What 18F-FDG PET Response-Assessment Method Best Predicts Survival After Curative-Intent Chemoradiation in Non-Small Cell Lung Cancer: EORTC, PERCIST, Peter Mac Criteria, or Deauville Criteria?

Clinical utility of [18F]FDG PET/CT in the assessment of mediastinal lymph node disease after neoadjuvant chemoimmunotherapy for non-small cell lung cancer

OBJECTIVES

The performance of positron emission tomography/computed tomography (PET/CT) for the prediction of ypN2 disease in non-small cell lung cancer (NSCLC) after neoadjuvant chemoimmunotherapy has not been reported. This multicenter study investigated the utility of PET/CT to assess ypN2 disease in these patients.

METHODS

A total of 181 consecutive patients (chemoimmunotherapy = 86, chemotherapy = 95) at four institutions were enrolled in this study. Every patient received a PET/CT scan prior to surgery and complete resection with systematic nodal dissection. The diagnostic performance was evaluated through area under the curve (AUC). Kaplan-Meier method and Cox analysis were performed to identify the risk factors affecting recurrences.

RESULTS

The sensitivity, specificity, and accuracy of PET/CT for ypN2 diseases were 0.667, 0.835, and 0.779, respectively. Therefore, the AUC was 0.751. Compared with the false positive cases, the mean value of max standardized uptake value (SUVmax) (6.024 vs. 2.672, p < 0.001) of N2 nodes was significantly higher in true positive patients. Moreover, the SUVmax of true positive (7.671 vs. 5.976, p = 0.365) and false (2.433 vs. 2.339, p = 0.990) positive cases were similar between chemoimmunotherapy and chemotherapy, respectively. Survival analysis proved that pathologic N (ypN) 2 patients could be stratified by PET/CT-N2(+ vs. -) for both chemoimmunotherapy (p = 0.023) and chemotherapy (p = 0.010).

CONCLUSIONS

PET/CT is an accurate and non-invasive test for mediastinal restaging of NSCLC patients who receive neoadjuvant chemoimmunotherapy. The ypN2 patients with PET/CT-N2( +) are identified as an independent prognostic factor compared with PET/CT-N2(-).

CLINICAL RELEVANCE STATEMENT

Imaging with 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) plays an integral role during disease diagnosis, staging, and therapeutic response assessments in patients with NSCLC. PET/CT could be an effective non-invasive tool for predicting ypN2 diseases after neoadjuvant chemoimmunotherapy.

KEY POINTS

• PET/CT could serve as an effective non-invasive tool for predicting ypN2 diseases. • The ypN2 patients with PET/CT-N2( +) were a strong and independent prognostic factor. • The application of PET/CT for restaging should be encouraged in clinical practice.

Evaluation of treatment response by Hopkins criteria on 18 F FDG PET-CT in patients of non-small cell lung cancer and its comparison with PERCIST response criteria

AIM

To assess treatment response on FDG PET-CT in NSCLC patients by visual Hopkins score compared to PERCIST criteria and its potential for prognostication (or its correlation with survival).

METHODS

Forty-four NSCLC patients with baseline and post-treatment FDG PET-CT scans were included, and interpreted using Hopkins and PERCIST criteria classifying patients into responders and non-responders. PERCIST-based CMR and PMR, and Hopkins Scores 1,2,3 were classified responders. PERCIST-based SD and PD and Hopkins scores 4,5 were classified as non-responders. Patients were followed upto 24 months after treatment completion. Cohen kappa for inter-criteria agreement and Kaplan Meir curve for overall survival (OS) analysis done.

