The impact of staging FDG-PET/CT on treatment for stage III NSCLC - an analysis of population-based data from Ontario, Canada

Purpose

Fluoro-2-deoxyglucose positron-emission tomography (FDG-PET/CT) is now considered a standard investigation for the staging of new cases of stage III NSCLC. However, there is not published level 3 evidence demonstrating the impact of FDG-PET/CT on appropriate therapy in this setting. Using retrospective population-based data, we sought to examine the role and timing that FDG-PET/CT scans play in influencing treatment choice, as well as survival in patients diagnosed with stage III NSCLC.

Materials and methods

A retrospective cohort of patients diagnosed with stage III NSCLC from 2009-2017 in Ontario were identified from the IC/ES (formerly Institute of Clinical Evaluative Sciences) database. FDG-PET/CT utilization over time, trends in mediastinal biopsy technique and usage, the impact of FDG-PET/CT on overall survival (OS), and its influence on use of concurrent chemoradiotherapy (CRT) were explored. The impact of timing of pre-treatment FDG-PET/CT on OS was also analyzed (≤28 days prior to treatment, 29-56 days prior, and >56 days prior).

Results

Between 2007 and 2017, a total of 13 796 people were diagnosed with stage III NSCLC in Ontario. FDG-PET/CT utilization increased over time with 0% of cases in 2007 and 74% in 2017 with pre-treatment FDG-PET/CT scans. The number of patients who received a mediastinal biopsy similarly increased in this timeframe increasing from 41% to 53%. More patients with pre-treatment FDG-PET/CT scans received curative-intent therapy than those who did not: 23% vs 13% for CRT (p<0.001), and 23% vs 10% for surgery (p<0.001). Median OS was longer in those with FDG-PET/CT scans prior to treatment (17 vs 11 months), as was 5-year survival (22% vs 14%, p<0.001), and this held true on both univariate and multivariate analyses. Timing of FDG-PET/CT scan relative to treatment was not associated with differences in OS.

Conclusion

Improvements in OS were seen in this cohort of stage III NSCLC patients who underwent a pre-treatment FDG-PET/CT scan. This can likely be attributed to stage-appropriate therapy due to more complete staging using FDG-PET/CT. This study stresses the importance of complete staging for suspected stage III NSCLC using FDG-PET/CT, and a need for continued advocacy for increased access to FDG-PET/CT scans.

COMP Report: CPQR technical quality control guidelines for use of positron emission tomography/computed tomography in radiation treatment planning

Positron emission tomography with x-ray computed tomography (PET/CT) is increasingly being utilized for radiation treatment planning (RTP). Accurate delivery of RT therefore depends on quality PET/CT data. This study covers quality control (QC) procedures required for PET/CT for diagnostic imaging and incremental QC required for RTP. Based on a review of the literature, it compiles a list of recommended tests, performance frequencies, and tolerances, as well as references to documents detailing how to perform each test. The report was commissioned by the Canadian Organization of Medical Physicists as part of the Canadian Partnership for Quality Radiotherapy initiative.

Reduction of inter-observer variability using MRI and CT fusion in delineating of primary tumor for radiotherapy in lung cancer with atelectasis

Purpose

To compare the difference between magnetic resonance imaging (MRI) and computed tomography (CT) in delineating the target area of lung cancer with atelectasis.

Method

A retrospective analysis was performed on 15 patients with lung cancer accompanied by atelectasis. All positioning images were transferred to Eclipse treatment planning systems (TPSs). Six MRI sequences (T1WI, T1WI+C, T1WI+C Delay, T1WI+C 10 minutes, T2WI, DWI) were registered with positioning CT. Five radiation oncologists delineated the tumor boundary to obtain the gross tumor volume (GTV). Conformity index (CI) and dice coefficient (DC) were used to measure differences among observers.

