Πέμπτη 29 Μαρτίου 2018

Radiation exposure for intraoperative 3D scans in a hybrid operating room: how to reduce radiation exposure for the surgical team

Abstract

Background

Hybrid operating rooms are used in different fields of surgery. In orthopedic surgery, the possibility of a 3D scan of difficult anatomical regions (spine, pelvis) showed promising results not only in navigated screw placement. The associated exposure to radiation raises questions regarding potential risks for the operating room personal and the patient. The present study focuses on scatter radiation during 3D scans in a hybrid operating room, the adjacent rooms, and methods to reduce radiation exposure.

Material and Methods

\(\hbox {RaySafe}^{\mathrm{TM}}\) i2 dosimeters were used to measure scatter radiation during 3D scans of different anatomical regions in different distances and heights in a hybrid operating room. The 3D scans were performed with a floor-based flat-panel robotic C-arm with 3D scan capability (Artis Zeego, Siemens; Germany). The 3D scans were performed using a human cadaver. The 3D scans were performed using a standard and a dose reduction protocol (DRP).

Results

The highest scatter radiation was measured during 3D scans of the pelvis on the side of the surgical assistant (39.5 Sv in height of 1 m) compared to the side of the main surgeon (23 Sv in height of 1 m). Scatter radiation was less on the position of the scrub nurse (6.8 Sv in height of 1 m) and during 3D scans of the other anatomical regions. The radiation dosage was about 66% less with the DRP. Low values of scatter radiation were measured behind a radiation protection wall and with open doors in the adjacent rooms.

Conclusion

While performing a scan scatter radiation was measured everywhere in the operating room especially during 3D scans of the pelvic girdle. Therefore, settings with lower dosage should be used whenever possible. Personnel should stand behind a radiation safety wall or leave the operating room and close the doors. For this study, six behavioral rules to avoid radiation in a hybrid operating room were established.



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Anatomical description of the umbilical arteries and impact of their ligation on pelvic and perineal vascular supply after cystectomy in women.

Related Articles

Anatomical description of the umbilical arteries and impact of their ligation on pelvic and perineal vascular supply after cystectomy in women.

Surg Radiol Anat. 2018 Mar 27;:

Authors: Chantalat E, Vaysse C, Delchier MC, Bordier B, Game X, Chaynes P, Cavaignac E, Roumiguié M

Abstract
OBJECTIVE: In radical cystectomy, the surgeon generally ligates the umbilical artery at its origin. This artery may give rise to several arteries that supply the sexual organs. Our aim was to evaluate pelvic and perineal devascularisation in women after total cystectomy.
PATIENTS AND METHODS: We carried out a prospective anatomical and radiological study. We performed bilateral pelvic dissections of fresh adult female cadavers to identify the dividing branches of the umbilical artery. In parallel, we examined and compared the pre- and postoperative imaging investigations [magnetic resonance imaging (MRI) angiography] in patients undergoing cystectomy for benign disease to quantify the loss of pelvic vascularisation on the postoperative images by identifying the occluded arteries.
RESULTS: The anatomical study together with the radiological study visualised 35 umbilical arteries (n = 70) with their branching patterns and collateral arteries. The uterine artery originated from the umbilical artery in more than 75% of cases (n = 54) of the internal pudendal artery in 34% (n = 24) and the vaginal artery in 43% (n = 30). The postoperative MRI angiograms showed pelvic devascularisation in four patients. Devascularisation was dependent on the level of surgical ligation. In the four patients with loss of pelvic vascular supply, the umbilical artery had been ligated at its origin.
CONCLUSION: The umbilical artery gives rise to various branches that supply the pelvis and perineum. If the surgeon ligates the umbilical artery at its origin during total cystectomy, there is a significant risk of pelvic and perineal devascularisation.

PMID: 29589145 [PubMed - as supplied by publisher]



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[Influence of glucocorticoid therapy on intratherapeutic biodistribution of 131I radioiodine therapy in Graves' disease].

[Influence of glucocorticoid therapy on intratherapeutic biodistribution of 131I radioiodine therapy in Graves' disease].