RESULTS

Out of 44 patients, PERCIST classified 27 (61.3%) as responders and 17 (38.6%) as non-responders, whereas Hopkins classified 12 patients (27.3%) as responders and 32 (72.7%) as non-responders. Inter-criteria agreement was low (kappa=0.19) with discordance in 45.5% of patients. Eighteen of 20 discordant cases were non-responders on Hopkins and responders on PERCIST, of which 88.8% were non-responders on follow-up as predicted by Hopkins. PERCIST responders had OS of 96.4% and 64.3% at 9 and 24 months, respectively, while non-responders OS was 93.5% and 40.2% at 9 and 24 months, respectively ( P -value = 0.049). However, responders on Hopkins had OS of 100% at 24 months, whereas non-responders had OS of 93.5% and 51.5% at 9 and 24 months, respectively ( P -value = 0.232).

CONCLUSION

Semi-quantitative PERCIST and visual Hopkins criteria show low inter-criteria agreement, with visual criteria better-predicting survival in patients of NSCLC.

Prognostic value of [18F]-FDG PET/CT in patients with meta-static breast cancer treated with cyclin-dependent inhibitors

Objective

The addition of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) to endocrine therapy impressively improved the outcome of patients with hormone receptor-positive metastatic breast cancer. Despite their great efficacy, not all patients respond to treatment and many of them develop acquired resistance. The aim of this retrospective study was to assess the role of [18F]-FDG PET/CT in predicting PFS and OS in breast cancer patients treated with CDK4/6i.

Methods

114 patients who performed an [18F]-FDG PET/CT scan before (PET1) and 2-6 months (PET2) after starting treatment were retrospectively enrolled. Metabolic response was evaluated by EORTC, PERCIST and Deauville Score and correlated to PFS and OS.

Results

In patients who did not progress at PET2 (n = 90), PFS rates were not significantly different between classes of response by EORTC and PERCIST. Conversely, patients showing a Deauville score ≤3 had a longer PFS (median PFS 42 vs 21.0 months; p = 0.008). A higher total metabolic tumor volume at PET1 (TMTV1) was also associated with a shorter PFS (median 18 vs 42 months; p = 0.0026). TMTV1 and Deauville score were the only independent prognostic factors for PFS at multivariate analysis and their combination stratified the population in four definite classes of relapse risk. Conversely, the above parameters did not affect OS which was only influenced by a progressive metabolic disease at PET2 (3-years survival rate 29.8 vs 84.9%; p<0.0001).

Conclusion

TMTV and metabolic response by Deauville score were significant prognostic factors for PFS in patients with breast cancer treated with CDK4/6i. Their determination could help physicians to select patients who may need a closer follow up.

Chemical Exchange Saturation Transfer MRI: Capability for Predicting Therapeutic Effect of Chemoradiotherapy on Non-Small Cell Lung Cancer Patients

BACKGROUND

Amide proton transfer (APT) weighted chemical exchange saturation transfer CEST (APTw/CEST) magnetic resonance imaging (MRI) has been suggested as having the potential for assessing the therapeutic effect of brain tumors or rectal cancer. Moreover, diffusion-weighted imaging (DWI) and positron emission tomography fused with computed tomography by means of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG-PET/CT) have been suggested as useful in same setting.

PURPOSE

To compare the capability of APTw/CEST imaging, DWI, and FDG-PET/CT for predicting therapeutic effect of chemoradiotherapy (CRT) on stage III non-small cell lung cancer (NSCLC) patients.

STUDY TYPE

Prospective.

POPULATION

Eighty-four consecutive patients with Stage III NSCLC, 45 men (age range, 62-75 years; mean age, 71 years) and 39 women (age range, 57-75 years; mean age, 70 years). All patients were then divided into two groups (Response Evaluation Criteria in Solid Tumors [RECIST] responders, consisting of the complete response and partial response groups, and RECIST non-responders, consisting of the stable disease and progressive disease groups).

FIELD STRENGTH/SEQUENCE

3 T, echo planar imaging or fast advanced spin-echo (FASE) sequences for DWI and 2D half Fourier FASE sequences with magnetization transfer pulses for CEST imaging.

ASSESSMENT

Magnetization transfer ratio asymmetry (MTRasym ) at 3.5 ppm, apparent diffusion coefficient (ADC), and maximum standard uptake value (SUVmax, ) on PET/CT were assessed by means of region of interest (ROI) measurements at primary tumor.

