Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Dose selection for brain metastases stereotactic radiosurgery (SRS) classically has been based on tumor diameter with a reduction of dose in the settings of prior brain irradiation, larger tumor volumes, and critical brain location. However, retrospective series have shown local control rates to be suboptimal with reduced doses. We hypothesized that lower doses could be effective for specific tumor biologies with concomitant systemic therapies. This study aims to report the local control (LC) and toxicity when using low-dose SRS in the era of modern systemic therapy. METHODS:We reviewed 102 patients with 688 tumors managed between 2014 and 2021 who had low-margin dose radiosurgery, defined as ≤14 Gy. Tumor control was correlated with demographic, clinical, and dosimetric data. RESULTS:The main primary cancer types were lung in 48 (47.1%), breast in 31 (30.4%), melanoma in 8 (7.8%), and others in 15 patients (11.7%). The median tumor volume was 0.037cc (0.002-26.31 cm3), and the median margin dose was 14 Gy (range 10-14). The local failure (LF) cumulative incidence at 1 and 2 years was 6% and 12%, respectively. On competing risk regression analysis, larger volume, melanoma histology, and margin dose were predictors of LF. The 1-year and 2-year cumulative incidence of adverse radiation effects (ARE: an adverse imaging-defined response includes increased enhancement and peritumoral edema) was 0.8% and 2%. CONCLUSION/CONCLUSIONS:It is feasible to achieve acceptable LC in BMs with low-dose SRS. Volume, melanoma histology, and margin dose seem to be predictors for LF. The value of a low-dose approach may be in the management of patients with higher numbers of small or adjacent tumors with a history of whole brain radio therapy or multiple SRS sessions and in tumors in critical locations with the aim of LC and preservation of neurological function.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Stereotactic radiosurgery (SRS) of larger arteriovenous malformations (AVM) is associated with an elevated incidence of adverse radiation effects (ARE). To date, volume-response and dose-response models have been used to predict such effects. To understand radiological outcomes and their hemodynamic effects on the regional brain. METHODS:A retrospective analysis was conducted at our institution using a prospective registry of patients managed between 2014 and 2020. We included patients with AVM with a nidus larger than 5 cc who received either single-session or volume-staged Gamma Knife radiosurgery. AVM volume changes, volumes of parenchymal response, and obliteration were analyzed and correlated with transit times and diameters of feeding arteries and draining veins. RESULTS:Sixteen patients underwent single-session SRS, and 9 patients underwent volume-staged SRS. The average AVM volume was 12.6 cc (5.5-23). The AVM locations were predominantly lobar (80%) and 17 (68%) were in critical locations. The mean margin dose was 17.2 Gy (15-21), and the median V12Gy was 25.5 cc. Fourteen (56%) AVMs had a transit time shorter than 1 second. The median vein-artery ratio (sum diameter of the veins/sum diameter of feeding arteries) was 1.63 (range, 0.60-4.19). Asymptomatic parenchymal effects were detected in 13 (52%) patients and were symptomatic in 4 (16%) patients. The median time to ARE was 12 months (95% CI 7.6-16.4). On univariate analysis, significant predictors of ARE were lower vein-artery ratio (P = .024), longer transit time (P = .05), higher mean dose (P = .028), and higher D95 (P = .036). CONCLUSION/CONCLUSIONS:Transit times and vessel diameters are valuable predictors of the subsequent parenchymal response after SRS. A more quantitative understanding of blood flow is critical for predicting the effects on the regional brain after AVM radiosurgery.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Advances in targeted therapies and wider application of stereotactic radiosurgery (SRS) have redefined outcomes of patients with brain metastases. Under modern treatment paradigms, there remains limited characterization of which aspects of disease drive demise and in what frequencies. This study aims to characterize the primary causes of terminal decline and evaluate differences in underlying intracranial tumor dynamics in patients with metastatic brain cancer. These fundamental details may help guide management, patient counseling, and research priorities. METHODS:Using NYUMets-Brain-the largest, longitudinal, real-world, open data set of patients with brain metastases-patients treated at New York University Langone Health between 2012 and 2021 with SRS were evaluated. A review of electronic health records allowed for the determination of a primary cause of death in patients who died during the study period. Causes were classified in mutually exclusive, but collectively exhaustive, categories. Multilevel models evaluated for differences in dynamics of intracranial tumors, including changes in volume and number. RESULTS:Of 439 patients with end-of-life data, 73.1% died secondary to systemic disease, 10.3% died secondary to central nervous system (CNS) disease, and 16.6% died because of other causes. CNS deaths were driven by acute increases in intracranial pressure (11%), development of focal neurological deficits (18%), treatment-resistant seizures (11%), and global decline driven by increased intracranial tumor burden (60%). Rate of influx of new intracranial tumors was almost twice as high in patients who died compared with those who survived (P < .001), but there was no difference in rates of volume change per intracranial tumor (P = .95). CONCLUSION/CONCLUSIONS:Most patients with brain metastases die secondary to systemic disease progression. For patients who die because of neurological disease, tumor dynamics and cause of death mechanisms indicate that the primary driver of decline for many may be unchecked systemic disease with unrelenting spread of new tumors to the CNS rather than failure of local growth control.

