scholarly journals A Dose–Volume Response Model for Brain Metastases Treated With Frameless Single-Fraction Robotic Radiosurgery: Seeking to Better Predict Response to Treatment

2016 ◽  
Vol 16 (3) ◽  
pp. 344-351 ◽  
Author(s):  
Mark J. Amsbaugh ◽  
Mehran B. Yusuf ◽  
Jeremy Gaskins ◽  
Anthony E. Dragun ◽  
Neal Dunlap ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Receiver Operating Characteristic ◽  
Stereotactic Radiosurgery ◽  
Local Control ◽  
Operating Characteristic ◽  
Response Relationship ◽  
Single Fraction ◽  
Robotic Radiosurgery ◽  
Dose Volume ◽  
Volume Response

Purpose/Objective(s): To establish a dose–volume response relationship for brain metastases treated with single-fraction robotic stereotactic radiosurgery and identify predictors of local control. Materials/Methods: We reviewed a prospective institutional database of all patients treated for intact brain metastases with stereotactic radiosurgery alone using the CyberKnife robotic radiosurgery system from 2012 to 2015. Tumor response was determined based on Response Evaluation Criteria In Solid Tumors version 1.1. Survival was estimated using the Kaplan-Meier method. Logistic regression modeling was used to identify predictors of outcome and establish a dose–volume response relationship. Receiver operating characteristic curves were constructed to evaluate the predictive capability of the relationship. Results: There were 357 metastases evaluated in 111 patients with a median diameter of 8.14 mm (2.00-40.77 mm). At 6 and 12 months, local control was 86.9% and 82.2%, respectively. For lesions of similar volumes, higher maximum dose, mean dose, and minimum dose (all P values <.05) predicted for better local control. Tumor volume and diameter were strongly correlated, and a dose–volume response relationship was constructed using mean dose per lesion diameter (Gy/mm) that was predictive of local control (odds ratio: 1.34, 95% confidence interval: 1.06-1.70). Area under the receiver operating characteristic curve for local control and mean dose by volume was 0.6199 with a threshold of 2.05 Gy/mm (local failure 7.6% above and 17.3% below 2.05 Gy/mm). Conclusion: A dose–volume response relationship exists for brain metastases treated with robotic stereotactic radiosurgery. Mean dose per volume is strongly predictive of local control and can be potentially useful during stereotactic radiosurgery plan evaluation while respecting previously established dose constraints.

Internal dose escalation associated with increased local control for melanoma brain metastases treated with stereotactic radiosurgery

2020 ◽  
pp. 1-7
Author(s):  
William R. Kennedy ◽  
Todd A. DeWees ◽  
Sahaja Acharya ◽  
Mustafaa Mahmood ◽  
Nels C. Knutson ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Brain Metastases ◽  
Stereotactic Radiosurgery ◽  
Treatment Planning ◽  
Local Control ◽  
Dose Escalation ◽  
High Dose ◽  
Internal Dose ◽  
Single Fraction ◽  
Dose Volume

OBJECTIVEThe internal high-dose volume varies widely for a given prescribed dose during stereotactic radiosurgery (SRS) to treat brain metastases (BMs). This may be altered during treatment planning, and the authors have previously shown that this improves local control (LC) for non–small cell lung cancer BMs without increasing toxicity. Here, they seek to identify potentially actionable dosimetric predictors of LC after SRS for melanoma BM.METHODSThe records of patients with unresected melanoma BM treated with single-fraction Gamma Knife RS between 2006 and 2017 were reviewed. LC was assessed on a per-lesion basis, defined as stability or a decrease in lesion size. Outcome-oriented approaches were utilized to determine optimal dichotomization for dosimetric variables relative to LC. Univariable and multivariable Cox regression analysis was implemented to evaluate the impact of collected parameters on LC.RESULTSTwo hundred eighty-seven melanoma BMs in 79 patients were identified. The median age was 56 years (range 31–86 years). The median follow-up was 7.6 months (range 0.5–81.6 months), and the median survival was 9.3 months (range 1.3–81.6 months). Lesions were optimally stratified by volume receiving at least 30 Gy (V30) greater than or equal to versus less than 25%. V30 was ≥ and < 25% in 147 and 140 lesions, respectively. For all patients, 1-year LC was 83% versus 66% for V30 ≥ and < 25%, respectively (p = 0.001). Stratifying by volume, lesions 2 cm or less (n = 215) had 1-year LC of 82% versus 70% (p = 0.013) for V30 ≥ and < 25%, respectively. Lesions > 2 to 3 cm (n = 32) had 1-year LC of 100% versus 43% (p = 0.214) for V30 ≥ and < 25%, respectively. V30 was still predictive of LC even after controlling for the use of immunotherapy and targeted therapy. Radionecrosis occurred in 2.8% of lesions and was not significantly associated with V30.CONCLUSIONSFor a given prescription dose, an increased internal high-dose volume, as indicated by measures such as V30 ≥ 25%, is associated with improved LC but not increased toxicity in single-fraction SRS for melanoma BM. Internal dose escalation is an independent predictor of improved LC even in patients receiving immunotherapy and/or targeted therapy. This represents a dosimetric parameter that is actionable at the time of treatment planning and warrants further evaluation.

