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Despite significant therapeutic advances, lung cancer remains the leading cause of cancer-related death worldwide1. Non-small cell lung cancer (NSCLC) patients have a very poor overall five-year survival rate of only 10–20%. Currently, TNM staging is the gold standard for predicting overall survival and selecting optimal initial treatment options for NSCLC patients, including those with curable stages of disease. However, many patients with locoregionally-confined NSCLC relapse and die despite curative-intent interventions, indicating a need for intensified, individualised therapies. Epithelial-to-mesenchymal transition (EMT), the phenotypic depolarisation of epithelial cells to elongated, mesenchymal cells, is associated with metastatic and treatment-refractive cancer. We demonstrate here that EMT-induced protein changes in small extracellular vesicles are detectable in NSCLC patients and have prognostic significance. Overall, this work describes a novel prognostic biomarker signature that identifies potentially-curable NSCLC patients at risk of developing metastatic NSCLC, thereby enabling implementation of personalised treatment decisions. EMT-induced protein changes in small extracellular vesicles are detectable in NSCLC patients and have prognostic significance. [ABSTRACT FROM AUTHOR]

Introduction: This study aims to investigate whether nodal metabolic tumour volume (nMTV) and nodal total lesion glycolysis (nTLG) on Fluorine‐18 fluoro‐deoxy‐glucose positron emission tomography–computed tomography (18F‐FDG PET/CT) in inoperable node‐positive stage II and III non‐small cell lung cancer (NSCLC) are independent predictors of overall survival (OS) in patients undergoing curative‐intent chemoradiotherapy/radiotherapy (CRT/RT). Methods: Data from two prospective trials between 2004 and 2016 were analysed retrospectively. Primary, nodal and total metabolic tumour volume and total lesion glycolysis (pMTV, nMTV, tMTV, pTLG, nTLG and tTLG, respectively) were derived from baseline 18F‐FDG PET/CT. Cox regressions were used to model OS by 18F‐FDG PET/CT parameters adjusting for overall stage. Results: 89 patients with stage II (8%) and stage III (92%) were included. The median age at diagnosis was 67 years; 62% were male. The median follow‐up was 6.9 years; the median OS was 2.2 years (95% CI 1.7–3.1). The median pMTV, nMTV and tMTV were 14 mL (range 0–360), 8 mL (range 0–250) and 34 mL (range 3–384), respectively. In 3 patients, the primary lesion could not be delineated from the central hilar mass. There was no association between nMTV (adjusted HR 1.04, 95% CI 0.95–1.15, P‐value 0.43), pMTV (adjusted HR 1.0, 95% CI 0.96–1.04, P‐value 0.92), tMTV (adjusted HR 1.0, 95% CI 0.97–1.04, P‐value 0.88), nTLG, pTLG or tTLG and OS. Consistent results were noted when patients with central hilar lesions were excluded from analysis. Conclusion: In node‐positive stage II and III NSCLC patients who underwent 18F‐FDG PET/CT‐guided target delineation curative‐intent concurrent CRT/RT, metabolic parameters did not appear to provide independent prognostication. [ABSTRACT FROM AUTHOR]

In locally advanced lung cancer, established baseline clinical variables show limited prognostic accuracy and 18F-fluorodeoxyglucose positron emission tomography (FDG PET) radiomics features may increase accuracy for optimal treatment selection. Their robustness and added value relative to current clinical factors are unknown. Hence, we identify robust and independent PET radiomics features that may have complementary value in predicting survival endpoints. A 4D PET dataset (n = 70) was used for assessing the repeatability (Bland-Altman analysis) and independence of PET radiomics features (Spearman rank: |ρ|<0.5). Two 3D PET datasets combined (n = 252) were used for training and validation of an elastic net regularized generalized logistic regression model (GLM) based on a selection of clinical and robust independent PET radiomics features (GLMall). The fitted model performance was externally validated (n = 40). The performance of GLMall (measured with area under the receiver operating characteristic curve, AUC) was highest in predicting 2-year overall survival (0.66±0.07). No significant improvement was observed for GLMall compared to a model containing only PET radiomics features or only clinical variables for any clinical endpoint. External validation of GLMall led to AUC values no higher than 0.55 for any clinical endpoint. In this study, robust independent FDG PET radiomics features did not have complementary value in predicting survival endpoints in lung cancer patients. Improving risk stratification and clinical decision making based on clinical variables and PET radiomics features has still been proven difficult in locally advanced lung cancer patients. [ABSTRACT FROM AUTHOR]

