Radiation-Related Fractures after Radical Radiotherapy for Cervical and Endometrial Cancers: Are There Any Differences?

In this study, we reviewed CT/MRI scans and studied the rates of radiation-related fractures in subjects treated for cervical cancer (CC, 63 subjects) by radical radiotherapy (RT) and in subjects treated for endometrial cancer (EC, 64 subjects) by radical surgery and RT. The differences between bone density measured in L1 on pretreatment CT, age and body mass index (BMI) were evaluated. Despite significant differences in RT total dose, age, BMI, etc., between both groups, the rate of radiation-related fractures was similar: 28.6% of CC versus 26.6% of EC subjects. CC subjects with fractures were significantly older (62.4 ± 10.1 vs. 49.0 ± 12.4 years; p < 0.001), and their bone densities were significantly lower (106.3 ± 40.0 vs. 168.2 ± 49.5 HU; p < 0.001); no difference in BMI was found. EC subjects with fractures were without significant difference in age but had significantly lower bone densities (103.8 ± 29.0 vs. 133.8 ± 42.3 HU; p = 0.009) and BMIs (26.1 ± 4.9 vs. 31.8 ± 6.9 kg/m2; p = 0.003). Bone density strongly correlated with age (r = -0.755) only in CC subjects. Subjects with fractures from both groups had similarly low bone densities (106.3 ± 40.0 vs. 103.8 ± 29.0 HU; p = 0.829); however, no correlation between bone density and BMI was found. The rate of radiation-related fractures in both groups was clearly associated only with low pretreatment bone density, reflecting osteoporosis.

Comparison of dose length product and image quality of a biphasic whole-body polytrauma CT protocol with and without the automatic tube voltage selection.

BACKGROUND AND AIMS: A significant source of man-made radiation is now linked to medical devices especially X-ray imaging based ones like CT scans which expose the body to cumulative ionizing radiation and thus attendant cancer risks. The aim of this study was to determine whether using a combination of Automatic Tube Current Modulation (ATCM) and Automatic Tube Voltage Selection (ATVS) during two-phase whole-body CT (2PWBCT) examinations would reduce the radiation dose while preserving the image quality. PATIENTS AND METHODS: This was a prospective, observational, single-centre study of 127 adult patients who had undergone the 2PWBCT polytraumatic protocol. All were examined on a Somatom Drive scanner (Siemens). The patients were divided into two groups: ATCM only (42 patients) and ATCM +ATVS (85 patients). Patients' arm positions during examination and the examination dose length product (DLP) values were recorded, as well the standard deviations (SD) of the density in reference areas on CT scans for the image quality assessment. The DLP values and image quality in the groups were compared using ANOVA. RESULTS: Mean Total DLP (in mGy*cm): ATCM only: 3337 +/-797, ATCM+ATVS: 3402 +/-830; P=0.674. No effect of arm position (P=0.586). Mean density SD values in reference areas (in HU) in ATCM only: 49 +/-45, 15 +/-6, 9 +/-2, 12 +/-4, 10 +/-3, in ATCM+ATVS: 48 +/-45, 17 +/-6, 11 +/-3, 15 +/-6, 12 +/-4. SD values was higher in ATCM+ATVS group (P<0.001). CONCLUSION: Combination of ATVS and ATCM in polytraumatic 2PWBCT leads to no significant radiation load reduction compared with ATCM only but does lead to a slight degradation of image quality. The radiation load is significantly reduced if the patient has their arms behind the head when scanning, regardless of the activation of ATVS.

Early and late infarct growth rate in ischemic stroke patients after successful endovascular treatment in early time window: correlation of imaging and clinical factors with clinical outcome.

