Gondi, Vinai

Abstract BACKGROUND Tumor Treating Fields (TTFields) are electric fields that disrupt cancer cell division. TTFields treatment showed efficacy in preclinical non-small cell lung cancer (NSCLC) models. Furthermore, TTFields therapy improved survival with a tolerable safety profile in patients with glioblastoma. The objective of the pivotal METIS trial [NCT02831959] is to evaluate the efficacy and safety of TTFields therapy in NSCLC patients with brain metastases. METHODS NSCLC patients (N=270) with 1–10 brain metastases will be randomized 1:1 to stereotactic radiosurgery (SRS) followed by continuous TTFields therapy using NovoTTF-200M (150 kHz, recommended >18 h/day) with best standard of care (BSC) or SRS followed by BSC alone. Follow-ups will be conducted every 2 months until second intracranial progression. Key inclusion criteria are: Karnofsky Performance Status ≥70, new diagnosis of 1 inoperable or 2–10 supra- and/or infratentorial brain metastases from NSCLC amenable to SRS, and optimal therapy for extracranial disease. Key exclusion criteria are: prior whole brain radiotherapy, single operable, or recurrent brain metastases. Primary endpoint is time to first intracranial progression. Secondary endpoints include time to neurocognitive failure, overall survival, radiological response rate (RANO-BM and RECIST V1.1), quality of life, adverse events, time to first/second intracranial progression for patients with 1–4 and 5–10 brain metastases, bi-monthly intracranial progression rate from 2–12 months, and time to second intracranial and distant progression. The study is powered at 80% (2-sided alpha of 0.05) to detect a hazard ratio of 0.57. In July 2021, an independent Data Monitoring Committee (DMC) reviewed the study data and recommended continuation as planned. The trial is currently recruiting at 92 sites in North America, Europe, Israel, mainland China and Hong Kong.

Abstract Background Global incidence for brain tumors varies substantially without explanation. Studies correlating radon exposure and incidence are inconclusive. Particulate pollution has been linked to increased tumor incidence. Particulates may disrupt the blood-brain barrier allowing intracranial exposure to oncogenic radon. We investigated the relationship between exposure to residential radon, particulate pollution, and brain tumor incidence in the United States (US). Methods County-level median radon testing results and annual air quality index values were obtained and divided into tertiles. Counties without both values were excluded. Four groups of counties were generated: high particulate/high radon (high/high), high/low, low/high, and low/low. Using incidence data from the Central Brain Tumor Registry of the US (provided by CDC’s National Program of Cancer Registries and NCI’s SEER), annual age-adjusted incidence rates (AAAIRs) by group were generated by behavior. Incidence rate ratios were calculated to examine for significant differences (α = .05). Poisson regression accounting for possible confounders was conducted. Results Counties with available data included 83% of the US population. High/high exposure was significantly associated with increased AAAIR of all non-malignant tumors (up to 26% higher, including most meningiomas) even after accounting for potential confounders. An increased AAAIR was noted for all malignant tumors (up to 10% higher), including glioblastoma, but was negated after accounting for demographic/socioeconomic differences. Conclusions We present the first report suggesting increased non-malignant brain tumor incidence in regions with high particulate and radon exposure. These findings provide insight into unexplained variation in tumor incidence. Future studies are needed to validate these findings in other populations.

