Leading the Way: AJR Podcast Series on Training and Education, Episode 1.

In this episode of the AJR Podcast Series on Training and Education, Pamela Schaefer, MD, joins host Monica Cheng, MD, to discuss incorporating education into radiology careers. Dr. Schaefer shares her journey, the role of leadership, and advice for aspiring educators.

In this episode of the AJR Podcast Series on Training and Education, Pamela Schaefer, MD, joins host Monica Cheng, MD, to discuss incorporating education into radiology careers. Dr. Schaefer shares her journey, the role of leadership, and advice for aspiring educators.

Trust: The Foundation of Radiologic Excellence.

OBJECTIVE. Although trust is a topic infrequently discussed at professional meetings and in professional journals, it constitutes the foundation of radiologic excellence. Trust is an attribute of persons; it cannot be attained by technology. CONCLUSION. Clarifying the meaning of trust and understanding how it is built up and lost and the steps radiologists can take to enhance trust are vital professional missions.

Humanism: AJR Podcast Series on Training and Education, Episode 3.

In this episode of the AJR Podcast Series on Training and Education, Richard Gunderman, MD, PhD, joins host Monica Cheng, MD, to discuss humanism in radiology, emphasizing compassionate patient care, stewardship, the role of personal and larger narratives, and maintaining human connection amidst rising clinical volumes and evolving radiology practices.

Science of Learning: AJR Podcast Series on Training and Education, Episode 4.

In this episode of the AJR Podcast Series on Training and Education, Eric Tung, MD, joins host Monica Cheng, MD, to discuss the value of clinician educator tracks, peer teaching, and evidence-based learning principles to maximize successful learning outcomes.

Insights Into Radiology Residency Education and Recruitment: AJR Podcast Series on Training and Education, Episode 2.

In this episode of the AJR Podcast Series on Training and Education, Shaunagh McDermott, MBBCH, BAO, radiology residency program director at Massachusetts General Hospital, joins host Monica Cheng, MD, to share insights into radiology residency education, recruitment, and ways to cultivate a culture of learning and growth.

Inherited forms of bladder cancer: a review of Lynch syndrome and other inherited conditions.

Environmental factors that play a role in the urothelial carcinogenesis have been well characterized. Current research is continuously exploring potential heritable forms of bladder cancer. Lynch syndrome is a well-known inheritable disease that increases the risk for a variety of cancers, including urothelial carcinomas. Screening of patients with known Lynch syndrome is important to evaluate for development of new primary tumors. Further study may provide more information on what level of follow-up each patient needs. Recent data suggest that mismatch repair mutations confer a greater risk for urothelial cancer. Additional large patient series as well as advancement of molecular testing may provide triage for Lynch syndrome patients in regards to the frequency and type of screening best suited for individual patient.

A Putative O-Linked ß-N-Acetylglucosamine Transferase Is Essential for Hormogonium Development and Motility in the Filamentous Cyanobacterium Nostoc punctiforme.

Most species of filamentous cyanobacteria are capable of gliding motility, likely via a conserved type IV pilus-like system that may also secrete a motility-associated polysaccharide. In a subset of these organisms, motility is achieved only after the transient differentiation of hormogonia, which are specialized filaments that enter a nongrowth state dedicated to motility. Despite the fundamental importance of hormogonia to the life cycles of many filamentous cyanobacteria, the molecular regulation of hormogonium development is largely undefined. To systematically identify genes essential for hormogonium development and motility in the model heterocyst-forming filamentous cyanobacterium Nostoc punctiforme, a forward genetic screen was employed. The first gene identified using this screen, designated ogtA, encodes a putative O-linked ß-N-acetylglucosamine transferase (OGT). The deletion of ogtA abolished motility, while ectopic expression of ogtA induced hormogonium development even under hormogonium-repressing conditions. Transcription of ogtA is rapidly upregulated (1 h) following hormogonium induction, and an OgtA-GFPuv fusion protein localized to the cytoplasm. In developing hormogonia, accumulation of PilA but not HmpD is dependent on ogtA Reverse transcription-quantitative PCR (RT-qPCR) analysis indicated equivalent levels of pilA transcript in the wild-type and ΔogtA mutant strains, while a reporter construct consisting of the intergenic region in the 5' direction of pilA fused to gfp produced lower levels of fluorescence in the ΔogtA mutant strain than in the wild type. The production of hormogonium polysaccharide in the ΔogtA mutant strain is reduced compared to that in the wild type but comparable to that in a pilA deletion strain. Collectively, these results imply that O-GlcNAc protein modification regulates the accumulation of PilA via a posttranscriptional mechanism in developing hormogonia.IMPORTANCE Filamentous cyanobacteria are among the most developmentally complex prokaryotes. Species such as Nostoc punctiforme develop an array of cell types, including nitrogen-fixing heterocysts, spore-like akinetes, and motile hormogonia, that function in dispersal as well as the establishment of nitrogen-fixing symbioses with plants and fungi. These symbioses are major contributors to global nitrogen fixation. Despite the fundamental importance of hormogonia to the life cycle of filamentous cyanobacteria and the establishment of symbioses, the molecular regulation of hormogonium development is largely undefined. We employed a genetic screen to identify genes essential for hormogonium development and motility in Nostoc punctiforme The first gene identified using this screen encodes a eukaryotic-like O-linked ß-N-acetylglucosamine transferase that is required for accumulation of PilA in hormogonia.

