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Purpose Biology-guided radiotherapy (BgRT) is a novel radiation delivery approach utilizing fluorodeoxyglucose (FDG) activity on positron emission tomography (PET) imaging performed in real-time to track and direct radiation. Adequate contrast in FDG activity between the tumor and the background tissue, referred to as the normalized SUV (NSUV), is necessary for optimal functioning of BgRT. This study seeks to characterize the NSUV in patients with liver metastases. Methods We reviewed the charts of 50 lung adenocarcinoma patients with liver metastases. The following variables were collected: SUVmax and SUVmean for each liver metastasis, SUVmean and SUVmax at 5 and 10 mm radially from the lesion, and NSUV at 5 mm and 10 mm (SUVmax of the liver metastasis divided by SUV mean at 5 mm at 10 mm respectively). Results 82 measurable liver metastases were included in the final analysis. The average SUVbackground of liver was 2.26 (95% confidence interval [CI] 2.17–2.35); average SUVmean for liver metastases was 5.31 (95% CI 4.87–5.75), and average SUVmax of liver metastases was 9.19 (95% CI 7.59–10.78). The average SUVmean at 5 mm and 10 mm radially from each lesion were 3.08 (95% CI 3.00-2.16) and 2.60 (95% CI 2.52–2.68), respectively. The mean NSUV at 5 mm and 10 mm were 3.13 (95% CI 2.53–3.73) and 3.69 (95% CI 3.00-4.41) respectively. Furthermore, 90% of lesions had NSUV greater than 1.45 at 5 mm and greater than 1.77 at 10 mm. Conclusion This is the first study to comprehensively characterize FDG contrast between the tumor and the background, or normalized SUV (NSUV), in liver metastases in the context of BgRT. Due to the high background SUV normally found in the liver, this work will be valuable for guiding optimization of BgRT for treating liver metastases in the future.

This study aimed to assess the prognostic value of baseline disease distribution for patients with the secondary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL) treated with chemotherapy and radiation (RT). 44 patients with secondary CNS DLBCL were reviewed. Twenty patients had leptomeningeal disease (LMD), and 24 had localized/targetable disease (LTD). Of 8 patients who received stem cell transplantation (SCT) after RT, 6 had LTD with a complete or partial response after RT. Median time to CNS relapse after RT was 10.1 months; 3/24 patients with LTD and 5/15 with LMD had CNS relapse. The median overall survival (OS) was 8 and 20 months for patients with LMD and LTD, respectively (

Background To determine if proton radiotherapy (PT), compared to intensity-modulated radiotherapy (IMRT), delayed time to cognitive failure in patients with newly diagnosed glioblastoma (GBM). Methods Eligible patients were randomized unblinded to PT vs IMRT. The primary endpoint was time to cognitive failure. Secondary endpoints included overall survival (OS), intracranial progression-free survival (PFS), toxicity, and patient-reported outcomes (PROs). Results A total of 90 patients were enrolled and 67 were evaluable with median follow-up of 48.7 months (range 7.1-66.7). There was no significant difference in time to cognitive failure between treatment arms (HR, 0.88; 95% CI, 0.45-1.75; P = .74). PT was associated with a lower rate of fatigue (24% vs 58%, P = .05), but otherwise, there were no significant differences in PROs at 6 months. There was no difference in PFS (HR, 0.74; 95% CI, 0.44-1.23; P = .24) or OS (HR, 0.86; 95% CI, 0.49-1.50; P = .60). However, PT significantly reduced the radiation dose for nearly all structures analyzed. The average number of grade 2 or higher toxicities was significantly higher in patients who received IMRT (mean 1.15, range 0-6) compared to PT (mean 0.35, range 0-3; P = .02). Conclusions In this signal-seeking phase II trial, PT was not associated with a delay in time to cognitive failure but did reduce toxicity and patient-reported fatigue. Larger randomized trials are needed to determine the potential of PT such as dose escalation for GBM and cognitive preservation in patients with lower-grade gliomas with a longer survival time.

A large proportion of patients with cancer are unresponsive to treatment with immune checkpoint blockade and other immunotherapies. Here, we report a mathematical model of the time course of tumour responses to immune checkpoint inhibitors. The model takes into account intrinsic tumour growth rates, the rates of immune activation and of tumour-immune cell interactions, and the efficacy of immune-mediated tumour killing. For 124 patients, four cancer types and two immunotherapy agents, the model reliably described the immune responses and final tumour burden across all different cancers and drug combinations examined. In validation cohorts from four clinical trials of checkpoint inhibitors (with a total of 177 patients), the model accurately stratified the patients according to reduced or increased long-term tumour burden. We also provide model-derived quantitative measures of treatment sensitivity for specific drug-cancer combinations. The model can be used to predict responses to therapy and to quantify specific drug-cancer sensitivities in individual patients.

