Dengue Fever Culminating in Cardiac Arrest: A Case Report.

Infection from the dengue virus can manifest with a variety of clinical presentations. Cardiac involvement from dengue fever is a rarely reported phenomenon with significant morbidity and mortality. We illustrate the case of a 47-year-old male admitted to the hospital with fevers. The hospital course was complicated with cardiac arrest. Clinicians need to be weary of this rare occurrence particularly in areas with a known prevalence of dengue for prompt recognition and improved patient outcomes.

Lower constraint testing enhances the testing effect for some contextual details but not others.

INTRODUCTION: Retrieval practice has been shown to be an effective means of learning new information, a memory phenomenon known as the testing effect or the retrieval practice effect. Some work suggests that the magnitude of the testing effect can be enhanced when the test used for retrieval practice uses fewer cues to retrieve previously studied information. It is unclear, however, whether such testing benefits extend to peripheral contextual details associated with studied materials (e.g., location where stimuli appear, font color in which items are presented, etc.). In this experiment, we examine both item memory (i.e., memory for the studied items) and context memory under conditions where the intervening test offers fewer cues (i.e., lower constraint) compared to more cues (higher constraint) to better understand item and context memory testing effects. METHODS: Participants first studied word pairs presented in one of eight locations as well as in either red or green font color. Then, in the re-exposure phase, participants processed materials in two types of intervening tests (lower constraint and a higher constraint test) as well as in a restudy condition, before a final memory test. RESULTS: For item memory, results showed that memory was better in the lower constraint testing condition compared to both the higher constraint testing condition as well as the restudy (control) condition. For context memory, results indicated improved memory for location context under lower constraint testing compared to both higher constraint testing and restudy conditions. There was no difference in memory, however, for color context across all conditions. CONCLUSION: Overall, these findings suggest that providing fewer cues to aid retrieval in the intervening test can induce better memory for both items as well as some contextual details.

The reciprocal relationship between episodic memory and future thinking: How the outcome of predictions is subsequently remembered.

Evidence suggests that memory is involved in making simulations and predictions about the future (i.e., future thinking), but less work has examined how the outcome of those predictions (whether events play out as predicted or expected) subsequently affects episodic memory. In this investigation, we examine whether memory is better for outcomes that are consistent with predictions, or whether memory is enhanced for outcomes that are inconsistent with predictions, after the predicted event occurs. In this experiment, participants learned a core trait associated with social targets (e.g., high in extroversion), before making predictions about behaviors targets would perform. Participants then were shown behaviors the social targets actually performed (i.e., prediction outcome), which was either consistent or inconsistent with predictions. After that, participants completed a memory test (recognition; recall) for the prediction outcomes. For recognition, the results revealed better memory for outcomes that were consistent with traits associated with targets (i.e., trait-consistent outcomes), compared to outcomes that were inconsistent (i.e., trait-inconsistent outcomes). Finding a memory advantage for trait-consistent outcomes suggests that outcomes that are in line with the contents of memory (e.g., what one knows; schemas) are more readily remembered than those that are inconsistent with memory, which may reflect an adaptive memory process. For recall, memory did not differ between trait-consistent and trait-inconsistent outcomes. Altogether, the results of this experiment advance understanding of the reciprocal relationship between episodic memory and future thinking and show that outcome of predictions has an influence on subsequent episodic memory, at least as measured by recognition.

Exploring the relationship between retrieval practice, self-efficacy, and memory.

Retrieval practice effect refers to improved memory on a final test for information retrieved one or more times. Although past theoretical work identifies cognitive mechanisms to explain retrieval practice benefits, it is possible that improving self-efficacy during learning may also contribute to better memory, in line with limited past work showing a relationship between self-efficacy and memory. Across two experiments, we examine the potential relationship between retrieval practice, self-efficacy, and memory. In Experiment 1, we examined the extent change in self-efficacy accounted for improved memory on a final test after retrieval practice compared with restudy. In Experiment 2, we gave participants (false) feedback that was either negative (i.e., you performed worse than others), neutral (i.e., you performed the same as others), or positive (i.e., you performed better than others) to more directly assess the effects of self-efficacy on memory under retrieval practice conditions. Results of Experiment 1 showed a significant retrieval practice effect, with memory on the final test being better after retrieval practice compared with restudy. Self-efficacy did not significantly mediate the retrieval practice effect. Results of Experiment 2, however, showed that decreases in self-efficacy due to (false) negative feedback resulted in worse memory performance compared with neutral feedback. Such findings may suggest that change in self-efficacy after retrieval practice attempts, particularly negative feedback, affects memory at final test. Overall, these findings suggest a relationship between retrieval practice, self-efficacy, and memory, and imply that interventions that influence self-efficacy may be a plausible mechanism to modulate memory under some conditions.