Purpose: Inflammatory FDG uptake in the lung (PET-pneumonitis) following curative-intent radiotherapy (RT)/chemo-RT (CRT) in non-small cell lung cancer (NSCLC) can pose a challenge in FDG-PET/CT response assessment. The aim of this study is to describe different patterns of PET-pneumonitis to guide the interpretation of FDG-PET/CT and investigate its association with tumor response and overall survival (OS). Methods: Retrospective analysis was performed on 87 NSCLC patients in three prospective trials who were treated with radical RT (n = 7) or CRT (n = 80), with baseline and post-treatment FDG-PET/CT. Visual criteria were performed for post-treatment FDG-PET/CT response assessment. The grading of PET-pneumonitis was based on relative lung uptake intensity compared to organs of reference and classified as per Deauville score from grade 1–5. Distribution patterns of PET-pneumonitis were defined as follows: A) patchy/sub-pleural; B) diffuse (involving more than a segment); and C) peripheral (diffusely surrounding a photopenic region). Results: Follow-up FDG-PET/CT scans were performed approximately 3 months (median, 89 days; interquartile range, 79–93) after RT. Overall, PET-pneumonitis was present in 62/87 (71%) of patients, with Deauville 2 or 3 in 12/62 (19%) and 4 or 5 in 50/62 (81%) of patients. The frequency of patterns A, B and C of PET-pneumonitis was 19/62 (31%), 20/62 (32%) and 23/62 (37%), respectively. No association was found between grade or pattern of PET-pneumonitis and overall response at follow-up PET/CT (p = 0.27 and p = 0.56, respectively). There was also no significant association between PET-pneumonitis and OS (hazard ratio [HR], 1.3; 95% confidence interval [CI], 0.6–2.5; p = 0.45). Early FDG-PET/CT response assessment, however, was prognostic for OS (HR, 1.7; 95% CI, 1.2–2.2; p < 0.001). Conclusion: PET-pneumonitis is common in early post-CRT/RT, but pattern recognition may assist in response assessment by FDG-PET/CT. While FDG-PET/CT is a powerful tool for response assessment and prognostication, PET-pneumonitis does not appear to confound early response assessment or to independently predict OS. [ABSTRACT FROM AUTHOR]

Purpose: Sarcopenia is associated with reduced survival in cancer. Currently, data on sarcopenia at presentation and muscle loss throughout treatment are unknown in patients receiving chemoradiation therapy (CRT) for non-small cell lung cancer (NSCLC). This study evaluated skeletal muscle changes in NSCLC patients receiving CRT and relationship with survival.Methods: Secondary analysis of 41 patients with NSCLC treated with CRT assessed for skeletal muscle area and muscle density by computed tomography pre-treatment and 3 months post-treatment. Images at week 4 of treatment were available for 32 (78%) patients. Linear mixed models were applied to determine changes in skeletal muscle over time and related to overall survival using Kaplan-Meier plots.Results: Muscle area and muscle density decreased significantly by week 4 of CRT (- 6.6 cm2, 95% CI - 9.7 to - 3.1, p < 0.001; - 1.3 HU, 95% CI - 1.9 to - 0.64, p < 0.001, respectively), with minimal change between week 4 of CRT and 3 months post-CRT follow-up (- 0.2 cm2, 95% CI - 3.6-3.1, p = 0.91; - 0.27, 95% CI - 0.91-0.36, p = 0.36, respectively). Sarcopenia was present in 25 (61%) and sarcopenic obesity in 6 (14%) of patients prior to CRT, but not associated with poorer survival. Median survival was shorter in patients with low muscle density prior to treatment although not statistically significant (25 months + 8.3 vs 53 months + 13.0, log-rank p = 0.17).Conclusion: Significant loss of muscle area and muscle density occurs in NSCLC patients early during CRT. A high proportion of patients are sarcopenic prior to CRT; however, this was not significantly associated with poorer survival. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the associations between interim tumor responses on 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and 18F-fluorothymidine (18F-FLT) PET and patient outcomes, especially progression-free survival (PFS) and overall survival (OS), in non-small cell lung cancer (NSCLC) patients.Methods and Materials: Patients with FDG-PET/computed tomography stage I-III NSCLC were prescribed concurrent chemotherapy and radiation therapy (60 Gy in 30 fractions). Scans were acquired at baseline (FDG-PET/computed tomography [FDGBL] for radiation therapy planning and FLT-PET [FLTBL]), week 2 (FDGwk2 and FLTwk2), and week 4 (FDGwk4 and FLTwk4) of chemoradiation therapy. Tumor responses were categorized as complete or partial responses or stable or progressive disease (SD, PD) using European Organization for Research and Treatment of Cancer criteria. Associations between response, OS, and PFS were analyzed with univariate Cox regressions and plotted using Kaplan-Meier curves.Results: Between 2009 and 2013, 60 patients were recruited. Thirty-seven (62%) were male, and the median age was 66 years (range, 31-86 years). Two-year OS and PFS were 0.51 and 0.26, respectively. Unexpectedly, SD on FLTwk2 compared with complete response/partial response was associated with longer OS (hazard ratio [95% confidence interval] 2.01 [0.87-4.65], P=.082) and PFS (2.01 [0.92-4.36], P=.061). Weeks 2 and 4 FDG PET/CT were not significantly associated with survival. Study scans provided additional information to FDGBL in 21 patients (35%). Distant metastases detected in 3 patients on FLTBL and in 2 patients on FDG/FLTwk2 changed treatment intent from curative to palliative. Locoregional progression during radiation therapy was observed in 5 (8%) patients, prompting larger radiation therapy fields.Conclusions: Stable uptake of 18F-FLT at week 2 was paradoxically associated with longer OS and PFS. This suggests that suppression of tumor cell proliferation may protect against radiation-induced tumor cell killing. Baseline FLT, FLTwk2, and FDGwk2 detected rapid distant and locoregional progression in 10 patients (17%), prompting changes in management. [ABSTRACT FROM AUTHOR]

