Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
26
result(s) for
"Shiau, Cheng-Ying"
Sort by:
Radiomics as prognostic factor in brain metastases treated with Gamma Knife radiosurgery
2020
PurposeGamma Knife radiosurgery (GKRS) is a non-invasive procedure for the treatment of brain metastases. This study sought to determine whether radiomic features of brain metastases derived from pre-GKRS magnetic resonance imaging (MRI) could be used in conjunction with clinical variables to predict the effectiveness of GKRS in achieving local tumor control.MethodsWe retrospectively analyzed 161 patients with non-small cell lung cancer (576 brain metastases) who underwent GKRS for brain metastases. The database included clinical data and pre-GKRS MRI. Brain metastases were demarcated by experienced neurosurgeons, and radiomic features of each brain metastasis were extracted. Consensus clustering was used for feature selection. Cox proportional hazards models and cause-specific proportional hazards models were used to correlate clinical variables and radiomic features with local control of brain metastases after GKRS.ResultsMultivariate Cox proportional hazards model revealed that higher zone percentage (hazard ratio, HR 0.712; P = .022) was independently associated with superior local tumor control. Similarly, multivariate cause-specific proportional hazards model revealed that higher zone percentage (HR 0.699; P = .014) was independently associated with superior local tumor control.ConclusionsThe zone percentage of brain metastases, a radiomic feature derived from pre-GKRS contrast-enhanced T1-weighted MRIs, was found to be an independent prognostic factor of local tumor control following GKRS in patients with non-small cell lung cancer and brain metastases. Radiomic features indicate the biological basis and characteristics of tumors and could potentially be used as surrogate biomarkers for predicting tumor prognosis following GKRS.
Journal Article
Vascular compactness of unruptured brain arteriovenous malformation predicts risk of hemorrhage after stereotactic radiosurgery
2024
The aim of the study was to investigate whether morphology (i.e. compact/diffuse) of brain arteriovenous malformations (bAVMs) correlates with the incidence of hemorrhagic events in patients receiving Stereotactic Radiosurgery (SRS) for unruptured bAVMs. This retrospective study included 262 adult patients with unruptured bAVMs who underwent upfront SRS. Hemorrhagic events were defined as evidence of blood on CT or MRI. The morphology of bAVMs was evaluated using automated segmentation which calculated the proportion of vessel, brain tissue, and cerebrospinal fluid in bAVMs on T2-weighted MRI. Compactness index, defined as the ratio of vessel to brain tissue, categorized bAVMs into compact and diffuse types based on the optimal cutoff. Cox proportional hazard model was used to identify the independent factors for post-SRS hemorrhage. The median clinical follow-ups was 62.1 months. Post-SRS hemorrhage occurred in 13 (5.0%) patients and one of them had two bleeds, resulting in an annual bleeding rate of 0.8%. Multivariable analysis revealed bAVM morphology (compact versus diffuse), bAVM volume, and prescribed margin dose were significant predictors. The post-SRS hemorrhage rate increased with larger bAVM volume only among the diffuse nidi (1.7 versus 14.9 versus 30.6 hemorrhage per 1000 person-years in bAVM volume < 20 cm
3
versus 20–40 cm
3
versus > 40 cm
3
; p = 0.022). The significantly higher post-SRS hemorrhage rate of Spetzler-Martin grade IV–V compared with grade I–III bAVMs (20.0 versus 3.3 hemorrhages per 1000 person-years; p = 0.001) mainly originated from the diffuse bAVMs rather than the compact subgroup (30.9 versus 4.8 hemorrhages per 1000 person-years; p = 0.035). Compact and smaller bAVMs, with higher prescribed margin dose harbor lower risks of post-SRS hemorrhage. The post-SRS hemorrhage rate exceeded 2.2% annually within the diffuse and large (> 40 cm
3
) bAVMs and the diffuse Spetzler-Martin IV–V bAVMs. These findings may help guide patient selection of SRS for the unruptured bAVMs.
Journal Article
Gamma knife radiosurgery for the treatment of cavernous sinus meningiomas: post-treatment long-term clinical outcomes, complications, and volume changes
2019
Purpose
To evaluate the outcomes of patients who underwent Gamma Knife radiosurgery (GKRS) for the treatment of cavernous sinus (CS) meningiomas.
