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"Myrehaug, Sten"
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Stereotactic body radiotherapy versus conventional external beam radiotherapy in patients with painful spinal metastases: an open-label, multicentre, randomised, controlled, phase 2/3 trial
2021
Conventional external beam radiotherapy is the standard palliative treatment for spinal metastases; however, complete response rates for pain are as low as 10–20%. Stereotactic body radiotherapy delivers high-dose, ablative radiotherapy. We aimed to compare complete response rates for pain after stereotactic body radiotherapy or conventional external beam radiotherapy in patients with painful spinal metastasis.
This open-label, multicentre, randomised, controlled, phase 2/3 trial was done at 13 hospitals in Canada and five hospitals in Australia. Patients were eligible if they were aged 18 years and older, and had painful (defined as ≥2 points with the Brief Pain Inventory) MRI-confirmed spinal metastasis, no more than three consecutive vertebral segments to be included in the treatment volume, an Eastern Cooperative Oncology Group performance status of 0–2, a Spinal Instability Neoplasia Score of less than 12, and no neurologically symptomatic spinal cord or cauda equina compression. Patients were randomly assigned (1:1) with a web-based, computer-generated allocation sequence to receive either stereotactic body radiotherapy at a dose of 24 Gy in two daily fractions or conventional external beam radiotherapy at a dose of 20 Gy in five daily fractions using standard techniques. Treatment assignment was done centrally by use of a minimisation method to achieve balance for the stratification factors of radiosensitivity, the presence or absence of mass-type tumour (extraosseous or epidural disease extension, or both) on imaging, and centre. The primary endpoint was the proportion of patients with a complete response for pain at 3 months after radiotherapy. The primary endpoint was analysed in the intention-to-treat population and all safety and quality assurance analyses were done in the as-treated population (ie, all patients who received at least one fraction of radiotherapy). The trial is registered with ClinicalTrials.gov, NCT02512965.
Between Jan 4, 2016, and Sept 27, 2019, 229 patients were enrolled and randomly assigned to receive conventional external beam radiotherapy (n=115) or stereotactic body radiotherapy (n=114). All 229 patients were included in the intention-to-treat analysis. The median follow-up was 6·7 months (IQR 6·3–6·9). At 3 months, 40 (35%) of 114 patients in the stereotactic body radiotherapy group, and 16 (14%) of 115 patients in the conventional external beam radiotherapy group had a complete response for pain (risk ratio 1·33, 95% CI 1·14–1·55; p=0·0002). This significant difference was maintained in multivariable-adjusted analyses (odds ratio 3·47, 95% CI 1·77–6·80; p=0·0003). The most common grade 3–4 adverse event was grade 3 pain (five [4%] of 115 patients in the conventional external beam radiotherapy group vs five (5%) of 110 patients in the stereotactic body radiotherapy group). No treatment-related deaths were observed.
Stereotactic body radiotherapy at a dose of 24 Gy in two daily fractions was superior to conventional external beam radiotherapy at a dose of 20 Gy in five daily fractions in improving the complete response rate for pain. These results suggest that use of conformal, image-guided, stereotactically dose-escalated radiotherapy is appropriate in the palliative setting for symptom control for selected patients with painful spinal metastases, and an increased awareness of the need for specialised and multidisciplinary involvement in the delivery of end-of-life care is needed.
Canadian Cancer Society and the Australian National Health and Medical Research Council.
Journal Article
Vertebral Compression Fracture After Spine Stereotactic Body Radiation Therapy: A Review of the Pathophysiology and Risk Factors
2018
Abstract
BACKGROUND
Vertebral compression fracture (VCF) is a challenging and not infrequent complication observed following spine stereotactic body radiation therapy (SBRT).
OBJECTIVE
To summarize the data from the multiple studies that have been published, addressing the risk and predictive factors for VCF post-SBRT.
METHODS
A systematic literature review was conducted. Studies were selected if they specifically addressed risk factors for post-SBRT VCF in their analyses.
