A phase 3 Radiation Therapy Oncology Group (RTOG) study subset analysis demonstrated improved overall survival (OS) with the addition of stereotactic radiosurgery (SRS) to whole brain radiation ...therapy (WBRT) in non-small cell lung cancer (NSCLC) patients with 1 to 3 brain metastases. Because temozolomide (TMZ) and erlotinib (ETN) cross the blood-brain barrier and have documented activity in NSCLC, a phase 3 study was designed to test whether these drugs would improve the OS associated with WBRT + SRS.
NSCLC patients with 1 to 3 brain metastases were randomized to receive WBRT (2.5 Gy × 15 to 37.5 Gy) and SRS alone, versus WBRT + SRS + TMZ (75 mg/m(2)/day × 21 days) or ETN (150 mg/day). ETN (150 mg/day) or TMZ (150-200 mg/m(2)/day × 5 days/month) could be continued for as long as 6 months after WBRT + SRS. The primary endpoint was OS.
After 126 patients were enrolled, the study closed because of accrual limitations. The median survival times (MST) for WBRT + SRS, WBRT + SRS + TMZ, and WBRT + SRS + ETN were qualitatively different (13.4, 6.3, and 6.1 months, respectively), although the differences were not statistically significant. Time to central nervous system progression and performance status at 6 months were better in the WBRT + SRS arm. Grade 3 to 5 toxicity was 11%, 41%, and 49% in arms 1, 2, and 3, respectively (P<.001).
The addition of TMZ or ETN to WBRT + SRS in NSCLC patients with 1 to 3 brain metastases did not improve survival and possibly had a deleterious effect. Because the analysis is underpowered, these data suggest but do not prove that increased toxicity was the cause of inferior survival in the drug arms.
Accurate and automatic brain metastases target delineation is a key step for efficient and effective stereotactic radiosurgery (SRS) treatment planning. In this work, we developed a deep learning ...convolutional neural network (CNN) algorithm for segmenting brain metastases on contrast-enhanced T1-weighted magnetic resonance imaging (MRI) datasets. We integrated the CNN-based algorithm into an automatic brain metastases segmentation workflow and validated on both Multimodal Brain Tumor Image Segmentation challenge (BRATS) data and clinical patients' data. Validation on BRATS data yielded average DICE coefficients (DCs) of 0.75±0.07 in the tumor core and 0.81±0.04 in the enhancing tumor, which outperformed most techniques in the 2015 BRATS challenge. Segmentation results of patient cases showed an average of DCs 0.67±0.03 and achieved an area under the receiver operating characteristic curve of 0.98±0.01. The developed automatic segmentation strategy surpasses current benchmark levels and offers a promising tool for SRS treatment planning for multiple brain metastases.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To confirm safety and feasibility of hypofractionated SBRT for early-stage glottic laryngeal cancer.
Twenty consecutive patients with cTis-T2N0M0 carcinoma of glottic larynx were enrolled. Patients ...entered dose-fractionation cohorts of incrementally shorter bio-equivalent schedules starting with 50 Gy in 15 fractions (fx), followed by 45 Gy/10 fx and, finally, 42.5 Gy/5 fx. Maximum combined CTV-PTV expansion was limited to 5 mm. Patients were treated on a Model G5 Cyberknife (Accuray, Sunnyvale, CA).
Median follow-up is 13.4 months (range: 5.6-24.6 months), with 12 patients followed for at least one year. Maximum acute toxicity consisted of grade 2 hoarseness and dysphagia. Maximum chronic toxicity was seen in one patient treated with 45 Gy/10 fx who continued to smoke >1 pack/day and ultimately required protective tracheostomy. At 1-year follow-up, estimated local disease free survival for the full cohort was 82%. Overall survival is 100% at last follow-up.
We were able to reduce equipotent total fractions of SBRT from 15 to 5 without exceeding protocol-defined acute/subacute toxicity limits. With limited follow-up, disease control appears comparable to standard treatment. We continue to enroll to the 42.5 Gy/5 fx cohort and follow patients for late toxicity.
ClinicalTrials.gov NCT01984502.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of the following adult CNS cancers: glioma (WHO grade 1, WHO grade 2-3 oligodendroglioma 1p19q codeleted, IDH-mutant, ...WHO grade 2-4 IDH-mutant astrocytoma, WHO grade 4 glioblastoma), intracranial and spinal ependymomas, medulloblastoma, limited and extensive brain metastases, leptomeningeal metastases, non-AIDS-related primary CNS lymphomas, metastatic spine tumors, meningiomas, and primary spinal cord tumors. The information contained in the algorithms and principles of management sections in the NCCN Guidelines for CNS Cancers are designed to help clinicians navigate through the complex management of patients with CNS tumors. Several important principles guide surgical management and treatment with radiotherapy and systemic therapy for adults with brain tumors. The NCCN CNS Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel's most recent recommendations regarding molecular profiling of gliomas.