Methods
We retrospectively reviewed the clinical and radiological outcomes of 95 patients with CS meningiomas at Taipei Veterans General Hospital between 1993 and 2011. The study cohort comprised 27 men and 68 women with a median age of 50 years (range 29–79 years). The median pre-GKRS tumor volume was 6.6 ml (range 0.9–35.7 ml). The median margin dose was 12 Gy (range 11–21 Gy). The clinical factors related to favorable outcomes were assessed.
Results
The median follow-up period was 59 (range 12–209) months. At the final follow-up, the tumor volume regressed in 70 patients (74%) and progressed in eight (8%). Kaplan–Meier analysis revealed that the progression-free survival rates at 5 and 10 years were 92.7% and 81.2%, respectively. Three patients (3.2%) experienced exacerbated cranial nerve dysfunction following radiosurgery. Confined tumors were found to be an independent prognostic factor for tumor control and shorter times to regression in the multivariable analyses. No risk factor for tumor progression was identified in either the univariate or multivariate analyses.
Conclusions
GKRS provides good long-term tumor control and is associated with low cranial nerve–related morbidity development rates in patients with small- to medium-sized CS meningiomas. Confined tumor could be an independent prognostic factor for tumor control and shorter times to regression in multivariate analysis. Life-long follow-up is mandatory in such settings, even for outpatients with shrunken or stabilized tumors.
Journal Article
Low-Dose Gamma Knife Radiosurgery for Acromegaly
by
Yen, Yu-Shu
,
Lin, Yi-Chun
,
Guo, Wan-Yuo
in
Acromegaly
,
Acromegaly - etiology
,
Acromegaly - therapy
2019
Abstract
Background
Remission rate is associated with higher dose of Gamma Knife Radiosurgery (GKRS; Gamma Knife: Elekta AB, Stockholm, Sweden) for acromegaly, but the dose ≥25 Gy is not always feasible when the functioning adenoma is close to optic apparatus
Objective
To evaluate the efficacy and safety of low-dose (<25 Gy) GKRS in the treatment of patients with acromegaly.
Methods
Single-center retrospective review of acromegaly cases treated with GKRS between June 1994 and December 2016. A total of 76 patients with the diagnosis of acromegaly who were treated with low-dose GKRS were selected for inclusion. Patients were treated with a median margin dose, isodose line, and treatment volume of 15.8 Gy, 57.5%, and 4.8 mL, respectively. Any identifiable portion of the optic apparatus was limited to a radiation dose of 10 Gy. All patients underwent full endocrine, ophthalmological, and imaging evaluation prior to and after GKRS treatments, and results of these were analyzed.
Results
Biochemical remission was achieved in 33 (43.4%) patients. Actuarial remission rates were 20.3%, 49.9%, and 76.3% at 4, 8, and 12 yr, respectively. Absence of cavernous sinus invasion (P = .042) and lower baseline insulin-like growth factor-1 levels (P = .019) were significant predictors of remission. New hormone deficiencies were found in 9 (11.8%) patients. Actuarial hormone deficiency rates were 3%, 14%, and 22.2% at 4, 8, and 10 yr, respectively. Two (2.6%) patients who achieved initial remission experienced recurrence. No optic complications were encountered.
CONCLUSION
Reasonable remission and new hormone deficiency rates can be achieved with low-dose GKRS for acromegaly. These rates may be comparable to those with standard GKRS margin doses.
Journal Article
Carbon Ion Radiotherapy: An Evidence-Based Review and Summary Recommendations of Clinical Outcomes for Skull-Base Chordomas and Chondrosarcomas
2023
Skull-base chordoma and chondrosarcoma are rare radioresistant tumors treated with surgical resection and/or radiotherapy. Because of the established dosimetric and biological benefits of heavy particle therapy, we performed a systematic and evidence-based review of the clinical outcomes of patients with skull-base chordoma and chondrosarcoma treated with carbon ion radiotherapy (CIRT). A literature review was performed using a MEDLINE search of all articles to date. We identified 227 studies as appropriate for review, and 24 were ultimately included. The published data illustrate that CIRT provides benchmark disease control outcomes for skull-base chordoma and chondrosarcoma, respectively, with acceptable toxicity. CIRT is an advanced treatment technique that may provide not only dosimetric benefits over conventional photon therapy but also biologic intensification to overcome mechanisms of radioresistance. Ongoing research is needed to define the magnitude of benefit, patient selection, and cost-effectiveness of CIRT compared to other forms of radiotherapy.