STOP SHOUTING AT ME: The Influence of Case and Self-Referencing on Explicit and Implicit Memory.

Evidence suggests that physical changes in word appearance, such as those written in all capital letters, and the use of effective encoding strategies, such as self-referential processing, improves memory. In this study we examined the extent both physical changes in word appearance (case) and encoding strategies engaged at study influence memory as measured by both explicit and implicit memory measures. Participants studied words written in upper and lower case under three encoding conditions (self-reference, semantic control, case judgment), which was followed by an implicit (word stem completion) and then an explicit (item and context) memory test. There were two primary results. First, analyses indicated a case enhancement effect for item memory where words written in upper case were better remembered than lower case, but only when participants were prompted to attend to the case of the word. Importantly, this case enhancement effect came at a cost to context memory for words written in upper case. Second, self-referencing increased explicit memory performance relative to control, but there was no effect on implicit memory. Overall, results suggest an item-context memory trade-off for words written in upper case, highlighting a potential downside to writing in all capital letters, and further, that both physical changes to the appearance of words and differing encoding strategies have a strong influence on explicit, but not implicit memory.

The electrocardiographic manifestations and derangements of 2019 novel coronavirus disease (COVID-19).

Electrocardiographic (ECG) findings in patients admitted with COVID-19 and a decision tree to predict their survival were assessed. 145 consecutive patients with severe COVID-19 infection were selected. Patient demographics, ECG variables, peak troponins, use of standard medications, and clinical outcomes were analyzed using descriptive and inferential statistics, and a predictive model of survival was developed using classification tree analysis. Of the 145 admitted patients, 38 (26%) died. Deceased patients were more likely to have a significantly higher incidence of poor R-Wave progression [6 of 37 (16.2%) Vs. 0 of 104 (0%), p < 0.001] as well as prolonged QTc values [24 of 37 (64.9%) Vs. 38 of 99 (38.4%), p 0.006]. Significant ST segment depressions were found in 5 of 37 (13.5%) of the deceased category compared to 0% in the non-deceased (p < 0.01). Right and/or left atrial enlargement was more prevalent in the deceased cohort [7 of 37 (18.9%) Vs. 4 of 104 (3.8%), p = 0.03]. Bundle branch blocks were more prevalent in the deceased group [9 of 35 (25.8%) Vs. 7 of 104 (6.7%), p 0.002]. Peak troponins were significantly higher in the deceased group (1.0 Vs 0.07 ng/ml, p < 0.001) A prediction tree built utilizing age, PACs, troponins and QTc had an accuracy of 85.5%. 65 of 74 patients (87.8%) were correctly predicted to survive, while 23 of 29 (79.3%) were correctly predicted to become deceased. Among patients hospitalized with Covid-19, the parameters of age, QT interval, troponin and PACs are useful for prognostication and help predict survival with reasonable accuracy.

Value-directed memory effects on item and context memory.

The ability to prioritize learning some information over others when that information is considered important or valuable is known as value-directed remembering. In these experiments, we investigate how value influences different aspects of memory, including item memory (memory for the to-be-learned materials) and context memory (memory for peripheral details that occurred when studying items) to get a better understanding of how people prioritize learning information. In this investigation, participants encoded words associated with a range of values (binned into higher, medium, and lower value in Experiment 1, and into higher and lower value in Experiment 2) for a subsequent memory test that measured item memory (Is this item old or new?) as well as both objective context memory (memory for an objectively verifiable contextual detail: In which voice was this item spoken?) and subjective context memory (How many visual, auditory, and extraneous thoughts/feelings can you remember associated with this item?). Results indicated that value influenced item memory but had no effect on objective context memory in both Experiments. In Experiment 2, results showed better subjective context memory for multiple episodic details for higher-value relative to lower-value materials. Overall, these findings suggest that value has a strong influence over some aspects of memory, but not others. This work gives a richer understanding of how people prioritize learning more important over less important information.

The implementation cost of a safety-net hospital program addressing social needs in Atlanta.

