Intracranial Radiation Research Articles

Safety of 177Lu-DOTATATE administration in a patient with recurrent meningioma complicated by radiation necrosis: a case report

Radiation-associated meningiomas are characterized by high rates of recurrence. 177Lu-DOTATATE may represent a treatment option for these tumors, but safety of this agent for patients with a history of radiation necrosis is unknown. In this case report, we describe the preliminary safety of 177Lu-DOTATATE administration for a patient with prior history of radiation necrosis. The patient was diagnosed with central nervous system (CNS) germinoma at age 17, managed with chemoradiation. Twenty years later, a left-parietal extra-axial mass was identified within the prior radiation field, with diagnosis of atypical meningioma established on subtotal resection. He received additional radiation therapy (RT, 60 Gy, 30 fractions). Seventeen months later, tumor progression was treated with gamma knife radiosurgery (GKRS, 15 Gy, single fraction). Seven months after GKRS, seizures recurred, with imaging consistent with radiation necrosis. The patient was treated with bevacizumab (7.5 mg/kg, every 3 weeks, 4 doses). One year later, magnetic resonance imaging (MRI) brain revealed tumor progression within the treatment field. 68 Ga-DOTATATE positron emission tomography demonstrated that the meningioma was DOTATATE-avid with no evidence of metastasis. The patient was treated with 177Lu-DOTATATE (two infusions, two months apart), which was well tolerated with no significant toxicities and no recurrence of radiation necrosis. Two months after the second infusion, the patient experienced disease progression and was transitioned to bevacizumab. In this patient with three prior courses of intracranial radiation and subsequent radiation necrosis, 177Lu-DOTATATE was well-tolerated. 177Lu-DOTATATE administration may be feasible for patients with a history of radiation necrosis.

18 Increasing Incidence of Brain Metastases and Intracranial Radiotherapy Among Gynecologic Cancer Patients

18 Increasing Incidence of Brain Metastases and Intracranial Radiotherapy Among Gynecologic Cancer Patients

A prospective evaluation of succinct prednisone tapering after brain tumor irradiation in dogs.

To ameliorate anticipated or ongoing neurological deficits, dogs undergoing brain tumor irradiation often are prescribed lengthy courses of prednisone PO during and after radiotherapy (RT). This practice can contribute to unwanted corticosteroid-associated morbidity and may be unnecessary. Determine whether long-term corticosteroid dependency can be minimized by use of succinct prednisone tapering. Fifty-five pet dogs undergoing brain tumor irradiation. Nineteen dogs were treated using a "rapid-taper" protocol wherein corticosteroid dose reduction began 0 to 20 days after completing RT. Outcomes were compared with a retrospectively studied control group ("slow-taper"; N = 36 dogs) in which corticosteroids were tapered more slowly according to individual clinician recommendations. Patient demographics were similar between groups. Mean time to lowest prednisone dose was 41 days postirradiation in the rapid-taper group and 117 days in the slow-taper group (P = .003). In the rapid-taper group, 15 of 19 dogs (84%) were completely tapered off prednisone, vs 18 of 36 (50%) in the slow-taper group (P = .04). Rates at which corticosteroids had to be reinstituted later were similar for the 2 groups (approximately 1 in 3 dogs). Adverse effect rates were similar for the 2 groups. Although no comparable questionnaire-derived data were available for the "slow-taper" group, overall and neurologic quality of life remained stable after RT in the rapid-taper group. For many dogs, lengthy courses of PO prednisone are avoidable after intracranial RT. Future efforts should aim to identify which dogs benefit most from accelerated prednisone tapering.