Fat-containing adnexal masses on MRI: solid tissue volume and fat distribution as a guide for O-RADS Score assignment.

PURPOSE: To explore ways to improve O-RADS MRI scoring for fat-containing adnexal masses, by investigating methods for quantifying solid tissue volume and fat distribution and evaluating their associations with malignancy. METHODS: This retrospective, single-center study included patients with fat-containing adnexal masses on MRI during 2008-2021. Two radiologists independently reviewed overall size (Sizeoverall), size of any solid tissue (Sizeanysolid), size of solid tissue that was not Rokitansky nodule (Sizenon-Rokitansky), and fat distribution. Wilcoxon test, Fisher-exact test, and ROC curve analysis were performed. Reference standard was pathology or follow-up > 24 months. RESULTS: 188 women (median age 35 years) with 163 benign and 25 malignant lesions were included. Sizeoverall (R1, 9.9 cm vs 5.9 cm; R2, 12.4 cm vs 6.0 cm), Sizeanysolid (R1, 5.1 cm vs 1.2 cm; R2, 3.2 cm vs 0.0 cm), Sizenon-Rokitansky (R1, 5.1 cm vs 0.0 cm; R2, 3.1 cm vs 0.0 cm), and fat distribution differed significantly between malignant and benign lesions (p < 0.01). Area under ROC curve was greatest using Sizenon-Rokitansky (R1, 0.83; R2, 0.86) vs Sizeoverall (R1, 0.78; R2, 0.81) or Sizeanysolid (R1, 0.79; R2, 0.81), though differences were non-significant (p = 0.48-0.93). Cutoffs for Sizenon-Rokitansky (R1, ≥ 1.2 cm; R2, ≥ 1.0 cm) yielded sensitivity and specificity of 0.72 and 0.93 (R1) and 0.76 and 0.95 (R2). Among immature teratomas, 85.7% displayed scattered fat. CONCLUSION: Overall size, size of (any or non-Rokitansky-nodule) solid tissue, and fat distribution differed between benign and malignant fat-containing adnexal masses. Incorporating these would constitute simple and practical approaches to refining O-RADS MRI scoring.

Sarcomatoid renal cell carcinoma: MRI features and their association with survival.