Background This retrospective study investigated the impact of, in addition to age, the management and outcomes of elderly patients with glioblastoma (GBM). Methods The National Cancer Database was queried between 2004 and 2015 for GBM patients age 60 years and older. Three age groups were created: 60 to 69, 70 to 79, and 80 years and older, and 4 age/KPS groups: “age ≥ 60/ KPS Results A total of 48 540 patients with a median age of 70 years (range, 60-90 years) at diagnosis, and a median follow-up of 6.8 months (range, 0-151 months) were included. Median survival was 5.0, 15.2, 9.6, and 6.8 months in groups 1, 2, 3, and 4, respectively (P Conclusions In elderly patients with newly diagnosed GBM, those with good KPS fared best with combined ChT and RT across all age groups. Performance status is a key prognostic factor that should be considered for management decisions in these patients.

PURPOSE: To ascertain the dose-toxicity relationship for the prevalence of self-reported trismus in long-term survivors after intensity-modulated radiotherapy (IMRT) for oropharyngeal carcinoma (OPC). MATERIALS AND METHODS: Self-reported mouth opening was ascertained prospectively via a cross-sectional survey of OPC survivors using the intraoral finger-test. RT dose-volume histograms (DVHs) were generated for the following masticatory regions of interest: medial pterygoid, lateral pterygoid, and masseter muscles which were designated as ipsilateral or contralateral to the primary tumor. Trismus was defined as self-reported mouth opening of

BACKGROUND We report outcomes for patients with T2N0M0 glottic squamous cell carcinoma (SCC) treated with radiation therapy (RT). METHODS Patients who received definitive RT for T2 glottic SCC from 2000 through 2013 were retrospectively reviewed. RESULTS One hundred and thirteen patients were analyzed (median follow-up time 91 months; 85 patients received three-dimensional conformal radiotherapy [3D-CRT] and 28 received intensity-modulated radiation therapy [IMRT]). Fractionation was conventional (58%) or altered (42%); 20 patients (18%) received concurrent chemotherapy. Five-year local control was 83% for the 3D-CRT vs 81% for the IMRT group (P = .76). The ultimate locoregional control at 5 years was 100% for IMRT vs 91% for 3D-CRT (P = .1). The 5-year overall survival (OS) was 78% for 3D-CRT vs 81% for IMRT (P = .83). On multivariate analysis, younger age was the only independent predictor of improved OS (P = .0002). CONCLUSIONS Oncologic and survival outcomes were excellent for patients with T2N0 glottic cancer. Patients treated with IMRT and 3D-CRT had no statistically significant differences in all investigated endpoints.

Highlights • There is a strong positive correlation between HU changes in the peri-tumoral region and the grade of RP after SBRT for NSCLC. • V20, MLD, and gEUD are significantly correlated with RP grade. • Relative to model-based methods, PB algorithms overestimate mean peri-tumoral dose. • Relative to model-based methods, PB algorithms show a 10–15% volume displacement of the high-dose region., Background and Purpose To investigate the correlation between normal lung CT density changes with dose accuracy and outcome after stereotactic body radiation therapy (SBRT) for patients with early stage non-small-cell lung cancer (NSCLC). Materials and Methods Thirty-one patients (with a total of 33 lesions) with non-small cell lung cancer were selected out of 270 patients treated with SBRT at a single institution between 2003 and 2009. Out of these 31 patients, 10 patients had developed radiation pneumonitis (RP). Dose distributions originally planned using a 1-D pencil beam-based dose algorithm were retrospectively recomputed using different algorithms. Prescription dose was 48 Gy in 4 fractions in most patients. Planning CT images were rigidly registered to follow-up CT datasets at 3–9 months after treatment. Corresponding dose distributions were mapped from planning to follow-up CT images. Hounsfield Unit (HU) changes in lung density in individual, 5 Gy, dose bins from 5 to 45 Gy were assessed in the peri-tumoral region. Correlations between HU changes in various normal lung regions, dose indices (V20, MLD, generalized equivalent uniform dose (gEUD)), and RP grade were investigated. Results Strong positive correlation was found between HU changes in the peri-tumoral region and RP grade (Spearman’s r = 0.760; p