RESULTS
A total of 11 studies were identified, reporting both the risk of VCF post-SBRT and an analysis of risk factors based on univariate and multivariate analysis. A total of 2911 spinal segments were treated with a crude VCF rate of 13.9%. The most frequently identified risk factors on multivariate analysis were: lytic disease (hazard ratio [HR] range, 2.76-12.2), baseline VCF prior to SBRT (HR range, 1.69-9.25), higher dose per fraction SBRT (HR range, 5.03-6.82), spinal deformity (HR range, 2.99-11.1), older age (HR range, 2.15-5.67), and more than 40% to 50% of vertebral body involved by tumor (HR range, 3.9-4.46). In the 9 studies that specifically reported on the use of post-SBRT surgical procedures, 37% of VCF had undergone an intervention (range, 11%-60%).
CONCLUSION
VCF is an important adverse effect following SBRT. Risk factors have been identified to guide the selection of high-risk patients. Evidence-based algorithms with respect to patient selection and intervention are needed.
Journal Article
Quantitative CEST and MT at 1.5T for monitoring treatment response in glioblastoma: early and late tumor progression during chemoradiation
2021
PurposeQuantitative MRI (qMRI) was performed using a 1.5T protocol that includes a novel chemical exchange saturation transfer/magnetization transfer (CEST/MT) approach. The purpose of this prospective study was to determine if qMRI metrics at baseline, at the 10th and 20th fraction during a 30 fraction/6 week standard chemoradiation (CRT) schedule, and at 1 month following treatment could be an early indicator of response for glioblastoma (GBM).MethodsThe study included 51 newly diagnosed GBM patients. Four regions-of-interest (ROI) were analyzed: (i) the radiation defined clinical target volume (CTV), (ii) radiation defined gross tumor volume (GTV), (iii) enhancing-tumor regions, and (iv) FLAIR-hyperintense regions. Quantitative CEST, MT, T1 and T2 parameters were compared between those patients progressing within 6.9 months (early), and those progressing after CRT (late), using mixed modelling. Exploratory predictive modelling was performed to identify significant predictors of early progression using a multivariable LASSO model.ResultsResults were dependent on the specific tumor ROI analyzed and the imaging time point. The baseline CEST asymmetry within the CTV was significantly higher in the early progression cohort. Other significant predictors included the T2 of the MT pools (for semi-solid at fraction 20 and water at 1 month after CRT), the exchange rate (at fraction 20) and the MGMT methylation status.ConclusionsWe observe the potential for multiparametric qMRI, including a novel pulsed CEST/MT approach, to show potential in distinguishing early from late progression GBM cohorts. Ultimately, the goal is to personalize therapeutic decisions and treatment adaptation based on non-invasive imaging-based biomarkers.
Journal Article
Quantitative mapping of individual voxels in the peritumoral region of IDH-wildtype glioblastoma to distinguish between tumor infiltration and edema
by
Chia-Lin, Tseng
,
Perry, James
,
Soliman Hany
in
Brain cancer
,
Brain tumors
,
Diffusion coefficient
2021
PurposeThe peritumoral region (PTR) in glioblastoma (GBM) represents a combination of infiltrative tumor and vasogenic edema, which are indistinguishable on magnetic resonance imaging (MRI). We developed a radiomic signature by using imaging data from low grade glioma (LGG) (marker of tumor) and PTR of brain metastasis (BM) (marker of edema) and applied it on the GBM PTR to generate probabilistic maps.Methods270 features were extracted from T1-weighted, T2-weighted, and apparent diffusion coefficient maps in over 3.5 million voxels of LGG (36 segments) and BM (45 segments) scanned in a 1.5T MRI. A support vector machine classifier was used to develop the radiomics model from approximately 50% voxels (downsampled to 10%) and validated with the remaining. The model was applied to over 575,000 voxels of the PTR of 10 patients with GBM to generate a quantitative map using Platt scaling (infiltrative tumor vs. edema).ResultsThe radiomics model had an accuracy of 0.92 and 0.79 in the training and test set, respectively (LGG vs. BM). When extrapolated on the GBM PTR, 9 of 10 patients had a higher percentage of voxels with a tumor-like signature over radiological recurrence areas. In 7 of 10 patients, the areas under curves (AUC) were > 0.50 confirming a positive correlation. Including all the voxels from the GBM patients, the infiltration signature had an AUC of 0.61 to predict recurrence.ConclusionA radiomic signature can demarcate areas of microscopic tumors from edema in the PTR of GBM, which correlates with areas of future recurrence.Graphic abstract