OBJECTIVE: To describe the cost of integrating social needs activities into a health care program that works toward health equity by addressing socioeconomic barriers. DATA SOURCES/STUDY SETTING: Costs for a heart failure health care program based in a safety-net hospital were reported by program staff for the program year May 2018-April 2019. Additional data sources included hospital records, invoices, and staff survey. STUDY DESIGN: We conducted a retrospective, cross-sectional, case study of a program that includes health education, outpatient care, financial counseling and free medication; transportation and home services for those most in need; and connections to other social services. Program costs were summarized overall and for mutually exclusive categories: health care program (fixed and variable) and social needs activities. DATA COLLECTION: Program cost data were collected using a activity-based, micro-costing approach. In addition, we conducted a survey that was completed by key staff to understand time allocation. PRINCIPAL FINDINGS: Program costs were approximately $1.33 million, and the annual per patient cost was $1455. Thirty percent of the program costs was for social needs activities: 18% for 30-day supply of medications and addressing socioeconomic barriers to medication adherence, 18% for mobile health services (outpatient home visits), 53% for navigating services through a financial counselor and community health worker, and 12% for transportation to visits and addressing transportation barriers. Most of the program costs were for personnel: 92% of the health care program fixed, 95% of the health care program variable, and 78% of social needs activities. DISCUSSION: Historically, social and health care services are funded by different systems and have not been integrated. We estimate the cost of implementing social needs activities into a health care program. This work can inform implementation for hospitals attempting to address social determinants of health and social needs in their patient population.

Examining the relationship between generation constraint and memory.

Self-generated information is often better remembered than read information (the generation effect). Recent research, however, has shown that generating information under fewer experimental constraints (i.e., fewer limitations on what can be generated) can increase the magnitude of the generation effect. This study systematically varied generation constraint to better understand the effects of constraint on memory. Participants encoded associated cue-target word pairs (above-below) on either the left or right side of a computer monitor. At encoding, generation constraint was manipulated by systematically varying the number of letters given to participants to generate the target word (i.e., above-below; option-choic_; bank-mon__; etc.). At retrieval, participants were given either a recognition, cued recall, or free recall test measuring both item (target word) and context memory (location on the computer monitor). Using mixed-effects logistic regression analyses to control for item-selection effects (e.g., participants producing idiosyncratic targets in some conditions relative to others), results indicated that generation constraint significantly influenced item, but not context (location) memory. The relationship between generation constraint and memory performance, however, differed by the type of memory test administered: Recognition data revealed a curvilinear relationship; cued recall showed a negative, linear relationship; and free recall showed no significant relationship. Overall, these findings provide more evidence that generation constraint has a strong yet complex effect on different aspects of memory, and further delineates some boundary conditions of the influence of generation constraint on memory.

Effects of Survival Processing on Item and Context Memory: Enhanced Memory for Survival-Relevant Details.

Due to the natural selection pressure, certain aspects of memory may have been selected to give humans a survival advantage. Research has demonstrated that processing information for survival relevance leads to better item memory (i.e., the content of information) compared to control conditions. The current study investigates the effects of survival processing on context memory (i.e., memory for peripheral episodic details) and item memory to better understand when the survival processing memory advantage emerges. In this study, participants studied pictures of objects in either a survival or moving (control) condition. Objects were presented in either a plausible color, for example, a red apple, or in an implausible color, such as a green pie. We chose this color plausibility manipulation because color is a detail that conveys information about the fitness (and other diagnostic information) about an item. After studying items, participants made item memory judgments (did you see this item before?) and two context memory judgments: color context (in which color did you see this item?) and source context (in which condition did you see this item?). Results indicated better item memory for materials processed in the survival relative to moving condition. Critically, for color context, there was a condition by plausibility interaction, where memory was best for plausibly colored items in the survival processing condition. There was no difference, however, in source context memory between the survival and moving conditions. These results suggest the survival processing memory advantage extends to contextual details that particularly reflect the survival utility of items such as color.

Theories of the generation effect and the impact of generation constraint: A meta-analytic review.