Background This secondary image analysis of a randomized trial of proton radiotherapy (PT) vs. photon intensity modulated radiotherapy (IMRT) compares tumor progression based on clinical radiological assessment vs. Response Assessment in Neuro-Oncology (RANO). Methods Eligible patients were enrolled in the randomized trial and had MR imaging at baseline and follow-up beyond 12 weeks from completion of radiotherapy. ‘Clinical progression’ was based on a clinical radiology report of progression and/or change in treatment for progression. Results Of 90 enrolled patients, 66 were evaluable. Median clinical progression-free survival (PFS) was 10.8 (Range: 9.4-14.7) months; 10.8 months IMRT vs. 11.2 months PT (p=0.14). Median RANO PFS was 8.2 (Range: 6.9, 12): 8.9 months IMRT vs. 6.6 months PT (p=0.24). RANO PFS was significantly shorter than clinical PFS overall (p=0.001) and for both the IMRT (p=0.01) and PT (p=0.04) groups. There were 31 (46.3%) discrepant cases of which 17 had RANO progression more than a month prior to clinical progression, and 14 had progression by RANO but not clinical criteria. Conclusion Based on this secondary analysis of a trial of PT vs. IMRT for GBM, while no difference in PFS was noted relative to treatment technique, RANO criteria identified progression more often and earlier than clinical assessment. This highlights the disconnect between measures of tumor response in clinical trials versus clinical practice. With growing efforts to utilize real-world data and personalized treatment with timely adaptation, there is a growing need to improve the consistency of determining tumor progression within clinical trials and clinical practice.

High-grade gliomas are an aggressive and invasive malignancy which are susceptible to treatment resistance due to heterogeneity in intratumoral properties such as cell proliferation and density and perfusion. Non-invasive imaging approaches can measure these properties, which can then be used to calibrate patient-specific mathematical models of tumor growth and response. We employed multiparametric magnetic resonance imaging (MRI) to identify tumor extent (via contrast-enhanced T1-weighted, and T2-FLAIR) and capture intratumoral heterogeneity in cell density (via diffusion-weighted imaging) to calibrate a family of mathematical models of chemoradiation response in nine patients with unresected or partially resected disease. The calibrated model parameters were used to forecast spatially-mapped individual tumor response at future imaging visits. We then employed the Akaike information criteria to select the most parsimonious member from the family, a novel two-species model describing the enhancing and non-enhancing components of the tumor. Using this model, we achieved low error in predictions of the enhancing volume (median: − 2.5%, interquartile range: 10.0%) and a strong correlation in total cell count (Kendall correlation coefficient 0.79) at 3-months post-treatment. These preliminary results demonstrate the plausibility of using multiparametric MRI data to inform spatially-informative, biologically-based predictive models of tumor response in the setting of clinical high-grade gliomas.

Osteoradionecrosis (ORN) is a major side-effect of radiation therapy in oropharyngeal cancer (OPC) patients. In this study, we demonstrate that early prediction of ORN is possible by analyzing the temporal evolution of mandibular subvolumes receiving radiation. For our analysis, we use computed tomography (CT) scans from 21 OPC patients treated with Intensity Modulated Radiation Therapy (IMRT) with subsequent radiographically-proven ≥ grade II ORN, at three different time points: pre-IMRT, 2-months, and 6-months post-IMRT. For each patient, radiomic features were extracted from a mandibular subvolume that developed ORN and a control subvolume that received the same dose but did not develop ORN. We used a Multivariate Functional Principal Component Analysis (MFPCA) approach to characterize the temporal trajectories of these features. The proposed MFPCA model performs the best at classifying ORN vs Control subvolumes with an area under curve (AUC) = 0.74 (95% confidence interval (C.I.): 0.61-0.90), significantly outperforming existing approaches such as a pre-IMRT features model or a delta model based on changes at intermediate time points, i.e. at 2- and 6-month follow-up. This suggests that temporal trajectories of radiomics features derived from sequential pre- and post-RT CT scans can provide markers that are correlates of RT-induced mandibular injury, and consequently aid in earlier management of ORN.

Objectives Stereotactic radiosurgery is a common treatment for brain metastases and is typically planned on magnetic resonance imaging (MRI). However, the MR acquisition parameters used for patient selection and treatment planning for stereotactic radiosurgery can vary within and across institutions. In this work, we investigate the effect of MRI slice thickness on the detection and contoured volume of metastatic lesions in the brain. Methods and Materials A retrospective cohort of 28 images acquired with a slice thickness of 1 mm were resampled to simulate acquisitions at 2- and 3-mm slice thickness. A total of 102 metastases ranging from 0.0030 cc to 5.08 cc (75-percentile 0.36 cc) were contoured on the original images. All 3 sets of images were recontoured by experienced physicians. Results Of all the images detected and contoured on the 1 mm images, 3% of lesions were missed on the 2 mm images, and 13% were missed on the 3 mm images. One lesion that was identified on both the 2 mm and 3 mm images was determined to be a blood vessel on the 1 mm images. Additionally, the lesions were contoured 11% larger on the 2 mm and 43% larger on the 3 mm images. Conclusions Using images with a slice thickness >1 mm effects detection and segmentation of brain lesions, which can have an important effect on patient management and treatment outcomes.

