scholarly journals Factors Affecting Volume Reduction Velocity for Arteriovenous Malformations After Treatment With Dose-Stage Stereotactic Radiosurgery

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiangyu Meng ◽  
Dezhi Gao ◽  
Hengwei Jin ◽  
Kuanyu Wang ◽  
Enmeng Bao ◽  
...  

Background and PurposeThe purpose of this study was to identify morphologic and dosimetric features associated with volume reduction velocity for arteriovenous malformation (AVM) after dose-stage stereotactic radiosurgery (DS-SRS).MethodsThirty patients with intracranial AVM were treated with DS fractionated SRS at Beijing Tiantan Hospital from 2011 to 2019. The AVM nidus was automatically segmented from DICOMRT files using the 3D Slicer software. The change in lesion volume was obtained from the decrease in the planning target volume (PTV) between the two treatment sessions. The volume reduction velocity was measured by the change in volume divided by the time interval between treatments. Fourteen morphologic features of AVM prior to treatment were extracted from the PTV using ‘Pyradiomics’ implemented in Python. Along with other dosimetric features, univariate and multivariate analyses were performed to explore predictors of the volume reduction velocity.ResultsAmong the 15 male (50.0%) and 15 female (50.0%) patients enrolled in this study, 17 patients (56.7%) initially presented with hemorrhage. The mean treatment interval between the initial and second SRS was 35.73 months. In multivariate analysis, the SurfaceVolumeRatio was the only independent factor associated with the volume reduction velocity (p=0.010, odds ratio=0.720, 95% confidence interval: 0.560–0.925). The area under the curve of this feature for predicting the volume reduction velocity after the initial treatment of DS-SRS was 0.83. (p=0.0018).ConclusionsThe morphologic features correlated well with the volume reduction velocity in patients with intracranial AVM who underwent DS-SRS treatment. The SurfaceVolumeRatio could predict the rate of volume reduction of AVMs after DS-SRS.

2021 ◽  
Vol 11 ◽  
Author(s):  
Gustavo R. Sarria ◽  
Zuzanna Smalec ◽  
Thomas Muedder ◽  
Jasmin A. Holz ◽  
Davide Scafa ◽  
...  

PurposeTo simulate and analyze the dosimetric differences of intraoperative radiotherapy (IORT) or pre-operative single-fraction stereotactic radiosurgery (SRS) in addition to post-operative external beam radiotherapy (EBRT) in Glioblastoma (GB).MethodsImaging series of previously treated patients with adjuvant radiochemotherapy were analyzed. For SRS target definition, pre-operative MRIs were co-registered to planning CT scans and a pre-operative T1-weighted gross target volume (GTV) plus a 2-mm planning target volume (PTV) were created. For IORT, a modified (m)GTV was expanded from the pre-operative volume, in order to mimic a round cavity as during IORT. Dose prescription was 20 Gy, homogeneously planned for SRS and calculated at the surface for IORT, to cover 99% and 90% of the volumes, respectively. For tumors > 2cm in maximum diameter, a 15 Gy dose was prescribed. Plan assessment was performed after calculating the 2-Gy equivalent doses (EQD2) for both boost modalities and including them into the EBRT plan. Main points of interest encompass differences in target coverage, brain volume receiving 12 Gy or more (V12), and doses to various organs-at-risk (OARs).ResultsSeventeen pre-delivered treatment plans were included in the study. The mean GTV was 21.72 cm3 (SD ± 19.36) and mGTV 29.64 cm3 (SD ± 25.64). The mean EBRT and SRS PTV were 254.09 (SD ± 80.0) and 36.20 cm3 (SD ± 31.48), respectively. Eight SRS plans were calculated to 15 Gy according to larger tumor sizes, while all IORT plans to 20 Gy. The mean EBRT D95 was 97.13% (SD ± 3.48) the SRS D99 99.91% (SD ± 0.35) and IORT D90 83.59% (SD ± 3.55). Accounting for only-boost approaches, the brain V12 was 49.68 cm3 (SD ± 26.70) and 16.94 cm3 (SD ± 13.33) (p<0.001) for SRS and IORT, respectively. After adding EBRT results respectively to SRS and IORT doses, significant lower doses were found in the latter for mean Dmax of chiasma (p=0.01), left optic nerve (p=0.023), right (p=0.008) and left retina (p<0.001). No significant differences were obtained for brainstem and cochleae.ConclusionDose escalation for Glioblastoma using IORT results in lower OAR exposure as conventional SRS.