The generation effect is the memory benefit for self-generated compared with read or experimenter-provided information. In recent decades, numerous theories have been proposed to explain the memory mechanism(s) and boundary conditions of the generation effect. In this meta-analysis and theoretical review, we analyzed 126 articles (310 experiments, 1,653 estimates) to assess 7 prominent theories to determine which theories are supported by the existing literature. Because some theories focus on item memory (memory for the generated target) and others focus on context memory (memory for details associated with the generated target), we examined memory effects for both types of details (item, context) in this meta-analysis. Further, we assessed the influence of generation constraint (how constrained participants are to generate a certain response), which recent work has shown affects the magnitude of the generation effect. Overall, the results of this meta-analysis support some theoretical accounts, but not others, as explanatory mechanisms of the generation effect. Results further showed that generation constraint significantly moderates the magnitude of the generation effect, suggesting that this factor should be rigorously investigated in future work. Overall, this meta-analysis provides a review and examination of generation effect theories, and reveals important areas of future research.

Future thinking about social targets: The influence of prediction outcome on memory.

Work on future thinking suggests that people use what they know about the world (e.g., contents of memory) to make predictions about events to come, which reflects an adaptive use of memory. Less work, however, has examined whether the outcomes of these predictions-whether the outcome is consistent or inconsistent with predictions-influences memory. In two experiments, participants learned trait information about social targets and used that information to predict which of two behaviors social targets would be most likely to engage in: one behavior consistent with previously learned trait information about the target and the other behavior inconsistent. Participants then learned which behavior the social target actually performed (outcome) and then judged whether or not they expected that outcome (expectancy). Across both studies, prediction-consistent outcomes were better remembered than inconsistent ones, suggesting that participants relied on their existing representations of social targets when making memory judgments rather than incorporating inconsistent information into memory. Further, there was a memory advantage for prediction-inconsistent outcomes, but only when participants subjectively rated these outcomes as unexpected. Overall, these findings extend understanding of future thinking and suggest a reliable memory advantage for outcomes that are consistent with predictions.

Fewer generation constraints increase the generation effect for item and source memory through enhanced relational processing.

Memory is often better for information that is self-generated versus read (i.e. the generation effect). Theoretical work attributes the generation effect to two mechanisms: enhanced item-specific and relational processing (i.e. the two-factor theory). Recent work has demonstrated that the generation effect increases when generation tasks place lower, relative to higher, constraints on what participants can self-generate. This study examined whether the effects of generation constraint on memory might be attributable to either mechanism of the two-factor theory. Across three experiments, participants encoded word pairs in two generation conditions (lower- and higher-constraint) and a read control task, followed by a memory test for item memory and two context memory details (source and font color). The results of these experiments support the idea that lower-constraint generation increases the generation effect via enhanced relational processing, as measured through both recognition and cued recall tasks. Results further showed that lower-constraint generation improves context memory for conceptual context (source), but not perceptual context (color), suggesting that this enhanced relational processing may extend to conceptually related details of an item. Overall, these results provide more evidence that fewer generation constraints increase the generation effect and implicate enhanced relational processing as a mechanism for this improvement.

Differential Age Effects of Transcranial Direct Current Stimulation on Associative Memory.

OBJECTIVES: Older adults experience associative memory deficits relative to younger adults (Old & Naveh-Benjamin, 2008). The aim of this study was to test the effect of transcranial direct current stimulation (tDCS) on face-name associative memory in older and younger adults. METHOD: Experimenters applied active (1.5 mA) or sham (0.1 mA) stimulation with the anode placed over the left dorsolateral prefrontal cortex (dlPFC) during a face-name encoding task, and measured both cued recall and recognition performance. Participants completed memory tests immediately after stimulation and after a 24-h delay to examine both immediate and delayed stimulation effects on memory. RESULTS: Results showed improved face-name associative memory performance for both recall and recognition measures, but only for younger adults, whereas there was no difference between active and sham stimulation for older adults. For younger adults, stimulation-induced memory improvements persisted after a 24-h delay, suggesting delayed effects of tDCS after a consolidation period. DISCUSSION: Although effective in younger adults, these results suggest that older adults may be resistant to this intervention, at least under the stimulation parameters used in the current study. This finding is inconsistent with a commonly seen trend, where tDCS effects on cognition are larger in older than younger adults.

Transcranial direct current stimulation of dorsolateral prefrontal cortex during encoding improves recall but not recognition memory.