Purpose
Stereotactic radiosurgery (SRS) has become a standard of care for patients' with brain metastases (BMs). However, the manual multiple BMs delineation can be time‐consuming and could create an ...efficiency bottleneck in SRS workflow. There is a clinical need for automatic delineation and quantitative evaluation tools. In this study, building on our previous developed deep learning‐based segmentation algorithms, we developed a web‐based automated BMs segmentation and labeling platform to assist the SRS clinical workflow.
Method
This platform was developed based on the Django framework, including a web client and a back‐end server. The web client enables interactions as database access, data import, and image viewing. The server performs the segmentation and labeling tasks including: skull stripping; deep learning‐based BMs segmentation; and affine registration‐based BMs labeling. Additionally, the client can display BMs contours with corresponding atlas labels, and allows further postprocessing tasks including: (a) adjusting window levels; (b) displaying/hiding specific contours; (c) removing false‐positive contours; (d) exporting contours as DICOM RTStruct files; etc.
Results
We evaluated this platform on 10 clinical cases with BMs number varied from 12‐81 per case. The overall operation took about 4–5 min per patient. The segmentation accuracy was evaluated between the manual contour and automatic segmentation with several metrics. The averaged center of mass shift was 1.55 ± 0.36 mm, the Hausdorff distance was 2.98 ± 0.63 mm, the mean of surface‐to‐surface distance (SSD) was 1.06 ± 0.31 mm, and the standard deviation of SSD was 0.80 ± 0.16 mm. In addition, the initial averaged false‐positive over union (FPoU) and false‐negative rate (FNR) were 0.43 ± 0.19 and 0.15 ± 0.10 respectively. After case‐specific postprocessing, the averaged FPoU and FNR were 0.19 ± 0.10 and 0.15 ± 0.10 respectively.
Conclusion
The evaluated web‐based BMs segmentation and labeling platform can substantially improve the clinical efficiency compared to manual contouring. This platform can be a useful tool for assisting SRS treatment planning and treatment follow‐up.
The purpose of this analysis is to evaluate the effect of institutional accrual volume on clinical outcomes among patients receiving chemoradiation for locally advanced non-small cell lung cancer ...(LA-NSCLC) on a phase III trial.
Patients with LA-NSCLC were randomly assigned to 60 Gy or 74 Gy radiotherapy (RT) with concurrent carboplatin/paclitaxel +/- cetuximab on NRG Oncology RTOG 0617. Participating institutions were categorized as low-volume centers (LVCs) or high-volume centers (HVCs) according to the number of patients accrued (≤3 vs > 3). All statistical tests were two-sided.
Range of accrual for LVCs (n = 195) vs HVCs (n = 300) was 1 to 3 vs 4 to 18 patients. Baseline characteristics were similar between the two cohorts. Treatment at a HVC was associated with statistically significantly longer overall survival (OS) and progression-free survival (PFS) compared with treatment at a LVC (median OS = 26.2 vs 19.8 months; HR = 0.70, 95% CI = 0.56 to 0.88, P = .002; median PFS: 11.4 vs 9.7 months, HR = 0.80, 95% CI = 0.65-0.99, P = .04). Patients treated at HVCs were more often treated with intensity-modulated RT (54.0% vs 39.5%, P = .002), had a lower esophageal dose (mean = 26.1 vs 28.0 Gy, P = .03), and had a lower heart dose (median = V5 Gy 38.2% vs 54.1%, P = .006; V50 Gy 3.6% vs 7.3%, P < .001). Grade 5 adverse events (AEs) (5.3% vs 9.2%, P = .09) and RT termination because of AEs (1.3% vs 4.1%, P = .07) were less common among patients treated at HVCs. HVC remained independently associated with longer OS (P = .03) when accounting for other factors.
Treatment at institutions with higher clinical trial accrual volume is associated with longer OS among patients with LA-NSCLC participating in a phase III trial.
Although the physical and biologic principles of radiation therapy have remained relatively unchanged, a technologic renaissance has led to continuous and ever-changing growth in the field of ...radiation oncology. As a result, medical devices, techniques, and indications have changed considerably during the past 20-30 years. For example, advances in CT and MRI have revolutionized the treatment planning process for a variety of central nervous system diseases, including primary and metastatic tumors, vascular malformations, and inflammatory diseases. The resultant improved ability to delineate normal from abnormal tissue has enabled radiation oncologists to achieve more precise targeting and helped to mitigate treatment-related complications. Nevertheless, posttreatment complications still occur and can pose a diagnostic challenge for radiologists. These complications can be divided into acute, early-delayed, and late-delayed complications on the basis of the time that they manifest after radiation therapy and include leukoencephalopathy, vascular complications, and secondary neoplasms. The different irradiation technologies and applications of these technologies in the brain, current concepts used in treatment planning, and essential roles of the radiation oncologist in the setting of brain disease are reviewed. In addition, relevant imaging findings that can be used to delineate the extent of disease before treatment, and the expected posttreatment imaging changes are described. Common and uncommon complications related to radiation therapy and the associated imaging manifestations also are discussed. Familiarity with these entities may aid the radiologist in making the diagnosis and help guide appropriate management.