Treatment for glioblastoma (GBM) includes surgical resection and adjuvant radiotherapy (RT) and chemotherapy. The optimal time interval between surgery and RT remains unclear. The National Cancer Database (NCDB) was queried for patients with GBM. Overall survival (OS) was estimated using Kaplan-Meier and log-rank tests. Univariate (UVA) and multivariable Cox regression (MVA) modeling was used to determine predictors of OS. A total of 45,942 patients were included. On MVA: younger age, female gender, black ethnicity, higher KPS, obtaining a gross total resection (GTR), MGMT promoter-methylated gene status, unifocal disease, higher RT dose, and RT delay of 4–8 weeks had improved OS. Patients who underwent a subtotal resection (STR) had worsened survival with RT delay ≤4 weeks and patients with GTR had worsened survival when RT was delayed >8 weeks. This analysis suggests that an interval of 4–8 weeks between resection and RT results in better survival. Delays >8 weeks in patients with a GTR and delays

Glioblastoma is an aggressive brain tumor with a propensity for intracranial recurrence. We hypothesized that tumors can be visualized with diffusion tensor imaging (DTI) before they are detected on anatomical magnetic resonance (MR) images. We retrospectively analyzed serial MR images from 30 patients, including the DTI and T1-weighted images at recurrence, at 2 months and 4 months before recurrence, and at 1 month after radiation therapy. The diffusion maps and T1 images were deformably registered longitudinally. The recurrent tumor was manually segmented on the T1-weighted image and then applied to the diffusion maps at each time point to collect mean FA, diffusivities, and neurite density index (NDI) values, respectively. Group analysis of variance showed significant changes in FA (p = 0.01) and NDI (p = 0.0015) over time. Pairwise t tests also revealed that FA and NDI at 2 months before recurrence were 11.2% and 6.4% lower than those at 1 month after radiation therapy (p &lt, 0.05), respectively. Changes in FA and NDI were observed 2 months before recurrence, suggesting that progressive microstructural changes and neurite density loss may be detectable before tumor detection in anatomical MR images. FA and NDI may serve as non-contrast MR-based biomarkers for detecting subclinical tumors.

Background Given the paucity of data and widely variable rates that have been reported, the main objective of this study was to examine the prevalence of HPV-positivity in oropharyngeal squamous cell carcinoma (OPSCC) in Middle Eastern patients presenting to one of the region’s largest tertiary care centers using polymerase chain reaction (PCR) amplification of the HPV E6/E7 oncogenes, a highly sensitive and specific method of detection. Methods Medical charts and archived pathological specimens were obtained for patients diagnosed with biopsy proven oropharyngeal cancer who presented to the American University of Beirut Medical Center between 1972 and 2017. DNA was extracted from paraffin-embedded specimens and tested for 30 high-risk and low-risk papilloma viruses using the PCR-based EUROarray HPV kit (EuroImmun). Results A total of 57 patients with oropharyngeal cancer were initially identified; only 34 met inclusion/exclusion criteria and were included in the present study. Most patients were males (73.5%) from Lebanon (79.4%). The most common primary tumor site was in the base of tongue (50%), followed by the tonsil (41.2%). The majority of patients (85.3%) tested positive for HPV DNA. Conclusion The prevalence of HPV-positivity amongst Middle Eastern OPSCC patients, specifically those from Lebanon, may be far greater than previously thought. The Lebanese population and other neighboring Middle Eastern countries may require a more vigilant approach towards HPV detection and awareness. On an international level, further research is required to better elucidate non-classical mechanisms of HPV exposure and transmission.

Brain metastases are the most common intracranial tumors, occurring in more than 15% of cancer patients. The treatment of brain metastases involves a multidisciplinary approach that may consist of surgery, radiation therapy (stereotactic radiosurgery or whole-brain radiation therapy), and/or systemic therapy. Unfortunately, all these treatment strategies, as well as the disease process itself, can be associated with debilitating and life-altering neurocognitive adverse effects. Balancing the benefits and toxicities of brain metastasis treatment is a challenging task that medical, radiation, and surgical oncologists face daily. Strategies have been developed to try mitigating these toxicities, such as stereotactic radiosurgery, hippocampal avoidance whole-brain radiation therapy, and “neuroprotective” drugs. Efforts have also been deployed in developing formal instruments/battery of tests to capture neurocognitive changes consistently in patients with brain metastases.