2012 ◽  
Vol 116 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Hideyuki Kano ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
Huai-che Yang ◽  
Thomas J. Flannery ◽  
...  

Object The object of this study was to evaluate the outcomes and risks of repeat stereotactic radiosurgery (SRS) for incompletely obliterated cerebral arteriovenous malformations (AVMs). Methods Between 1987 and 2006, Gamma Knife surgery was performed in 996 patients with AVMs. During this period, repeat SRS was performed in 105 patients who had incompletely obliterated AVMs at a median of 40.9 months after initial SRS (range 27.5–139 months). The median AVM target volume was 6.4 cm3 (range 0.2–26.3 cm3) at initial SRS but was reduced to 2.3 cm3 (range 0.1–18.2 cm3) at the time of the second procedure. The median margin dose at both initial SRS and repeat SRS was 18 Gy. Results The actuarial rate of total obliteration by angiography or MR imaging after repeat SRS was 35%, 68%, 77%, and 80% at 3, 4, 5, and 10 years, respectively. The median time to complete angiographic or MR imaging obliteration after repeat SRS was 39 months. Factors associated with a higher rate of AVM obliteration were smaller residual AVM target volume (p = 0.038) and a volume reduction of 50% or more after the initial procedure (p = 0.014). Seven patients (7%) had a hemorrhage in the interval between initial SRS and repeat SRS. Seventeen patients (16%) had hemorrhage after repeat SRS and 6 patients died. The cumulative actuarial rates of new AVM hemorrhage after repeat SRS were 1.9%, 8.1%, 10.1%, 10.1%, and 22.4% at 1, 2, 3, 5, and 10 years, respectively, which translate to annual hemorrhage rates of 4.05% and 1.79% of patients developing new post–repeat-SRS hemorrhages per year for Years 0–2 and 2–10 following repeat SRS. Factors associated with a higher risk of hemorrhage after repeat SRS were a greater number of prior hemorrhages (p = 0.008), larger AVM target volume at initial SRS (p = 0.010), larger target volume at repeat SRS (p = 0.002), initial AVM volume reduction less than 50% (p = 0.019), and a higher Pollock-Flickinger score (p = 0.010). Symptomatic adverse radiation effects developed in 5 patients (4.8%) after initial SRS and in 10 patients (9.5%) after repeat SRS. Prior embolization (p = 0.022) and a higher Spetzler-Martin grade (p = 0.004) were significantly associated with higher rates of adverse radiation effects after repeat SRS. Delayed cyst formation occurred in 5 patients (4.8%) at a median of 108 months after repeat SRS (range 47–184 months). Conclusions Repeat SRS for incompletely obliterated AVMs increases the eventual obliteration rate. Hemorrhage after obliteration did not occur in this series. The best results for patients with incompletely obliterated AVMs were seen in patients with a smaller residual nidus volume and no prior hemorrhages.


2022 ◽  
Vol 12 ◽  
Author(s):  
Yu Zhang ◽  
Yuqi Luo ◽  
Xin Kong ◽  
Tao Wan ◽  
Yunling Long ◽  
...  

Objective: To investigate the ability of a MRI-based radiomics-clinicopathological model to predict pituitary macroadenoma (PMA) recurrence within 5 years.Materials and Methods: We recruited 74 recurrent and 94 non-recurrent subjects, following first surgery with 5-year follow-up data. Univariate and multivariate analyses were conducted to identify independent clinicopathological risk factors. Two independent and blinded neuroradiologists used 3D-Slicer software to manually delineate whole tumors using preoperative axial contrast-enhanced T1WI (CE-T1WI) images. 3D-Slicer was then used to extract radiomics features from segmented tumors. Dimensionality reduction was carried out by the least absolute shrinkage and selection operator (LASSO). Two multilayer perceptron (MLP) models were established, including independent clinicopathological risk factors (Model 1) and a combination of screened radiomics features and independent clinicopathological markers (Model 2). The predictive performance of these models was evaluated by receiver operator characteristic (ROC) curve analysis.Results: In total, 1,130 features were identified, and 4 of these were selected by LASSO. In the test set, the area under the curve (AUC) of Model 2 was superior to Model 1 {0.783, [95% confidence interval (CI): 0.718—.860] vs. 0.739, (95% CI: 0.665–0.818)}. Model 2 also yielded the higher accuracy (0.808 vs. 0.692), sensitivity (0.826 vs. 0.652), and specificity (0.793 vs. 0.724) than Model 1.Conclusions: The integrated classifier was superior to a clinical classifier and may facilitate the prediction of individualized prognosis and therapy.