Journal Article
MRI radiomics to differentiate between low grade glioma and glioblastoma peritumoral region
2021
BackgroundThe peritumoral region (PTR) of glioblastoma (GBM) appears as a T2W-hyperintensity and is composed of microscopic tumor and edema. Infiltrative low grade glioma (LGG) comprises tumor cells that seem similar to GBM PTR on MRI. The work here explored if a radiomics-based approach can distinguish between the two groups (tumor and edema versus tumor alone).MethodsPatients with GBM and LGG imaged using a 1.5 T MRI were included in the study. Image data from cases of GBM PTR, and LGG were manually segmented guided by T2W hyperintensity. A set of 91 first-order and texture features were determined from each of T1W-contrast, and T2W-FLAIR, diffusion-weighted imaging sequences. Applying filtration techniques, a total of 3822 features were obtained. Different feature reduction techniques were employed, and a subsequent model was constructed using four machine learning classifiers. Leave-one-out cross-validation was used to assess classifier performance.ResultsThe analysis included 42 GBM and 36 LGG. The best performance was obtained using AdaBoost classifier using all the features with a sensitivity, specificity, accuracy, and area of curve (AUC) of 91%, 86%, 89%, and 0.96, respectively. Amongst the feature selection techniques, the recursive feature elimination technique had the best results, with an AUC ranging from 0.87 to 0.92. Evaluation with the F-test resulted in the most consistent feature selection with 3 T1W-contrast texture features chosen in over 90% of instances.ConclusionsQuantitative analysis of conventional MRI sequences can effectively demarcate GBM PTR from LGG, which is otherwise indistinguishable on visual estimation.
Journal Article
Quantitative MRI Biomarkers of Stereotactic Radiotherapy Outcome in Brain Metastasis
2019
About 20–40% of cancer patients develop brain metastases, causing significant morbidity and mortality. Stereotactic radiation treatment is an established option that delivers high dose radiation to the target while sparing the surrounding normal tissue. However, up to 20% of metastatic brain tumours progress despite stereotactic treatment, and it can take months before it is evident on follow-up imaging. An early predictor of radiation therapy outcome in terms of tumour local failure (LF) is crucial, and can facilitate treatment adjustments or allow for early salvage treatment. In this study, an MR-based radiomics framework was proposed to derive and investigate quantitative MRI (qMRI) biomarkers for the outcome of LF in brain metastasis patients treated with hypo-fractionated stereotactic radiation therapy (SRT). The qMRI biomarkers were constructed through a multi-step feature extraction/reduction/selection framework using the conventional MR imaging data acquired from 100 patients (133 lesions), and were applied in conjunction with machine learning techniques for outcome prediction and risk assessment. The results indicated that the majority of the features in the optimal qMRI biomarkers characterize the heterogeneity in the surrounding regions of tumour including edema and tumour/lesion margins. The optimal qMRI biomarker consisted of five features that predict the outcome of LF with an area under the curve (AUC) of 0.79, and a cross-validated sensitivity and specificity of 81% and 79%, respectively. The Kaplan-Meier analyses showed a statistically significant difference in local control (p-value < 0.0001) and overall survival (p = 0.01). Findings from this study are a step towards using qMRI for early prediction of local failure in brain metastasis patients treated with SRT. This may facilitate early adjustments in treatment, such as surgical resection or salvage radiation, that can potentially improve treatment outcomes. Investigations on larger cohorts of patients are, however, required for further validation of the technique.
