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Pre-Operative Versus Post-Operative Radiosurgery of Brain Metastases-Volumetric and Dosimetric Impact of Treatment Sequence and Margin Concept.

ABSTRACT: BACKGROUND:Pre-operative radiosurgery (SRS) preceding the resection of brain metastases promises to circumvent limitations of post-operative cavity SRS. It minimizes uncertainties regarding delineation and safety margins and could reduce dose exposure of the healthy brain (HB). METHODS:We performed a systematic treatment plan comparison on 24 patients who received post-operative radiosurgery of the resection cavity at our institution. Comparative treatment plans were calculated for hypofractionated stereotactic radiotherapy (7 × 5 Gray (Gy)) in a hypothetical pre-operative (pre-op) and two post-operative scenarios, either with (extended field, post-op-E) or without the surgical tract (involved field, post-op-I). Detailed volumetric comparison of the resulting target volumes was performed, as well as dosimetric comparison focusing on targets and the HB. RESULTS:The resection cavity was significantly smaller and different in morphology from the pre-operative lesion, yielding a low Dice Similarity Coefficient (DSC) of 53% (p = 0.019). Post-op-I and post-op-E targets showed high similarity (DSC = 93%), and including the surgical tract moderately enlarged resulting median target size (18.58 ccm vs. 22.89 ccm, p < 0.001). Dosimetric analysis favored the pre-operative treatment setting since it significantly decreased relevant dose exposure of the HB (Median volume receiving 28 Gy: 6.79 vs. 10.79 for pre-op vs. post-op-E, p < 0.001). Dosimetrically, pre-operative SRS is a promising alternative to post-operative cavity irradiation that could furthermore offer practical benefits regarding delineation and treatment planning. Comparative trials are required to evaluate potential clinical advantages of this approach.

SUBMITTER: El Shafie RA

PROVIDER: S-EPMC6468393 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Pre-Operative Versus Post-Operative Radiosurgery of Brain Metastases-Volumetric and Dosimetric Impact of Treatment Sequence and Margin Concept.

El Shafie Rami A RA Tonndorf-Martini Eric E Schmitt Daniela D Weber Dorothea D Celik Aylin A Dresel Thorsten T Bernhardt Denise D Lang Kristin K Hoegen Philipp P Adeberg Sebastian S Paul Angela A Debus Jürgen J Rieken Stefan S

Cancers 20190301 3

<h4>Background</h4>Pre-operative radiosurgery (SRS) preceding the resection of brain metastases promises to circumvent limitations of post-operative cavity SRS. It minimizes uncertainties regarding delineation and safety margins and could reduce dose exposure of the healthy brain (HB).<h4>Methods</h4>We performed a systematic treatment plan comparison on 24 patients who received post-operative radiosurgery of the resection cavity at our institution. Comparative treatment plans were calculated fo ...[more]

PMID: 30832257

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Project description:BackgroundAfter brain metastasis resection, whole brain radiotherapy decreases local recurrence, but might cause cognitive decline. We did this study to determine if stereotactic radiosurgery (SRS) to the surgical cavity improved time to local recurrence compared with that for surgical resection alone.MethodsIn this randomised, controlled, phase 3 trial, we recruited patients at a single tertiary cancer centre in the USA. Eligible patients were older than 3 years, had a Karnofsky Performance Score of 70 or higher, were able to have an MRI scan, and had a complete resection of one to three brain metastases (with a maximum diameter of the resection cavity ≤4 cm). Patients were randomly assigned (1:1) with a block size of four to either SRS of the resection cavity (within 30 days of surgery) or observation. Patients were stratified by histology of the primary tumour, metastatic tumour size, and number of metastases. The primary endpoint was time to local recurrence in the resection cavity, assessed by blinded central review of brain MRI scans by the study neuroradiologist in the modified intention-to-treat population that analysed patients by randomised allocation but excluded patients found ineligible after randomisation. Participants and other members of the treatment team (excluding the neuroradiologist) were not masked to treatment allocation. The trial is registered with ClinicalTrials.gov, number NCT00950001, and is closed to new participants.FindingsBetween Aug 13, 2009, and Feb 16, 2016, 132 patients were randomly assigned to the observation group (n=68) or SRS group (n=64), with 128 patients available for analysis; four patients were ineligible (three from the SRS group and one from the observation group). Median follow-up was 11·1 months (IQR 4·8-20·4). 12-month freedom from local recurrence was 43% (95% CI 31-59) in the observation group and 72% (60-87) in the SRS group (hazard ratio 0·46 [95% CI 0·24-0·88]; p=0·015). There were no adverse events or treatment-related deaths in either group.InterpretationSRS of the surgical cavity in patients who have had complete resection of one, two, or three brain metastases significantly lowers local recurrence compared with that noted for observation alone. Thus, the use of SRS after brain metastasis resection could be an alternative to whole-brain radiotherapy.FundingNational Institutes of Health.