Background: The prospective study assessed infarct growth rate (IGR) in acute ischemic stroke (AIS) with large vessel occlusion (LVO) after recanalization in early time window. Early IGR (EIGR) and late IGR (LIGR) were correlated with imaging and clinical data; we searched for outcome predictors. Methods: We included 71 consecutive patients. Subjects underwent computed tomography perfusion (CTP) for ischemic core volume assessment at 99.0 minutes (median) from stroke onset, recanalization was performed at 78.0 minutes (median) from CTP. Final infarct volume (FIV) was measured on 24±2 hours imaging follow-up. EIGR was calculated as the core volume/time between stroke onset and CTP; LIGR was calculated as FIV/time between CTP and imaging follow-up. Twenty-two subjects were assessed as poor outcome, 49 as good outcome. Group differences were tested by Mann-Whitney test and χ2 test. Bayesian logistic regression models were used to predict clinical outcome, Pearson correlations for the log-transformed predictors. Results: Subjects with poor outcome were older, median age 78.0 [interquartile range (IQR): 71.8, 83.8] versus 68.0 (IQR: 57.0, 73.0) years; 95% confidence interval (CI): 6.00 to 16.00; P<0.001. Their stroke severity scale was higher, median 19.0 (IQR: 16.0, 20.0) versus 15.5 (IQR: 10.8, 18.0); 95% CI: 1.00 to 6.00; P<0.001. They had higher EIGR, median 23.9 (IQR: 6.4, 104.0) versus 6.7 (IQR: 1.7, 13.0) mL/h; 95% CI: 3.26 to 53.68; P=0.002; and larger core, median 52.5 (IQR: 13.1, 148.5) versus 10.0 (IQR: 1.4, 20.0) mL; 95% CI: 11.00 to 81.00; P<0.001. In subjects with poor outcome, infarct growth continued after thrombectomy with LIGR 2.0 (IQR: 1.2, 9.7) versus 0.3 (IQR: 0.0, 0.7) mL/h; 95% CI: 1.10 to 6.10; P<0.001; resulting in larger FIV, median 186.5 (IQR: 49.3, 280.8) versus 18.5 (IQR: 8.0, 34.0) mL; 95% CI: 55.30 to 214.00; P<0.001. Strong correlations among predictors were found e.g., core and EIGR (r=0.942), LIGR and FIV (r=0.779), core and FIV (r=0.761). Clinical outcome was best predicted using data from later measurements as FIV and LIGR. Conclusions: Data from later measurements were more predictive, there was no major benefit to use growth over volume data.

Predicting tumor consistency and extent of resection in non-functioning pituitary tumors.

PURPOSE: To (1) identify a radiological parameter to predict non-functioning pituitary tumor (NFPT) consistency, (2) examine the relationship between NFPT consistency and extent of resection (EOR), (3) investigate if tumor consistency predictors can anticipate EOR. METHODS: The ratio (T2SIR) between the T2 min signal intensity (SI) of the tumor and the T2 mean SI of the CSF was the main radiological parameter, being determined through a radiomic-voxel analysis and calculated using the following formula: T2SIR = [(T2 tumor mean SI - SD)/T2 CSF SI]. The tumor consistency was pathologically estimated as collagen percentage (CP). EOR of NFPTs was evaluated by exploiting a volumetric technique and its relationship with the following explanatory variables was explored: CP, Knosp-grade, tumor volume, inter-carotid distance, sphenoidal sinus morphology, Hardy-grade, suprasellar tumor extension. RESULTS: A statistically significant inverse correlation between T2SIR and CP was demonstrated (p = 0.0001), with high diagnostic power of T2SIR in predicting NFPT consistency (ROC curve analysis' AUC = 0.88; p = 0.0001). The following predictors of EOR were identified in the univariate analysis: CP (p = 0.007), preoperative volume (p = 0.045), Knosp grade (p = 0.0001), tumor suprasellar extension (p = 0.044). The multivariate analysis demonstrated two variables as unique predictors of EOR: CP (p = 0.002) and Knosp grade (p = 0.001). The T2SIR was a significant predictor of EOR both in the univariate (p = 0.01) and multivariate model (p = 0.003). CONCLUSION: This study offers the potential to improve NFPT preoperative surgical planning and patient counseling by employing the T2SIR as a preoperative predictor of tumor consistency and EOR. Meanwhile, tumor consistency and Knosp grade were found to play an important role in predicting EOR.

CT Brain Perfusion in the Prediction of Final Infarct Volume: A Prospective Study of Different Software Settings for Acute Ischemic Core Calculation.