Memantine to Reduce Cognitive Impairment After Radiation in Children: A Pilot Study Evaluating the Feasibility of Memantine in Reducing Cognitive Impairment in Pediatric Patients after Radiation Therapy for Central Nervous System Tumors

Memantine is standard in certain adults receiving brain radiation therapy (RT) to decrease cognitive impacts, but it is unknown whether pediatric patients can take, tolerate, and/or benefit from memantine. In this prospective single-arm feasibility study, we hypothesized that pediatric patients receiving central nervous system (CNS) RT would tolerate memantine with good adherence. Patients aged 4 to 18 years with a primary CNS malignancy (excluding World Health Organization grade 4 astrocytoma, glioblastoma) receiving intracranial RT were eligible. A 6-month memantine course was given during and after RT, with dose titration in 5 mg increments over 4 weeks targeting a weight-based maximum (0.4 mg/kg to the closest 5 mg), not to exceed 10 mg twice a day. The primary endpoint was to achieve 80% drug adherence rate in 80% of patients measured 1 month after RT. Secondary objectives included memantine feasibility at 3 and 6 months. Eighteen patients enrolled from 2020 to 2022 and were prescribed memantine with RT. The study closed early to avoid competing with the phase 3 randomized Children's Oncology Group study ACCL2031. No predefined stopping rules were met. One patient withdrew for cognition-altering substance use, leaving 17 patients available for analysis. One patient discontinued memantine after one dose due to nausea. For the remaining 16 patients, there was a median of 100% pill completion rate (range, 74%-100%; n = 9/17 with 100% adherence) at 1 month after RT, with 15/16 (94%) with adherence rates >80%. At the 3- and 6-month post-RT time points for secondary endpoints, the median adherence rates were 100% (range, 55%-100%) and 96% (range, 33%-100%), respectively. Grade 1 to 2 fatigue, headache, and nausea were the most common toxicity events, at least possibly related to the study drug (n = 27), without attributable grade 3+ events. Memantine is a feasible, safe, and well-tolerated addition to multimodality treatment for pediatric CNS malignancies. Results of ACCL2031 are awaited to define the value of memantine in this population.

The Effect of Intracranial Control After Intracranial Local Therapy on the Prognosis of Patients with Brain Metastasis of Lung Adenocarcinoma.

The aim of the present study was to assess the clinical outcomes and prognostic factors of lung adenocarcinoma patients with brain metastases (BMs) after intracranial local therapy. A total of 83 lung adenocarcinoma patients with BMs who underwent craniotomy combined with radiotherapy or intracranial radiotherapy alone were retrospectively analyzed. The intracranial tumor response was determined according to the Response Assessment in Neuro-Oncology of Brain Metastases (RANO-BM) criteria. The median overall survival (OS), intracranial progression-free survival (iPFS), and related prognostic factors were analyzed with the Kaplan‒Meier estimator method and Cox proportional hazards regression model. Among 83 patients, 20 patients received craniotomy combined with radiotherapy, and 63 patients received intracranial radiotherapy alone. Following intracranial local therapy, 11 patients (13.3%) achieved complete response (CR); among them, 8 patients underwent neurosurgical resection. In addition, 32 patients (38.55%) achieved partial response (PR), 32 patients (38.55%) experienced stable disease (SD), and 8 (9.6%) experienced progressive disease (PD). The median follow-up period was 25.4 months (range 0.8-49.6 months). The median follow-up time for the iPFS was 16.2 months (range 0.6-41.2 months). The median OS, iPFS were 28.2 months and 24.7 months. Epidermal growth factor receptor (EGFR) / anaplastic lymphoma kinase (ALK) mutations (HR 3.216, 95% confidence interval (CI) 1.269-8.150, p = 0.014) and iPFS (HR 0.881, 95% CI 0.836-0.929, p < 0.001) were found to be beneficial factors for OS. An intracranial-tumor CR was associated with a longer iPFS (PR: HR 0.052, 95% CI 0.009-0.297, p = 0.001; SD: HR 0.081, 95% CI 0.025-0.259, p < 0.001; PD: HR 0.216, 95% CI 0.077-0.606, p = 0.004). Prolonged iPFS was associated with better OS in lung adenocarcinoma patients with BMs following intracranial local therapy, and mutations of EGFR / ALK or an intracranial-tumor CR are independent prognostic factors for prolonged survival.

Big Decisions on Small Cell Lung Cancer: A Focus on Clinical Care Updates and Patient Perspectives.