There is renewed interest in the immune regulatory role of the spleen in oncology. To date, very few studies have examined macroscopic variations of splenic volume in the setting of cancer, prior to or during therapy, especially in humans. Changes in splenic volume may be associated with changes in splenic function. The purpose of this study was to investigate variations in spleen volume in NSCLC patients during chemo-radiotherapy. Sixty patients with stage I-IIIB NSCLC underwent radiotherapy (60Gy/30 fractions) for six weeks with concomitant carboplatin/paclitaxel (Ca/P; n = 32) or cisplatin/etoposide (Ci/E; n = 28). A baseline PET/CT scan was performed within 2 weeks prior to treatment and during Weeks 2 and 4 of chemo-radiotherapy. Spleen volume was measured by contouring all CT slices. Significant macroscopic changes in splenic volume occurred early after the commencement of treatment. A significant decrease in spleen volume was observed for 66% of Ca/P and 79% of Ci/E patients between baseline and Week 2. Spleen volume was decreased by 14.2% for Ca/P (p<0.001) and 19.3% for Ci/E (p<0.001) patients. By Week 4, spleen volume was still significantly decreased for Ca/P patients compared to baseline, while for Ci/E patients, spleen volume returned to above baseline levels. This is the first report demonstrating macroscopic changes in the spleen in NSCLC patients undergoing radical chemo-radiotherapy that can be visualized by non-invasive imaging. [ABSTRACT FROM AUTHOR]

18F-fluorothymidine (FLT) positron emission tomography (PET) enables sensitive imaging of bone marrow (BM) proliferation. Sequential FLT-PET/computed tomography scans before and during chemoradiation therapy (CRT) for non-small cell lung cancer were repurposed to investigate the dose-response effects of radiation on BM proliferation. Twenty-six non-small cell lung cancer patients underwent platinum-based CRT to 60 Gy in 30 fractions with FLT-PET/computed tomography scans at baseline, week 2 (20 Gy), and week 4 (40 Gy). FLT uptake in BM was isolated using Medical Image Merge software. Weeks 2 and 4 FLT-PET BM scans were fused with contemporaneous radiation isodose distributions. Relationships between radiation dose and FLT BM uptake (highest standardized uptake values within the volume and visual parameters) were analyzed using generalized linear and restricted cubic spline models. Percentage volumes of total BM without appreciable FLT uptake ("ablated") on weeks 2 and 4 FLT-PET scans were calculated by comparisons with baseline scans. Thoracic FLT uptake was ablated in BM regions exposed to cumulative radiation doses ≥3 Gy by week 2. In all cases, BM FLT's highest standardized uptake values within the volume declined rapidly as the radiation dose increased. BM proliferation significantly decreased by >95% after ≥3 to 4 Gy at 2 weeks and ≥4 to 5 Gy at 4 weeks. The ablated BM volume increased from week 2 to week 4 as BM in the penumbra accumulated radiation dose. The median percentage of total BM ablated was 13.1% (range, 5.6%-20.3%) at 2 weeks and 15.7% (range, 9.2%-24.1%) at 4 weeks. Mean lymphocyte counts fell from a baseline of 2.01 × 109/L to 0.77 at week 2 and 0.60 at week 4. Lymphocyte decline strongly correlated with the percentage of total BM ablated by week 4 (y = −46 to 1.64x; R2 adj = 0.34; P =.001). BM ablation associated with low-dose radiation exposure during CRT correlated significantly with lower week 4 lymphocyte counts. BM is a potential organ at risk, and reducing the BM volume exposed to ≥3 Gy may help preserve lymphocytes, which is essential for effective adjuvant immunotherapy. [ABSTRACT FROM AUTHOR]