We compiled a sampling of the treatment techniques of intensity-modulated total body irradiation, total marrow irradiation and total marrow and lymphoid irradiation utilized by several centers across North America and Europe. This manuscript does not serve as a consensus guideline, but rather is meant to serve as a convenient reference for centers that are considering starting an intensity-modulated program.

PURPOSE/OBJECTIVE:Acute radiation dermatitis (ARD) is common after radiation therapy for breast cancer, with data indicating that ARD may disproportionately affect Black or African American (AA) patients. We evaluated the effect of skin of color (SOC) on physician-reported ARD in patients treated with radiation therapy. METHODS AND MATERIALS/METHODS:We identified patients treated with whole breast or chest wall ± regional nodal irradiation or high tangents using 50 Gy in 25 fractions from 2015 to 2018. Baseline skin pigmentation was assessed using the Fitzpatrick scale (I = light/pale white to VI = black/very dark brown) with SOC defined as Fitzpatrick scale IV to VI. We evaluated associations among SOC, physician-reported ARD, late hyperpigmentation, and use of oral and topical treatments for RD using multivariable models. RESULTS:A total of 325 patients met eligibility, of which 40% had SOC (n = 129). On multivariable analysis, Black/AA race and chest wall irradiation had a lower odds of physician-reported grade 2 or 3 ARD (odds ratio [OR], 0.110; 95% confidence interval [CI], 0.030-0.397; P = .001; OR, 0.377; 95% CI, 0.161-0.883; P = .025), whereas skin bolus (OR, 8.029; 95% CI, 3.655-17.635; P = 0) and planning target volume D0.03cc (OR, 1.001; 95% CI, 1.000-1.001; P = .028) were associated with increased odds. On multivariable analysis, SOC (OR, 3.658; 95% CI, 1.236-10.830; P = .019) and skin bolus (OR, 26.786; 95% CI, 4.235-169.432; P = 0) were associated with increased odds of physician-reported late grade 2 or 3 hyperpigmentation. There was less frequent use of topical steroids to treat ARD and more frequent use of oral analgesics in SOC versus non-SOC patients (43% vs 63%, P < .001; 50% vs 38%, P = .05, respectively). CONCLUSIONS:Black/AA patients exhibited lower odds of physician-reported ARD. However, we found higher odds of late hyperpigmentation in SOC patients, independent of self-reported race. These findings suggest that ARD may be underdiagnosed in SOC when using the physician-rated scale despite this late evidence of radiation-induced skin toxicity.

The altered metabolism of tumor cells is a well-known hallmark of cancer and is driven by multiple factors such as mutations in oncogenes and tumor suppressor genes, the origin of the tissue where the tumor arises, and the microenvironment of the tumor. These metabolic changes support the growth of cancer cells by providing energy and the necessary building blocks to sustain proliferation. Targeting these metabolic alterations therapeutically is a potential strategy to treat cancer, but it is challenging due to the metabolic plasticity of tumors. Cancer cells have developed ways to scavenge nutrients through autophagy and macropinocytosis and can also form metabolic networks with stromal cells in the tumor microenvironment. Understanding the role of the tumor microenvironment in tumor metabolism is crucial for effective therapeutic targeting. This review will discuss tumor metabolism and the contribution of the stroma in supporting tumor growth through metabolic interactions.

