Predictors of radiation dose for uterine artery embolisation are angiography system-dependent

This study sought to achieve radiation dose reductions for patients receiving uterine artery embolisation (UAE) by evaluating radiation dose measurements for the preceding generation (Allura) and upgraded (Azurion) angiography system. Previous UAE regression models in the literature could not be applied to this centre’s practice due to being based on different angiography systems and radiation dose predictor variables. The aims of this study were to establish whether radiation dose is reduced with the upgraded angiography system and to develop a regression model to determine predictors of radiation dose specific to the upgraded angiography system. A comparison between Group I (Allura, n = 95) and Group II (Azurion, n = 95) demonstrated a significant reduction in KAP (kerma-area product) and Ka, r (reference air kerma) by 63% (143.2 Gy·cm2 vs 52.9 Gy·cm2; P < 0.001, d = 0.8) and 67% (0.6 Gy vs 0.2 Gy; P < 0.001, d = 0.8), respectively. The multivariable linear regression (MLR) model identified the UAE radiation dose predictors for KAP on the upgraded angiography system as total fluoroscopy dose, Ka, r, and total uterus volume. The predictive accuracy of the MLR model was assessed using a Bland-Altman plot. The mean difference was 0.39 Gy·cm2 and the limits of agreement (LoA) were +28.49 and -27.71 Gy·cm2, and thus illustrated no proportional bias. Our findings validated the upgraded angiography system and its advance capabilities to significantly reduce radiation dose for our patients. Interventional radiologist and interventional radiographer familiarisation of the system’s features and the implementation of the newly established MLR model would further facilitate dose optimisation for all centres performing UAE procedures using the upgraded angiography system.

Deep learning-based fully automated Z-axis coverage range definition from scout scans to eliminate overscanning in chest CT imaging

Background Despite the prevalence of chest CT in the clinic, concerns about unoptimized protocols delivering high radiation doses to patients still remain. This study aimed to assess the additional radiation dose associated with overscanning in chest CT and to develop an automated deep learning-assisted scan range selection technique to reduce radiation dose to patients. Results A significant overscanning range (31 ± 24) mm was observed in clinical setting for over 95% of the cases. The average Dice coefficient for lung segmentation was 0.96 and 0.97 for anterior–posterior (AP) and lateral projections, respectively. By considering the exact lung coverage as the ground truth, and AP and lateral projections as input, The DL-based approach resulted in errors of 0.08 ± 1.46 and − 1.5 ± 4.1 mm in superior and inferior directions, respectively. In contrast, the error on external scout views was − 0.7 ± 4.08 and 0.01 ± 14.97 mm for superior and inferior directions, respectively.The ED reduction achieved by automated scan range selection was 21% in the test group. The evaluation of a large multi-centric chest CT dataset revealed unnecessary ED of more than 2 mSv per scan and 67% increase in the thyroid absorbed dose. Conclusion The proposed DL-based solution outperformed previous automatic methods with acceptable accuracy, even in complicated and challenging cases. The generizability of the model was demonstrated by fine-tuning the model on AP scout views and achieving acceptable results. The method can reduce the unoptimized dose to patients by exclunding unnecessary organs from field of view.

Examination of Hysterosalpingography in Patients With Suspected Infertility at The Radiology Department of Dr.R. Soetrasno Rembang Hospital

Hysterosalpingography (HSG) is the most commonly used imaging diagnostic to determine the tubal patency in patient with indications of infertility. The technique used in the HSG procedure is different in some studies. The aim of this study was to determine the technique of hysterosalpingography (HSG) examination with patients suspected of infertility in dr.R. Soetrasno Rembang hospital. The method was a case study approach. Results showed HSG examination using plain photo Anteroposterior (AP) projection, AP projection with 3 cc contrast media and 7 cc contrast media, then post evacuation. The AP projection already revealed uterus, fallopian tubes, spill on the peritoneum, reduce radiation dose, and the pain of patients. They used 3 cc and 7 cc of contrast media because the examination did not use fluoroscopy. The 3 cc of contrast media views the uterus only then 7 cc view the fallopian tube and its spill. HSG plays a crucial role to determine the cause of infertility, especially to evaluate the morphology and patency of the fallopian tubes in women so the radiology team should become familiar with examination techniques used, give the patient education to avoid movement, and hold their body motionless also taking a mild pain reliever before the HSG examination.

The Feasibility of 3D Intraoperative Navigation in Lateral Lumbar Interbody Fusion: Perioperative Outcomes, Accuracy of Cage Placement and Radiation Exposure

Study Design: Retrospective cohort study. Objectives: To evaluate perioperative outcomes, accuracy of cage placement and radiation exposure in lateral lumbar interbody fusion (LLIF) using 3D intraoperative navigation (ION), compared to conventional 2D fluoroscopy only. Methods: The perioperative outcomes and accuracy of cage placement were examined in all patients who underwent LLIF using ION (ION group) or fluoroscopy only (non-ION group) by a single surgeon. The radiation exposure was examined in patients who underwent stand-alone LLIF. Results: A total of 87 patients with 154 levels (ION 49 patients with 79 levels/ non-ION 38 patients with 75 levels) were included. There were no significant differences in operative time (ION 143.5 min vs. non-ION 126.0 min, P = .406), time from induction end to surgery start (ION 31.0 min vs. non-ION 31.0 min, P = .761), estimated blood loss (ION 37.5 ml vs. non-ION 50.0 ml, P = .351), perioperative complications (ION 16.3% vs. non-ION 7.9%, P = .335) and length of stay (ION 50.6 hours vs. non-ION 41.7 hours, P = .841). No significant difference was found in the accuracy of cage placement ( P = .279). ION did not significantly increase total radiation dose (ION 51.0 mGy vs. non-ION 47.4 mGy, P = .237) and tended to reduce radiation dose during the procedure (ION 32.2 mGy vs. non-ION 47.4 mGy, P = .932). Conclusions: The perioperative outcomes, accuracy of cage placement and radiation exposure in LLIF using ION were comparable to those using fluoroscopy only. The use of ION in LLIF was feasible, safe and accurate and may reduce radiation dose to the surgeon and surgical team.