2019 ◽  
Vol 130 (3) ◽  
pp. 797-803 ◽  
Author(s):  
Jaymin Jhaveri ◽  
Mudit Chowdhary ◽  
Xinyan Zhang ◽  
Robert H. Press ◽  
Jeffrey M. Switchenko ◽  
...  

OBJECTIVEThe optimal margin size in postoperative stereotactic radiosurgery (SRS) for brain metastases is unknown. Herein, the authors investigated the effect of SRS planning target volume (PTV) margin on local recurrence and symptomatic radiation necrosis postoperatively.METHODSRecords of patients who received postoperative LINAC-based SRS for brain metastases between 2006 and 2016 were reviewed and stratified based on PTV margin size (1.0 or > 1.0 mm). Patients were treated using frameless and framed SRS techniques, and both single-fraction and hypofractionated dosing were used based on lesion size. Kaplan-Meier and cumulative incidence models were used to estimate survival and intracranial outcomes, respectively. Multivariate analyses were also performed.RESULTSA total of 133 patients with 139 cavities were identified; 36 patients (27.1%) and 35 lesions (25.2%) were in the 1.0-mm group, and 97 patients (72.9%) and 104 lesions (74.8%) were in the > 1.0–mm group. Patient characteristics were balanced, except the 1.0-mm cohort had a better Eastern Cooperative Group Performance Status (grade 0: 36.1% vs 19.6%), higher mean number of brain metastases (1.75 vs 1.31), lower prescription isodose line (80% vs 95%), and lower median single fraction–equivalent dose (15.0 vs 17.5 Gy) (all p < 0.05). The median survival and follow-up for all patients were 15.6 months and 17.7 months, respectively. No significant difference in local recurrence was noted between the cohorts. An increased 1-year rate of symptomatic radionecrosis was seen in the larger margin group (20.9% vs 6.0%, p = 0.028). On multivariate analyses, margin size > 1.0 mm was associated with an increased risk for symptomatic radionecrosis (HR 3.07, 95% CI 1.13–8.34; p = 0.028), while multifraction SRS emerged as a protective factor for symptomatic radionecrosis (HR 0.13, 95% CI 0.02–0.76; p = 0.023).CONCLUSIONSExpanding the PTV margin beyond 1.0 mm is not associated with improved local recurrence but appears to increase the risk of symptomatic radionecrosis after postoperative SRS.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2005
Author(s):  
Aikaterini Soufleri ◽  
Georgios Banos ◽  
Nikolaos Panousis ◽  
Dimitrios Fletouris ◽  
Georgios Arsenos ◽  
...  

The objective of this study was to conduct a large-scale investigation of colostrum composition and yield and an evaluation of factors affecting them. In this study, 1017 clinically healthy Holstein cows from 10 farms were used. The colostrum TS were measured using a digital Brix refractometer. Fat, protein and lactose content were determined using an infrared Milk Analyzer. Statistical analysis was conducted using a series of univariate general linear models. The mean (±SD) percentage of colostrum fat, protein, lactose and TS content were 6.37 (3.33), 17.83 (3.97), 2.15 (0.73) and 25.80 (4.68), respectively. Parity had a significant positive effect on the protein and TS content and a negative one on fat content. The time interval between calving and colostrum collection had a significant negative effect on the fat, protein and TS contents and a positive one on lactose. Colostrum yield had a significant negative effect on the protein and TS content, and it was affected by all factors considered. In addition to TS, the evaluation of the colostrum fat content appears essential when neonates’ energy needs are considered. The Brix refractometer, an inexpensive and easy to use devise, can be used effectively in colostrum quality monitoring.