INTRODUCTION:Radiation therapy is a promising modality for treating keloids after surgical excision. However, it is currently not standard practice among physicians because of concern surrounding the risk of radiation-induced secondary cancers, especially among pediatric patients. There is minimal research assessing the complications for radiation therapy in keloid management. AIM:The goal of this study was to determine radiation oncologists' perspectives about the utility and appropriateness of radiation therapy for keloid management in both adult and pediatric patients. This study also aimed to characterize radiation modality, dose, fractionation, and secondary complications observed by providers. METHODS:An electronic survey was delivered to 3102 members of the American Society for Radiation Oncology. The survey subjects were radiation oncologists who are currently practicing in the United States. Rates of responses were analyzed. RESULTS:A total of 114 responses from practicing radiation oncologists were received. Of these, 113 providers (99.1%) supported radiation therapy for keloid management in adults, whereas only 54.9% supported radiation therapy for pediatric patients. Of 101 providers that treated adults in the past year, the majority used external beam: electrons (84.2%), applied 3 fraction regimens (54.4%), and delivered radiation within 24 hours postexcision (45.5%). In pediatric patients, only 42 providers reported treating at least 1 patient. The majority used electron beam radiation (76.2%), applied 3 faction regimens (65%), and delivered radiation on the same day of keloid excision (50.0%) The main concern when treating pediatric patients were risk of secondary malignancy (92.1%). CONCLUSION:Although radiation therapy appears to be a widely accepted adjuvant treatment option for adults with keloids, the use of radiation therapy for pediatric patients is less widely accepted because of concerns regarding secondary malignancy. The findings suggest additional studies need to be carried out to assess the risk of those complications.

BACKGROUND:Brain metastases (BM) have long been considered a terminal diagnosis with management mainly aimed at palliation and little hope for extended survival. Use of brain stereotactic radiosurgery (SRS) and/or resection, in addition to novel systemic therapies, has enabled improvements in overall and progression-free (PFS) survival. OBJECTIVE:To explore the possibility of extended survival in patients with non-small-cell lung cancer (NSCLC) BM in the current era. METHODS:During the years 2008 to 2020, 606 patients with NSCLC underwent their first Gamma Knife SRS for BM at our institution with point-of-care data collection. We reviewed clinical, molecular, imaging, and treatment parameters to explore the relationship of such factors with survival. RESULTS:The median overall survival was 17 months (95% CI, 13-40). Predictors of increased survival in a multivariable analysis included age <65 years (P < .001), KPS ≥80 (P < .001), absence of extracranial metastases (P < .001), fewer BM at first SRS (≤3, P = .003), and targeted therapy (P = .005), whereas chemotherapy alone was associated with shorter survival (P = .04). In a subgroup of patients managed before 2016 (n = 264), 38 (14%) were long-term survivors (≥5 years), of which 16% required no active cancer treatment (systemic or brain) for ≥3 years by the end of their follow-up. CONCLUSION/CONCLUSIONS:Long-term survival in patients with brain metastases from NSCLC is feasible in the current era of SRS when combined with the use of effective targeted therapeutics. Of those living ≥5 years, the chance for living with stable disease without the need for active treatment for ≥3 years was 16%.

INTRODUCTION/BACKGROUND:In KRAS-mutant NSCLC, co-occurring alterations in LKB1 confer a negative prognosis compared with other mutations such as TP53. LKB1 is a tumor suppressor that coordinates several signaling pathways in response to energetic stress. Our recent work on pharmacologic and genetic inhibition of histone deacetylase 6 (HDAC6) revealed the impaired activity of numerous enzymes involved in glycolysis. On the basis of these previous findings, we explored the therapeutic window for HDAC6 inhibition in metabolically-active KRAS-mutant lung tumors. METHODS:Using cell lines derived from mouse autochthonous tumors bearing the KRAS/LKB1 (KL) and KRAS/TP53 mutant genotypes to control for confounding germline and somatic mutations in human models, we characterize the metabolic phenotypes at baseline and in response to HDAC6 inhibition. The impact of HDAC6 inhibition was measured on cancer cell growth in vitro and on tumor growth in vivo. RESULTS:Surprisingly, KL-mutant cells revealed reduced levels of redox-sensitive cofactors at baseline. This is associated with increased sensitivity to pharmacologic HDAC6 inhibition with ACY-1215 and blunted ability to increase compensatory metabolism and buffer oxidative stress. Seeking synergistic metabolic combination treatments, we found enhanced cell killing and antitumor efficacy with glutaminase inhibition in KL lung cancer models in vitro and in vivo. CONCLUSIONS:Exploring the differential metabolism of KL and KRAS/TP53-mutant NSCLC, we identified decreased metabolic reserve in KL-mutant tumors. HDAC6 inhibition exploited a therapeutic window in KL NSCLC on the basis of a diminished ability to compensate for impaired glycolysis, nominating a novel strategy for the treatment of KRAS-mutant NSCLC with co-occurring LKB1 mutations.