Project description:Background and objectivesAlmost one third of cancer patients in the United States will develop brain metastases on an annual basis. Surgical resection is indicated in the setting of brain metastases for reasons, such as maximizing local control in select patients, decompression of mass effect, and/or tissue diagnosis. The current standard of care following resection of a brain metastasis has shifted from whole brain radiation therapy to post-operative stereotactic radiosurgery (SRS). However, there is a significant rate of local recurrence within one year of postoperative SRS. Emerging retrospective and prospective data suggest pre-operative SRS is a safe and potentially effective treatment paradigm for surgical brain metastases. This trial intends to determine, for patients with an indication for resection of a brain metastasis, whether there is an increase in the time to a composite endpoint of adverse outcomes; including the first occurrence of either: local recurrence, leptomeningeal disease, or symptomatic radiation brain necrosis - in patients who receive pre-operative SRS as compared to patients who receive post-operative SRS.MethodsThis randomized phase III clinical trial compares pre-operative with post-operative SRS for brain metastases. A dynamic random allocation procedure will allocate an equal number of patients to each arm: pre-operative SRS followed by surgery or surgery followed by post-operative SRS.Expected outcomesIf pre-operative SRS improves outcomes relative to post-operative SRS, this will establish pre-operative SRS as superior. If post-operative SRS proves superior to pre-operative SRS, it will remain a standard of care and halt the increasing utilization of pre-operative SRS. If there is no difference in pre- versus post-operative SRS, then pre-operative SRS may still be preferred, given patient convenience and the potential for a condensed timeline.DiscussionEmerging retrospective and prospective data have demonstrated some benefits of pre-op SRS vs. post-op SRS. This study will show whether there is an increase in the time to the composite endpoint. Additionally, the study will compare overall survival; patient-reported outcomes; morbidity; completion of planned therapies; time to systemic therapy; time to regional progression; time to CNS progression; time to subsequent treatment; rate of radiation necrosis; rate of local recurrence; and rate of leptomeningeal disease.Trial registration numberNCT03750227 (Registration date: 21/11/2018).

Project description:Abstract In our ongoing phase III randomized trial (NCT03741673) evaluating risk of leptomeningeal disease (LMD) in patients with brain metastasis, patients are stratified by tumor size, location, and histology, and randomized to pre-operative SRS versus post-operative SRS. The primary endpoint is 1-year LMD-free rate, and exploratory endpoints include neurocognitive function (NCF). NCF is assessed prior to treatment and longitudinally (1.5, 6, and 12 months from the start of treatment) with the HVLT-R, TMT, and COWA yielding the Clinical Trial Battery Composite score (CTB COMP). Patients also complete the MDASI-BT, which includes a Cognitive Factor measuring patient reported cognitive concerns. Currently, 41 patients completed pre-treatment NCF baseline. Characteristics of patients with pre-treatment NCF baseline include mean (SD): age 60.0+/-11.7 years, 2.6+/-2.2 metastases, 15.2+/-10.1 cc brain metastases volume, median KPS 90 (range: 70-100), 83% white, 52% male, and 50% received AEDs at time of surgery. The most common primary cancers among this cohort were: 31% NSCLC, 19% RCC, 14% melanoma, 7% breast, 2% thyroid, and 26% other. Mean (SD) NCF z-scores ranged from z= -0.09 (1.08) to -3.09 (6.13), CTB COMP z=-1.13 (1.65), and the mean (SD) MDASI-BT Cognitive Factor score was 1.1 (1.3). Using multivariable linear regression including CTB COMP, MDASI-BT Cognitive and Affective Factor, KPS, number of and intracranial volume of metastases, only intracranial volume of metastases was statistically significantly associated with CTB COMP (B=-.058, p=.034) and only the MDASI-BT Affective Factor was statistically significantly associated with the MDASI-BT Cognitive Factor (B=.305, p=<.001). At baseline, disease factors such as tumor burden appear to be the primary driver of objectively measured neurocognitive dysfunction and mood factors appear to be the primary driver of subjective patient reported neurocognitive concerns. This has important implications for interpretation of these different clinical outcome assessments in clinical trials measuring objective neurocognitive function and subjective neurocognitive concerns.