2021 ◽  
pp. 1-7
Author(s):  
Stylianos Pikis ◽  
Adomas Bunevicius ◽  
Cheng-Chia Lee ◽  
Huai-Che Yang ◽  
Brad E. Zacharia ◽  
...  

OBJECTIVE As novel therapies improve survival for men with prostate cancer, intracranial metastatic disease has become more common. The purpose of this multicenter study was to evaluate the safety and efficacy of stereotactic radiosurgery (SRS) in the management of intracranial prostate cancer metastases. METHODS Demographic data, primary tumor characteristics, SRS treatment parameters, and clinical and imaging follow-up data of patients from nine institutions treated with SRS from July 2005 to June 2020 for cerebral metastases from prostate carcinoma were collected and analyzed. RESULTS Forty-six patients were treated in 51 SRS procedures for 120 prostate cancer intracranial metastases. At SRS, the mean patient age was 68.04 ± 9.05 years, the mean time interval from prostate cancer diagnosis to SRS was 4.82 ± 4.89 years, and extracranial dissemination was noted in 34 (73.9%) patients. The median patient Karnofsky Performance Scale (KPS) score at SRS was 80, and neurological symptoms attributed to intracranial involvement were present prior to 39 (76%) SRS procedures. Single-fraction SRS was used in 49 procedures. Stereotactic radiotherapy using 6 Gy in five sessions was utilized in 2 procedures. The median margin dose was 18 (range 6–28) Gy, and the median tumor volume was 2.45 (range 0.04–45) ml. At a median radiological follow-up of 6 (range 0–156) months, local progression was seen with 14 lesions. The median survival following SRS was 15.18 months, and the 1-year overall intracranial progression-free survival was 44%. The KPS score at SRS was noted to be associated with improved overall (p = 0.02) and progression-free survival (p = 0.03). Age ≥ 65 years at SRS was associated with decreased overall survival (p = 0.04). There were no serious grade 3–5 toxicities noted. CONCLUSIONS SRS appears to be a safe, well-tolerated, and effective management option for patients with prostate cancer intracranial metastases.


Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 227-228
Author(s):  
Hideyuki Kano ◽  
Nathaniel Sisterson ◽  
Dale Ding ◽  
Jason P Sheehan ◽  
Roberto Martinez-Alvarez ◽  
...  

Abstract INTRODUCTION To evaluate the outcomes and risks of repeat stereotactic radiosurgery (SRS) for incompletely obliterated cerebral arteriovenous malformations (AVM). METHODS Six participating centers of the International Gamma Knife Research Foundation (IGKRF) identified 335 patients who had incompletely obliterated AVMs at a median follow-up of 45.6 months after initial SRS (range, 15–283 months). The median AVM target volume at initial SRS was 4.3 cc but was reduced to 1.4cc at the time of the second procedure. The median margin dose at both initial SRS and repeat SRS was 20 Gy. The median follow-up after repeat SRS was 64 months (range, 6–218 months). RESULTS >The actuarial rate of total obliteration by angiography or MRI after repeat SRS was 31%, 50%, 61%, and 80% at 3, 4, 5, and 10 years, respectively. Factors associated with a higher rate of AVM obliteration were smaller residual AVM target volume, and >50% of volume reduction after the initial procedure. The cumulative actuarial rates of new AVM hemorrhage after repeat SRS were 1.8%, 4.5%, 6.6%, 8.9% and 14.9% at 1, 2, 3, 5, and 10 years. Factors associated with a higher risk of hemorrhage after repeat SRS were a larger number of a prior hemorrhages, larger AVM target volume, and initial AVM volume reduction <50%. Symptomatic adverse radiation effect (ARE) developed in 29 patients (8.6%) after initial SRS and 27 patients (8.1%) after repeat SRS. CONCLUSION Repeat SRS for incompletely obliterated AVMs increases the eventual obliteration rate but patients remain at risk of hemorrhage until obliteration occurs. The best results for incompletely obliterated AVMs were seen in patients with a smaller residual AVM volume and no prior hemorrhages.