RONC-04. RE-IRRADIATION AFTER TREATMENT OF MEDULLOBLASTOMA; RELAPSED CASES AND SECOND CANCER CASES

PURPOSE Late complications such as brainstem necrosis are great concern of re-irradiation for brain tumor. Proton beam therapy can reduce radiation dose of organs at risk such as brainstem, so is expected to reduce late complications. PATIENTS AND METHODS Patients with medulloblastoma treated with re-irradiation from January 2015 to February 2019 at the Kobe Children’s Hospital and the Kobe Proton Center were reviewed. There were three cases of relapsed medulloblastoma and three cases of second cancer (glioblastomas). RESULTS In relapsed cases, all three cases treated with 12 Gy in 8 fractions cranio-spinal irradiation followed by gamma knife radiosurgery (one) or 28.8 Gy (RBE) in 16 fractions of proton beam therapy (two). Follow-up periods were 8 to 19 months (median 12 months) and all three cases survived without relapse. In second cancer cases, all three cases were treated with 40.05 Gy per 15 fractions of radiation therapy (2 cases were treated with photon and one case with proton). However, all cases relapsed and two cases died of disease. CONCLUSION Twelve Gy in 8 fractions cranio-spinal irradiation followed by 28.8 Gy (RBE) in 16 fractions of proton beam therapy is thought to be useful for the relapsed case. Re-irradiation for second cancer was disappointing and further study is warranted.

The difference in dose and image quality between magnification methods used after the introduction of larger 60-inch operator screens

Objective: To determine whether the use of display matrix magnification on larger operator screens without the use of conventional magnification can reduce radiation dose to the patient, and what effect it would have on image quality. Methods: The kerma-area product (KAP) resulting from standard projections in cardiac angiography were measured when an anthropomorphic phantom was imaged using conventional magnification method and display matrix magnification. The image quality was also evaluated by three observers using a TOR 18FG test tool for both magnification method. Results: The mean radiation KAP for the seven views with conventional magnification was 36.65 µGy m−2 whilst a reduction in KAP of 20.4% is possible using display matrix magnification (p < 0.05). The image resolution during acquisition was identical between both methods and only slightly reduced for the display matrix (1.6 LP mm−1) compared to conventional magnification (1.8 LP mm−1) when images were stored and retrieved on a Picture Archiving and Communication Systems (PACS) system. Both methods retained the same low-contrast detectability to PACS, with only a slight increase in detectability of 18 for display matrix magnification compared to 17 for conventional. Conclusion: Using display matrix magnification instead of conventional equipment magnification significantly reduces radiation does in all standard cardiac views without reducing image quality for the operator. This reduction in radiation dose is significant (p < 0.05) for the patients. The resolution did not change during acquisition, but contrast improved slightly (0.9% threshold contrast), but lost resolution of 0.2 LP mm−1 when archived to PACS. Advances in knowledge: This is a new method of reducing significant dose to the patient during cardiology examinations and may encourage further studies in other fluoroscopy lead examination to see if it could work for them.

Impact of tube angulation on radiation dose using image noise reduction technology

Objectives This study sought to evaluate the impact of tube angulation on radiation dose using image noise reduction technology in a clinical setting. Image noise reduction technology has been shown to significantly reduce radiation dose in coronary angiography in particular by reduction of radiation in cine mode. Methods In 500 coronary angiograms performed by the same operator the dose-area product (DAP) was determined. The DAP was determined for the cine mode as well as for the fluoroscopy mode. Furthermore, in the cine mode, the DAP on a per image (DAP/frame) basis was determined for the posterior-anterior projection (PA) as well as a left anterior oblique (LAO) cranial (LAO 20°/20°) and caudal (LAO 45°/−20°), right anterior oblique (RAO) cranial (RAO 20°/20°) and caudal (RAO 30°/−20°) angulations. The image intensifier area was kept constant for all angulations. Results Mean body mass index was 28.6±5.5 kg/m2. Mean total DAP was 1227±1417 cGy cm2. The mean ratio of DAP in cine mode/DAP in fluoro mode was 0.54±0.32. Mean DAP/frame in PA angulation was 5.5±3.3 (cGy cm2). Considering the cine mode, for the LAO cranial and LAO caudal angulations, the relative DAP/ frame compared to the PA angulation was 2.8±1.8 and 4.2±1.6, respectively. For the RAO cranial and RAO caudal angulations, the relative DAP/frame compared to the PA angulation was 1.7±2.2 and 1.8±1.4. Conclusions Using image noise reduction technology, radiation during fluoroscopy mode contributes more to total radiation dose than radiation during cine mode. In cine mode, the PA angulation has least radiation/ frame. The LAO caudal angulation is associated with greatest increase in radiation dose compared to the PA angulation, while LAO cranial angulation and RAO cranial and caudal angulations increase radiation dose to a lesser extent. Funding Acknowledgement Type of funding source: None