Results

The differences in delineation mean volumes, CI, and DC among CT and MRIs were significant. Multiple comparisons were made between MRI sequences and CT. Among them, DWI, T2WI, and T1WI+C 10 minutes sequences were statistically significant with CT in mean volumes, DC, and CI. The mean volume of DWI, T2WI, and T1WI+C 10 minutes sequence in the target area is significantly smaller than that on the CT sequence, but the consistency is higher than that of CT sequences.

Conclusions

The recognition of atelectasis by MRI was better than that by CT, which could reduce interobserver variability of primary tumor delineation in lung cancer with atelectasis. Among them, DWI, T2WI, T1WI+C 10 minutes may be a better choice to improve the GTV delineation of lung cancer patients with atelectasis.

Patterns of Pretreatment Diagnostic Assessment in Patients Treated with Stereotactic Body Radiation Therapy (SBRT) for Non-Small Cell Lung Cancer (NSCLC): Special Characteristics in the COVID Pandemic and Influence on Outcomes

The pandemic raised a discussion about the postponement of medical interventions for non-small cell lung cancer (NSCLC). We analyzed the characteristics of pretreatment diagnostic assessment in the pandemic and the influence of diagnostic assessment on outcomes. A total of 96 patients with stereotactic body radiation therapy (SBRT) for NSCLC were included. The number of patients increased from mean 0.9 (2012–2019) to 1.45 per month in the COVID era (p < 0.05). Pandemic-related factors (contact reduction, limited intensive care unit resources) might have influenced clinical decision making towards SBRT. The time from pretreatment assessment (multidisciplinary tumor board decision, bronchoscopy, planning CT) to SBRT was longer during the COVID period (p < 0.05). Reduced services, staff shortage, or appointment management to mitigate infection risks might explain this finding. Overall survival, progression-free survival, locoregional progression-free survival, and distant progression-free survival were superior in patients who received a PET/CT scan prior to SBRT (p < 0.05). This supports that SBRT guidelines advocate the acquisition of a PET/CT scan. A longer time from PET/CT scan/conventional staging to SBRT (<10 vs. ≥10 weeks) was associated with worse locoregional control (p < 0.05). The postponement of diagnostic or therapeutic measures in the pandemic should be discussed cautiously. Patient- and tumor-related features should be evaluated in detail.

Evolving target volume concepts in locally advanced non-small cell lung cancer

Radiotherapy (RT) target volume concepts for locally advanced lung cancer have been under discussion for years. Although they may be as important as treatment doses, many aspects of them are still based on conventions, which, due to the paucity of prospective data, rely on long-term practice or on clinical knowledge and experience (e.g., on patterns of spread or recurrence). However, in recent years, large improvements have been made in medical imaging and molecular imaging methods have been implemented, which are of great interest in RT. For lung cancer, in recent years, 18F-fluoro-desoxy-glucose (FDG)-positron-emission tomography (PET)/computed tomography (CT) has shown a superior diagnostic accuracy as compare to conventional imaging and has become an indispensable standard tool for diagnostic workup, staging and response assessment. This offers the chance to optimize target volume concepts in relation to modern imaging. While actual recommendations as the EORTC or ESTRO-ACROP guidelines already include imaging standards, the recently published PET-Plan trial prospectively investigated conventional versus imaging guided target volumes in relation to patient outcome. The results of this trial may help to further refine standards. The current review gives a practical overview on procedures for pre-treatment imaging and target volume delineation in locally advanced non-small cell lung cancer (NSCLC) in synopsis of the procedures established by the PET-Plan trial with the actual EORTC and ACROP guidelines.

Non-small cell lung cancer stage migration as a function of wait times from diagnostic imaging: A pooled analysis from five international centres

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Validating impact of pretreatment tumor growth rate on outcome of early-stage lung cancer treated with stereotactic body radiation therapy

BACKGROUND

To assess correlation of pretreatment specific growth rate (SGR) value of 0.43 × 10^-2 with overall and failure-free survival of patients with early-stage non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT).