Prior work demonstrates that application of transcranial direct current stimulation (tDCS) improves memory. In this study, we investigated tDCS effects on face-name associative memory using both recall and recognition tests. Participants encoded face-name pairs under either active (1.5mA) or sham (.1mA) stimulation applied to the scalp adjacent to the left dorsolateral prefrontal cortex (dlPFC), an area known to support associative memory. Participants' memory was then tested after study (day one) and then again after a 24-h delay (day two), to assess both immediate and delayed stimulation effects on memory. Results indicated that active relative to sham stimulation led to substantially improved recall (more than 50%) at both day one and day two. Recognition memory performance did not differ between stimulation groups at either time point. These results suggest that stimulation at encoding improves memory performance by enhancing memory for details that enable a rich recollective experience, but that these improvements are evident only under some testing conditions, especially those that rely on recollection. Overall, stimulation of the dlPFC could have led to recall improvement through enhanced encoding from stimulation or from carryover effects of stimulation that influenced retrieval processes, or both.

Transcranial stimulation over the left inferior frontal gyrus increases false alarms in an associative memory task in older adults.

BACKGROUND: Transcranial direct current stimulation (tDCS) is a potential tool for alleviating various forms of cognitive decline, including memory loss, in older adults. However, past effects of tDCS on cognitive ability have been mixed. One important potential moderator of tDCS effects is the baseline level of cognitive performance. METHODS: We tested the effects of tDCS on face-name associative memory in older adults, who suffer from performance deficits in this task relative to younger adults. Stimulation was applied to the left inferior prefrontal cortex during encoding of face-name pairs, and memory was assessed with both a recognition and recall task. RESULTS: Face-name memory performance was decreased with the use of tDCS. This result was driven by increased false alarms when recognizing rearranged face-name pairs. CONCLUSIONS: This result suggests that tDCS can lead to increased false alarm rates in recognition memory, and that effects of tDCS on a specific cognitive task may depend upon cognitive capability for that task.

The Role of Lung Lobes in Radiation Pneumonitis and Radiation-Induced Inflammation in the Lung: A Retrospective Study.

OBJECTIVE: We examined the relative response to radiation of the upper lung lobes (UL) versus lower lung lobes (LL) of normal lung tissue using normalized [18F]-fluorodeoxyglucose (FDG) uptake per radiation dose received per lung voxel in patients treated with either photons or protons and tested for correlation of the radiation response with clinical pneumonitis. METHODS: Seventy-five patients (photon (n = 51) or proton (n = 24)) treated for esophageal cancer from November 1, 2003 to May 15, 2011 who received restaging FDG-positron emission tomography (PET) imaging 1 to 3 months after chemoradiation were selected. UL and LL were contoured using the major fissure as the boundary, with the right middle lobe being included in the right UL structure. Pneumonitis toxicity was scored using the Common Terminology Criteria for Adverse Events, version 4.0 based on the consensus of 5 clinicians. RESULTS: LL had a higher mean dose (15.6 Gy vs. 10.4 Gy, p<0.001), higher mean standard uptake value (SUV) (0.78 vs. 0.56, p=0.001) and SUV in low dose regions (0.80 vs. 0.66 for 10 to 20 Gy, p=0.001), and lower mean dose response (0.015 vs. 0.019, p=0.003) compared to the UL. The mean dose ratio of UL vs. LL (p < 0.001), and SUV in the region of lung receiving 0-10 Gy (p=0.04), but not the dose response ratio of UL vs. LL (p=0.53) correlated with symptomatic pneumonitis. CONCLUSION: Upper lung lobes had a greater pulmonary metabolic radiation response than lower lung lobes. Greater dose to UL relative to LL and higher SUV in the low dose region (10-20 Gy) on post-treatment PET correlated with symptomatic pneumonitis.

Metformin use and improved response to therapy in esophageal adenocarcinoma.

BACKGROUND: We investigated the radiographic and pathologic response rate of esophageal adenocarcinoma treated with neoadjuvant chemoradiation in patients taking metformin. MATERIAL AND METHODS: Two hundred eighty-five patients with esophageal adenocarcinoma treated with concurrent chemoradiation (CRT) followed by esophagectomy from 1997 to 2012 were included in the study, including 29 diabetics taking metformin, 21 diabetics not taking metformin and 235 non-diabetics. Pre- and post-treatment positron emission tomography (PET) scans were available for 204 patients. Pathologic response was graded at the time of surgery. Response rates were compared using both the χ(2) statistic as well as ANOVA with post-hoc LSD analysis. Multivariate logistic regression analysis was performed to control for predictors of pathologic complete response (CR) after CRT. RESULTS: The overall rate of pathologic CR for the study population was 20%. The pathologic CR rate was higher in patients taking metformin (34.5%), compared to diabetic patients not taking metformin (4.8%, p = 0.01) and non-diabetic patients (19.6%, p = 0.05). Pathologic CR was related to metformin dose, with ≥ 1500 mg/d associated with a higher CR rate. No significant difference seen in pre-CRT maximum tumor SUV (p = 0.93), however post-CRT maximum SUV was significantly decreased in patients taking metformin (p = 0.05). On multivariate logistic regression, metformin use was independently associated with pathologic CR (p = 0.04). Metformin use was also associated with decreased in field loco-regional failure following radiation (p = 0.05). CONCLUSION: Metformin use is associated with a dose-dependent increased response to CRT in esophageal cancer and may be a sensitizer to this therapy.