Nuklearmedizin. 2018 Apr;57(2):43-49

Authors: Halstenberg J, Kranert WT, Korkusuz H, Mayer A, Ackermann H, Grünwald F, Happel C

Abstract
AIM: Radioiodine therapy (RIT) is an important therapeutic method in the definitive treatment of Graves' disease (GD). However, RIT may trigger development of Graves' ophthalmopathy (GO) or exacerbate a pre-existing GO. Therefore, the procedure recommendation of the DGN (German Society of Nuclear Medicine) for RIT of benign thyroid diseases recommends an additional glucocorticoid therapy for patients with pre-existing GO. Aim of this study was to analyze the influence of a protective glucocorticoid therapy on 131I biokinetics during RIT of patients with GD.
MATERIAL AND METHODS: In this retrospective analysis 211 patients with GD who underwent RIT without additional thyreostatic medication were examined. To analyze 131I biokinetics the extrapolated maximum uptake (EMU) and the effective half-life of 131I in the thyroid were determined. Patients suffering from GO received glucocorticoids according to a fixed scheme starting one day prior to RIT, patients without GO did not receive glucocorticoids. Subsequently the ratios of values measured during RIT and those measured during radioactive iodine uptake test were compared among the groups. To take into account other factors, the groups were also compared regarding age, weight, TSH, TRAb, TgAb and TPOAb.
RESULTS: In patients with additional glucocorticoid therapy, a reduction of the median EMU from 44 % in radioiodine uptake test to 35 % during RIT was observed. The pretherapeutic (47 %) and intratherapeutic (46 %) EMU of the control group without glucocorticoids remained constant. Comparison of the change in the EMU showed a statistically significant difference between both groups (p < 0.001). Comparison of all other parameters including the effective half-life of 131I (p = 0.79) did not show any statistically significant difference.
CONCLUSION: The present study suggests that glucocorticoids affect the biokinetics of 131I by reducing its thyroidal uptake. As a result of this study, for patients without antithyroid medication undergoing glucocorticoid therapy, an adjustment of therapeutic 131I activity determined in radioiodine uptake test could be considered.

PMID: 29590674 [PubMed - in process]



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Evaluation and Management of the Child with Thyrotoxicosis.

Evaluation and Management of the Child with Thyrotoxicosis.

Recent Pat Endocr Metab Immune Drug Discov. 2018 Mar 26;:

Authors: Leung AKC, Leung AAC

Abstract
BACKGROUND: Uncontrolled thyrotoxicosis, especially in early infancy, may cause irreversible damage to the central nervous system as well as profound effects on the function of many organs. Thyrotoxicosis has multiple etiologies and treatment depends on the underlying etiology. An accurate diagnosis is essential so that appropriate treatment can be initiated without undue delay.
OBJECTIVE: To review in depth the evaluation, diagnosis, and treatment of children with thyrotoxicosis.
METHODS: A PubMed search was completed in Clinical Queries using the key terms "thyrotoxicosis" and "hyperthyroidism". The search strategy included meta-analysis, randomized controlled trials, clinical trials, observational studies, and reviews. Patents were searched using the key terms "thyrotoxicosis" and "hyperthyroidism" from https://ift.tt/N1R7MD and www.google.com/patents.
RESULTS: Graves' disease accounts for approximately 96% of pediatric cases of thyrotoxicosis. Other causes include Hashitoxicosis, toxic adenoma, toxic multinodular goiter, subacute granulomatous thyroiditis, acute suppurative thyroiditis, pituitary thyroid-stimulating hormone-secreting adenoma, pituitary thyroid hormone resistance, iodine-induced thyrotoxicosis, and drug-induced thyrotoxicosis. Familiarity of the clinical features would allow prompt diagnosis and institution of treatment. The underlying cause of thyrotoxicosis should be treated if possible. Treatment options for Graves' disease include antithyroid medications, radioiodine therapy, and surgery. Recent patents related to the management of thyrotoxicosis are discussed.
CONCLUSION: Currently, antithyroid medications are considered to be the initial treatment of choice for Graves' disease in the pediatric age group. Radioactive iodine treatment is generally used for children with poor compliance with antithyroid medications, children not in remission after 1 to 2 years of antithyroid medications, and children with a major adverse effect while receiving an antithyroid medication. Total or near-total thyroidectomy should be considered in children younger than 5 years of age who do not respond to or experience a major adverse effect to antithyroid medications. Surgery should also be considered in those with very large goiter, severe ophthalmopathy, pregnancy, persistent hyperthyroidism in spite of treatment with antithyroid medications and radioactive iodine, and personal preference.