Background and purpose To assess the impact of a standardized delineation protocol and training interventions on PET/CT-based target volume delineation (TVD) in NSCLC in a multicenter setting. Material and methods Over a one-year period, 11 pairs, comprised each of a radiation oncologist and nuclear medicine physician with limited experience in PET/CT-based TVD for NSCLC from nine different countries took part in a training program through an International Atomic Energy Agency (IAEA) study (NCT02247713). Teams delineated gross tumor volume of the primary tumor, during and after training interventions, according to a provided delineation protocol. In-house developed software recorded the performed delineations, to allow visual inspection of strategies and to assess delineation accuracy. Results Following the first training, overall concordance indices for 3 repetitive cases increased from 0.57 ± 0.07 to 0.66 ± 0.07. The overall mean surface distance between observer and expert contours decreased from −0.40 ± 0.03 cm to −0.01 ± 0.33 cm. After further training overall concordance indices for another 3 repetitive cases further increased from 0.64 ± 0.06 to 0.80 ± 0.05 ( p = 0.01). Mean surface distances decreased from −0.34 ± 0.16 cm to −0.05 ± 0.20 cm ( p = 0.01). Conclusion Multiple training interventions improve PET/CT-based TVD delineation accuracy in NSCLC and reduce interobserver variation. [ABSTRACT FROM AUTHOR]

• Wait time is detrimental to lung cancer patients due to disease progression. • Successive PET/CT scans can assess disease stage migration. • Metastatic and nodal disease progression occur much sooner for adenocarcinoma or stage IIIB patients. • Reducing wait times may have a positive impact on treatment outcome and survival. Patients with non-small cell lung cancer (NSCLC) can experience rapid disease progression between initial staging FDG-PET scans and commencement of curative-intent radiotherapy (RT). Previous studies that estimated stage migration rates by comparing staging PET/CT and treatment-planning PET/CT images were limited by small sample sizes. This multicenter, international study combined prospective data from five institutions for PET-staged patients with NSCLC who were intended to receive curative-intent RT. TNM status was compared for staging and RT planning scans and the probability of TNM status and overall stage migration was analyzed as a function of the interval between PET/CT scans. The impacts of N classification, overall stage, and pathology were also studied. Pooled data from 181 patients were analyzed. The median interval between PET/CT scans was 42 days (range, 2–208). Upstaging occurred in 32 % of patients. The overall rate of stage migration was higher for patients presenting with initial stage IIIB/IIIC disease (p = 0.006) and patients with N2−3 nodal disease (p = 0.019). Upstaging to M1 disease was significantly associated with initial stage IIIB/IIIC disease (HR = 15.2) and adenocarcinoma (HR = 10) histology. Longer intervals between imaging and treatment in patients with NSCLC were associated with high rates disease progression with consequent risks of geographic miss in RT planning and futile treatment in patients with M1 disease. Patients with more extensive initial nodal involvement and those with adenocarcinoma had the highest rates of stage migration. Dedicated RT planning PET/CT imaging is recommended, especially if >3 weeks have elapsed after initial staging. [ABSTRACT FROM AUTHOR]

Purpose Proliferating bone marrow is exquisitely sensitive to ionizing radiation. Knowledge of its distribution could improve radiation therapy planning to minimize unnecessary marrow exposure and avoid consequential prolonged myelosuppression. [18F]-Fluoro-3-deoxy-3-L-fluorothymidine (FLT)–positron emission tomography (PET) is a novel imaging modality that provides detailed quantitative images of proliferating tissues, including bone marrow. We used FLT-PET imaging in cancer patients to produce an atlas of marrow distribution with potential clinical utility. Methods and Materials The FLT-PET and fused CT scans of eligible patients with non-small cell lung cancer (no distant metastases, no prior cytotoxic exposure, no hematologic disorders) were reviewed. The proportions of skeletal FLT activity in 10 predefined bony regions were determined and compared according to age, sex, and recent smoking status. Results Fifty-one patients were studied: 67% male; median age 68 (range, 31-87) years; 8% never smokers; 70% no smoking in the preceding 3 months. Significant differences in marrow distribution occurred between sex and age groups. No effect was detected from smoking in the preceding 3 months. Using the mean percentages of FLT uptake per body region, we created an atlas of the distribution of functional bone marrow in 4 subgroups defined by sex and age. Conclusions This atlas has potential utility for estimating the distribution of active marrow in adult cancer patients to guide radiation therapy planning. However, because of interindividual variation it should be used with caution when radiation therapy risks ablating large proportions of active marrow; in such cases, individual FLT-PET scans may be required. [ABSTRACT FROM AUTHOR]