STATISTICAL TESTS

Kaplan-Meier method followed by log-rank test and Cox proportional hazards regression analysis with multivariate analysis. A P value <0.05 was considered statistically significant.

RESULTS

Progression-free survival (PFS) and overall survival (OS) had significant difference between two groups. MTRasym at 3.5 ppm (hazard ratio [HR] = 0.70) and SUVmax (HR = 1.41) were identified as significant predictors for PFS. Tumor staging (HR = 0.57) was also significant predictors for OS.

DATA CONCLUSION

APTw/CEST imaging showed potential performance as DWI and FDG-PET/CT for predicting the therapeutic effect of CRT on stage III NSCLC patients.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 1.

PET/CT reading for relapse in non-small cell lung cancer after chemoradiotherapy in the PET-Plan trial cohort

BACKGROUND

Current studies indicate that fluorine-18-fluorodeoxyglucose positron emission tomography/ computed tomography ([¹⁸F]FDG PET/CT) is the most accurate imaging modality for the detection of relapsed locally advanced non-small cell lung cancer (NSCLC) after curatively intended chemoradiotherapy. To this day, there is no objective and reproducible definition for the diagnosis of disease recurrence in PET/CT, the reading of which is relevantly influenced by post radiation inflammatory processes. The aim of this study was to evaluate and compare visual and threshold-based semi-automated evaluation criteria for the assessment of suspected tumor recurrence in a well-defined study population investigated during the randomized clinical PET-Plan trial.

METHODS

This retrospective analysis comprises 114 PET/CT data sets of 82 patients from the PET-Plan multi-center study cohort who underwent [¹⁸F]FDG PET/CT imaging at different timepoints for relapse, as suspected by CT. Scans were first analyzed visually by four blinded readers using a binary scoring system for each possible localization and the associated reader certainty of the evaluation. Visual evaluations were conducted repeatedly without and with additional knowledge of the initial staging PET and radiotherapy delineation volumes. In a second step, uptake was measured quantitatively using maximum standardized uptake value (SUVmax), peak standardized uptake value corrected for lean body mass (SULpeak), and a liver threshold-based quantitative assessment model. Resulting sensitivity and specificity for relapse detection were compared to the findings in the visual assessment. The gold standard of recurrence was independently defined by prospective study routine including external reviewers using CT, PET, biopsies and clinical course of the disease.

RESULTS

Overall interobserver agreement (IOA) of the visual assessment was moderate with a high difference between secure (ĸ = 0.66) and insecure (ĸ = 0.24) evaluations. Additional knowledge of the initial staging PET and radiotherapy delineation volumes improved the sensitivity (0.85 vs 0.92) but did not show significant impact on the specificity (0.86 vs 0.89). PET parameters SUVmax and SULpeak showed lower accuracy compared to the visual assessment, whereas threshold-based reading showed similar sensitivity (0.86) and higher specificity (0.97).

CONCLUSION

Visual assessment especially if associated with high reader certainty shows very high interobserver agreement and high accuracy that can be further increased by baseline PET/CT information. The implementation of a patient individual liver threshold value definition, similar to the threshold definition in PERCIST, offers a more standardized method matching the accuracy of experienced readers albeit not providing further improvement of accuracy.

Biology-Guided Radiation Therapy

Biology-guided radiation therapy is an emerging field whereby delivery of external beam radiotherapy incorporates biological/molecular imaging to inform radiation treatment. At present, there is evidence for the use of functional imaging such as PET to evaluate treatment response in patients both during and after radiation treatment as well as to provide a method of adapting or selecting patient-specific treatments. Examples in thoracic, gastrointestinal, and hematologic malignancies are provided. Improvements in PET metrics, thresholds, and novel radiotracers will further move this novel field forward.