To identify a clinically meaningful cut-point for the single item dry mouth question of the MD Anderson Symptom Inventory-Head and Neck module (MDASI-HN).Head and neck cancer survivors who had received radiation therapy (RT) completed the MDASI-HN, the University of Michigan Hospital Xerostomia Questionnaire (XQ), and the health visual analog scale (VAS) of the EuroQol Five Dimension Questionnaire (EQ-5D). The Bayesian information criteria (BIC) were used to test the prediction power of each tool for EQ-5D VAS. The modified Breiman recursive partitioning analysis (RPA) was used to identify a cut point of the MDASI-HN dry mouth score (MDASI-HN-DM) with EQ-5D VAS, using a ROC-based approach; regression analysis was used to confirm the threshold effect size.Two-hundred seven respondents formed the cohort. Median follow-up from the end of RT to questionnaire completion was 88 months. The single item MDASI-HN-DM score showed a linear relationship with the XQ composite score (ρ = 0.80, p 0.001). The MDASI-HN-DM displayed improved model performance for association with EQ-5D VAS as compared to XQ (BIC of 1803.7 vs. 2016.9, respectively). RPA showed that an MDASI-HN-DM score of ≥6 correlated with EQ-5D VAS decline (LogWorth 5.5).The single item MDASI-HN-DM correlated with the multi-item XQ and performed favorably in the prediction of QOL. A MDASI-HN-DM cut point of ≥6 correlated with decline in QOL.

Brain metastases are the most common intracranial tumors, with an incidence rate ranging from 7 to 14 per 100,000. Both the disease process itself and its treatments can be associated with debilitating and life-altering neurocognitive adverse effects. The treatment of brain metastases involves a multidisciplinary team that aims to maximize the benefits and minimize the toxicities of treatment, which may include surgical resection, radiation therapy (stereotactic radiosurgery or whole-brain radiation therapy), and/or systemic therapy. Additionally, strategies have been investigated to prevent and treat these toxicities, such as stereotactic radiosurgery, hippocampal avoidance whole-brain radiation therapy, and “neuroprotective” drugs, respectively. In order to better detect and measure treatment toxicity, efforts have also been deployed in tracking neurocognitive changes consistently in patients with brain metastases.

BACKGROUND While glioblastoma (GBM) is more prevalent in males, studies show that females with GBM tend to have longer overall survival (OS) than males. Pretreatment neutrophil to lymphocyte ratio (NLR) has also proven to be prognostic in GBM, with lower NLR having favorable outcomes. This secondary analysis of a prospective randomized trial of proton vs. photon intensity modulated radiotherapy aims to explore the interaction of gender and NLR on GBM outcomes. METHODS Analysis was performed on the full patient population. Kaplan-Meier methods estimated OS with censoring at last follow-up for those who were alive. Univariate (UVA) and multivariate (MVA)Cox proportional hazards models assessed predictors of OS. RESULTS Of 90 patients, 77 were included (43 males; 34 females) with median age of 52 years (range: 26–82 years). Median OS was longer for females than males (30.7 vs 18.2 months, p=0.004). On UVA, patients with NLR below median value (NLR= 3.1) tended to have longer OS than those above median, though not meeting statistical significance (23.1 vs. 17.9 months, p=0.051). Difference in OS was statistically significant in females (OS 36.4 months NLR >median vs. 16.7 months NLR< median, p=0.002), but not in males (OS 17.8 months NLR >median vs. 19.1 NLR< median, p=0.95). MVA analysis was consistent, with female gender predicting reduced hazard ratio (HR) (0.28, p=0.034) and females with below median NLR showing a reduced HR over those with above median (0.28, p=0.005). Again, males did not benefit (HR 0.90, p=0.77). CONCLUSION Consistent with prior publications, females and all patients with lower pre-treatment NLR with newly diagnosed GBM had longer OS. However, combining these two factors revealed that the benefits from lower pre-treatment NLR were conferred only in females with no impact on males. This different impact of NLR between genders may suggest innate immune differences in gender during response to malignancy.

Objectives: We sought to determine whether smokers with oral cavity squamous cell carcinoma (OCSCC) have tumors with more adverse pathological features than in nonsmokers and whether or not these are predictive of outcomes. Materials and Methods: We retrospectively identified 163 patients with American Joint Committee on Cancer stages I–IVa OCSCC diagnosed between 2005 and 2015 and treated with curative intent. A pathological risk score (PRS) was calculated using the National Comprehensive Cancer Network adverse risk factors: positive margin, extracapsular extension of lymph node metastases, pT3 or pT4 primary, N2 or N3 nodal disease, perineural invasion, and lymphovascular space invasion. Multivariable models were constructed to determine the independent predictors of overall survival (OS), recurrence-free survival (RFS), and PRS. Results: A total of 108 (66.26%) were smokers and 55 nonsmokers. Three-year actuarial OS and RFS were 62% and 68% in smokers and 81% and 69% in nonsmokers, respectively (P = 0.06 and P = 0.63). Smokers were more likely to have advanced disease stage and tumors with aggressive pathological features than nonsmokers. Smokers had significantly worse PRS (mean ± standard deviation; 2.38 ± 2.19, median; 2.00) than nonsmokers (0.89 ± 1.21, 0.00) (P < 0.001). Older age, higher PRS, and smoking status were independent predictors of OS. Smoking or PRS did not predict for worse RFS. On multivariate analysis, independent predictors of PRS were smoking status and grade (P < 0.001). Conclusion: In patients with OCSCC, smokers have more aggressive disease as evidenced by more adverse pathological features than nonsmokers. Moreover, smoking is an independent predictor of OS but not RFS. The PRS is a significant predictor of OS and needs validation in the future studies.

