Project description:IntroductionRadiation-induced brain necrosis ["radionecrosis" (rn)] is a relatively uncommon but potentially severe adverse effect of stereotactic radiosurgery (srs) for brain metastasis. Although dose, volume, and hypofractionation have been suggested to affect rn rates, patient and treatment variability in this population make it difficult to clearly delineate the risk. We set out to establish the effect of fractionation on rn rates by reviewing patients receiving simultaneous multi-fraction and single-fraction treatment at our centre.MethodsPatients receiving simultaneous (within 1 month) 1-fraction (ssrs) and 3-fraction (fsrs) radiosurgery treatments during 2012-2015 were identified in our institution's database. Serial post-srs magnetic resonance imaging (mri) was reviewed to determine rn and local recurrence. The effect of maximum dose, volume, whole-brain radiotherapy (wbrt), and fractionation on rn development was assessed using logistic regression for paired data. Results are reported using odds ratios (ors) and corresponding 95% confidence intervals (cis).ResultsOf 90 patients identified, 22 had at least a 6-month mri follow-up. Median follow-up was 320 days. The most common primary tumour type was non-small-cell lung cancer, followed by breast and rectal cancer. Radionecrosis developed in 16 patients [21 of 62 lesions (34%), with 4 being symptomatic (20%)]. Of the 21 lesions in which rn developed, 11 received 3 fractions, and 10 received 1 fraction. The or for the association between the incidence of rn and maximum dose was 1.0 (95% ci: 0.9 to 1.1); for fractionation it was 1.0 (95% ci: 0.3 to 3.6); for previous wbrt, it was 0.4 (95% ci: 0.2 to 1.2); and for a 10-unit increase in volume, it was 3.1 (95% ci: 1.0 to 9.6). Local recurrence developed in 8 patients (12%), 6 of whom belonged to the ssrs group.ConclusionsOur results indicate that patients receiving srs for multiple brain metastases experience a higher rate of rn than is reported in the literature and poorer survival despite having equivalent local control. Maximum dose did not appear to be associated with rn risk in our cohort, but volume was significantly associated with rn risk. Although fractionated treatment did not directly lower the rate of rn in this population, it might have played a role in reducing the magnitude of the rn risk in large-volume lesions. Further investigation will help to delineate optimal dose and fractionation so as to minimize rn while maintaining local control in this group.
Project description:PurposeOur purpose was to develop a rodent model of brain radionecrosis using clinical linear accelerator based stereotactic radiosurgery.Methods and materialsSingle fraction maximum prescription points in the mouse's left hemisphere were irradiated using linear accelerator-based stereotactic radiosurgery with multiple arcs at 60 (n = 5), 100 (n = 5), and 140 (n = 5) Gy. Rats (n = 6) were similarly treated with 140 Gy. Gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) was used to track radiation injury in mice over weeks (100 and 140 Gy) or months (60 Gy). Target accuracy was measured by the distance from the prescription point to the center of the earliest Gd-MRI enhancement. Confirmation of necrosis via histology was performed at the subject endpoints.ResultsRadiation injury as indicated by Gd-MRI was first identified at 2 weeks (140 Gy), 4 to 6 weeks (100 Gy), and 8 months (60 Gy). A volumetric time course showed rapid growth in the volume of Gd-MRI signal enhancement after the appearance of apparent necrosis. Histopathologic features were consistent with radionecrosis.ConclusionsThe presented method uses a commonly available clinical linear accelerator to induce radiation necrosis in both mice and rats. The treatment is modeled after patient therapy for a more direct model of human tissue under a range of doses used in clinical neuro-ablation techniques. The short time to onset of apparent necrosis, accurate targeting of the prescription point, high incidence of necrosis, and similar pathologic features make this a suitable animal model for further research in radionecrosis.
Project description:Radionecrosis is a well-characterized effect of stereotactic radiosurgery (SRS) and is occasionally associated with serious neurologic sequelae. Here, we investigated the incidence of and clinical variables associated with the development of radionecrosis and related radiographic changes after SRS for brain metastases in a cohort of patients with long-term follow up. 271 brain metastases treated with single-fraction linear accelerator-based SRS were analyzed. Radionecrosis was diagnosed either pathologically or radiographically. Univariate and multivariate Cox regression was performed to determine the association between radionecrosis and clinical factors available prior to treatment planning. After median follow up of 17.2 months, radionecrosis was observed in 70 (25.8%) lesions, including 47 (17.3%) symptomatic cases. 22 of 70 cases (31.4%) were diagnosed pathologically and 48 (68.6%) were diagnosed radiographically. The actuarial incidence of radionecrosis was 5.2% at 6 months, 17.2% at 12 months and 34.0% at 24 months. On univariate analysis, radionecrosis was associated with maximum tumor diameter (HR 3.55, p < 0.001), prior whole brain radiotherapy (HR 2.21, p = 0.004), prescription dose (HR 0.56, p = 0.02) and histology other than non-small cell lung, breast or melanoma (HR 1.85, p = 0.04). On multivariate analysis, only maximum tumor diameter (HR 3.10, p < 0.001) was associated with radionecrosis risk. This data demonstrates that with close imaging follow-up, radionecrosis after single-fraction SRS for brain metastases is not uncommon. Maximum tumor diameter on pre-treatment MR imaging can provide a reliable estimate of radionecrosis risk prior to treatment planning, with the greatest risk among tumors measuring >1 cm.