OBJECTIVE: To evaluate MRI features of sarcomatoid renal cell carcinoma (RCC) and their association with survival. METHODS: This retrospective single-center study included 59 patients with sarcomatoid RCC who underwent MRI before nephrectomy during July 2003-December 2019. Three radiologists reviewed MRI findings of tumor size, non-enhancing areas, lymphadenopathy, and volume (and percentage) of T2 low signal intensity areas (T2LIA). Clinicopathological factors of age, gender, ethnicity, baseline metastatic status, pathological details (subtype and extent of sarcomatoid differentiation), treatment type, and follow-up were extracted. Survival was estimated using Kaplan-Meier method and Cox proportional-hazards regression model was used to identify factors associated with survival. RESULTS: Forty-one males and eighteen females (median age 62 years; interquartile range 51-68) were included. T2LIAs were present in 43 (72.9%) patients. At univariate analysis, clinicopathological factors associated with shorter survival were: greater tumor size (> 10 cm; HR [hazard ratio] = 2.44, 95% CI 1.15-5.21; p = 0.02), metastatic lymph nodes (present; HR = 2.10, 95% CI 1.01-4.37; p = 0.04), extent of sarcomatoid differentiation (non-focal; HR = 3.30, 95% CI 1.55-7.01; p < 0.01), subtypes other than clear cell, papillary, or chromophobe (HR = 3.25, 95% CI 1.28-8.20; p = 0.01), and metastasis at baseline (HR = 5.04, 95% CI 2.40-10.59; p < 0.01). MRI features associated with shorter survival were: lymphadenopathy (HR = 2.24, 95% CI 1.16-4.71; p = 0.01) and volume of T2LIA (> 3.2 mL, HR = 4.22, 95% CI 1.92-9.29); p < 0.01). At multivariate analysis, metastatic disease (HR = 6.89, 95% CI 2.79-16.97; p < 0.01), other subtypes (HR = 9.50, 95% CI 2.81-32.13; p < 0.01), and greater volume of T2LIA (HR = 2.51, 95% CI 1.04-6.05; p = 0.04) remained independently associated with worse survival. CONCLUSION: T2LIAs were present in approximately two thirds of sarcomatoid RCCs. Volume of T2LIA along with clinicopathological factors were associated with survival.

Highly variable biodistribution of 68Ga labeled somatostatin analogues 68Ga-DOTA-NOC and 68Ga-DOTA-TATE in neuroendocrine tumors: clinical implications for somatostatin receptor directed PET/CT.

Background: Somatostatin receptor (SSTR)-targeted positron emission tomography/computed tomography (PET/CT) imaging has risen to the forefront for neuroendocrine tumor (NET) detection and management, yet the variability of significant uptake variability (SUV) as a semiquantitative measure of disease detection and tumor response to treatment has not been fully explored. Methods: We assess the reproducibility and interscan variability of SUV metrics of normal tissue and NET in serial 68Ga-DOTA-NOC and 68Ga-DOTA-TATE PET imaging to clinically monitor disease state. Eighty-one patients were enrolled in this retrospective study. Results: Both primary and metastatic hepatic lesions demonstrated SUV (SUVmean 16.5±8.0). The median SUVmean was 16 for the spleen, 9.7 for the pituitary, 12.6 for the adrenal glands, and 4.8 for the liver. The normal pituitary gland demonstrates focal homogenous uptake with SUVmax range of 4.5-23. The adrenal gland showed uptake with SUVmax range of 4.1-29.4, which is more than two times greater than liver uptake (SUVmean range, 2.3-12.4). Highest physiological uptake seen in the spleen (average SUVmean of 17.3, range of 5.4-34.4). Conclusions: The highly variable nature of regional SUVmean and SUVmax in both physiologic tissue and lesions suggests the need for incorporation of more reliable quantitative measures for clinical decision making.

In Vivo Quantitative Whole-Body Perfusion Imaging Using Radiolabeled Copper(II) Bis(Thiosemicarbazone) Complexes and Positron Emission Tomography (PET).

Traditional quantitative perfusion imaging methods require complex data acquisition and analysis strategies; typically require ancillary arterial blood sampling for measurement of input functions; are limited to single organ or tissue regions in an imaging session; and because of their complexity, are not well suited for routine clinical implementation in a standardized fashion that can be readily repeated across diverse clinical sites. The whole-body perfusion method described in this chapter has the advantages of on-demand radiotracer production; simple tissue pharmacokinetics enabling standardized estimation of perfusion; short-lived radionuclides, facilitating repeat or combination imaging procedures; and scalability to support widespread clinical implementation. This method leverages the unique physiological characteristics of radiolabeled copper(II) bis(thiosemicarbazone) complexes and the detection sensitivity of positron emission tomography (PET) to produce quantitatively accurate whole-body perfusion images. This chapter describes the synthesis of ethylglyoxal bis(thosemicarbazonato)copper(II) labeled with copper-62 ([62Cu]Cu-ETS), its unique physiological characteristics, a simple tracer kinetic model for estimation of perfusion using image-derived input functions, and validation of the method against a reference standard perfusion tracer. A detailed description of the methods is provided to facilitate implementation of the perfusion imaging method in PET imaging facilities.

Medication Complexity Among Older Adults with HF: How Can We Assess Better?