Utility of 18F-FDG PET/CT uptake values in predicting response to neoadjuvant chemoimmunotherapy in resectable non-small cell lung cancer

INTRODUCTION

Reliable predictive markers are lacking for resectable non-small cell lung cancer (NSCLC) patients treated with neoadjuvant chemoimmunotherapy. The present study investigated the utility of SUV_max values acquired from PET/CT to predict the response to neoadjuvant chemoimmunotherapy for resectable NSCLC.

MATERAL AND METHODS

SUV_max, clinical and pathological outcomes, were collected from patients in 5 hospitals. Patients who received dynamic PET/CT surveillance were divided into cohorts A (chemoimmunotherapy) and B (chemotherapy), respectively, while cohort C (chemoimmunotherapy) comprised patients undergoing post-therapy PET/CT. Associations between SUV_max and major pathologic response (MPR) were evaluated through receiver operating characteristic (ROC) curves.

RESULTS

A total of 129 cases with an MPR rate of 46.5 % was identified. In neoadjuvant chemoimmunotherapy, ΔSUV_max% (AUC: 0.890, 95 % CI: 0.761-0.949) and post-therapy SUV_max (AUC: 0.933, 95 % CI: 0.802-0.959) could accurately predict MPR. On the contrary, the baseline SUV_max was not associated with MPR (p = 0.184). Furthermore, an independent cohort C proved that post-therapy SUV_max could serve as an independent predictor (AUC: 0.928, 95 % CI: 0.823-0.958). In addition, robust predictive performance could be observed when we use the optimal cut-off point of both ΔSUV_max% (54.4 %, AUC: 0.912, 95 % CI: 0.824-0.994) and post-therapy SUV_max (3.565, AUC: 0.912, 95 % CI: 0.824-0.994) in neoadjuvant chemoimmunotherapy. The RNA data revealed that the expression of PFKFB4, a key enzyme in glycolysis, was positively correlated with SUV_max value and tumor cell proliferation after neoadjuvant chemoimmunotherapy.

CONCLUSION

These findings highlighted that the ΔSUV_max% and remained SUV_max were accurate and non-invasive tests for the prediction of MPR after neoadjuvant chemoimmunotherapy.

Predictive value of 18F-FDG PET/CT for evaluating the response to hypofractionated radiotherapy combined with PD-1 blockade in non-small cell lung cancer

Purpose

This retrospective study aimed to investigate ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG)-positron emission tomography/computed tomography (PET/CT) as a predictor of response to hypofractionated radiotherapy (HFRT) combined with programmed cell death-1 (PD-1) blockade for lung cancer.

Methods

We included 41 patients with advanced non-small cell lung cancer (NSCLC) in this study. PET/CT was performed before (SCAN-0) and one month (SCAN-1), three months (SCAN-2), and six months (SCAN-3) after treatment. Using the European Organization for Research and Treatment of Cancer 1999 criteria and PET response criteria in solid tumors, treatment responses were classified as complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), or progressive metabolic disease (PMD). Patients were further categorized as those with metabolic benefits (MB; SMD, PMR, and CMR) and those without MBs (NO-MB; PMD). We analyzed the prognosis and overall survival (OS) of patients with new visceral/bone lesions during treatment. Based on the findings, we generated a nomogram to predict survival. Receiver operating characteristics and calibration curves were used to evaluate the accuracy of the prediction model.

Results

The mean OS based on SCANs 1, 2, and 3 was significantly higher in patients with MB and those without new visceral/bone lesions. The prediction nomogram for survival had a high area under the curve and a high predictive value based on the receiver operating characteristics and calibration curves.

Conclusion

¹⁸FDG-PET/CT has the potential to predict the outcomes of HFRT combined with PD-1 blockade in NSCLC. Therefore, we recommend using a nomogram to predict patient survival.