Journal Article
Survival outcomes among patients with breast cancer and leptomeningeal disease
2025
Despite advances in metastatic breast cancer (MBC) management, leptomeningeal disease (LMD) prognosis remains poor. This study evaluates clinicopathological and treatment factors influencing outcomes of MBC patients with LMD treated with radiotherapy (RT). We conducted a retrospective analysis of patients with MBC treated with RT for brain metastases (BrM) between 2005 and 2019. LMD diagnosis was made via magnetic resonance imaging (MRI). Multivariable analysis (MVA) identified variables associated with brain-specific progression-free survival (bsPFS) and overall survival (OS). Among 691 MBC patients treated with RT for BrM, 161 (23%) had LMD, either at initial presentation (50/161) or after BrM treatment. Patients with LMD were younger, more likely to have ER + disease, more likely to have undergone surgery for BrM, and less likely to have received prior whole-brain RT. HER2+ LMD was associated with longer bsPFS (HR 0.47, 95% CI: 0.25–0.86,
p
= 0.01) and OS (HR 0.38, 95% CI: 0.2–0.75,
p
= 0.002). Median OS for triple-negative breast cancer was 3.7 months, 5.1 months for HR+/HER2 − and 15.4 months for HER2 + MBC. HER2-targeted therapy, either at or after LMD diagnosis, improved long-term survival (> 2 years) (Fisher’s test,
p
< 0.05). Low Karnofsky Performance Status (KPS < 60) was linked to shorter bsPFS (HR 2.91, 95% CI: 1.49–5.69,
p
< 0.01) and OS (HR 3.37, 95% CI: 1.78–6.41,
p
< 0.001). These findings highlight the need for effective CNS-penetrating systemic therapies for HER2-negative breast cancer.
Journal Article
Local control and patterns of failure for “Radioresistant” spinal metastases following stereotactic body radiotherapy compared to a “Radiosensitive” reference
2021
PurposeThe concept of a radioresistant (RR) phenotype has been challenged with use of stereotactic body radiotherapy (SBRT). We compared outcomes following SBRT to RR spinal metastases to a radiosensitive cohort.MethodsRenal cell, melanoma, sarcoma, gastro-intestinal, and thyroid spinal metastases were identified as RR and prostate cancer (PCA) as radiosensitive. The primary endpoint was MRI-based local failure (LF). Secondary endpoints included overall survival (OS) and vertebral compression fracture (VCF).ResultsFrom a prospectively maintained database of 1394 spinal segments in 605 patients treated with spine SBRT, 173 patients/395 RR spinal segments were compared to 94 patients/185 PCA segments. Most received 24–28 Gy in 2 fractions (68.9%) and median follow-up was 15.5 months (range, 1.4–84.2 months). 1- and 2-year LF rates were 19.2% and 22.4% for RR metastases, respectively, which were significantly greater (p < 0.001) than PCA (3.2% and 8.4%, respectively). Epidural disease (HR: 2.47, 95% CI 1.65–3.71, p < 0.001) and RR histology (HR: 2.41, 95% CI 1.45–3.99, p < 0.001) predicted for greater LF. Median OS was 17.4 and 61.0 months for RR and PCA cohorts, respectively. Lung/liver metastases, polymetastatic disease and epidural disease predicted for worse OS. 2-year VCF rates were ~ 13% in both cohorts. Coverage of the CTV V90 (clinical target volume receiving 90% of prescription dose) by ≥ 87% (HR: 2.32, 95% CI 1.29–4.18, p = 0.005), no prior spine radiotherapy (HR: 1.96, 95% CI 1.09–3.55, p = 0.025), and a greater Spinal Instability Neoplasia Score (p = 0.013) predicted for VCF.ConclusionsHigher rates of LF were observed after spine SBRT in RR metastases. Optimization strategies include dose escalation and aggressive management of epidural disease.