CT perfusion (CTP) is used for the evaluation of brain tissue viability in patients with acute ischemic stroke (AIS). We studied the accuracy of three different syngo.via software (SW) settings for acute ischemic core estimation in predicting the final infarct volume (FIV). The ischemic core was defined as follows: Setting A: an area with cerebral blood flow (CBF) < 30% compared to the contralateral healthy hemisphere. Setting B: CBF < 20% compared to contralateral hemisphere. Setting C: area of cerebral blood volume (CBV) < 1.2 mL/100 mL. We studied 47 AIS patients (aged 68 ± 11.2 years) with large vessel occlusion in the anterior circulation, treated in the early time window (up to 6 h), who underwent technically successful endovascular thrombectomy (EVT). FIV was measured on MRI performed 24 ± 2 h after EVT. In general, all three settings correlated with each other; however, the absolute agreement between acute ischemic core volume on CTP and FIV on MRI was poor; intraclass correlation for all three settings was between 0.64 and 0.69, root mean square error of the individual observations was between 58.9 and 66.0. Our results suggest that using CTP syngo.via SW for prediction of FIV in AIS patients in the early time window is not appropriate.

Clinical and radiological factors predicting stroke outcome after successful mechanical intervention in anterior circulation.

The recanalization effect of large-vessel occlusion (LVO) in anterior circulation is well documented but only some patients benefit from endovascular treatment. We analysed clinical and radiological factors determining clinical outcome after successful mechanical intervention. We included 146 patients from the Prague 16 study enrolled from September 2012 to December 2020, who had initial CT/CTA examination and achieved good recanalization status after mechanical intervention (TICI 2b-3). One hundred and six (73%) patients achieved a good clinical outcome (modified Rankin Scale 0-2 in 3 months). It was associated with age, leptomeningeal collaterals (LC), onset to intervention time, ASPECTS, initial NIHSS, and leukoaraiosis (LA) in univariate analysis. The regression model identified good collateral status [odds ratio (OR) 5.00, 95% confidence interval (CI) 1.91-13.08], late thrombectomy (OR 0.24, 95% CI 0.09-0.65), LA (OR 0.44, 95% CI 0.19-1.00), ASPECTS (OR 1.45, 95% CI 1.08-1.95), and NIHSS score (OR 0.86, 95% CI 0.78-0.95) as independent outcome determinants. In the late thrombectomy subgroup, 14 out of 33 patients (42%) achieved a favourable clinical outcome, none of whom with poor collateral status. The presence of LC and absence of LA predicts a good outcome in acute stroke patients after successful recanalization of LVO in anterior circulation. Late thrombectomy was associated with higher rate of unfavourable clinical outcome. Nevertheless, collateral status in this subgroup was validated as a reliable selection criterion.

Silent strokes after thoracoscopic epicardial ablation and catheter ablation for atrial fibrillation: not all lesions are permanent on follow-up magnetic resonance imaging.

BACKGROUND: Invasive treatments for atrial fibrillation (AF) pose a risk of ischemic stroke due to periprocedural brain embolization, which may be manifest or silent. The primary aim of our study was to compare the rate of silent strokes after percutaneous catheter-based and thoracoscopic epicardial ablation for AF. The secondary aim was to evaluate the development of silent strokes over time. METHODS: We included 39 subjects (aged 64.1±8.9 years) treated for persistent symptomatic AF with thoracoscopic ablation and 30 subjects (aged 64.1±10.5 years) treated for paroxysmal or persistent symptomatic AF with catheter ablation. Subjects underwent brain MRI before and early after the ablation, moreover, the surgical group underwent late MRI 6 months after therapy. On early MRI, the presence of silent strokes and their number and size were evaluated. On late MRI, transformation of previously-detected acute ischemic lesions into chronic infarction or their reversibility were assessed. RESULTS: Initially, different chronic ischemic findings were found in 64% of patients from the surgical group and in 70% from catheter group. Early MRI results: acute ischemic lesions were detected in 2 (6.7%) subjects (overall 3 lesions sized <5 mm) in the catheter group and in 17 (43.6%) subjects in surgical group. Most subjects in the surgical group showed multiple lesions (88%); 195 lesions were detected, a median 6 (IQR 8) lesions per case. Eighty-two percent of lesions were <5 mm, 12% 5-10 mm, 5% 10-30 mm, and 2% were large territorial ischemia. Only 1 case was symptomatic, the rest were silent strokes. On late MRI, 53.5% of all acute lesions were reversible. Lesions <5 mm were reversible in 63.1% of cases, lesions 5-10 mm were reversible in 21.7% and all lesions larger than 10 mm persisted. In 29.4% of patients all acute ischemic lesions were fully reversible. CONCLUSIONS: Periprocedural silent strokes were significantly more common after thoracoscopic epicardial ablation compared to catheter ablation considering both the number of affected patients and number of lesions. The majority of acute ischemic brain lesions were small, up to 5 mm in diameter, roughly half of which were reversible. Reversibility of acute ischemic lesions decreased with size. However, in 29.4% of affected patients, all lesions were fully reversible.