Medical management of heart failure (HF) has evolved and has achieved significant survival benefits, resulting in highly complex medication regimens. Complex medication regimens create challenges for older adults, including nonadherence and increased adverse drug events, especially associated with cognitive impairment, physical limitations, or lack of social support. However, the association between medication complexity and patients' health outcomes among older adults with HF is unclear. The purpose of this review is to address how the complexity of HF medications has been assessed in the literature and what clinical outcomes are associated with medication regimen complexity in HF. Further, we aimed to explore how older adults were represented in those studies. The Medication Regimen Complexity Index was the most commonly used tool for assessment of medication regimen complexity. Rehospitalization was most frequently assessed as the clinical outcome, and other studies used medication adherence, quality of life, healthcare utilization, healthcare cost, or side effect. However, the studies showed inconsistent results in the association between the medication regimen complexity and clinical outcomes. We also identified an extremely small number of studies that focused on older adults. Notably, current medication regimen complexity tools did not consider a complicated clinical condition of an older adult with multimorbidity, therapeutic competition, drug interactions, or altered tolerance to the usual dose strength of the medications. Furthermore, the outcomes that studies assessed were rarely comprehensive or patient centered. More studies are required to fill the knowledge gap identifying more comprehensive and accurate medication regimen complexity tools and more patient-centered outcome assessment.

T1 mapping for the diagnosis of early chronic pancreatitis: correlation with Cambridge classification system.

OBJECTIVE: This study aims to determine if T1 relaxation time of the pancreas can detect parenchymal changes in early chronic pancreatitis (CP). METHODS: This study retrospectively analyzed 42 patients grouped as no CP (Cambridge 0; n = 21), equivocal (Cambridge 1; n = 12) or mild CP (Cambridge 2; n = 9) based on magnetic resonance cholangiopancreatography findings using the Cambridge classification as the reference standard. Unenhanced T1 maps were acquired using a three-dimensional dual flip-angle gradient-echo technique on the same 1.5 T scanner with the same imaging parameters. RESULTS: There was no significant difference between the T1 relaxation times of Cambridge 0 and 1 group (p = 0.58). There was a significant difference (p = 0.0003) in the mean T1 relaxation times of the pancreas between the combined Cambridge 0 and 1 (mean = 639 msec, 95% CI: 617, 660) and Cambridge 2 groups (mean = 726 msec, 95% CI: 692, 759). There was significant difference (p = 0.0009) in the mean T1 relaxation times of the pancreas between the Cambridge 0 (mean = 636 msec, 95% CI: 606, 666) and Cambridge 2 groups (mean = 726 msec, 95% CI: 692,759) as well as between Cambridge 1 (mean = 643 msec, 95% CI: 608, 679) and Cambridge 2 groups (mean = 726 msec, 95% CI: 692,759) (p = 0.0017). Bland-Altman analysis showed measurements of one reader to be marginally higher than the other by 15.7 msec (2.4%, p = 0.04). CONCLUSION: T1 mapping is a practical method capable of quantitatively reflecting morphologic changes even in the early stages of chronic pancreatitis, and demonstrates promise for future implementation in routine clinical imaging protocols. ADVANCES IN KNOWLEDGE: T1 mapping can distinguish subtle parenchymal changes seen in early stage CP, and demonstrates promise for implementation in routine imaging protocols for the diagnosis of CP.

Genetic Variations in the Transforming Growth Factor-ß1 Pathway May Improve Predictive Power for Overall Survival in Non-small Cell Lung Cancer.

Purpose: Transforming growth factor-ß1 (TGF-ß1), a known immune suppressor, plays an important role in tumor progression and overall survival (OS) in many types of cancers. We hypothesized that genetic variations of single nucleotide polymorphisms (SNPs) in the TGF-ß1 pathway can predict survival in patients with non-small cell lung cancer (NSCLC) after radiation therapy. Materials and Methods: Fourteen functional SNPs in the TGF-ß1 pathway were measured in 166 patients with NSCLC enrolled in a multi-center clinical trial. Clinical factors, including age, gender, ethnicity, smoking status, stage group, histology, Karnofsky Performance Status, equivalent dose at 2 Gy fractions (EQD2), and the use of chemotherapy, were first tested under the univariate Cox's proportional hazards model. All significant clinical predictors were combined as a group of predictors named "Clinical." The significant SNPs under the Cox proportional hazards model were combined as a group of predictors named "SNP." The predictive powers of models using Clinical and Clinical + SNP were compared with the cross-validation concordance index (C-index) of random forest models. Results: Age, gender, stage group, smoking, histology, and EQD2 were identified as significant clinical predictors: Clinical. Among 14 SNPs, BMP2:rs235756 (HR = 0.63; 95% CI:0.42-0.93; p = 0.022), SMAD9:rs7333607 (HR = 2.79; 95% CI 1.22-6.41; p = 0.015), SMAD3:rs12102171 (HR = 0.68; 95% CI: 0.46-1.00; p = 0.050), and SMAD4: rs12456284 (HR = 0.63; 95% CI: 0.43-0.92; p = 0.016) were identified as powerful predictors of SNP. After adding SNP, the C-index of the model increased from 84.1 to 87.6% at 24 months and from 79.4 to 84.4% at 36 months. Conclusion: Genetic variations in the TGF-ß1 pathway have the potential to improve the prediction accuracy for OS in patients with NSCLC.