Journal Article
Effect of Age and Biological Subtype on the Risk and Timing of Brain Metastasis in Breast Cancer Patients
2014
Brain metastasis is a major complication of breast cancer. This study aimed to analyze the effect of age and biological subtype on the risk and timing of brain metastasis in breast cancer patients.
We identified subtypes of invasive ductal carcinoma of the breast by determining estrogen receptor, progesterone receptor and HER2 status. Time to brain metastasis according to age and cancer subtype was analyzed by Cox proportional hazard analysis.
Of the 2248 eligible patients, 164 (7.3%) developed brain metastasis over a median follow-up of 54.2 months. Age 35 or younger, HER2-enriched subtype, and triple-negative breast cancer were significant risk factors of brain metastasis. Among patients aged 35 or younger, the risk of brain metastasis was independent of biological subtype (P = 0.507). Among patients aged 36-59 or >60 years, those with triple-negative or HER2-enriched subtypes had consistently increased risk of brain metastasis, as compared with those with luminal A tumors. Patients with luminal B tumors had higher risk of brain metastasis than luminal A only in patients >60 years.
Breast cancer subtypes are associated with differing risks of brain metastasis among different age groups. Patients age 35 or younger are particularly at risk of brain metastasis independent of biological subtype.
Journal Article
Empirical versus progression-guided stereotactic radiosurgery for non-functional pituitary macroadenomas after subtotal resection
by
Chen, Ching-Jen
,
Shiau, Cheng-Ying
,
Guo, Wan-Yuo
in
Clinical Study
,
Endocrine disorders
,
Hypopituitarism
2019
Objective
There is a lack of consensus regarding whether if residual non-functional macroadenomas (NFM) should undergo empirical stereotactic radiosurgery (SRS) or be monitored until tumor progression before SRS treatment. The aim of this study is to compare the risks and benefits of empirical versus progression-guided SRS for NFM after subtotal resection.
Methods
This is a retrospective study of consecutive NFM patients who subtotal surgical resection followed by SRS between 1999 and 2014. Patients were dichotomized into two groups: empirical SRS (SRS without evidence of tumor progression) and progression-guided SRS (SRS after demonstration of tumor progression) groups. Tumor response was categorized into: (1) regression, ≥ 10% decrease in tumor volume; (2) stable, < 10% increase or decrease in tumor volume; and (3) progression, ≥ 10% increase in tumor volume. Tumor control comprised stable tumor response and tumor regression.
Results
Of the 112 patients who underwent SRS for NFM, 106 patients were treated for residual NFM after surgical resection, and included in the final analysis. The empirical SRS and progression-guided SRS groups comprised 46 and 60 patients, respectively. Overall tumor control rate was 88.7%. Higher rate of tumor control was achieved in the empirical SRS group compared to the progression-guided SRS group (95.65% vs. 83.33%, p = 0.047). Rates of new visual field deficit, cranial neuropathy and endocrinopathy were comparable between the two groups. Empirical SRS group had higher rates of progression-free survival compared to progression-guided SRS group (p = 0.015). Actuarial progression-free survival rates for the empirical SRS group were 93.2%, 93.2%, and 81.5% at 3, 5, and 10 years after SRS. Actuarial progression-free survival rates for the progression-guided SRS were 86.4%, 82.1%, and 68.4% at 3, 5, and 10 years after SRS.
Conclusion
Empirical SRS offers higher rates of tumor control and progression-free survival compared to progression-guided SRS in patients with residual NFM after surgical resection. Rates of new hypopituitarism and cranial neuropathies were comparable between the two groups.
Journal Article
A Survival Metadata Analysis Responsive Tool (SMART) for web-based analysis of patient survival and risk
by
Tarng, Der-Cherng
,
Lee, Chung-Yuan
,
Shiau, Cheng-Ying
in
692/4028/67
,
692/499
,
Clinical trials
2018
Health information systems contain extensive amounts of patient data. Information relevant to public health and individuals’ medical histories are both available. In clinical research, the prediction of patient survival rates and identification of prognosis factors are major challenges. To alleviate the difficulties related to these factors, Metadata Utilities was developed to help researchers manage column definitions and information such as import/query/generator Metadata files. These utilities also include an automatic update mechanism to ensure consistency between the data and parameters of the batch produced in the conversion procedure. Survival Metadata Analysis Responsive Tool (SMART) provides a comprehensive set of statistical tests that are easy to understand, including support for analyzing nominal variables, ordinal variables, interval variables or ratio variables as means, standard deviations, maximum values, minimum values, and percentages. In this article, the development of a raw data source and transfer mechanism, Extract-Transform-Load (ETL), is described for data cleansing, extraction, transformation and loading. We also built a handy method for data presentation, which can be customized to the trial design. As demonstrated here, SMART is useful for risk-adjusted baseline cohort and randomized controlled trials.