RSNA, 2020.
The goal of this study was to explore conceptual benefits of characterizing delineated target volumes based on surface area and to utilize the concept for assessing risk of therapeutic toxicity in ...radiosurgery.
Four computer-generated targets, a sphere, a cylinder, an ellipsoid and a box, were designed for two distinct scenarios. In the first scenario, all targets had identical volumes, and in the second one, all targets had identical surface areas. High quality stereotactic radiosurgery plans with at least 95% target coverage and selectivity were created for each target in both scenarios. Normal brain volumes V12Gy, V14Gy and V16Gy corresponding to received dose of 12 Gy, 14 Gy and 16 Gy, respectively, were computed and analyzed. Additionally, V12Gy and V14Gy volumes and values for seven prospective toxicity variables were recorded for 100 meningioma patients after Gamma Knife radiosurgery. Multivariable stepwise linear regression and best subset linear regression analyses were performed in two statistical software packages, SAS/STAT and R, respectively.
In a phantom study, for the constant volume targets, the volumes of 12 Gy, 14 Gy and 16 Gy isodose clouds were the lowest for the spherical target as an expected corollary of the isoperimetric inequality. For the constant surface area targets, a conventional wisdom is confirmed, as the target volume increases the corresponding volumes V12Gy, V14Gy and V16Gy also increase. In the 100-meningioma patient cohort, the best univariate model featured tumor surface area as the most significantly associated variable with both V12Gy and V14Gy volumes, corresponding to the adjusted R2 values of 0.82 and 0.77, respectively. Two statistical methods converged to matching multivariable models.
In a univariate model, target surface area is a better predictor of spilled dose to normal tissue than target largest dimension or target volume itself. In complex multivariate models, target surface area is an independent variable for modeling radiosurgical normal tissue toxicity risk.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Stereotactic radiosurgery (SRS) is a well-established treatment for vestibular schwannomas (VS). Hearing loss remains a main morbidity of VS and its treatments, including SRS. The effects of ...radiation parameters of SRS on hearing remain unknown. The goal of this study is to determine the effect of tumor volume, patient demographics, pretreatment hearing status, cochlear radiation dose, total tumor radiation dose, fractionation, and other radiotherapy parameters on hearing deterioration.
Multicenter retrospective analysis of 611 patients who underwent SRS for VS from 1990–2020 and had pre- and post-treatment audiograms.
Pure tone averages (PTAs) increased and word recognition scores (WRSs) decreased in treated ears at 12–60 months while remaining stable in untreated ears. Higher baseline PTA, higher tumor radiation dose, higher maximum cochlear dose, and usage of single fraction resulted in higher post radiation PTA; WRS was only predicted by baseline WRS and age. Higher baseline PTA, single fraction treatment, higher tumor radiation dose, and higher maximum cochlear dose resulted in a faster deterioration in PTA. Below a maximum cochlear dose of 3 Gy, there were no statistically significant changes in PTA or WRS.
Decline of hearing at one year in VS patients after SRS is directly related to maximum cochlear dose, single versus 3-fraction treatment, total tumor radiation dose, and baseline hearing level. The maximum safe cochlear dose for hearingtbrowd preservation at one year is 3 Gy, and the use of 3 fractions instead of one fraction was better at preserving hearing.
The purpose of this work is to develop an automated landmark-guided deformable image registration (LDIR) algorithm between the planning CT and daily cone-beam CT (CBCT) with low image quality. This ...method uses an automated landmark generation algorithm in conjunction with a local small volume gradient matching search engine to map corresponding landmarks between the CBCT and the planning CT. The landmarks act as stabilizing control points in the following Demons deformable image registration. LDIR is implemented on graphics processing units (GPUs) for parallel computation to achieve ultra fast calculation. The accuracy of the LDIR algorithm has been evaluated on a synthetic case in the presence of different noise levels and data of six head and neck cancer patients. The results indicate that LDIR performed better than rigid registration, Demons, and intensity corrected Demons for all similarity metrics used. In conclusion, LDIR achieves high accuracy in the presence of multimodality intensity mismatch and CBCT noise contamination, while simultaneously preserving high computational efficiency.
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