PURPOSE American Society of Radiation Oncology (ASTRO) has developed a guideline on appropriate radiation therapy for brain metastases. ASCO has a policy and set of procedures for endorsing clinical practice guidelines that have been developed by other professional organizations. METHODS “Radiation Therapy for Brain Metastases: An ASTRO Clinical Practice Guideline” 2 was reviewed for developmental rigor by methodologists. An ASCO Endorsement Panel subsequently reviewed the content and the recommendations. RESULTS The ASCO Endorsement Panel determined that the recommendations from the ASTRO guideline, published May 6, 2022, are clear, thorough, and based upon the most relevant scientific evidence. ASCO endorses “Radiation Therapy for Brain Metastases: An ASTRO Clinical Practice Guideline.” 2 RECOMMENDATIONS Within the guideline, stereotactic radiosurgery (SRS) is recommended for patients with Eastern Cooperative Oncology Group performance status of 0-2 and up to four intact brain metastases, and conditionally recommended for patients with up to 10 intact brain metastases. The guideline provides detailed dosing and fractionation recommendations on the basis of the size of the metastases. For patients with resected brain metastases, radiation therapy (SRS or whole-brain radiation therapy [WBRT]) is recommended to improve intracranial disease control; if there are limited additional brain metastases, SRS is recommended over WBRT. For patients with favorable prognosis and brain metastases ineligible for surgery and/or SRS, WBRT is recommended with hippocampal avoidance where possible and the addition of memantine is recommended. For patients with brain metastases, limiting the single-fraction V 12Gy to brain tissue to ≤ 10 cm 3 is conditionally recommended. Additional information is available at www.asco.org/neurooncology-guidelines .

Abstract Purpose To provide guidance to clinicians regarding therapy for patients with brain metastases from solid tumors. Methods ASCO convened an Expert Panel and conducted a systematic review of the literature. Results Thirty-two randomized trials published in 2008 or later met eligibility criteria and form the primary evidentiary base. Recommendations Surgery is a reasonable option for patients with brain metastases. Patients with large tumors with mass effect are more likely to benefit than those with multiple brain metastases and/or uncontrolled systemic disease. Patients with symptomatic brain metastases should receive local therapy regardless of the systemic therapy used. For patients with asymptomatic brain metastases, local therapy should not be deferred unless deferral is specifically recommended in this guideline. The decision to defer local therapy should be based on a multidisciplinary discussion of the potential benefits and harms that the patient may experience. Several regimens were recommended for non–small-cell lung cancer, breast cancer, and melanoma. For patients with asymptomatic brain metastases and no systemic therapy options, stereotactic radiosurgery (SRS) alone should be offered to patients with one to four unresected brain metastases, excluding small-cell lung carcinoma. SRS alone to the surgical cavity should be offered to patients with one to two resected brain metastases. SRS, whole brain radiation therapy, or their combination are reasonable options for other patients. Memantine and hippocampal avoidance should be offered to patients who receive whole brain radiation therapy and have no hippocampal lesions and 4 months or more expected survival. Patients with asymptomatic brain metastases with either Karnofsky Performance Status ≤ 50 or Karnofsky Performance Status < 70 with no systemic therapy options do not derive benefit from radiation therapy. Additional information is available at www.asco.org/neurooncology-guidelines.

PURPOSE To provide guidance to clinicians regarding therapy for patients with brain metastases from solid tumors. METHODS ASCO convened an Expert Panel and conducted a systematic review of the literature. RESULTS Thirty-two randomized trials published in 2008 or later met eligibility criteria and form the primary evidentiary base. RECOMMENDATIONS Surgery is a reasonable option for patients with brain metastases. Patients with large tumors with mass effect are more likely to benefit than those with multiple brain metastases and/or uncontrolled systemic disease. Patients with symptomatic brain metastases should receive local therapy regardless of the systemic therapy used. For patients with asymptomatic brain metastases, local therapy should not be deferred unless deferral is specifically recommended in this guideline. The decision to defer local therapy should be based on a multidisciplinary discussion of the potential benefits and harms that the patient may experience. Several regimens were recommended for non–small-cell lung cancer, breast cancer, and melanoma. For patients with asymptomatic brain metastases and no systemic therapy options, stereotactic radiosurgery (SRS) alone should be offered to patients with one to four unresected brain metastases, excluding small-cell lung carcinoma. SRS alone to the surgical cavity should be offered to patients with one to two resected brain metastases. SRS, whole brain radiation therapy, or their combination are reasonable options for other patients. Memantine and hippocampal avoidance should be offered to patients who receive whole brain radiation therapy and have no hippocampal lesions and 4 months or more expected survival. Patients with asymptomatic brain metastases with either Karnofsky Performance Status ≤ 50 or Karnofsky Performance Status < 70 with no systemic therapy options do not derive benefit from radiation therapy. Additional information is available at www.asco.org/neurooncology-guidelines .