METHODS

A retrospective chart review of 160 patients with pathologically confirmed stage I NSCLC treated with SBRT between June 2010 and December 2012 in a large, tertiary cancer institute was undertaken. Both diagnostic and archived planning CT were uploaded to the treatment planning system to determine tumor volume at diagnosis (GTV1) and planning time (GTV2). The time (t) between both CTs was recorded. SGR was calculated using GTV1, GTV2, and t. The median SGR (0.43 × 10^-2 ) from our previous data was used to group patients into low and high SGR cohorts. Log-rank test was used to compare overall (OS) and failure-free survivals (FFS) of SGR groups.

RESULTS

The median time interval between diagnostic and planning CT scans was 87 days. The median OS was 38 and 66 months for high and low SGR cohorts, respectively (P = 0.03). The median FFS was 27 and 55 months for high and low SGR cohorts, respectively (P = 0.005). High SGR (P < 0.05), male gender (P = <0.01), and GTV2 (P = <0.05) were associated with poorer FFS.

CONCLUSIONS

High SGR was associated with poorer outcome in patients with early-stage NSCLC treated with SBRT. SGR can be used in conjunction with other well-known predictive factors to formulate a practical predictive model to identify subgroups of the patient at higher risk of recurrence after SBRT.

Influence of timeliness and receipt of first treatment on geographic variation in non-small cell lung cancer mortality

Mortality from non-small cell lung cancer (NSCLC) exhibits substantial geographical disparities. However, there is little evidence on whether this variation could be attributed to patients' clinical characteristics and/or socioeconomic inequalities. This study evaluated the independent and relative contribution of the individual- and area-level risk factors on geographic variation in 2-year all-cause mortality among NSCLC patients. In the Hierarchical-related regression approach, we used the Bayesian spatial multilevel logistic regression model to combine individual- and area-level predictors with outcomes while accounting for geographically structured and unstructured correlation. Individual-level data included 3330 NSCLC cases reported to the Victoria Lung Cancer Registry between 2011 and 2016. Area-level data comprised socioeconomic disadvantage, remoteness and pollution data at the postal area level in Victoria, Australia. With the inclusion of significant individual- and area-level risk factors, timely (≤14 days) first definitive treatment (odds ratio [OR] = 0.73, 95% credible interval [Crl] = 0.56-0.94) and multidisciplinary meetings (MDM) (OR = 0.74, 95% Crl = 0.59-0.93) showed an independent association with a lower likelihood of NSCLC 2-year all-cause mortality. Timely and delayed (>14 days) first nondefinitive treatment, no treatment, advanced clinical stage, smoking, poor performance status, public hospital insurance and area-level deprivation were independently associated with a higher likelihood of 2- and 5-year all-cause mortality. NSCLC's 2-year all-cause mortality exhibited substantial geographic variation, mainly associated with timeliness and receipt of first definitive treatment, no treatment followed by patient prognostic factors with some contribution from area-level deprivation, MDM and public hospital insurance. This study highlights NSCLC patients should receive the first definitive treatment within the recommended 14-days from diagnosis.

Implications of COVID-19 pandemic on lung cancer management: A multidisciplinary perspective

Treatment of patients with lung cancer during the current COVID-19 pandemic is challenging. Lung cancer is a heterogenous disease with a wide variety of therapeutic options. Oncologists have to determine the risks and benefits of modifying the treatment plans of patients especially in situation where the disease biology and treatment are complex. Health care visits carry a risk of transmission of SARS-CoV-2 and the similarities of COVID-19 symptoms and lung cancer manifestations represent a dominant problem. Efforts to modify treatment of lung cancer during the current pandemic have been adapted by many healthcare institutes to reduce exposure of lung cancer patients to SARS-CoV-2. We summarized the implications of COVID-19 pandemic on the management of lung cancer from the perspective of different specialties of thoracic oncology multidisciplinary team.