Small cell lung cancer (SCLC) is an uncommon, aggressive high-grade neuroendocrine carcinoma, associated with tobacco use. It is a highly chemosensitive disease that initially responds quickly to systemic therapy, although patients with SCLC tend to develop relapse. Although the landscape of SCLC treatment has remained stagnant for many decades, the field has seen notable advances in the past few years, including the use of immunotherapy, the development of further lines of systemic therapy, the refinement of thoracic and intracranial radiotherapy, and-most recently-the promise of more targeted therapies. Patients with SCLC also must face unique psychosocial burdens in their experience with their cancer, distinct from patients with other lung cancer. In this article, we review the latest literature and future directions in the management and investigation of SCLC, as well as the critical decisions that providers and patients must navigate in the current landscape. We also present the perspectives of several patients with SCLC in conjunction with this summary, to spotlight their individual journeys in the context of this challenging disease.

Neuro-oncology anywhere: A decentralized approach to clinical trials in brain tumors and beyond.

TPS1647 Background: The majority of patients with primary and secondary central nervous system (CNS) malignancy develop cognitive impairment, fatigue, and mood-related symptoms. Radiotherapy has been shown to contribute to symptom burden often limiting quality of life and functional status. The development of interventions mitigating neurocognitive toxicity requires an accurate assessment of function and symptom burden. Formal neuropsychological evaluation is resource and time intensive, and often challenging to incorporate in routine clinical practice. There is a critical need to accurately assess cognition without causing undue burden to cancer patients while evaluating the efficacy of interventions that can be scaled and implemented at a population level. Methods: To adequately assess the neurocognitive function and related symptoms in patients with CNS malignancy we have designed an open-label decentralized clinical trial that will randomize patients who received intracranial radiation for primary or metastatic brain tumors in a 1:1 allocation to a therapy targeting radiation-related toxicity (metformin shipped to patient home) plus health promotion with a wearable device vs. health promotion with a wearable device alone. Participants will be stratified based on tumor type (glioblastoma vs. other glioma vs. brain metastases vs. meningioma) and age (&lt;70 vs. 70+ years). Participants will be provided a wearable device for monitoring health status. Participants will undergo serial remote cognitive assessments with the Mayo Test Development Through Rapid Iteration, Validation and Expansion platform (Mayo Test Drive). Remote reported symptom collection via patient surveys and remote neurologic examination by telehealth will also be incorporated. Cognitive assessments and symptom surveys will be designed for completion on a smartphone, tablet, or computer device. Health data will be collected from the wearable device, including the number of steps per day and sleep quality/duration. Participants receiving metformin will utilize device apps to report medication adherence and adverse events. Study-related laboratory assessments will be completed remotely and transmitted electronically. This decentralized clinical trial will provide real-world cognitive and quality-of-life data for patients with primary and metastatic brain tumors while providing preliminary data on the effectiveness of device-based health promotion with or without metformin for treating radiation-related cognitive decline. Results gained from this study will guide future trials in neuro-oncology and other fields. This study is expected to open in March 2024.

285: Metal artifact in MR-based synthetic CT for intracranial radiotherapy: impact on dosimetry and setup

285: Metal artifact in MR-based synthetic CT for intracranial radiotherapy: impact on dosimetry and setup

PD-L1 inhibitors combined with whole brain radiotherapy in patients with small cell lung cancer brain metastases: Real-world evidence.

Numerous studies have demonstrated that brain metastases patients may benefit from intracranial radiotherapy combined with immune checkpoint inhibitors (ICIs). However, it is unclear whether this treatment is effective for patients with small cell lung cancer brain metastases (SCLC-BMs). We conducted a retrospective study by analyzing medical records of patients with SCLC-BMs from January 1, 2017 to June 1, 2022. Data related to median overall survival (mOS), median progression-free survival (mPFS), and intracranial progression-free survival (iPFS) were analyzed. A total of 109 patients were enrolled, of which 60 received WBRT and 49 received WBRT-ICI. Compared to the WBRT alone cohort, the WBRT-ICI cohort showed longer mOS (20.4 months vs. 29.3 months, p = 0.021), mPFS (7.9 months vs. 15.1 months, p < 0.001), and iPFS (8.3 months vs. 16.5 months, p < 0.001). Furthermore, WBRT-ICI cohort had a better response rate for both BMs. (p = 0.035) and extracranial diseases (p < 0.001) compared to those receiving WBRT alone. Notably, the use of WBRT before ICI was associated with longer mOS compared to the use of WBRT after ICI (23.3 months for the ICI-WBRT group vs. 34.8 months for the WBRT-ICI group, p = 0.020). Our results indicated that WBRT combined with immunotherapy improved survival in SCLC-BMs patients compared to WBRT monotherapy. Administering WBRT prior to ICI treatment is associated with improved survival outcomes compared to WBRT following ICI treatment, for patients with SCLC-BMs. These findings highlight the significance of conducting further prospective researches on combination strategies of intracranial radiotherapy and ICI in SCLC-BMs patients.