The value of the Standardized Uptake Value (SUV) and Metabolic Tumor Volume (MTV) in lung cancer

The diagnosis, staging and therapeutic monitoring of lung cancer were amongst the first applications for which the utility of FDG PET was documented and FDG PET/CT is now a routine diagnostic tool for clinical decision-making. As well as having high sensitivity for detection of disease sites, which provides critical information about stage, the intensity of uptake provides deeper biological characterization, while the burden of disease also has potential clinical significance. These disease characteristics can easily be quantified on delayed whole-body imaging as the maximum standardized uptake value (SUV_max) and metabolic tumor volume (MTV), respectively. There have been significant efforts to harmonize the measurement of these features, particularly within the context of clinical trials. Nevertheless, however calculated, in general, a high SUV_max and large MTV have been shown to have an adverse prognostic significance. Nevertheless, the use of these parameters in the interpretation and reporting of clinical scans remains inconsistent and somewhat controversial. This review details the current status of semi-quantitative FDG PET/CT in the evaluation of lung cancer.

Radiomics for Predicting Lung Cancer Outcomes Following Radiotherapy: A Systematic Review

Lung cancer's radiomic phenotype may potentially inform clinical decision-making with respect to radical radiotherapy. At present there are no validated biomarkers available for the individualisation of radical radiotherapy in lung cancer and the mortality rate of this disease remains the highest of all other solid tumours. MEDLINE was searched using the terms 'radiomics' and 'lung cancer' according to the Preferred Reporting Items for Systematic Reviews and Met-Analyses (PRISMA) guidance. Radiomics studies were defined as those manuscripts describing the extraction and analysis of at least 10 quantifiable imaging features. Only those studies assessing disease control, survival or toxicity outcomes for patients with lung cancer following radical radiotherapy ± chemotherapy were included. Study titles and abstracts were reviewed by two independent reviewers. The Radiomics Quality Score was applied to the full text of included papers. Of 244 returned results, 44 studies met the eligibility criteria for inclusion. End points frequently reported were local (17%), regional (17%) and distant control (31%), overall survival (79%) and pulmonary toxicity (4%). Imaging features strongly associated with clinical outcomes include texture features belonging to the subclasses Gray level run length matrix, Gray level co-occurrence matrix and kurtosis. The median cohort size for model development was 100 (15-645); in the 11 studies with external validation in a separate independent population, the median cohort size was 84 (21-295). The median number of imaging features extracted was 184 (10-6538). The median Radiomics Quality Score was 11% (0-47). Patient-reported outcomes were not incorporated within any studies identified. No studies externally validated a radiomics signature in a registered prospective study. Imaging-derived indices attained through radiomic analyses could equip thoracic oncologists with biomarkers for treatment response, patterns of failure, normal tissue toxicity and survival in lung cancer. Based on routine scans, their non-invasive nature and cost-effectiveness are major advantages over conventional pathological assessment. Improved tools are required for the appraisal of radiomics studies, as significant barriers to clinical implementation remain, such as standardisation of input scan data, quality of reporting and external validation of signatures in randomised, interventional clinical trials.