Primary midgut volvulus in a patient with Marfan syndrome.

Marfan syndrome is a mutation in the fibrillin-1 gene resulting in a connective tissue disorder primarily affecting musculoskeletal, cardiovascular and ocular systems. However, patients with Marfan's rarely manifest gastrointestinal symptoms. Midgut volvulus is abnormal twisting of small bowel around its mesentery that can result in compromising blood flow to the bowel causing intestinal ischemia and obstruction. Primary midgut volvulus is a term used when there is no underlying cause for the volvulus. This case describes an 80-year-old female with Marfan syndrome presenting with primary midgut volvulus, which preoperatively was suspected based on imaging, and later confirmed upon operative exploration. The small bowel mesentery was long with a narrow base twisted around its mesentery 360°. The long narrow base and floppy mesentery likely contributed to hypermobility leading to volvulus and small bowel obstruction. To our knowledge, this is the first reported case of primary midgut volvulus associated with Marfan's syndrome.

Modern Radiation Further Improves Survival in Non-Small Cell Lung Cancer: An Analysis of 288,670 Patients.

Background: Radiation therapy plays an increasingly important role in the treatment of patients with non-small-cell lung cancer (NSCLC). The purpose of the present study is to assess the survival outcomes of radiotherapy treatment compared to other treatment modalities and to determine the potential role of advanced technologies in radiotherapy on improving survival. Methods: We used cancer incidence and survival data from the Surveillance, Epidemiology, and End Results database linked to U.S. Census data to compare survival outcomes of 288,670 patients with stage I-IV NSCLC treated between 1999 and 2008. The primary endpoint was overall survival. Results: Among the 288,670 patients diagnosed with stage I-IV NSCLC, 92,374 (32%) patients received radiotherapy-almost double the number receiving surgery (51,961, 18%). Compared to other treatment groups and across all stages of NSCLC, patients treated with radiotherapy showed greater median and overall survival than patients without radiation treatment (p < 0.0001). Radiotherapy had effectively improved overall survival regardless of age, gender, and histological categorization. Radiotherapy treatment received during the recent time period 2004 - 2008 is correlated with enhanced survival compared to the earlier time period 1999 - 2003. Conclusion: Radiation therapy was correlated with increased overall survival for all patients with primary NSCLC across stages. Combined surgery and radiotherapy treatment also correlates with improved survival, signaling the value of bimodal or multimodal treatments. Population-based increases in overall survival were seen in the recent time period, suggesting the potential role of advanced radiotherapeutic technologies in enhancing survival outcomes for lung cancer patients.

Relationship Between Clinicopathological Characteristics and PET/CT Uptake in Esophageal Squamous Cell Carcinoma: [18F]Alfatide versus [18F]FDG.