A review on the impact of lung cancer multidisciplinary care on patient outcomes

International guidelines recommend a multidisciplinary approach to the management of lung cancer due to the complexity of both patients and their disease and the multiple treatment options available. This care can be provided through patient discussion at multidisciplinary meetings where relevant medical and allied health staff formulate a consensus management plan taking all factors into consideration. This model can be extended further to include multidisciplinary clinics where the patient is present for assessment and discussion. However, conducting regular multidisciplinary meetings or clinics has significant time, resource and financial costs and therefore, it is important to assess the impact of multidisciplinary care. We aimed to review published evidence, from 2000 to 2019, to evaluate the impact of multidisciplinary care on lung cancer outcomes. There were 29 studies found, 11 evaluating multidisciplinary clinics, 14 studying multidisciplinary meetings and four where the model of care was not defined. There was only one randomised trial and three prospective studies, the remainder being retrospective studies. Despite limitations in trial design and confounding factors, overall, multidisciplinary care in lung cancer was associated with improvements in patient outcomes, in particular improved survival for all stages of lung cancer. Lung cancer patients managed in a multidisciplinary setting were more likely to receive active treatment and had improved utilisation of all treatment modalities: surgery, radiotherapy and chemotherapy. In addition, the treatment recommendations were more likely to be consistent with lung cancer management guidelines. These improved outcomes support the recommendations for a multidisciplinary approach to lung cancer care.

Effect of time interval from diagnosis to treatment for non-small cell lung cancer on survival: a national cohort study in Taiwan

OBJECTIVES

This study aimed to determine if treatment delay after non-small cell lung cancer (NSCLC) diagnosis impacts patient survival rate.

STUDY DESIGN

This study is a natural experiment in Taiwan. A retrospective cohort investigation was conducted from 2004 to 2010, which included 42 962 patients with newly diagnosed NSCLC.

METHODS

We identified 42 962 patients with newly diagnosed NSCLC in the Taiwan Cancer Registry from 2004 to 2010. We calculated the time interval between diagnosis and treatment initiation. All patients were followed from the index date to death or the end of 2012. Cox proportional hazard models were used to examine the relationship between mortality and time interval.

RESULTS

We included 42 962 patients (15 799 men and 27 163 women) with newly diagnosed NSCLC. The mortality rate exhibited a significantly positive correlation to time interval from cancer diagnosis to treatment initiation. The adjusted HRs ranged from 1.04 to 1.08 in all subgroups time interval more than 7 days compared with the counterpart subgroup of the interval from cancer diagnosis to treatment ≤7 days. The trend was also noted regardless of the patients with lung cancer in stage I, stage II and stage III.

CONCLUSIONS

There is a major association between time to treat and mortality of patients with NSCLC, especially in stages I and II. We suggest that efforts should be made to minimise the interval from diagnosis to treatment while further study is ongoing to determine causation.

Reduced delays in diagnostic pathways for non-small cell lung cancer after local and National initiatives

OBJECTIVES

Patients with non-small cell lung cancer (NSCLC) may experience progression and stage shift due to delays in a complex and time-consuming diagnostic work-up. We have analyzed the impact of both a local and national intervention on total time to treatment (TTT).

MATERIAL AND METHODS

All patients diagnosed with NSCLC at a Norwegian county hospital from 2007 to 2016 were reviewed. Logistic bottlenecks and delays were identified (2007-12) resulting in implementation of a local initiative with new diagnostic algorithm introduced by the beginning of 2013. In 2015, national diagnostic cancer pathways were implemented. TTT defined as time from received referral from the primary physician to start of treatment was compared in the three diagnostic time periods; baseline (2007-12), local (2013-14) and national (2015-16).