Imaging for Response Assessment in Cancer Clinical Trials

The use of biomarkers is integral to the routine management of cancer patients, including diagnosis of disease, clinical staging and response to therapeutic intervention. Advanced imaging metrics with computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) are used to assess response during new drug development and in cancer research for predictive metrics of response. Key components and challenges to identifying an appropriate imaging biomarker are selection of integral vs integrated biomarkers, choosing an appropriate endpoint and modality, and standardization of the imaging biomarkers for cooperative and multicenter trials. Imaging biomarkers lean on the original proposed quantified metrics derived from imaging such as tumor size or longest dimension, with the most commonly implemented metrics in clinical trials coming from the Response Evaluation Criteria in Solid Tumors (RECIST) criteria, and then adapted versions such as immune-RECIST (iRECIST) and Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) for immunotherapy response and PET imaging, respectively. There have been many widely adopted biomarkers in clinical trials derived from MRI including metrics that describe cellularity and vascularity from diffusion-weighted (DW)-MRI apparent diffusion coefficient (ADC) and Dynamic Susceptibility Contrast (DSC) or dynamic contrast enhanced (DCE)-MRI (Ktrans, relative cerebral blood volume (rCBV)), respectively. Furthermore, Fluorodexoyglucose (FDG), fluorothymidine (FLT), and fluoromisonidazole (FMISO)-PET imaging, which describe molecular markers of glucose metabolism, proliferation and hypoxia have been implemented into various cancer types to assess therapeutic response to a wide variety of targeted- and chemotherapies. Recently, there have been many functional and molecular novel imaging biomarkers that are being developed that are rapidly being integrated into clinical trials (with anticipation of being implemented into clinical workflow in the future), such as artificial intelligence (AI) and machine learning computational strategies, antibody and peptide specific molecular imaging, and advanced diffusion MRI. These include prostate-specific membrane antigen (PSMA) and trastuzumab-PET, vascular tumor burden extracted from contrast-enhanced CT, diffusion kurtosis imaging, and CD8 or Granzyme B PET imaging. Further excitement surrounds theranostic procedures such as the combination of 68Ga/111In- and 177Lu-DOTATATE to use integral biomarkers to direct care and personalize therapy. However, there are many challenges in the implementation of imaging biomarkers that remains, including understand the accuracy, repeatability and reproducibility of both acquisition and analysis of these imaging biomarkers. Despite the challenges associated with the biological and technical validation of novel imaging biomarkers, a distinct roadmap has been created that is being implemented into many clinical trials to advance the development and implementation to create specific and sensitive novel imaging biomarkers of therapeutic response to continue to transform medical oncology.

Patient Selection of Sublobar Resection Using Visual Evaluation of Positron-Emission Tomography (PET) for Early-Stage Lung Adenocarcinoma

BACKGROUND

This study aimed to investigate the efficacy of the Deauville criteria (a 5-point visual scale criteria) in assessing the accumulation of [18F]-fluoro-2-deoxy-D-glucose (FDG) on positron-emission tomography (PET)/computed tomography (CT) for predicting prognosis of early-stage lung adenocarcinoma and selecting candidates for sublobar resection.

METHODS

This retrospective study included 648 patients undergoing curative resection for clinical N0 lung adenocarcinoma with a whole tumor size of 3 cm or smaller between April 2007 and March 2019. Accumulations of the FDG on PET/CT scans were scored using the Deauville criteria (Deauville score), and correlations between the Deauville score and prognosis were analyzed.

RESULTS

The recurrence-free survival (RFS) was significantly better for the patients with a Deauville score of 1 or 2 (n = 415, 5-year RFS, 92.6%) than for those with a score of 3 (n = 82, 5-year RFS, 72.7%; P < 0.001) or a score of 4 or 5 (n = 151, RFS, 70.8%; P < 0.001). The RFS did not differ significantly among the patients with Deauville scores of 1 and 2 who underwent wedge resection (n = 102, 5-year RFS, 90.5%), segmentectomy (n = 188, RFS, 95.1%; P = 0.355), and lobectomy (n = 125, RFS, 91.1%; P = 0.462).

CONCLUSION

The 5-point-scale evaluation of FDG accumulation on PET/CT was useful in predicting the prognosis for patients with early-stage lung adenocarcinoma. Lung adenocarcinoma patients with a whole tumor size of 3 cm or smaller and a Deauville score of 1 or 2 can be candidates for sublobar resection.

It's About Quality, Not Quantity: Qualitative FDG PET/CT Criteria for Therapy Response Assessment in Clinical Practice

OBJECTIVE. FDG PET/CT has emerged as an effective tool for the timely accurate assessment of how tumors respond to therapy. To standardize interpretation and reporting, numerous response criteria have been developed. This article will review the evolution of these criteria along with their strengths and weaknesses. CONCLUSION. Several qualitative assessments applicable to common malignancies have been developed in recent years that solve many of the challenges faced by their quantitative predecessors. These are reviewed, and information is provided regarding individual treatment efficacy and prognosis.

Maximum standardized uptake value of primary tumor (SUVmax_PT) and horizontal range between two most distant PET-positive lymph nodes predict patient outcome in inoperable stage III NSCLC patients after chemoradiotherapy

Background

18F-FDG-positron emission tomography (PET)/computed tomography (CT) is a standard for initial staging in patients with locally advanced stage III non-small cell lung cancer (NSCLC). We evaluated a PET/CT staging score to characterize disease extension and patient outcome in this disease.