PURPOSE: To assess a novel radiotracer aluminum [18F]fluoride-1,4,7-triazacyclononane-triacetic acid-pegylated dimeric RGD ([18F]ALF-NOTA-PRGD2, denoted as [18F]Alfatide) for positron emission tomography (PET)/X-ray computed tomography (CT) and explore the relationships between clinicopathological characteristics and maximum standard uptake values in primary (SUVP) and metastatic lymph nodes (SUVLN) of patients with esophageal squamous cell carcinoma (ESCC), as verified by pathologic examination and compared with those obtained with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]DG) PET. PROCEDURES: We prospectively enrolled patients with newly diagnosed ESCC who agreed to undergo [18F]Alfatide PET/CT or [18F]FDG PET/CT scans before surgery at Shandong Cancer Hospital from May 2011 to July 2017. SUVs and the pathological tumor-node-metastasis (pTNM) stages of primary tumors and metastatic lymph nodes (LNs) were measured and confirmed pathologically. Immunohistochemical (IHC) staining for integrin αvß3 was performed on tumor samples (both primary tumors and metastatic LNs) collected from nine patients. RESULTS: Of 61 patients who underwent PET/CT scans, 46 then underwent curative surgery and were included in our analysis (n = 21 for [18F]Alfatide PET/CT and n = 25 for [18F]FDG PET/CT). No significant differences in the SUVP on [18F]Alfatide PET/CT or [18F]FDG PET/CT were observed among the cohorts according to gender, pathological stage, T stage, status of LNs, and differentiation (all P > 0.05). The SUVLN differed significantly between the pathological stages and status of LNs both on [18F]Alfatide PET/CT (P = 0.03, 0.003) and [18F]FDG PET/CT (P = 0.001. < 0.001), but not according to gender (P = 0.128, 0.129), T stage (P = 0.791, 0.727), or tumor differentiation (P = 0.049, 0.053). Significant positive correlations were observed between the SUVLN on [18F]Alfatide PET/CT and [18F]FDG PET/CT, and pathological stage (r = 0.52, P = 0.016; r = 0.503, P = 0.01), LN status (r = 0.73, P < 0.001; r = 0.649, P < 0.001), and differentiation (r = 0.509, P < 0.019; r = 0.459, P = 0.021) were observed. No significant differences were found between the relationships of SUVP with SUVLN, length, age, gender, pathological stage, T stage, status of LN, or differentiation, or of SUVLN with length, age, gender, or T stage both on [18F]Alfatide PET/CT and [18F]FDG PET/CT (all P > 0.05). The quantitated expression levels of αvß3 in primary tumors and metastatic LNs were 1.67 ± 1.12 and 3.42 ± 2.93, respectively (P = 0.031). CONCLUSIONS: Our results suggest that SUVLN is influenced by pathological stage, LN status, and differentiation. SUVLN may therefore serve as a new parameter for risk stratification of with ESCC patients. Moreover, [18F]Alfatide PET can provide complementary molecular information about ESCC metastasis.

Greater reduction in mid-treatment FDG-PET volume may be associated with worse survival in non-small cell lung cancer.

BACKGROUND AND PURPOSE: This study tested the hypotheses that 1) changes in mid-treatment fluorodeoxyglucose (FDG)-positron emission tomography (PET) parameters are predictive of overall survival (OS) and 2) mid-treatment FDG-PET-adapted treatment has the potential to improve survival in patients with non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: Patients with stage I-III NSCLC requiring daily fractionated radiation were eligible. FDG-PET-CT scans were obtained prior to and mid-treatment with radiotherapy at 40-50 Gy. The normalized maximum standardized uptake value (NSUVmax), normalized mean SUV (NSUVmean), PET-metabolic tumor volume (MTV), total lesion glycolysis (TLG), and computed tomography-based gross tumor volume (CT-GTV) were consistently measured for all patients. The primary study endpoint was OS. RESULTS: The study is comprised of 102 patients who received 3-dimensional conformal radiotherapy, among whom 30 patients who received mid-treatment PET-adapted dose escalation radiotherapy. All PET-CT parameters decreased significantly (P < 0.001) mid-treatment, with greater reductions in FDG-volumetric parameters compared to FDG-activity factors. Mid-treatment changes in MTV (P = 0.053) and TLG (P = 0.021) were associated with OS, while changes in NSUVmax, NSUVmean, and CT-GTV were not (all Ps>0.1). Patients receiving conventional radiation (60-70 Gy) with MTV reductions greater than the mean had a median survival of 14 months, compared to those with MTV reductions less than the mean who had a median survival of 22 months. By contrast, patients receiving mid-treatment PET-adapted radiation with MTV reductions greater than the mean had a median survival of 33 months, compared to those with MTV reductions less than the mean who had a median survival of 19 months. Overall, PET-adapted treatment resulted in a 19% better 5-year survival than conventional radiation. CONCLUSION: Changes in mid-treatment PET-volumetric parameters were significantly associated with survival in NSCLC. A greater reduction in the mid-treatment MTV was associated with worse survival in patients treated with standard radiation, but with better survival in patients who received mid-treatment PET-adapted treatment.