RESULTS

A total of 780 patients were included. Among patients treated with curative intent the median TTT decreased by 21 days, from 64 to 43 days (p < 0.001) while the mean number of diagnostic procedures increased from 3.5 to 3.9. In median regression analysis, the local initiative was associated with a reduction of estimated 7.8 days (95% CI 3.2, 12.3) in TTT, while the national initiative correlated with a reduction of estimated 14.9 days (95% CI 10.2, 19.6) compared to time at baseline. Covariates associated with longer TTT were stage I, use of PET-CT, diagnostic procedure at external hospital, and number of diagnostic procedures.

CONCLUSION

Local and national initiatives significantly reduced TTT in NSCLC. The effect was most pronounced among patients with disease available for curative treatment.

Improving regional lung cancer optimal care pathway compliance through a rapid-access respiratory clinic

BACKGROUND

Lung cancer is the leading cause of cancer-related morbidity and mortality in Australia and delays in diagnosis and management increase the potential for disease progression. Incidence and mortality from lung cancer in our region, Gippsland, are higher than the national average, yet there is no known standard referral pathway for diagnosis in the region.

AIM

To identify the current standard of care for lung cancer diagnosis and the impact a rapid access clinic, led by a respiratory physician, has on optimal care pathway (OCP) compliance.

METHODS

A retrospective audit of patients with lung cancer managed through our regional hospital between January and December 2018 (Standard Care group), and a prospective audit of a new rapid access, respiratory-physician led, lung lesion assessment clinic over the same period, were conducted. The primary outcomes were compliance with the OCP target for time from initial computed tomography scan identification of a lung lesion to tissue diagnosis and treatment commencement (target 42 days) when malignancy was confirmed.

RESULTS

There were 25 cases audited in the Standard Care group and 21 cases seen through the Rapid Access Clinic. The Standard Care group met the target for treatment commencement in 33.3% of cases whereas the Rapid Access Clinic group achieved this in 77%.

CONCLUSIONS

Our project highlights the disjointed and delayed lung cancer care in our region and the improvements a dedicated rapid access clinic can have on diagnosis and treatment commencement timeframes.

ICORG 06-35: a prospective evaluation of PET-CT scan in patients with non-operable or non-resectable non-small cell lung cancer treated by radical 3-dimensional conformal radiation therapy: a phase II study

BACKGROUND

Radiotherapy (RT) is a key treatment modality in the curative treatment of patients with non-small cell lung cancer (NSCLC). Incorrect definition of the gross, or clinical, target volume is a common source of error which can lead to a reduced probability of tumour control.

OBJECTIVE

This was a pilot and a phase II study. The pilot evaluated the technical feasibility of integrating positron emission tomography-computed tomography (PET-CT) fusion. The primary outcome of the phase II study was to evaluate the safety of PET-CT scan-based RT by evaluating the rate of loco-regional recurrence outside the PET-CT planning target volume (PTV) but within conventional 3-D PTV.

METHODS

Patients underwent standard post-treatment follow-up, including repeated three monthly CT scans of the thorax. In case of loco-regional recurrence, three categories were considered, with only extra-PET scan PTV and intra-CT scan PTV recurrences considered as a failure. Our hypothesis was that the rate of these events would be < 10%.

RESULTS

Twelve patients were recruited; the study closed early due to poor recruitment. The primary endpoint of the pilot was met; it was feasible to deliver a PET-CT-based plan to ≥ 60% of patients. Two patients had intra-PET scan PTV recurrences, six had extra-PET scan PTV and extra-CT, and three patients had both. Another patient had extra-PET scan PTV and extra-CT as well as extra-PET scan PTV and intra-CT scan PTV recurrence.

CONCLUSION/ADVANCES IN KNOWLEDGE

PET-based planning has the potential to reduce radiation treatment volumes because of the avoidance of mediastinal lymph nodes that are PET negative.

Clinical significance of pretreatment tumor growth rate for locally advanced non-small cell lung cancer

Background

Locally advanced non-small cell lung cancer (NSCLC) may exhibit significant tumor growth before the initiation of definitive chemoradiation therapy (CRT). We thus investigated the prognostic value of pretreatment tumor growth rate as measured by specific growth rate (SGR).