Introduction: Metformin, the most widely used treatment for diabetes, is lethal to cancer cells and increases in toxicity when used in combination with radiation. In addition to various molecular and metabolic mechanisms that have been previously proposed, the studies presented provide evidence of an additional, novel mechanism of sensitization following high dose radiotherapy; the magnitude of sensitization depends on the microenvironmental levels of glucose and oxygen which are in turn affected by high dose radiation. Methods: Cancer cells (A549 and MCF7) were studied in vitro under various controlled conditions. Endpoints included clonogenic cell survival and ROS expression measured by DHE and DCFDA. CD1 nu/nu athymic mice implanted with A549 cells received metformin alone (200 mg/kg, i.p.), radiation alone (15 Gy) or a combination of metformin and radiation; the effect of treatment sequence on efficacy was assessed by tumor growth delay and histology. In a separate set of experiments, tumor blood flow was measured using a tracer clearance technique using SPECT after the administration of metformin alone, radiation alone and the combined treatment. Results: In vivo, metformin provided equally effective tumor growth delay when given 24 hours after radiation as when given 1hour or 4 hours before radiation, an observation not previously reported and, in fact, unexpected based on published scientific literature. When drug followed radiation, the tumors were histologically characterized by massive cellular necrosis. In vitro, cancer cells when glucose depleted and/or hypoxic were preferentially killed by metformin, in a drug dose dependent manner. A549 cells exposed to 5.0 mM of metformin was reduced seven fold in survival when in a glucose deprived as compared to a low-glucose medium (0 vs 1.0 g/L). Finally, using a SPECT detector to follow the washout of a radioactive tracer, it was shown that a high single dose of radiosurgery (15 Gy) could dramatically inhibit blood flow and presumably diminish glucose and oxygen. Discussion: Insight into the best timing of drug and radiation administration is gained through an understanding of the mechanisms of interaction. A new mechanism of metformin sensitization by high dose radiation is proposed based on the blood flow, glucose and oxygen.

Introduction: Using patient-specific imaging data, we aimed to calibrate biologically-based mathematical models of tumor growth and treatment response to forecast the progression of high-grade glioma on an individual patient basis. Methods: Four patients with partially resected or biopsy only, histologically confirmed high grade gliomas were imaged with T2-FLAIR, diffusion weighted (DW-) MRI, and post-contrast T1-weighted MRI at baseline (prior to chemoradiation), and at 1-, 3-, and 5-months following chemoradiation. Patients received standard of care radiotherapy (RT) with concurrent and adjuvant temozolomide. The gross tumor volume (GTV) defined as enhancing tumor and clinical tumor volume (CTV) defined as non-enhancing, T2-hyperintense region were expertly segmented from the post-contrast T1-weighted and T2-FLAIR images, respectively. The apparent diffusion coefficient (ADC) estimated from DW-MRI was used to assign tumor cell number within the GTV. Within the CTV, we interpolated the tumor cell number from 2% of the carrying capacity (at the periphery of the CTV) to the number of cells calculated at the periphery of the GTV. Using this data, a 3D mechanically-coupled, reaction-diffusion model was developed to describe the spatiotemporal evolution of tumor cell number due to proliferation, diffusion, and death due to chemoradiation on an individual patient basis. For each patient, model parameters were calibrated using their cellularity measurements from the entire time course (to evaluate how well the model describes the data) and separately from a subset of the time course (to evaluate how well the model predicts future data). For the prediction scenario, we then used the calibrated parameters in a forward evaluation of the model to predict future tumor growth at the final imaging visit. The model estimates of tumor cellularity where compared directly to the measured tumor distributions at the volume and voxel levels. Results: For the model fit scenario, a strong level of voxel-wise correlation (Pearson correlation coefficients, PCC, ranging from 0.68 to 0.94) and agreement (concordance correlation coefficients, CCC, 0.76 to 0.99) were observed between the calibrated model and the measured cellularity for each patient. Additionally, Dice coefficients (measuring the degree of overlap between calibrated and observed values) ranged from 0.76 to 0.92 at all time points. For the prediction scenario, a strong of voxel-wise correlation (PCC ranging from 0.61 to 0.90) and agreement (CCC ranging from 0.72 to 0.92) were observed between the predicted and estimated cellularity for each patient. A strong level of spatial agreement was also observed with Dice values ranging from 0.65 to 0.84 at all time points. Conclusions: This preliminary study demonstrates that patient-specific imaging data can be used to calibrate a mathematical model that can accurately predict the spatio-temporal distribution of enhancing and non-enhancing glioma. Funding: NCI U01 CA174706, CPRIT RR160005. AAPM Grant 2018 Citation Format: David Andrew Hormuth, Karine Al Feghali, Andrew M. Elliot, Caroline Chung, Thomas E. Yankeelov. A biologically-motivated mathematical model for forecasting chemoradiationresponse in high grade gliomas: Initial results [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5487.