Project description:PurposeTo compare the dosimetric differences in stereotactic radiosurgery between use of passively scattered protons (PSRS) versus photons (XSRS) for pituitary adenomas.Methods and materialsNine patients with pituitary adenomas were selected among patients receiving single-fraction proton stereotactic radiosurgery (PSRS) between 2016 and 2017. These cases were replanned with XSRS using volumetric-modulated arc therapy with 2.5 mm and 5 mm multileaf collimators (2.5XSRS and 5XSRS, respectively). PSRS was planned with a dedicated single scattering stereotactic proton unit delivered via 3 equally or unequally weighted isocentric fields. XSRS plans were created with optimization to spare organs at risk. Plans were generated using the original total treatment dose delivered in 1 fraction.ResultsPlans were evaluated for target volume dosimetry and estimated clinical toxicity. There was no significant difference in clinical target volume V100%, V95%, V90% or homogeneity index between treatment modalities. PSRS offered lower maximum dose (Dmax) to organs at risk and equivalent uniform dose (EUD) compared with 5XSRS and 2.5XSRS, respectively, for critical structures including optic nerve (right, Dmax 4.18, 5.32, 5.41; EUD 3.35, 4.08, 4.20) and hypothalamus (Dmax 1.71, 3.94, 3.77; EUD 0.94, 2.47, 2.39; P < .05 for PSRS vs 5XSRS and 2.5XSRS). The projected risk of secondary tumors in excess of baseline was lowest for PSRS plans (PSRS 5.28, 5XSRS 12.93, 2.5XSRS 12.66 cases per 10,000 patient-years; P = .008 for PSRS vs 5XSRS, PSRS vs 2.5XSRS, and P = .77 for 5XSRS vs 2.5XSRS).ConclusionsWe demonstrate that neither modality has empirically superior dosimetry and identify potential clinical advantages as well as limitations of each technique. PSRS, 5XSRS and 2.5XSRS demonstrate comparable target volume dosimetry for pituitary adenoma. PSRS compared with XSRS modalities offers modestly decreased maximum dose and EUD to critical proximal structures and decreases risk of radiation-induced secondary tumors by more than half.

Project description: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.