2020 ◽  
Vol 132 (5) ◽  
pp. 1473-1479 ◽  
Author(s):  
Eun Young Han ◽  
He Wang ◽  
Dershan Luo ◽  
Jing Li ◽  
Xin Wang

OBJECTIVEFor patients with multiple large brain metastases with at least 1 target volume larger than 10 cm3, multifractionated stereotactic radiosurgery (MF-SRS) has commonly been delivered with a linear accelerator (LINAC). Recent advances of Gamma Knife (GK) units with kilovolt cone-beam CT and CyberKnife (CK) units with multileaf collimators also make them attractive choices. The purpose of this study was to compare the dosimetry of MF-SRS plans deliverable on GK, CK, and LINAC and to discuss related clinical issues.METHODSTen patients with 2 or more large brain metastases who had been treated with MF-SRS on LINAC were identified. The median planning target volume was 18.31 cm3 (mean 21.31 cm3, range 3.42–49.97 cm3), and the median prescribed dose was 27.0 Gy (mean 26.7 Gy, range 21–30 Gy), administered in 3 to 5 fractions. Clinical LINAC treatment plans were generated using inverse planning with intensity modulation on a Pinnacle treatment planning system (version 9.10) for the Varian TrueBeam STx system. GK and CK planning were retrospectively performed using Leksell GammaPlan version 10.1 and Accuray Precision version 1.1.0.0 for the CK M6 system. Tumor coverage, Paddick conformity index (CI), gradient index (GI), and normal brain tissue receiving 4, 12, and 20 Gy were used to compare plan quality. Net beam-on time and approximate planning time were also collected for all cases.RESULTSPlans from all 3 modalities satisfied clinical requirements in target coverage and normal tissue sparing. The mean CI was comparable (0.79, 0.78, and 0.76) for the GK, CK, and LINAC plans. The mean GI was 3.1 for both the GK and the CK plans, whereas the mean GI of the LINAC plans was 4.1. The lower GI of the GK and CK plans would have resulted in significantly lower normal brain volumes receiving a medium or high dose. On average, GK and CK plans spared the normal brain volume receiving at least 12 Gy and 20 Gy by approximately 20% in comparison with the LINAC plans. However, the mean beam-on time of GK (∼ 64 minutes assuming a dose rate of 2.5 Gy/minute) plans was significantly longer than that of CK (∼ 31 minutes) or LINAC (∼ 4 minutes) plans.CONCLUSIONSAll 3 modalities are capable of treating multiple large brain lesions with MF-SRS. GK has the most flexible workflow and excellent dosimetry, but could be limited by the treatment time. CK has dosimetry comparable to that of GK with a consistent treatment time of approximately 30 minutes. LINAC has a much shorter treatment time, but residual rotational error could be a concern.


2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 262-265
Author(s):  
C. P. Yu ◽  
Joel Y. C. Cheung ◽  
Josie F. K. Chan ◽  
Samuel C. L. Leung ◽  
Robert T. K. Ho

Object. The authors analyzed the factors involved in determining prolonged survival (≥ 24 months) in patients with brain metastases treated by gamma knife surgery (GKS). Methods. Between 1995 and 2003, a total of 116 patients underwent 167 GKS procedures for brain metastases. There was no special case selection. Smaller and larger lesions were treated with different protocols. The mean patient age was 56.9 years, the mean number of initial lesions was 3.15, and the mean lesion volume was 10.45 cm.3 The mean follow-up time was 9.2 months. The median patient survival was 8.68 months. One-, 2-, 3-, 4-, and 5-year actuarial survival rates were 31.8%, 19.8%, 14.6%, 7.7%, and 6.9%, respectively. Patient age, number of lesions at presentation, and lesion volume had no influence on patient survival. Twenty-three (19.8%) patients survived for 24 months or more. Certain factors were associated with increased survival time. These were stable primary disease (21 of 23 patients), a long latency between diagnosis of the primary tumor and the occurrence of brain metastases (mean 28.4 months, median 16 months), absence of third-organ involvement, and repeated local procedures. Ten patients underwent repeated GKS (mean 3.4 per patient). Seven patients required open surgery for local treatment failures (recurrence or radiation necrosis). Two patients had both. Fifteen patients underwent repeated procedures. Conclusions. Aggressive local therapy with GKS, repeated GKS, and GKS plus surgery can achieve increased survival in a subgroup of patients with stable primary disease, no third-organ involvement, and long primary-brain secondary intervals.


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