The Efficacy and Safety of Hybrid Ablations for Atrial Fibrillation.

OBJECTIVES: This study sought to comprehensively determine the procedural safety and midterm efficacy of hybrid ablations. BACKGROUND: Hybrid ablation of atrial fibrillation (AF) (thoracoscopic ablation followed by catheter ablation) has been used for patients with nonparoxysmal AF; however, accurate data regarding efficacy and safety are still limited. METHODS: Patients with nonparoxysmal AF underwent thoracoscopic, off-pump ablation using the COBRA Fusion radiofrequency system (Estech) followed by a catheter ablation 3 months afterward. The safety of the procedure was assessed using sequential brain magnetic resonance and neuropsychological examinations at baseline (1 day before), postoperatively (2-4 days for brain magnetic resonance imaging or 1 month for neuropsychological examination), and at 9 months after the surgical procedure. Implantable loop recorders were used to detect arrhythmia recurrence. Arrhythmia-free survival (the primary efficacy endpoint) was defined as no episodes of AF or atrial tachycardia while off antiarrhythmic drugs, redo ablations or cardioversions. RESULTS: Fifty-nine patients (age: 62.5 ± 10.5 years) were enrolled, 37 (62.7%) were men, and the mean follow-up was 30.3 ± 10.8 months. Thoracoscopic ablation was successfully performed in 55 (93.2%) patients. On baseline magnetic resonance imaging, chronic ischemic brain lesions were present in 60.0% of patients. New ischemic lesions on postoperative magnetic resonance imaging were present in 44.4%. Major postoperative cognitive dysfunction was present in 27.0% and 17.6% at 1 and 9 months postoperatively, respectively. The probability of arrhythmia-free survival was 54.0% (95% CI: 41.3-66.8) at 1 year and 43.8% (95% CI: 30.7-57.0) at 2 years. CONCLUSIONS: The thoracoscopic ablation is associated with a high risk of silent cerebral ischemia. The midterm efficacy of hybrid ablations is moderate.

Is limited-coverage CT perfusion helpful in treatment decision-making in patients with acute ischemic stroke?

BACKGROUND: The initial core infarct volume predicts treatment outcome in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). According to the literature, CT perfusion (CTP) is able to evaluate cerebral parenchymal viability and assess the initial core in AIS. We prospectively studied whether limited-coverage CTP with automated core calculation correlates with the final infarct volume on follow-up non-enhanced CT (NECT) in patients successfully treated by mechanical thrombectomy. METHODS: We enrolled 31 stroke patients (20 women aged 74.4±12.9 years and 11 men aged 66±15.4 years; median initial NIHSS score 15.5) with occlusion of the medial cerebral artery and/or the internal carotid artery that were treated by successful mechanical thrombectomy. CTP performed in a 38.6 mm slab at the level of basal ganglia was included in the CT stroke protocol, but was not used to determine indication for mechanical thrombectomy. The infarction core volume based on CTP was automatically calculated using dedicated software with a threshold defined as cerebral blood flow <30% of the value in the contralateral healthy hemisphere. The final infarction volume was measured on 24-hour follow-up NECT in the same slab with respect to CTP. Pearson and Spearman correlation coefficients and robust linear regression were used for comparison of both volumes, P values <0.05 were considered as statistically significant. RESULTS: The median time from stroke onset to CT was 77 minutes (range, 31-284 minutes), and the median time from CT to vessel recanalization was 95 minutes (range, 55-215 minutes). The mean CTP-calculated core infarct volume was 24.3±19.2 mL (median 19 mL, range 1-79 mL), while the mean final infarct volume was 21.5±39.5 mL (median 8 mL; range 0-210 mL). Only a weak relationship was found between the CTP-calculated core and final infarct volume [Pr(29) =0.32, P=0.078; rho =0.40, P=0.028]. Regression analysis showed CTP significantly overestimated lower volumes. CONCLUSIONS: In our prospective study, the infarction core calculated using limited-coverage CTP only weakly correlated with the final infarction volume measured on 24-hour follow-up NECT; moreover, CTP significantly overestimated lower volumes. Our results do not support the use of limited-coverage CTP for guiding treatment recommendations in patients with AIS.