Proton therapy radiation pneumonitis local dose-response in esophagus cancer patients.

PURPOSE: This study quantifies pulmonary radiation toxicity in patients who received proton therapy for esophagus cancer. MATERIALS/METHODS: We retrospectively studied 100 esophagus cancer patients treated with proton therapy. The linearity of the enhanced FDG uptake vs. proton dose was evaluated using the Akaike Information Criterion (AIC). Pneumonitis symptoms (RP) were assessed using the Common Toxicity Criteria for Adverse Events version 4.0 (CTCAEv4). The interaction of the imaging response with dosimetric parameters and symptoms was evaluated. RESULTS: The RP scores were: 0 grade 4/5, 7 grade 3, 20 grade 2, 37 grade 1, and 36 grade 0. Each dosimetric parameter was significantly higher for the symptomatic group. The AIC winning models were 30 linear, 52 linear quadratic, and 18 linear logarithmic. There was no significant difference in the linear coefficient between models. The slope of the FDG vs. proton dose response was 0.022 for the symptomatic and 0.012 for the asymptomatic (p=0.014). Combining dosimetric parameters with the slope did not improve the sensitivity or accuracy in identifying symptomatic cases. CONCLUSIONS: The proton radiation dose response on FDG PET/CT imaging exhibited a predominantly linear dose response on modeling. Symptomatic patients had a higher dose response slope.

[18F]-FDG uptake dose-response correlates with radiation pneumonitis in lung cancer patients.

PURPOSE: To quantify the post-radiotherapy 2-[(18)F]-fluoro-2-deoxyglucose (FDG) pulmonary uptake dose-response in lung cancer patients and determine its relationship with radiation pneumonitis symptoms. METHODS AND MATERIALS: The data from 24 patients treated for lung cancer with thoracic radiotherapy who received restaging PET/CT imaging between 4 and 12 weeks after radiotherapy completion were evaluated. Their radiation dose distribution was registered with the post-treatment restaging PET/CT. Using histogram analysis, the voxel average FDG-PET uptake vs. radiation dose was obtained for each case and linear regression was performed. The resulting slope, the pulmonary metabolic radiation response (PMRR), was used to characterize the dose-response. The Common Toxicity Criteria version 3 was used to score clinical pulmonary toxicity symptoms. Receiver operating characteristic (ROC) curves were used to determine the level of FDG uptake vs. dose, MLD, V(5), V(10), V(20), and V(30) that can best predict symptomatic and asymptomatic patients. RESULTS: The median time between radiotherapy completion and FDG-PET imaging was 59 days (range, 26-70 days). The median of the mean SUV from lung that received 0-5 Gy was 1.00 (range, 0.37-1.48), 5-10 Gy was 1.01 (range, 0.37-1.77), 10-20 Gy was 1.04 (0.42-1.53), and >20 Gy was 1.29 (range, 0.41-8.01). Using the dose range of 0 Gy to the maximum dose minus 10 Gy, hierarchical linear regression model of the radiation dose and normalized FDG uptake per case found an adequate fit with the linear model. Pneumonitis scores were: Grade 0 for 13, Grade 1 for 5, Grade 2 for 6, and Grade 3, 4 or 5 for none. Using a PMRR threshold of 0.017 yields an associated true positive rate of 0.67 and false positive rate of 0.15 with average error of 30%. A V(5) threshold of 57.6 gives an associated true positive rate of 0.67 and false positive rate of 0.05 with a 20% average error. CONCLUSION: The metabolic radiation pneumonitis dose-response was evaluated from post-treatment FDG-PET/CT imaging. Statistical modeling found a linear relationship. The FDG uptake dose-response and V(5) correlated with symptomatic radiation pneumonitis.