Abstract Background:The standard of care for elderly glioblastoma (GBM) patients is 40 Gy in 15 fraction radiotherapy with temozolomide (TMZ). However, this regimen has a lower biologic equivalent dose (BED) compared to the Stupp regimen of 60 Gy in 30 fractions. We hypothesize that accelerated hypofractionated radiation of 52.5 Gy in 15 fractions (BED equivalent to Stupp) will have superior survival compared to 40 Gy in 15 fractions.Methods:Elderly patients (≥ 65 years old) who received hypofractionated radiation with TMZ from 2010-2020 were included in this analysis. Overall survival (OS) and progression free survival (PFS) were defined as the time elapsed between surgery/biopsy and death from any cause or progression. Baseline characteristics were compared between patients who received 40 Gy and 52.5 Gy. Univariable and multivariable analyses were performed.Results: Sixty-six newly diagnosed patients were eligible for analysis. Thirty-nine patients were treated with 40 Gy in 15 fractions while twenty-seven were treated with 52.5 Gy in 15 fractions. Patients had no significant differences in age, sex, methylation status, or performance status. Overall survival (OS) was superior in the 52.5 Gy group (14.1 months) when compared to the 40 Gy group (7.9 months, p = 0.011). Isoeffective dosing to 52.5 Gy was shown to be an independent prognostic factor for improved OS on multivariable analysis. Conclusions:Isoeffective dosing to 52.5 Gy in 15 fractions was associated with superior OS compared to standard of care 40 Gy in 15 fractions. These hypothesis generating data support accelerated hypofractionation in future prospective trials.

Abstract Purpose: The optimal salvage treatment for malignant glioma after prior radiotherapy (RT) is not well established. Proton therapy (PT) is an attractive treatment modality for reirradiation (ReRT) of recurrent disease; however, data are limited.Methods: The prospective, multi-institutional Proton Collaborative Group (PCG) registry was queried for patients with malignant glioma who previously received RT and underwent PT-ReRT between 7/2011-10/2018. Overall survival (OS) and progression-free survival (PFS) were assessed using the Kaplan-Meier method and Cox proportional hazards regression analysis. Results: 109 consecutive patients were identified. Median follow-up was 11.2 months and median time interval (TI) from prior RT (median 59.3 Gy) to PT-ReRT (median 49.6 Gy) was 45.7 months. Primary histology was glioblastoma (n=62), oligodendroglioma (n=26), and astrocytoma (n=20). Median PFS and OS was 6.1 and 11.1 months, respectively. On UVA, improved PFS was associated with oligodendroglioma (HR 0.39) and astrocytoma (HR 0.55) histologies, WHO Grade III (HR 0.36), TI (HR 0.989), surgical resection (HR 0.39), and PT-ReRT dose ≥50 Gy (HR 0.59) (all p<0.03), while improved OS was associated with oligodendroglioma histology (HR 0.35), WHO grade III (HR 0.33), ECOG 0 (HR 0.47), TI (HR 0.985), and PT-ReRT dose ≥50 Gy (HR 0.58) (all p<0.04). Late Grade 3 toxicities occurred in 5.6% of patients with no attributable acute or late Grade 4-5 events.Conclusion: In the largest series of glioma PT-ReRT reported to date, retreatment appears well tolerated with acceptable outcomes and favorable toxicities compared to photon historical controls. Dose escalation achievable with PT may improve outcomes for well-selected patients.