PMID: 29589552 [PubMed - as supplied by publisher]



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Dissolution of studtite [UO2(O2)(H2O)4] in various geochemical conditions

Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Jungjin Kim, HyunJu Kim, Won-Seok Kim, Wooyong Um
This study determined the dissolution rate of studtite, (UO2)O2(H2O)4, which can be formed by reaction between H2O2 and UO22+ that leaks from spent nuclear fuel (SNF) in deep geological repositories. The batch dissolution experiments were conducted using synthesized studtite under different solution conditions with varying pHs and concentrations of HCO3 and [H2O2] in synthetic groundwater. The experimental results suggested that carbonate ligand and H2O2 in groundwater accelerated the dissolution of studtite and uranium (U) release. Above 10−5 M of H2O2 initial concentration, the released uranium concentration in solution decreased, possibly as a result of reprecipitation of studtite due to reaction between uranium and H2O2. The results will be useful to assess the comprehensive transport of uranium from both nuclear waste and SNF stored in deep geological repositories.

Graphical abstract

image


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Possible Balo concentric sclerosis : MRI

Case Report: 23 year old left hemiparesis. Clinical diagnosis MS. CSF OCB positive . Poor response to steroid. CEMR images are provided.MRI images  reveal rounded lesion with alternating layers of increased and reduced signal, along with diffusion restriction.  Case Submitted by Dr Rahul Rajeev, DM (Neurology std)

Quick Notes: Balo concentric sclerosis  is a rare and severe monophasic demyelinating disease, considered a subtype of multiple sclerosis, appearing as a rounded lesion with alternating layers of increased and reduced signal giving it a characteristic 'bulls eye or 'onion bulb' appearance

balo1.png
FLAIR AXIAL MRI

balo2.png
DW-MRI AXIAL

balo3.jpg
CEMR

balo.png
AXIAL T2 WI

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Τετάρτη 28 Μαρτίου 2018

Comparing the performances of Magnetic Resonance Imaging size versus pharmacokinetic parameters to predict response to neoadjuvant chemotherapy and survival in breast cancer patients

Publication date: Available online 28 March 2018
Source:Current Problems in Diagnostic Radiology
Author(s): Basak Dogan, Qing Yuan, Roland Bassett, Inanc Guvenc, Edward F. Jackson, Massimo Cristofanilli, Gary J. Whitman
PurposeTo compare the value of dynamic contrast-enhanced MRI (DCE-MRI)-pharmacokinetic (PK) parameters versus tumor volume in predicting breast cancer neoadjuvant chemotherapy response (NACR) and patient survival.Subjects and MethodsSixty-six patients with locally advanced breast cancer who underwent breast MRI monitoring of NACR were retrospectively analyzed. We compared baseline transfer constant (Ktrans), reflux rate contrast (kep), and extracellular extravascular volume fraction (ve) with the same parameters obtained at early post-chemotherapy MRI, and examined model-independent changes in time-intensity curves (maximum slope, contrast enhancement ratio, and IAUC90). Tumor size changes (tumor volume, single dimension, and RECIST) were also analyzed. The Spearman correlation test was used to assess the association between size and PK parameters, and regression analysis to assess the association with 5-year disease free survival.ResultsHigher ve values at baseline were associated with greater decreases in tumor size (P=0.008). Changes in Ktrans and IAUC90 were the strongest predictors of NACR. Changes in IAUC90 (P=0.04) and RECIST (P=0.003) were independently associated with pathological response. The only parameter significantly associated with 5-year survival was change in RECIST (P=0.001). However, there was a trend toward statistical significance for changes in ve and Ktrans, with greater changes associated with longer survival.ConclusionChanges in PK and DCE-MRI kinetic parameters may have a role in predicting NACR in breast tumors. While changes in Ktrans and IAUC90 are helpful in predicting NACR, they do not show significant association with survival. Early RECIST size change measured by MRI remains the strongest predictor of overall patient survival.



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