Project description:BackgroundThe benefits of adding upfront whole-brain radiotherapy (WBRT) to surgery or stereotactic radiosurgery (SRS) when compared to surgery or SRS alone for treatment of brain metastases are unclear.ObjectivesTo compare the efficacy and safety of surgery or SRS plus WBRT with that of surgery or SRS alone for treatment of brain metastases in patients with systemic cancer.Search methodsWe searched MEDLINE, EMBASE and The Cochrane Central Register of Controlled Trials (CENTRAL) up to May 2013 and annual meeting proceedings of ASCO and ASTRO up to September 2012 for relevant studies.Selection criteriaRandomised controlled trials (RCTs) comparing surgery or SRS plus WBRT with surgery or SRS alone for treatment of brain metastases.Data collection and analysisTwo review authors undertook the quality assessment and data extraction. The primary outcome was overall survival (OS). Secondary outcomes include progression free survival (PFS), local and distant intracranial disease progression, neurocognitive function (NF), health related quality of life (HRQL) and neurological adverse events. Hazard ratios (HR), risk ratio (RR), confidence intervals (CI), P-values (P) were estimated with random effects models using Revman 5.1 MAIN RESULTS: We identified five RCTs including 663 patients with one to four brain metastases. The risk of bias associated with lack of blinding was high and impacted to a greater or lesser extent on the quality of evidence for all of the outcomes. Adding upfront WBRT decreased the relative risk of any intracranial disease progression at one year by 53% (RR 0.47, 95% CI 0.34 to 0.66, P value < 0.0001, I(2) =34%, Chi(2) P value = 0.21, low quality evidence) but there was no clear evidence of a difference in OS (HR 1.11, 95% CI 0.83 to 1.48, P value = 0.47, I(2) = 52%, Chi(2) P value = 0.08, low quality evidence) and PFS (HR 0.76, 95% CI 0.53 to 1.10, P value = 0.14, I(2) = 16%, Chi(2) P value = 0.28, low quality evidence). Subgroup analyses showed that the effects on overall survival were similar regardless of types of focal therapy used, number of brain metastases, dose and sequence of WBRT. The evaluation of the impact of upfront WBRT on NF, HRQL and neurological adverse events was limited by the unclear and high risk of reporting, performance and detection bias, and inconsistency in the instruments and methods used to measure and report results across studies.Authors' conclusionsThere is low quality evidence that adding upfront WBRT to surgery or SRS decreases any intracranial disease progression at one year. There was no clear evidence of an effect on overall and progression free survival. The impact of upfront WBRT on neurocognitive function, health related quality of life and neurological adverse events was undetermined due to the high risk of performance and detection bias, and inconsistency in the instruments and methods used to measure and report results across studies.

Project description:Importance: Trichiasis surgery programs globally have faced high rates of poor surgical outcomes. Identifying correctable risk factors for improving long-term outcomes is essential for countries targeting elimination of trachoma as a public health problem.Objective: To determine whether the location of trichiatic eyelashes prior to surgery influences development of post-operative trichiasis (PTT) within two years after surgery.Design: Secondary data analysis of four randomized clinical trials evaluating methods to improve trichiasis surgery outcomes. These include the Surgery for Trichiasis, Antibiotics for Recurrence (STAR) trial, Partnership for Rapid Elimination of Trachoma (PRET-Surgery), absorbable versus silk sutures trial, and epilation versus surgery for minor trichiasis trial.Setting: Primary trials were conducted in rural areas of Ethiopia and Tanzania.Interventions or exposures: Trichiasis surgery performed with either the bilamellar tarsal rotation procedure or posterior lamellar rotation procedure.Main outcomes: Prevalence of PTT within two years after surgery, location of trichiatic eyelashes pre-operatively and post-operatively.Results: 6,747 eyelids that underwent first-time trichiasis surgery were included. PTT rates varied by study, ranging from 10-40%. PTT was less severe (based on number of trichiatic eyelashes) than initial trichiasis for 72% of those developing PTT, and only 2% of eyelids were worse at follow up than pre-operatively. Eyelids with central only-trichiasis pre-operatively had lower rates of PTT than eyelids with peripheral only trichiasis in each of the three trials that included severe TT cases. 10% of eyelids with peripheral trichiasis pre-operatively that develop PTT have central TT post-operatively.Conclusions and relevance: Pre-operative central trichiasis is less likely than peripheral trichiasis to be associated with subsequent PTT. Regardless of type of surgery, surgeon skill levels, or pre-operative trichiasis severity, the presence of peripheral trichiasis pre-operatively is associated with higher rates of PTT. Making an incision that extends the length of the eyelid and adequately rotating the nasal and temporal aspects of the eyelid when suturing may help to minimize the chance of developing peripheral PTT.Trial registration: ClinicalTrials.gov PRET: NCT00886015; Suture: NCT005228560; Epilation: NCT00522912.

Dataset Information

Pre-Operative Versus Post-Operative Radiosurgery of Brain Metastases-Volumetric and Dosimetric Impact of Treatment Sequence and Margin Concept.

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Pre-Operative Versus Post-Operative Radiosurgery of Brain Metastases-Volumetric and Dosimetric Impact of Treatment Sequence and Margin Concept.

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