Repeatability quantification of brain diffusion-weighted imaging for future clinical implementation at a low-field MR-linac

BackgroundLongitudinal assessments of apparent diffusion coefficients (ADCs) derived from diffusion-weighted imaging (DWI) during intracranial radiotherapy at magnetic resonance imaging-guided linear accelerators (MR-linacs) could enable early response assessment by tracking tumor diffusivity changes. However, DWI pulse sequences are currently unavailable in clinical practice at low-field MR-linacs. Quantifying the in vivo repeatability of ADC measurements is a crucial step towards clinical implementation of DWI sequences but has not yet been reported on for low-field MR-linacs. This study assessed ADC measurement repeatability in a phantom and in vivo at a 0.35 T MR-linac.MethodsEleven volunteers and a diffusion phantom were imaged on a 0.35 T MR-linac. Two echo-planar imaging DWI sequence variants, emphasizing high spatial resolution (“highRes”) and signal-to-noise ratio (“highSNR”), were investigated. A test–retest study with an intermediate outside-scanner-break was performed to assess repeatability in the phantom and volunteers’ brains. Mean ADCs within phantom vials, cerebrospinal fluid (CSF), and four brain tissue regions were compared to literature values. Absolute relative differences of mean ADCs in pre- and post-break scans were calculated for the diffusion phantom, and repeatability coefficients (RC) and relative RC (relRC) with 95% confidence intervals were determined for each region-of-interest (ROI) in volunteers.ResultsBoth DWI sequence variants demonstrated high repeatability, with absolute relative deviations below 1% for water, dimethyl sulfoxide, and polyethylene glycol in the diffusion phantom. RelRCs were 7% [5%, 12%] (CSF; highRes), 12% [9%, 22%] (CSF; highSNR), 9% [8%, 12%] (brain tissue ROIs; highRes), and 6% [5%, 7%] (brain tissue ROIs; highSNR), respectively. ADCs measured with the highSNR variant were consistent with literature values for volunteers, while smaller mean values were measured for the diffusion phantom. Conversely, the highRes variant underestimated ADCs compared to literature values, indicating systematic deviations.ConclusionsHigh repeatability of ADC measurements in a diffusion phantom and volunteers’ brains were measured at a low-field MR-linac. The highSNR variant outperformed the highRes variant in accuracy and repeatability, at the expense of an approximately doubled voxel volume. The observed high in vivo repeatability confirms the potential utility of DWI at low-field MR-linacs for early treatment response assessment.

132 (PB-132) Poster - Single center analysis of safety profile and survival outcomes of intracranial radiation therapy in combination with trastuzumab-emtansine (T-DM1)

132 (PB-132) Poster - Single center analysis of safety profile and survival outcomes of intracranial radiation therapy in combination with trastuzumab-emtansine (T-DM1)

Abstract TP233: Cerebral Microbleeds Are More Frequent With BRCA Mutations: A Single-Center Retrospective Study