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:Stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HFSRT) have become important treatment modalities for brain metastases. While effective, there are still areas of extensive debate on its appropriate use in patients with life-limiting diseases. This review provides an overview of the indications and challenges of SRS and HFSRT in the management of brain metastases.
Project description:Brain metastases (BM) affect approximately a third of all cancer patients with systemic disease. Treatment options include surgery, whole-brain radiotherapy, or stereotactic radiosurgery (SRS) while chemotherapy has only limited activity. In cases where patients undergo resection before irradiation, intraoperative radiotherapy (IORT) to the tumor bed may be an alternative modality, which would eliminate the repopulation of residual tumor cells between surgery and postoperative radiotherapy. Accumulating evidence has shown that high single doses of ionizing radiation can be highly efficient in eliciting a broad spectrum of local, regional, and systemic tumor-directed immune reactions. Furthermore, immune checkpoint blockade (ICB) has proven effective in treating antigenic BM and, thus, combining IORT with ICB might be a promising approach. However, it is not known if a low number of residual tumor cells in the tumor bed after resection is sufficient to act as an immunizing event opening the gate for ICB therapies in the brain. Because immunological data on tumor bed irradiation after resection are lacking, a rationale for combining IORT with ICB must be based on mechanistic insight from experimental models and clinical studies on unresected tumors. The purpose of the present review is to examine the mechanisms by which large radiation doses as applied in SRS and IORT enhance antitumor immune activity. Clinical studies on IORT for brain tumors, and on combined treatment of SRS and ICB for unresected BM, are used to assess the safety, efficacy, and immunogenicity of IORT plus ICB and to suggest an optimal treatment sequence.
Project description:PurposeWe aimed to compare Australian health system costs at 12 months for adjuvant whole-brain radiotherapy (WBRT) treatment after stereotactic radiosurgery (SRS) and/or surgery versus observation among adults with one to three melanoma brain metastases. We hypothesized that treatment with adjuvant WBRT and subsequent healthcare would be more expensive than SRS/surgery alone.MethodsThe analysis was conducted alongside a multicentre, randomized phase III trial. A bespoke cost questionnaire was used to measure healthcare use, including hospitalizations, specialist and primary care visits, imaging, and medicines over 12 months. Mean per-patient costs were calculated based on the quantity of resources used and unit costs, reported in Australian dollars ($AU), year 2018 values. Skewness of cost data was determined using normality tests and censor-adjusted costs reported using the Kaplan-Meier sample average method. The analysis of difference in mean costs at each 2-month time point and at 12 months was performed and checked using Kruskal-Wallis, generalized linear models with gamma distribution and log link, modified Park test, ordinary least squares, and non-parametric bootstrapping.ResultsIn total, 89 patients with similar characteristics at baseline were included in the cost analysis (n = 43 WBRT; n = 46 observation). Hospitalization cost was the main cost, ranging from 63 to 89% of total healthcare costs. The unadjusted 12-monthly cost for WBRT was $AU71,138 ± standard deviation 41,475 and for observation $AU69,848 ± 33,233; p = 0.7426. The censor-adjusted 12-monthly cost for WBRT was $AU90,277 ± 36,274 and $AU82,080 ± 34,411 for observation. There was no significant difference in 2-monthly costs between groups (p > 0.30 for all models).ConclusionsMost costs were related to inpatient hospitalizations associated with disease recurrence. Adding WBRT after local SRS/surgery for patients with one to three melanoma brain metastases did not significantly increase health system costs during the first 12 months.Trial registrationACTRN12607000512426, prospectively registered 14 September 2007.