Methods

Ninety-nine consecutive patients with NSCLC stage IIIA–B (UICC 7th edition), who underwent 18F-FDG-PET/CT before the start of chemoradiotherapy (CRT) were analyzed. Maximum standardized uptake value of primary tumor (SUVmax_PT) and range between two most distant PET-positive (SUV ≥2.5) lymph nodes in two directions were analyzed for their correlation with patient outcome. The vertical distance was defined as A- and the horizontal as a B-line.

Results

According to the results of univariate analysis, score included the SUVmax_PT and horizontal B-line, patients were divided into three risk subgroups: low, intermediate and high-risk subgroups. Subgroups were defined as SUVmax_PT <8 and B-line <3.7 cm, SUVmax_PT >8 or B-line >3.7 cm and SUVmax_PT >8 plus B-line >3.7 cm, respectively. Twenty-eight (28%), 45 (46%) and 26 (26%) patients were assigned to the low, intermediate and high-risk subgroup, respectively. Median event-free survival (EFS) in low, intermediate and high-risk subgroups was 16 (95% CI: 7–25), 13 (95% CI: 12–15) and 10 (95% CI: 7–13) months (P=0.002, log-rank test). Median OS in the low, intermediate and high-risk subgroups was 40 (95% CI: 11–69), 23 (95% CI: 15–31) and 14 (95% CI: 13–14) months (P=0.0001, log-rank test). In the multivariate analysis, SUV, B-line and PET/CT score were significantly associated with EFS [harard ratio (HR) 2.12 (95% CI: 1.27–3.55) and intermediate risk HR 2.01 (95% CI: 1.13–3.59), P=0.003] and OS [high-risk HR 2.79 (95% CI: 1.16–4.55) and intermediate risk HR 2.30 (95% CI: 1.58–4.94), P=0.001].

Conclusions

A PET/CT score was developed for inoperable stage III NSCLC patients treated with CRT and was an independent predictor of patient outcome in the single-center cohort.

Bridging the Radiation Oncology and Diagnostic Radiology Communication Gap: A Survey to Determine Usefulness and Optimal Presentation of Radiotherapy Treatment Plans for Radiologists

RATIONALE AND OBJECTIVES

We hypothesized that providing visual-spatial information to radiologists on where radiation has been delivered in an easily accessible way may improve the accuracy of image interpretation and thereby improve quality of patient care. We present a national representation of radiologists' opinions regarding the usefulness and optimal approach for implementing a system to promote access to radiotherapy (RT) plans.

METHODS

An anonymous survey was sent to the members of the Association of University Radiologists. Descriptive statistics were performed.

RESULTS

Questionnaires were returned by 95 of 1383 members. Demographics comprised of 76% attendings with 94% practicing within an academic setting. Only 40% of radiologists reported that they knew most of the time whether a patient has received RT in the field scanned. A large majority of respondents (88%) felt that a history of prior radiation in a cancer patient was at least an occasional barrier that affected the ability to interpret imaging findings in a clinically useful way. The following types of information was considered helpful when interpreting a scan: screenshots of the radiation plan (85%), scrollable DICOM data on planning CT showing delivered RT dose lines (54%), and written text RT treatment summary (47%). Nearly all (89%) desired DICOM data within the clinical radiology Picture Archiving and Communication System system. Radiologists expected the ease of accessibility to RT plans to result in increased efficiency (76%) and accuracy (88%).

CONCLUSION

Diagnostic radiologists desire improved access and integration of radiotherapy plans into the diagnostic radiology clinical workup in the form of visual-spatial data.

PET-detected pneumonitis following curative-intent chemoradiation in non-small cell lung cancer (NSCLC): recognizing patterns and assessing the impact on the predictive ability of FDG-PET/CT response assessment

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.