Introduction: Breast cancer susceptibility gene (BRCA) mutations are well-known causes of systemic cancers. We have previously identified that those with BRCA mutations have a higher likelihood of cerebral microbleeds (CMBs) on brain MRI compared to BRCA wildtype. We aimed to confirm our prior findings in a subsequent cohort. Methods: We performed a single-center retrospective review of all individuals with a confirmed diagnosis of BRCA 1 or 2 mutation and a standard-of-care brain MRI. All individuals were ≥ 18 years old, without intracranial radiation, cerebral metastases, or other cerebral processes which may impact interpretation. Our comparative cohort were individuals with breast cancer who have a genetically confirmed BRCA wildtype status. The primary outcome was the presence of CMBs, defined by consensus criteria. Standard descriptive techniques were used. Likelihood ratios were calculated by binary logistic regression and adjusted for significant variables. Results: We identified 49 individuals who met inclusion criteria: 15 with BRCA mutation and 34 with BRCA wildtype. Only one patient was with aspirin use in the BRCA mutation cohort. All cancers were of breast origin with 4 BRCA mutations patients with cancer staging ≥ 3 compared with 14 in the BRCA wildtype cohort. Chemotherapy rates did not differ. Patients with BRCA were younger, less often with hyperlipidemia, and more commonly had CMBs, Table 1. The presence of BRCA mutation trended towards higher odds of having a CMB (OR 5.8, 95%CI 0.93 - 36.16, p = 0.059) after adjustment for age and hyperlipidemia. Conclusion: We found that CMBs were more common in the BRCA mutation cohort, with a trend towards a 5-fold higher likelihood in the regression analysis. While underpowered, our findings support prior data highlighting this association. Further studies with larger sample sizes are warranted.

RADT-04. DOSE PAINTING WITH THE GAMMA KNIFE LIGHTNING OPTIMIZER TO ESCALATE RADIATION DOSE TO RESIDUAL TUMOR WITHIN BRAIN METASTASIS RESECTION CAVITIES

Abstract BACKGROUND The novel Gamma Knife (GK) Lightning optimizer allows simultaneous automated optimization of multiple intracranial radiotherapy targets. We used this optimizer to create a dose-painting treatment plan where an escalated dose was prescribed to residual disease within a brain metastasis resection cavity. We validated this method by measuring dose-delivery accuracy using radiochromic film in an anthropomorphic phantom. METHODS A 15.7cc irregular contour was drawn to represent a brain metastasis resection cavity, a 2mm expansion contour created, and a 1.6cc contour drawn representing a nodule of residual disease. In GammaPlan v11.3.1, three targets were created with overlapping dose matrices. Targets were prescribed 3Gy (2mm expansion), 4Gy (resection cavity), and 5Gy (residual disease) in one fraction. On the GK Icon system, an occipital mold was made, an unexposed film placed in the phantom’s cranium, cone-beam coregistration conducted, and treatment delivered. The film was scanned and calibrated for absolute dosimetry. To evaluate dose-painting accuracy, global gamma index (GI) analyses were performed at various dose and distance tolerances, excluding points below 30% of the maximum dose. RESULTS An 18-minute treatment plan with 40 shots was created and delivered. Prescription isodose lines were 3Gy at 55% (2mm expansion, mean 4.8Gy), 4Gy at 69% (resection cavity, mean 5.2Gy), and 5Gy at 75% (residual disease, mean 6.1Gy). All target volumes had ≥ 99% prescription dose coverage and the maximum dose was 6.9Gy. Paddick conformality indices were 0.79 (2mm expansion), 0.74 (resection cavity), and 0.15 (residual disease). Gamma index pass rate/mean GI/median GI were 73%/0.68/0.55 at 1%/1mm tolerance, 85%/0.58/0.48 at 2%/1mm tolerance, and 97%/0.34/0.28 at 2%/2mm tolerance. An average of 17,883 points were evaluated per analysis. CONCLUSIONS We successfully performed GK dose painting with the Lightning optimizer, verifying dose delivery within clinically acceptable tolerances. Future work is needed to determine optimal dose levels for use in clinical practice.

A - 114 Long Term Cognitive Sequela of Intracranial Radiation Therapy in a Pediatric Cerebellar Medulloblastoma Survivor.