IMPORTANCE:The long-term outcomes associated with adding bevacizumab, a vascular endothelial growth factor inhibitor, to standard chemoradiation have continued to be favorable for a group of patients with locoregionally advanced nasopharyngeal carcinoma (NPC). OBJECTIVE:To assess long-term toxic effects and clinical outcomes associated with chemotherapy, radiation therapy (RT), and bevacizumab for NPC. DESIGN, SETTING, AND PARTICIPANTS:This single-arm phase II nonrandomized controlled trial was conducted by the National Cancer Trials Network group and NRG Oncology (formerly Radiation Therapy Oncology Group), with accrual from December 13, 2006, to February 5, 2009, and data analysis from June 26 to July 1, 2019. The study was conducted at 19 cancer centers with a median (IQR) follow-up of 9.0 (7.7-9.3) years. Included patients were adults (aged ≥18 years) with NPC that was World Health Organization (WHO) histologic grade I to IIb or III, American Joint Committee on Cancer stage IIB or greater, and with or without lymph node involvement. INTERVENTIONS:Patients received 3 cycles of bevacizumab (15 mg/kg) concurrently with standard cisplatin (100 mg/m2) and RT (69.96 Gy) followed by 3 cycles of adjuvant bevacizumab (15 mg/kg) given concurrently with cisplatin (80 mg/m2) and fluorouracil (1000 mg/m2/d). MAIN OUTCOMES AND MEASURES:The primary end point was grade 4 hemorrhage or grade 5 adverse events in the first year. Secondary end points were locoregional progression-free (LRPF) interval, distant metastasis-free (DMF) interval, progression-free survival (PFS), overall survival (OS), and other adverse events. Long-term toxic effects and clinical outcomes were reported due to the limited follow-up in the initial report for this trial and the importance of long-term outcomes when combining bevacizumab with chemoradiation. RESULTS:Among 46 patients with NPC who were enrolled, 44 patients were analyzed (29 males [65.9%]; 23 Asian [52.3%], 2 Black [4.5%], and 16 White [36.4%]; 38 not Hispanic [86.4%]; median [IQR] age, 48.5 [39.0-56.0] years). There were 33 patients with a Zubrod performance status of 0, indicating that they were fully functional and asymptomatic (75.0%); 32 patients with a WHO histologic grade of IIb or III (72.7%); and 39 patients with stage III or IVB disease (88.6%). Among analyzed patients, 42 individuals received radiation therapy of 69.96 Gy or greater (95.5%; dose range, 65.72-70.00 Gy); 30 patients received 3 cycles of cisplatin (68.2%) with RT, and 31 patients received 3 cycles of bevacizumab with RT (70.5%); this was followed by 3 cycles of adjuvant cisplatin in 21 patients (47.7%), fluorouracil in 24 patients (54.5%), and bevacizumab in 23 patients (52.3%). No grade 4 hemorrhage or grade 5 AEs were reported in the first year or thereafter. Late grade 3 AEs occurred in 16 patients (36.4%), including 7 patients with dysphagia (15.9%), 6 patients with hearing impairment (13.6%), and 2 patients with dry mouth (4.5%). The 1- and 5-year rates of feeding tube use were 5 of 41 patients (12.2%) and 0 of 27 patients, respectively. There were 19 patients (43.2%) who progressed or died without disease progression (6 patients with locoregional progression [13.6%], 8 patients with distant progression [18.2%], and 5 patients who died without progression [11.4%]). The 5- and 7-year rates were 79.5% (95% CI, 67.6%-91.5%) and 69.7% (95% CI, 55.9%-83.5%) for OS, 61.2% (95% CI, 46.8%-75.6%) and 56.3% (95% CI, 41.5%-71.1%) for PFS, 74.9% (95% CI, 61.4%-86.6%) and 72.3% (95% CI, 58.4%-84.7%) for LRPF interval, and 79.5% (95% CI,66.4%-90.0%) for both times for DMF interval. Among 13 patients who died, death was due to disease in 8 patients (61.5%). CONCLUSIONS AND RELEVANCE:In this nonrandomized controlled trial, no grade 4 hemorrhage or grade 5 AEs were reported in the first year or thereafter among patients with NPC receiving bevacizumab combined with chemoradiation. The rate of distant metastasis was low although 89% of patients had stage III to IVB disease, suggesting that further investigation may be warranted. TRIAL REGISTRATION:ClinicalTrials.gov Identifier: NCT00408694.