OBJECTIVES: This retrospective study evaluates the impact of Karnofsky performance status (KPS) in addition to age on the management and outcomes of elderly patients with glioblastoma (GBM). METHODS: The National Cancer Database (NCDB) was queried between 2004–2015 for GBM patients with age 60 and reported KPS. Four groups were created: Age 60/ KPS

Background We systematically reviewed the literature for trials addressing the efficacy of prophylactic cranial irradiation (PCI) in patients with non-small-cell lung cancer (NSCLC) treated with a curative intent. Methods Randomized controlled trials (RCT) comparing PCI to no PCI in patients with NSCLC treated with a curative intent were eligible for inclusion. We searched EMBASE, MEDLINE, PubMed, and CENTRAL between 1946 and July 2016. We also received continual search alerts from PubMed through September 2017. Search terms included "non-small-cell lung carcinoma," "cranial irradiation," and "randomized controlled trials." We conducted meta-analyses using random-effects models for relative measures of treatment effect for the incidence of brain metastasis, overall survival (OS), and disease-free survival (DFS). We used Parmar's methodology to derive hazard ratios (HR) when not explicitly stated in RCTs. We narratively synthesized data for the impact of PCI on quality of life (QoL) and neurocognitive function (NCF). We assessed the quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation methodology. Results Out of 3,548 citations captured by the search strategy, we retained 8 papers and 1 abstract, reporting on 6 eligible trials. Patients who received PCI had a significant reduction in the risk of developing brain metastases as compared with patients who did not [relative risk (RR) = 0.37; 95% confidence interval (CI): 0.26-0.52; moderate quality evidence]. However, there was no OS benefit (HR = 1.08, 95% CI: 0.90-1.31; moderate quality evidence). Sensitivity analysis excluding older studies did not show substantively different findings. DFS was reported in the two most recent trials that included only stage III patients. There was significant improvement in DFS with PCI (HR = 0.67; 95% CI: 0.46-0.98; high quality evidence). Two studies that reported on QoL reported no statistically significant differences. There was no significant difference in NCF decline in the only study that reported on this outcome, except in immediate and delayed recall, as assessed by the Hopkins Verbal Learning Test. Conclusion There is moderate quality evidence that the use of PCI in patients with NSCLC decreases the risk of brain metastases, but does not provide an OS benefit. However, data limited to stage III patients suggests that PCI improves DFS, with no effect on QoL.

PURPOSE To compare tumor progression based on clinical radiological assessment and on Response Assessment in Neuro-Oncology (RANO) criteria between GBM patients treated with proton radiotherapy (PT) vs. photon intensity modulated radiotherapy (IMRT). METHODS Eligible patients were enrolled on the described prospective phase II trial and had MR imaging at baseline and follow-up beyond 12 weeks from treatment completion. ‘Clinical’ progression was based on a radiology report of progression in combination with changes in treatment due to suspected disease progression. A single blinded observer applied RANO criteria to determine the RANO-based tumor progression. RESULTS Of 90 enrolled patients, 66 were evaluable, with median follow-up of 19.8 (Range: 3.2–65.1) months; median of 22.6 months for PT (n=25) vs. 18.9 months for IMRT (n=41). Median time to progression (TTP) was 7.9 months based on clinical progression criteria (8.1 months IMRT, 6.3 months PT) and 7.2 months (7.3 months IMRT, 5.7 months PT) by RANO criteria (p=ns for all). Median ‘clinical’ progression-free survival (PFS) was 8.7 (Range: 6.4–11.1) months; 8.9 months IMRT vs. 8.7 months PT (p=0.065). Median RANO PFS was 8.3 (range, 5.8–11.6) months: 8.3 months IMRT vs. 6.9 months PT (p=0.226). There were 14 discrepant cases: 3 had progression based on ‘clinical’ but not RANO criteria, and 11 had progression based on RANO but not ‘clinical’ criteria. CONCLUSION Based on this secondary analysis of a randomized trial of PT vs. IMRT for GBM, there was no difference in tumor progression relative to treatment technique used. There was no statistical difference in PFS noted between clinical and RANO-based assessments, but RANO criteria identified progression more often than clinical assessment, and TTP was shortened with the use of RANO criteria alone. Further development of tumor assessment tools that improve consistency and accuracy of determining tumor progression are needed to guide therapeutic trials in GBM.