Methods

We conducted a retrospective review of 42 patients with locally advanced NSCLC treated with definitive concurrent CRT. For each patient, we contoured the primary gross tumor volume (GTV) on the pretreatment diagnostic chest computed tomography (CT) scan and the radiation therapy (RT) planning CT scan. We then calculated SGR based on the primary GTV from each scan and the time interval between scans. We used log-rank tests and univariate Cox regression models to quantify differences in progression-free survival (PFS), overall survival (OS) and recurrence based on SGR.

Results

We divided patients into two groups for analysis: those with an SGR greater than or equal to the upper tercile value of 0.94%/day (high SGR) and those with SGR less than 0.94%/day (low SGR). Patients with high SGRs versus low SGRs experienced inferior PFS (median, 5.6 vs. 13.6 months, P=0.016), without a significant difference in OS. The inferior PFS in the high SGR group persisted on multivariate analysis [adjusted hazard ratio (HR) 2.37, 95% confidence interval (CI): 1.07-5.25, P=0.034]. The risk of distant recurrence was higher in the high SGR group (HR 2.62, 95% CI: 1.08-6.38, P=0.033), but there was no difference in the risk of locoregional recurrence between groups.

Conclusions

Pretreatment SGR was associated with inferior PFS and distant control among patients with locally advanced NSCLC treated with concurrent CRT. Further studies in larger populations may aid in elucidating optimal SGR cut-off points for risk stratification.

Using a Dedicated Interventional Pulmonology Practice Decreases Wait Time Before Treatment Initiation for New Lung Cancer Diagnoses

PURPOSE

While there is significant mortality and morbidity with lung cancer, early stage diagnoses carry a better prognosis. As lung cancer screening programs increase with more pulmonary nodules detected, expediting definitive treatment initiation for newly diagnosed patients is imperative. The objective of our analysis was to determine if the use of a dedicated interventional pulmonology practice decreases time delay from new diagnosis of lung cancer or metastatic disease to the chest to treatment initiation.

METHODS

Retrospective chart analysis was done of 87 consecutive patients with a new diagnosis of primary lung cancer or metastatic cancer to the chest from our interventional pulmonology procedures. Demographic information and time intervals from abnormal imaging to procedure and to treatment initiation were recorded.

RESULTS

Patients were older (mean age 69) and former or current smokers (72%). A median of 27 days (1-127 days) passed from our diagnostic biopsy to treatment initiation. A median of 53 total days (2-449 days) passed from abnormal imaging to definitive treatment. Endobronchial ultrasound-guided transbronchial needle aspiration was the most commonly used diagnostic procedure (59%), with non-small cell lung cancer the majority diagnosis (64%). For surgical patients, all biopsy-negative lymph nodes from our procedures were cancer-free at surgical excision.

CONCLUSIONS

Compared to prior reports from international and United States cohorts, obtaining a tissue biopsy diagnosis through a gatekeeper interventional pulmonology practice decreases median delay from abnormal imaging to treatment initiation. This finding has the potential to positively impact patient outcomes and requires further evaluation.

Small cell lung cancer in the young: Characteristics, diagnosis and outcome data

BACKGROUND

Patients with small cell lung cancer (SCLC) younger than 40 years are limited in number. Our research aimed to assess the characteristics, diagnosis and outcomes of this patient population.

METHODS

Records of patients under the age of 40 with SCLC at the Chinese Academy of Medical Sciences between January 2006 and December 2015 were reviewed and evaluated.