Intracranial radiation therapy (IRT) for pediatric brain tumors is associated with late delayed brain injury due to cerebrovascular abnormality, white matter necrosis, demyelination, and gliosis which are irreversible. As a result, persistent cognitive deficits in adulthood emerge which are aggravated by younger age at diagnosis, higher radiation dose, whole brain radiation (WBR), and concurrent chemotherapy. The case is a childhood brain tumor survivor seen 18years post treatment who displayed cognitive deficits reflecting the cognitive sequela of WBR that overlapped with the anatomical distribution of white matter damage sustained. 23-year-old Black male with a history of childhood cerebellar medulloblastoma diagnosed at age 4, tumor resection, WBR, chemotherapy, more recent seizure disorder and medullary stroke, diabetes, and hypertension was seen for a neuropsychological evaluation due to memory complaints. His neuroimaging showed white matter hyperintensities in bilateral temporal and occipital lobes, bilateral cerebellar hemispheres, bilateral frontal lobes, medial posterior right cerebellar cyst, and 10 x 5mm cyst in the left temporal lobe. Results showed FSIQ = 59 and deficits in language, processing speed, visuospatial abilities, executive functioning, and verbal memory. His auditory working memory and visual memory were preserved. Based on his numerous adaptive limitations, moderate intellectual development disorder diagnosis was given. Deficits across several cognitive domains were consistent with multi-focal white matter lesions seen in patient's neuroimaging which reflect radiographic findings related to long-term sequela of previous intracranial radiation. A unique finding was relatively preserved visual memory as findings related to asymmetrical memory dysfunction in childhood medulloblastoma survivors are scarce.

Efficacy and Safety of PD-1/PD-L1 Inhibitors Combined with Radiotherapy in Patients with Brain Metastases Caused by Non-Small Cell Lung Cancer: A Multi-Center Retrospective Analysis

To investigate efficacy and safety of PD-1/PD-L1 inhibitors plus radiotherapy in patients that brain metastases (BMs) from non-small cell lung cancer (NSCLC). All 234 eligible patients were divided into PD-1/PD-L1 inhibitors plus intracranial radiotherapy (BM-RT) group and immunotherapy (non-BM-RT) group. 144 patients in BM-RT group were divided into patients received extracranial radiotherapy for NSCLC (extra-RT) group and had not (non-extra-RT) group. According to the Lung Immune Prognostic Index (LIPI), patients were stratified into good, intermediate, and poor groups. The toxicity was assessed with Common Terminology Criteria for Adverse Events (CTCAE) 5.0. Kaplan-Meier method and Log-rank test were used to analyze intracranial progression-free survival (iPFS) and overall survival (OS). The median iPFS (11.6 months vs. 9.9 months, P = 0.001) and median OS (17.3 months vs. 14.6 months, P = 0.029) had a significant difference in BM-RT group and non-BM-RT group. Meanwhile, median iPFS (15.7 months vs. 10.5 months, P<0.001) and median OS (20.2 months vs. 15.1 months, P = 0.024) in extra-RT group were longer than non-extra-RT group. The median iPFS (12.9 months vs. 10.4 vs. 8.4 months, P = 0.001) and median OS (20.1 months vs. 16.7 months vs. 12.6 months, P = 0.025) were longer in good group than intermediate group and poor group in LIPI. Our data suggested there was a significant difference in iPFS and OS with or without radiotherapy in patients of BMs from NSCLC, and with safety profiles. LIPI helped predict prognosis of BMs in NSCLC.

Frameless Linear Accelerator (LINAC) Based Radiosurgery (SRS) vs. Framed Gamma Knife SRS for Idiopathic Trigeminal Neuralgia (TN)