Background Linear accelerator–based stereotactic radiosurgery delivered to cardiac arrhythmogenic foci could be a promising catheter‐free ablation modality. We tested the feasibility of in vivo atrioventricular ( AV ) node ablation in swine using stereotactic radiosurgery. Methods and Results Five Large White breed swine (weight 40–75 kg; 4 females) were studied. Single‐chamber St Jude pacemakers were implanted in each pig. The pigs were placed under general anesthesia, and coronary/cardiac computed tomography simulation scans were performed to localize the AV node. Cone beam computed tomography was used for target positioning. Stereotactic radiosurgery doses ranging from 35 to 40 Gy were delivered by a linear accelerator to the AV node, and the pigs were followed up with weekly pacemaker interrogations to observe for potential electrocardiographic changes. Once changes were observed, the pigs were euthanized, and pathology specimens of various tissues, including the AV node and tissues surrounding the AV node, were taken to study the effects of radiation. All 5 pigs had disturbances of AV conduction with progressive transition into complete heart block. Macroscopic inspection did not reveal damage to the myocardium, and pigs had preserved systolic function on echocardiography. Immunostaining revealed fibrosis in the target region of the AV node, whereas no fibrosis was detected in the nontargeted regions. Conclusions Catheter‐free radioablation using linear accelerator–based stereotactic radiosurgery is feasible in an intact swine model.

Every year, almost 62,000 are diagnosed with a head and neck cancer (HNC) and 13,000 will succumb to their disease. In the primary setting, intraoperative radiation therapy (IORT) can be used as a boost in select patients in order to optimize local control. Addition of external beam radiation to limited volumes results in improved disease control over surgery and IORT alone. In the recurrent setting, IORT can improve outcomes from salvage surgery especially in patients previously treated with external beam radiation. The use of IORT remains limited to select institutions with various modalities being currently employed including orthovoltage, electrons, and high-dose rate brachytherapy. Practically, execution of IORT requires a coordinated effort and careful planning by a multidisciplinary team involving the head and neck surgeon, radiation oncologist, and physicist. The current review summarizes common uses, outcomes, toxicities, and technical aspects of IORT in HNC patients.

ObjectiveThe negative impact of comorbidity on survival in women with endometrial carcinoma (EC) is well-known. Few validated comorbidity indices are available for clinical use, such as the Charlson Comorbidity Index (CCI), the Age-Adjusted CCI (AACCI), and the Adult Comorbidity Evaluation-27 (ACE-27). The aim of the study is to determine which index best correlates with survival endpoints in women with EC.Materials and MethodsWe identified 1132 women with early-stage EC treated at an academic center. Three scores were calculated for each patient using CCI, AACCI, and ACE-27 at the time of hysterectomy. Univariate and multivariable modeling was used to determine predictors of survival.ResultsFor each of the studied comorbidity indices, the highest scores were significantly correlated with poorer overall survival. The hazard ratio of death from any cause was 3.92 for AACCI, 2.25 for CCI, and 1.57 for ACE-27. All 3 indices were independent predictors of overall survival with a P value of less than 0.001 on multivariate analysis. In addition, lymphovascular space invasion, lower uterine segment involvement, and tumor grade were predictors of overall survival. Lymphovascular space invasion, grade (P < 0.001), and high AACCI score were the only significant predictors of recurrence-free survival (RFS). Lymphovascular space invasion and tumor grade were the only 2 predictors of disease-specific survival.ConclusionsAlthough all 3 studied comorbidity indices were significant predictors of overall survival in women with early-stage EC, AACCI showed a stronger association. It should be considered for evaluating comorbidity in women with early-stage EC.

Basaloid squamous cell carcinoma (BSCC) is a rare variant of squamous cell carcinoma (SCC), which is highly aggressive, with a tendency for multifocality, local invasion, and with a high metastatic potential. Less than forty cases of BSCC of the sinonasal tract have been reported in the literature, and no reports were found on sinonasal BSCC arising from the ethmoid sinus. We report the case of a 78-year-old man who presented with BSCC arising from the ethmoid sinus with extensive bone destruction and intracranial extension. He was treated with craniofacial resection followed by adjuvant intensity-modulated radiation therapy to the tumor bed (60 Gy in 30 fractions), and the upper neck lymph nodes (50 Gy in 25 fractions). At the patient’s last follow-up, four months after diagnosis, there was no evidence of disease. Aggressive management using craniofacial resection followed by adjuvant radiation therapy with or without radiosensitizing chemotherapy seems to be a reasonable approach to this challenging disease.