Abstract BACKGROUND Tumor Treating Fields (TTFields) are non-invasive, loco-regional, anti-mitotic treatment modality comprising alternating electric fields. TTFields have demonstrated efficacy in preclinical non-small cell lung cancer (NSCLC) models. TTFields treatment to the brain was safe and extended overall survival in newly-diagnosed glioblastoma. The objective of the METIS study [NCT02831959] is evaluation of the efficacy and safety of TTFields in NSCLC patients with brain metastases. METHODS NSCLC patients (N=270) with 1-10 brain metastases were randomized 1:1 to stereotactic radio surgery (SRS) followed by continuous TTFields ((150 kHz, &gt; 18 hours/day) within 7 days of SRS or supportive care. The portable device delivered TTFields to the brain using 4 transducer arrays, while patients received the best standard-of-care for systemic disease. Patients were followed every two months until second intracranial progression. Key inclusion criteria: KPS ≥70, new diagnosis of 1 inoperable or 2–10 supra- and/or infratentorial brain metastases from NSCLC amenable to SRS; and optimal therapy for extracranial disease. Prior WBRT, surgical resection of metastases, or recurrent brain metastases were exclusionary. Primary endpoint was time to 1st intracranial progression. Secondary endpoints included time to neurocognitive failure (HVLT, COWAT and TMT), overall survival, radiological response rate (RANO-BM and RECIST V1.1); quality-of-life; adverse events; time to first/second intracranial progression for patients with 1–4 and 5–10 brain metastases; bi-monthly intracranial progression rate from 2–12 months; and time to second intracranial and distant progression. The sample size (N=270) was calculated using a log-rank test (Lakatos 1988 and 2002) with 80% power at two sided alpha of 0.05 to detect a hazard ratio of 0.57. On September, 2019, an independent Data Monitoring Committee (DMC) reviewed METIS trial data collected to that point. The DMC concluded that no unexpected safety issues had emerged and recommended continuation of the METIS study as planned.

Abstract PURPOSE Previous secondary analysis of NRG/RTOG 0933 provided hypothesis-generating data supporting a relationship between larger volumes of MR-determined pre-treatment WMI and developing neurocognitive decline following HA-WBRT. The current study examines the relationship between pre-treatment WMI and neurocognitive function (NCF) following WBRT+memantine +/-HA in a substantially larger cohort. METHODS NCF testing was performed at baseline,2,4,6,and 12 months post-WBRT, and included Hopkins Verbal Learning Test–Revised (HVLT-R), Trail Making Test (TMT) Parts A and B, and Controlled Oral Word Association (COWA). Pre-treatment WMI was measured by FLAIR volume corrected for whole brain volume and corrected for the FLAIR volume associated with metastases (FLAIR/(whole brain volume – metastasis FLAIR volume). Pearson correlation coefficients were used to assess association between pre-treatment WMI and change from baseline for each standardized NCF score. RESULTS Of 518 randomized patients, 442 (217,WBRT+Memantine; 225,HA-WBRT+Memantine) had WMI data and were included. In the entire cohort, mean FLAIR volume was 9.3cc (0.1-68.2cc), mean metastases FLAIR volume was 61.5cc (0-423.5cc), mean Whole Brain volume was 1336.4cc (949.4-2397.8cc). At 2 months, there were no significant correlations between neurocognitive test change scores and pre-treatment WMI volume. However, at 4 months, both HVLT-R Total Recall and TMT Part B change score and pre-treatment WMI volume were significantly negatively correlated on the HA-WBRT+Memantine arm (ρ=-0.22 p=0.042 and ρ=-0.27, p=0.013). At 12 months, both TMT Part A and TMT Part B change scores and pre-treatment WMI volume were significantly negatively correlated on the HA-WBRT+Memantine arm (ρ=-0.30, p=0.046 and ρ=-0.53, p&lt; 0.001). CONCLUSIONS Pre-treatment WMI volume was a significant imaging-biomarker predictor of post-treatment neurocognitive decline at 4-and 12-months following HA-WBRT+Memantine. This suggests patients with greater pre-treatment WMI were more susceptible to neurocognitive decline, specifically when undergoing HA-WBRT, but not following standard WBRT. Dose heterogeneity inherent to HA-WBRT delivery may contribute to these findings and are hypothesis generating.