiation Exposure in Minimally Invasive Pedicle Screw Placement Using a Tubular Retractor: A Pilot Study

Monitoring and Protection against Radiation Dose to Eyes of Operators Performing Neuroendovascular Procedures: A Nationwide Study in Japan

A new reference point for patient dose estimation in neurovascular interventional radiology

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