scholarly journals Dose-Response Effect and Dose-Toxicity in Stereotactic Radiotherapy for Brain Metastases: A Review

Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 6086
Author(s):  
Maxime Loo ◽  
Jean-Baptiste Clavier ◽  
Justine Attal Khalifa ◽  
Elisabeth Moyal ◽  
Jonathan Khalifa
Keyword(s):  
Brain Metastases ◽  
Stereotactic Radiosurgery ◽  
Local Control ◽  
Stereotactic Radiotherapy ◽  
Local Control Rate ◽  
Dose Effect ◽  
Published Data ◽  
High Dose ◽  
Single Fraction ◽  
Fractionation Schedule

For more than two decades, stereotactic radiosurgery has been considered a cornerstone treatment for patients with limited brain metastases. Historically, radiosurgery in a single fraction has been the standard of care but recent technical advances have also enabled the delivery of hypofractionated stereotactic radiotherapy for dedicated situations. Only few studies have investigated the efficacy and toxicity profile of different hypofractionated schedules but, to date, the ideal dose and fractionation schedule still remains unknown. Moreover, the linear-quadratic model is being debated regarding high dose per fraction. Recent studies shown the radiation schedule is a critical factor in the immunomodulatory responses. The aim of this literature review was to discuss the dose–effect relation in brain metastases treated by stereotactic radiosurgery accounting for fractionation and technical considerations. Efficacy and toxicity data were analyzed in the light of recent published data. Only retrospective and heterogeneous data were available. We attempted to present the relevant data with caution. A BED10 of 40 to 50 Gy seems associated with a 12-month local control rate >70%. A BED10 of 50 to 60 Gy seems to achieve a 12-month local control rate at least of 80% at 12 months. In the brain metastases radiosurgery series, for single-fraction schedule, a V12 Gy < 5 to 10 cc was associated to 7.1–22.5% radionecrosis rate. For three-fractions schedule, V18 Gy < 26–30 cc, V21 Gy < 21 cc and V23 Gy < 5–7 cc were associated with about 0–14% radionecrosis rate. For five-fractions schedule, V30 Gy < 10–30 cc, V 28.8 Gy < 3–7 cc and V25 Gy < 16 cc were associated with about 2–14% symptomatic radionecrosis rate. There are still no prospective trials comparing radiosurgery to fractionated stereotactic irradiation.

scholarly journals The Judicious Use of Stereotactic Radiosurgery and Hypofractionated Stereotactic Radiotherapy in the Management of Large Brain Metastases

Cancers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 70
Author(s):  
Tyler Gutschenritter ◽  
Vyshak A. Venur ◽  
Stephanie E. Combs ◽  
Balamurugan Vellayappan ◽  
Anoop P. Patel ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Stereotactic Radiosurgery ◽  
Local Control ◽  
Stereotactic Radiotherapy ◽  
Leptomeningeal Disease ◽  
Hypofractionated Stereotactic Radiotherapy ◽  
Treatment Techniques ◽  
Dose Volume ◽  
Clinical Scenarios ◽  
Large Brain

Brain metastases are the most common intracranial malignant tumor in adults and are a cause of significant morbidity and mortality for cancer patients. Large brain metastases, defined as tumors with a maximum dimension >2 cm, present a unique clinical challenge for the delivery of stereotactic radiosurgery (SRS) as patients often present with neurologic symptoms that require expeditious treatment that must also be balanced against the potential consequences of surgery and radiation therapy—namely, leptomeningeal disease (LMD) and radionecrosis (RN). Hypofractionated stereotactic radiotherapy (HSRT) and pre-operative SRS have emerged as novel treatment techniques to help improve local control rates and reduce rates of RN and LMD for this patient population commonly managed with post-operative SRS. Recent literature suggests that pre-operative SRS can potentially half the risk of LMD compared to post-operative SRS and that HSRT can improve risk of RN to less than 10% while improving local control when meeting the appropriate goals for biologically effective dose (BED) and dose-volume constraints. We recommend a 3- or 5-fraction regimen in lieu of SRS delivering 15 Gy or less for large metastases or resection cavities. We provide a table comparing the BED of commonly used SRS and HSRT regimens, and provide an algorithm to help guide the management of these challenging clinical scenarios.