Journal Article
Hypofractionated stereotactic radiosurgery (HSRS) as a salvage treatment for brain metastases failing prior stereotactic radiosurgery (SRS)
by
Myrehaug, Sten
,
Yeboah, Collins
,
Soliman, Hany
in
Brain cancer
,
Brain Neoplasms - secondary
,
Humans
2023
Introduction
Various treatment options exist to salvage stereotactic radiosurgery (SRS) failures for brain metastases, including repeat SRS and hypofractionated SRS (HSRS). Our objective was to report outcomes specific to salvage HSRS for brain metastases that failed prior HSRS/SRS.
Methods
Patients treated with HSRS to salvage local failures (LF) following initial HSRS/SRS, between July 2010 and April 2020, were retrospectively reviewed. The primary outcomes were the rates of LF, radiation necrosis (RN), and symptomatic radiation necrosis (SRN). Univariable (UVA) and multivariable (MVA) analyses using competing risk regression were performed to identify predictive factors for each endpoint.
Results
120 Metastases in 91 patients were identified. The median clinical follow up was 13.4 months (range 1.1–111.1), and the median interval between SRS courses was 13.1 months (range 3.0–56.5). 115 metastases were salvaged with 20–35 Gy in 5 fractions and the remaining five with a total dose ranging from 20 to 24 Gy in 3-fractions. 67 targets (56%) were postoperative cavities. The median re-treatment target volume and biological effective dose (BED
10
) was 9.5 cc and 37.5 Gy, respectively. The 6- and 12- month LF rates were 18.9% and 27.7%, for RN 13% and 15.6%, and for SRN were 6.1% and 7.0%, respectively. MVA identified larger re-irradiation volume (hazard ratio [HR] 1.02, p = 0.04) and shorter interval between radiosurgery courses (HR 0.93, p < 0.001) as predictors of LF. Treatment of an intact target was associated with a higher risk of RN (HR 2.29, p = 0.04).
Conclusion
Salvage HSRS results in high local control rates and toxicity rates that compare favorably to those single fraction SRS re-irradiation experiences reported in the literature.
Journal Article
Inter-fraction dynamics during post-operative 5 fraction cavity hypofractionated stereotactic radiotherapy with a MR LINAC: a prospective serial imaging study
2022
Purpose/Objective(s)
This study examined changes in the clinical target volume (CTV) and associated clinical implications on a magnetic resonance imaging linear accelerator (MR LINAC) during hypofractionated stereotactic radiotherapy (HSRT) to resected brain metastases. In addition, the suitability of using T2/FLAIR (T2f) sequence to define CTV was explored by assessing contouring variability between gadolinium-enhanced T1 (T1c) and T2f sequences.
Materials/Methods
Fifteen patients treated to either 27.5 or 30 Gy with five fraction HSRT were imaged with T1c and T2f sequences during treatment; T1c was acquired at planning (FxSim), and fraction 3 (Fx3), and T2f was acquired at FxSim and all five fractions. The CTV were contoured on all acquired images. Inter-fraction cavity dynamics and CTV contouring variability were quantified using absolute volume, Dice similarity coefficient (DSC), and Hausdorff distance (HD) metrics.
Results
The median CTV on T1c and T2f sequences at FxSim were 12.0cm
3
(range, 1.2–30.1) and 10.2cm
3
(range, 2.9–27.9), respectively. At Fx3, the median CTV decreased in both sequences to 9.3cm
3
(range, 3.7–25.9) and 8.6cm
3
(range, 3.3–22.5), translating to a median % relative reduction of − 11.4% on T1c (p = 0.009) and − 8.4% on T2f (p = 0.032). We observed a median % relative reduction in CTV between T1c and T2f at FxSim of − 6.0% (p = 0.040). The mean DSC was 0.85 ± 0.10, and the mean HD was 5.3 ± 2.7 mm when comparing CTV on T1c and T2f at FxSim.
Conclusion
Statistically significant reductions in cavity CTV was observed during HSRT, supporting the use of MR image guided radiation therapy and treatment adaptation to mitigate toxicity. Significant CTV contouring variability was seen between T1c and T2f sequences.
Trial registration
NCT04075305 – August 30, 2019
Journal Article