Stereotactic radiosurgery (SRS) is an effective treatment for idiopathic trigeminal neuralgia (TN). Conventional treatment is done through frame-based solution due to small target and high radiation dose. More recently, LINAC based frameless SRS technique has been established as a patient friendly alternative. Herein we compared our single institution experience of LINAC based frameless SRS vs frame-based gamma knife SRS for TN. The hypothesis is LINAC based frameless SRS can provide equivalent dosimetric and clinical outcome as compared frame-based gamma knife treatment. Patients with idiopathic TN who received SRS treatment (LINAC based frameless treatment or Gamma knife framed treatment) at our institution from 2015-2022 were included. A minimum follow up of 1 year was required. Patient data was extracted from electronic medical records and radiation treatment planning system. Pain intensity was evaluated utilizing a modified 0-4 Barrow Neurological Institute (BNI) pain intensity score, and then dichotomized where BNI score 0-2 represented response to treatment and BNI score 3-4 represented no response. Statistical analysis was conducted with a linear regression model accounting for race, gender, prior pain, pain distribution including laterality and branch involvement, medication regimen at time of treatment, previous radiation treatment, and prior procedures. Response was then compared between both modalities overall and within each sub-group with chi-square testing and linear regression. A total of 81 patients were identified, 14 patients were excluded due to lack of adequate follow-up, leaving 67 for analysis. 12 (17.9%) were male and, 55 (82.1%) were female. All patients were managed with medication prior to SRS treatment. 5 (7.5%) had rhizotomy and 13 (19.4) had microvascular decompression, and 8 (11.9%) had previous gamma-knife radiosurgery prior to SRS treatment at our institution. Of the 67 patients, 23 (34.3%) received frame-based gamma knife SRS, 44(65.7%) received frameless LINAC treatment. 58 (86.6%) radiation naïve patients received 90 Gy in 1 fraction, while out of the 9 who had previously had intracranial radiation treatment 7 (10.4%) received 70 Gy and 2 (3%) received 80 Gy all prescribed to 100% isodose line. All patients were treated with 4 mm cone. There was no significant difference in brainstem dose between these two techniques. Between LINAC-based or Gamma Knife modalities rate of pain control (77.3 % vs 82.6 %, respectively, p = 0.61) as well as toxicity in facial numbness (31.8% vs 21.7%, respectively, p = 0.38) showed no statistical difference. There was no statistically significant signal (p > 0.05) detected within the subgroups analyzed. The linear regression model also showed no significant difference. LINAC based frameless SRS provides comparable dosimetry and pain control for TN as compared to frame-based gamma knife treatment. It is a patient friendly solution for patients with TN.

Impact of multidisciplinary team on the pattern of care for brain metastasis from breast cancer.

The aim of this study was to explore how a multidisciplinary team (MDT) affects patterns of local or systematic treatment. We retrospectively reviewed the data of consecutive patients in the breast cancer with brain metastases (BCBM) database at our institution from January 2011 to April 2021. The patients were divided into an MDT group and a non-MDT group. A total of 208 patients were analyzed, including 104 each in the MDT and non-MDT groups. After MDT, 56 patients (53.8%) were found to have intracranial "diagnosis upgrade". In the matched population, patients in the MDT group recorded a higher proportion of meningeal metastases (14.4% vs. 4.8%, p = 0.02), symptomatic tumor progression (11.5% vs. 5.8%, p = 0.04), and an increased number of occurrences of brain metastases (BM) progression (p < 0.05). Attending MDT was an independent factor associated with ≥2 courses of intracranial radiotherapy (RT) [odds ratio (OR) 5.4, 95% confidence interval (CI): 2.7-10.9, p < 0.001], novel RT technique use (7.0, 95% CI 3.5-14.0, p < 0.001), and prospective clinical research (OR 5.7, 95% CI 2.4-13.4, p < 0.001). Patients with complex conditions are often referred for MDT discussions. An MDT may improve the qualities of intracranial RT and systemic therapy, resulting in benefits of overall survival for BC patients after BM. This encourages the idea that treatment recommendations for patients with BMBC should be discussed within an MDT.

Impact of first-line immunotherapy on survival and intracranial outcomes in a cohort of non-small cell lung cancer patients with brain metastases at diagnosis

BackgroundAlthough brain metastases (BM) at diagnosis are common in non-squamous NSCLC patients (ns-NSCLC), they have been mostly excluded from randomized trials. The aim of this retrospective study was to evaluate real-word outcomes of frontline immune checkpoint inhibitor (ICI) in these patients. MethodsOur study assess the intracranial and overall efficacy of first-line ICI-based therapy compared to chemotherapy (CT) in ns-NSCLC patients diagnosed with BM, showing no targetable alterations. Patients were divided according to systemic therapy: CT, ICI, or CT-ICI. Primary endpoint was overall survival (OS), compared using Kaplan-Meier and Cox methodology. Secondary endpoint was intracranial progression free survival (icPFS). ResultsBetween 01 and 2018 and 05–2021, 118 patients were included (52 CT, 38 ICI and 28 CT-ICI). Median follow-up was 30.0 months. Intracranial radiotherapy was delivered for 75.0%, 68.4% and 67.9% of patients for CT, ICI and CT-ICI groups (p = 0.805). After adjustment, ICI and CT-ICI were associated with a better OS compared to CT (HR = 0.46, 95 %CI: 0.23–0.89, and HR = 0.52, 95 %CI: 0.27–1.01, respectively). ICI and CT-ICI were associated with a significant reduction in the risk of intracranial progression by 54% (HR = 0.46, 95 %CI: 0.25–0.84) and 59% (HR = 0.41, 95 %CI: 0.23–0.77) compared to CT. Stereotactic radiosurgery was associated with an increased icPFS compared to systemic therapy alone (HR = 0.51, 95% CI: 0.29 – 0.92), whereas whole-brain was not. ConclusionsReal-life ns-NSCLC patients with BM at diagnosis treated frontline with ICI presented OS and icPFS benefit compared to CT alone. A prospective assessment of the ideal type and sequence of systemic and local therapy should be conducted.