scholarly journals Clinical and volumetric predictors of local control after robotic stereotactic radiosurgery for cerebral metastases: active systemic disease may affect local control in the brain

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sławomir Blamek ◽  
Magdalena Stankiewicz ◽  
Bogusław Maciejewski
Keyword(s):  
Stereotactic Radiosurgery ◽  
Local Control ◽  
Cox Model ◽  
Systemic Disease ◽  
Univariate Analysis ◽  
Effective Control ◽  
Single Fraction ◽  
Robotic Radiosurgery ◽  
Fractionation Schedule ◽  
The Brain

AbstractBackgroundThe aim of the study was to assess the association between physical and biological dose normalized to volume of the metastatic tumor as well as clinical factors with local control in patients with brain metastases who underwent robotic stereotactic radiosurgery.Patients and methodsA cohort of 69 patients consecutively treated with robotic radiosurgery between 2011 and 2016 was analyzed. The patients were treated with either single fraction radiosurgery or hypofractionated regimens. Biologically effective dose (BED) was calculated assuming alpha/beta value = 10 and both physical dose and BED were normalized to the tumor volume to allow dose-volume effect evaluation. Moreover, clinical and treatment-related variables were evaluated to asses association with local control.ResultsA total of 133 tumors were irradiated and their volumes ranged between 0.001 and 46.99 cm3. Presence of extracranial progression was associated with worse local control whereas higher total dose, BED10 > 59 Gy and single metastasis predicted statistically significantly better local outcome. BED10/cm3 > 36 Gy, and BED2 > 60 Gy negatively affected local control in univariate analysis. In multivariate analysis performed on all these variables, presence of a single metastasis, BED10 > 59 Gy and extracranial progression retained their significance. Excluding a priori the BED2/ cm3 parameter resulted with a Cox model confirming significance of all remaining variables.ConclusionsHypofractionated treatment schemes have similar efficiency to single fraction treatment in terms of local control and the effect depends on BED irrespective of fractionation schedule. Effective control of extracranial sites of the disease is associated with higher probability of local control in the brain which in turn is consistently lower in patients with multiple lesions.

Post-operative stereotactic radiosurgery of brain metastases: A single-center retrospective review of clinical outcomes

2019 ◽  
Vol 19 (2) ◽  
pp. 127-131
Author(s):  
Zachary T. Smith ◽  
Syed U. Ashruf ◽  
Charles Mylander ◽  
Kerry J. Thompson ◽  
Charles Geraghty ◽  
...  
Keyword(s):  
Overall Survival ◽  
Brain Metastases ◽  
Stereotactic Radiosurgery ◽  
Local Control ◽  
Retrospective Review ◽  
Categorical Variables ◽  
Community Practice ◽  
Continuous Variables ◽  
Survival Times ◽  
Single Fraction

AbstractAim:We sought to retrospectively report our outcomes using post-operative stereotactic radiosurgery (SRS)/stereotactic radiotherapy (SRT) in place of whole-brain radiation therapy (WBRT) following resection of brain metastases from our hospital-based community practice.Materials and Methods:A retrospective review of 23 patients who underwent post-operative SRS at our single institution from 2013 to 2017 was undertaken. Patient records, treatment plans and diagnostic images were reviewed. Local failure, distant intracranial failure and overall survival were studied. Categorical variables were analyzed using Fisher’s exact tests. Continuous variables were analyzed using Mann–Whitney tests. The Kaplan–Meier method was used to estimate survival times.Results:16 (70%) were single-fraction SRS, whereas the remaining 7 patients received a five-fraction treatment course. The median single-fraction dose was 16 Gy (range, 16–18). The median total dose for fractionated treatments was 25 Gy (range, 25–35). Overall survival at 6 and 12 months was 95 and 67%, respectively. Comparison of SRS versus SRT local control rates at 6 and 12 months revealed control rates of 92 and 78% versus 29 and 14%, respectively. Every patient with dural/pial involvement at the time of surgery had distant intracranial failure at the 12-month follow-up.Findings:Single-fraction frameless SRS proved to be an effective modality with excellent local control rates. However, the five-fraction SRT course was associated with an increased rate of local recurrence. Dural/pial involvement may portend a high risk for distant intracranial disease; therefore, it may be prudent to consider alternative approaches in these cases.

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