Project description:Maintenance of quality of life is the primary goal during treatment of brain metastases (BM). This is a protocol of an ongoing phase III randomised multicentre study. This study aims to determine the exact additional palliative value of stereotactic radiosurgery (SRS) over whole brain radiotherapy (WBRT) in patients with 4-10 BM.The study will include patients with 4-10 BM from solid primary tumours diagnosed on a high-resolution contrast-enhanced MRI scan with a maximum lesional diameter of 2.5 cm in any direction and a maximum cumulative lesional volume of 30 cm3. Patients will be randomised between WBRT in five fractions of 4 Gy to a total dose of 20 Gy (standard arm) and single dose SRS to the BMs (study arm) in the range of 15-24 Gy. The largest BM or a localisation in the brainstem will determine the prescribed SRS dose. The primary endpoint is difference in quality of life (EQ5D EUROQOL score) at 3 months after radiotherapy with regard to baseline. Secondary endpoints are difference in quality of life (EQ5D EUROQOL questionnaire) at 6, 9 and 12 months after radiotherapy with regard to baseline. Other secondary endpoints are at 3, 6, 9 and 12 months after radiotherapy survival, Karnofsky ? 70, WHO performance status, steroid use (mg), toxicity according to CTCAE V4.0 including hair loss, fatigue, brain salvage during follow-up, type of salvage, time to salvage after randomisation and Barthel index. Facultative secondary endpoints are neurocognition with the Hopkins verbal learning test revised, quality of life EORTC QLQ-C30, quality of life EORTC BN20 brain module and fatigue scale EORTC QLQ-FA13.Worldwide, most patients with more than 4 BM will be treated with WBRT. Considering the potential advantages of SRS over WBRT, i.e. limiting radiation doses to uninvolved brain and a high rate of local tumour control by just a single treatment with fewer side effects, such as hair loss and fatigue, compared to WBRT, SRS might be a suitable alternative for patients with 4-10 BM.Trial registration number: NCT02353000 , trial registration date 15th January 2015, open for accrual 1st July 2016, nine patients were enrolled in this trial on 14th April 2017.
Project description:ObjectiveThe objective of this study was to investigate outcomes for patients with brainstem metastases treated with stereotactic radiosurgery (SRS).MethodsPatients with brainstem metastases treated with SRS between April 2006 and June 2012 were identified from a prospective database. Patient and treatment-related factors were recorded. Kaplan-Meier analysis was used to calculate survival and freedom from local and distant brain progression. Univariate and multivariate Cox regression was used to identify factors important for overall survival.ResultsIn total, 44 patients received SRS for 48 brainstem metastases of whom 33 (75 %) also received whole brain radiotherapy (WBRT): 23 patients (52 %) WBRT prior to SRS, 6 (13.6 %) WBRT concurrently with SRS and 4 (9.0 %) WBRT after SRS. Eight patients received a second course of WBRT at further progression. Median target volume was 1.33 cc (range 0.04-12.17) and median prescribed marginal dose was 15 Gy (range 10-22). There were four cases of local failure, and 6-month and 1-year freedom from local failure was 84.6 and 76.9 %, respectively. Median overall survival (OS) was 5.4 months. There were four cases of radionecrosis, 2 (4.8 %) of which were symptomatic. The absence of external beam brain radiotherapy (predominantly WBRT) showed a trend towards improved OS on univariate analysis. Neither local nor distant brain failure significantly impacted OS.ConclusionThis retrospective series of patients treated with SRS for brainstem metastases, largely in combination with at least one course of WBRT, demonstrates that this approach is safe and results in good local control. In this cohort, no variables significantly impacted OS, including intracranial control.
Project description:BackgroundUntil 50% of patients with renal cancer or melanoma, develop brain metastases during the course of their disease. Stereotactic radiotherapy has become a standard of care for patients with a limited number of brain metastases. Given the radioresistant nature of melanoma and renal cancer, optimization of the fractionation of stereotactic radiotherapy is needed. The purpose of this retrospective study was to elucidate if hypofractionated stereotactic radiotherapy (HFSRT) impacts local control of brain metastases from radioresistant tumors such as melanoma and renal cancer, in comparison with radiosurgery (SRS).MethodsBetween 2012 and 2016, 193 metastases, smaller than 3 cm, from patients suffering from radioresistant primaries (melanoma and renal cancer) were treated with HFSRT or SRS. The primary outcome was local progression free survival (LPFS) at 6, 12 and 18 months. Overall survival (OS) and cerebral progression free survival (CPFS) were secondary outcomes, and were evaluated per patient. Objective response rate and radionecrosis incidence were also reported. The statistical analysis included a supplementary propensity score analysis to deal with bias induced by non-randomized data.ResultsAfter a median follow-up of 7.4 months, LPFS rates at 6, 12 and 18 months for the whole population were 83, 74 and 70%, respectively. With respect to fractionation, LPFS rates at 6, 12 and 18 months were 89, 79 and 73% for the SRS group and 80, 72 and 68% for the HFSRT group. The fractionation schedule was not statistically associated with LPFS (HR = 1.39, CI95% [0.65-2.96], p = 0.38). Time from planning MRI to first irradiation session longer than 14 days was associated with a poorer local control rate. Over this time, LPFS at 12 months was reduced from 86 to 70% (p = 0.009). Radionecrosis occurred in 7.1% for HFSRT treated metastases to 9.6% to SRS treated metastases, without any difference according to fractionation (p = 0.55). The median OS was 9.6 months. Six, 12 and 18 months CPFS rates were 54, 24 and 17%, respectively.ConclusionFractionation does not decrease LPFS. Even for small radioresistant brain metastases (< 3 cm), HFSRT, with 3 or 6 fractions, leads to an excellent local control rate of 72% at 1 year with a rate of 7.1% of radionecrosis. HFSRT is a safe and efficient alternative treatment to SRS.