Journal Article
Repeated gamma knife radiosurgery enables longer tumor control in cases of highly-recurrent intracranial ependymoma
2020
PurposeStereotactic radiosurgery (SRS) is a potential re-irradiation treatment for recurrent intracranial ependymoma after prior radiation therapy. The purpose of this study was to examine the efficacy and safety of repeated SRS in the treatment of recurrent intracranial ependymomas.MethodsThis is a retrospective study of consecutive patients with residual or recurrent intracranial ependymomas who were treated with SRS between 1993 and 2018. Tumor progression was defined as a ≥ 10% increase in tumor volume. Tumor regression was defined as a ≥ 10% reduction in tumor volume. A tumor that remained within 10% of its original volume was defined as stable. Tumor control comprised tumor regression and stability. Time-dependent analyses were performed using two treatment failure endpoint definitions: (1) evidence of local tumor progression or distant metastasis (single SRS analysis), and (2) lack of tumor response to SRS (repeated SRS analysis). These analyses were adjusted for the competing risk of death.ResultsThe study comprised 37 patients (65 intracranial ependymomas) who underwent multiple SRS sessions (range: 1–7). Median age was 10.2 years (range: 0.8–53.8 years), and median tumor volume was 1.5 mL (range: 0.01–22.5 mL). The median radiation dose was 13.3 Gy (range: 7.9–22.0 Gy) at a median isodose line of 57% (range: 50–90%). Overall tumor control rates in the single SRS analysis adjusting for the competing risk of death were 53.6%, 30.5%, and 23.6% at 1, 3, and 5 years, respectively. Overall tumor control rates in the repeated SRS analysis adjusting for the competing risk of death were 70.6%, 50.4%, and 43.1% at 1, 3, and 5 years, respectively. Prior gross total resection was the only independent predictor of overall tumor control after SRS (aHR = 25.62 (1.55–422.1), p = 0.02).ConclusionsRepeated GKRS appeared to be an effective treatment strategy for recurrent or residual intracranial ependymomas, with acceptable complication rates.
Journal Article
Soft Tissue Sarcoma of Extremities: The Prognostic Significance of Adequate Surgical Margins in Primary Operation and Reoperation After Recurrence
by
Chen, Tain-Hsiung
,
Yen, Chueh-Chuan
,
Liu, Chien-Lin
in
Analysis of Variance
,
Bone and Soft Tissue Sarcomas
,
Disease-Free Survival
2010
Background
Adult soft tissue sarcomas (STS) of extremities are prone to recurrence despite apparently complete resection. This study aimed to explore the impact of clinicopathological factors on outcome and to define an “oncological safe margin” in these patients.
Methods
A total of 181 patients with extremity STS were enrolled in a retrospective study. The prognostic influence of margin status and other clinicopathological characteristics on local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-specific survival (DSS), were examined by univariate and multivariate analyses. The influence of surgical margins on postrecurrence survival (PRS) of patients undergoing reoperation for relapsed lesions during follow-up was analyzed by the Kaplan–Meier method.
Results
Surgical margin width <10 mm and deep tumor depth at primary operation were consistently statistically significant independent adverse factors for LRFS, DMFS, and DSS. Patients with liposarcoma or low grade tumors had significantly higher chances of achieving adequate margins. Of 83 patients who experienced recurrence or metastasis, 53 (63.9%) received reoperation for their relapsed lesions. Patients who achieved microscopically negative margins (R0) at reoperation had significantly better PRS than those who did not (
P
< 0.007). Overall, patients with no recurrences had the best DSS, while relapsed patients receiving R0 reoperation had better DSS than those receiving either non-R0 reoperation or no reoperation at all.
Conclusion
Surgical margins prognostically influence survival in both patients undergoing primary surgery and those undergoing reoperation for relapse of extremity STS. In primary surgery, the chance of achieving adequate margin may reflect the underlying aggressiveness of tumors.
Journal Article