RADIATIONINDUCED CENTRAL DEMYELINATING LEUKOENCEPHALOPATHY

Background. Great improvement in survival has resulted from the contemporary treatment of cancer.However, this has been associated with the appearance of various previously unobserved neurological complications that have recently been reviewed.That radiotherapy is responsible is suggested by many features.Leukoencephalopathy appears after a quite regular delay following irradiation.They electively involve the endothelial cells with a break down of the blood-brain barrier, fibrinoid necrosis, perivascular exudation and mononuclear infiltration leading to foci of myelin destruction of different ages. Case. A 63 year old male patient was diagnosed with metastatic small cell lung cancer 20 months ago, and cisplatin+vepesid chemotherapy is started.At the 6th month of the treatment, prophylactic intracranial radiotherapy is given 3 times with an interval of 2 months. After the treatment,he had oversleeping,sluggishness, and epileptic seizures.Diffuse T2 hyperintensities were observed in the Cranial MRG taken.There was no pathology to explain the situation in the blood tests of the patient with diffuse slowing in his EEG.The patient was started on antiepileptic and steroid treatment and was followed up. Conclusion. Clinically there is progressive psychomotor deterioration.Convulsions are very rare and were seen in our patient.The MRG pattern was also very characteristic in our case especially affecting the white matter.In our case,the striking white matter predominance of the lesions was clearly shown in the pons where circumscribed areas of demyelination affected the ponto-cerebellar fibres whereas the neurons of the pontine nuclei were spared.That radiotherapy is responsible is suggested by many features.As in the cases of De Vivo et al,Rosemberg and Bleyer and Griffin,leukoencephalopathy appears after a quite regular delay following irradiation.The lesions are limited to the irradiated brain and spare the unirradiated spinal cord.The frequency of leukoencephalopathy increases with increasing doses of irradiation.This case suggests Demyelinating Leukoencephalopathy with clinical and radiological findings, biopsy is required for definitive diagnosis.

Commissioning and clinical evaluation of the IDENTIFYTM surface imaging system for frameless stereotactic radiosurgery.

To commission and assess the clinical performance of a new commercial surface imaging (SI) system by analyzing intra-fraction motion from the initial cohort of patients treated with frameless stereotactic radiosurgery (fSRS). The IDENTIFYTM SI system was commissioned for clinical use on an Edge (Varian Medical Systems, Palo Alto, CA) linear accelerator. All patients who received intracranial radiotherapy with HyperArcTM (Varian Medical Systems, Palo Alto, CA) were immobilized with the EncompassTM (Qfix, Avondale, PA) thermoplastic mask and monitored for intra-fraction motion with SI. IDENTIFYTM log files were correlated with trajectory log files to correlate treatment parameters with SI-reported offsets. IDENTIFYTM reported offsets were correlated with gantry and couch angles to assess system performance for obstructed and clear camera field of view. Data were stratified by race to evaluate performance differences due to skin tone. All commissioning data were found to meet recommended tolerances. IDENTIFYTM was used to monitor intra-fraction motion on 1164 fractions from 386 patients. The median magnitude of translational SI reported offsets at the end of treatment was 0.27mm. SI reported offsets were shown to increase when camera pods are blocked by the gantry with larger increases seen at non-zero couch angles. With camera obstruction, the median magnitude of the SI reported offset was 0.50 and 0.80mm for White and Black patients, respectively. IDENTIFYTM performance during fSRS is comparable to other commercially available SI systems where offsets are shown to increase at non-zero couch angles and during camera pod blockage.