RESULTS

One hundred and three patients (67.0% limited stage, 33.0% extensive stage) were included, along with 54 (52.4%) never-smokers. The median diagnostic interval and the median survival time (MST) were 51.0 days and 24.0 months, respectively. A total of 41 (39.8%) patients claimed to have undergone antibiotic treatment before diagnosis, with a median duration of 2 weeks. In univariate analysis, survival was better for the limited stage group than the extensive stage group (MST, 28.0 vs. 13.0 months, P < 0.0001). Also, patients who received concurrent radiochemotherapy had better survival than those who received chemotherapy alone (MST, 29.0 vs. 18.0 months, P = 0.001). Patients with antibiotic treatment before SCLC diagnosis have worse prognosis than those without (MST, 21.0 vs. 27.0 months, P = 0.008). Moreover, a timely diagnosis (≤1 month) exerted a positive impact on the overall survival in limited stage patients (48.0 vs. 26.0 months, P = 0.047) and on progression-free survival in extensive stage patients (6.0 vs. 3.0 months, P = 0.030). Multivariate analysis suggested that disease stage, history of antibiotic treatment before SCLC diagnosis and performance status independently correlated with survival.

CONCLUSION

Our study identified distinct characteristics and prognostic factors of SCLC patients under 40 years. More timely care may improve patient prognosis.

CT-pathologic correlation in lung adenocarcinoma and squamous cell carcinoma

Distinguishing lung adenocarcinoma from squamous cell carcinoma (SCC) is clinically important. Computed tomography (CT) scan is an economical, effective, noninvasive, commonly available, and quick diagnostic way for lung cancer. In this study, we aim to compare the CT characteristics in adenocarcinoma and SCC.Data from 275 cases (259 adenocarcinoma and 16 SCC) were retrospectively compared. CT characteristics, including lesion size and shape, single/multifocal lesions, location of the tumor, the margin of lobes, whether the lesion had deep lobulated margin, bronchial cut-off sign, signs of dilated bronchial arteries, signs of vascular bundle thickening, signs of short burrs, spinous processes, and pleural indentation, were compared in 148 cases (137 adenocarcinoma and 11 SCC).Patients with adenocarcinoma were more likely to be female (44.2% vs 25.0%, P = .017). Compared with SCC, adenocarcinomas were more likely to have deep lobulated margin (81.0% vs 54.5%, P = .038), less likely to have smooth lobes margin (2.7% vs 83.3%, P < .001), more likely to have vascular bundle thickening (37.2% vs 0, P = .016) and pleural indentation (59.9% vs 18.2%, P = .01), and marginally less likely to have dilated bronchial arteries (17.5% vs 45.5%, P = .064). No significant difference was observed regarding to characteristics, including tumor size, location of the tumor, signs of bronchial cut-off, dilated bronchial arteries, short burrs, or spinous processes.CT scan has the potential to help to distinguish lung adenocarcinoma and SCC in a fast and commonly available way. CT could be a rough but fast way to diagnosis, and may thus shorten the waiting time to treatment and allow more time for clinicians, patients, and their families to prepare for future treatment.

Comparison of SUVmax and SUVpeak based segmentation to determine primary lung tumour volume on FDG PET-CT correlated with pathology data

PURPOSE

The aim of the study was to compare simple SUVmax and SUVpeak based segmentation methods for calculating the lung tumour volume, compared to a pathology ground truth.

METHODS

Thirty patients diagnosed with early stage Non-Small Cell lung cancer (NSCLC) underwent surgical resection in the Netherlands between 2006 and 2008. FDG PET-CT scans for these patients were acquired within a median of 20 days before surgery. The tumour volume for each percentage SUVmax and SUVpeak threshold, with and without background correction, was calculated for each patient. The percentage threshold that provided the tumour volume that corresponded best with the pathology volume was considered to be the optimal threshold. The optimal thresholds were plotted as a function of tumour volume using a power law function and cross validated using the leave-one-out technique.

RESULTS

The mean optimal percentage threshold was 50% ± 10% and 62% ± 15% for the SUVmax and SUVpeak without background correction respectively and 47% ± 10% and 60 ± 15% for the SUVmax and SUVpeak with background correction respectively. The optimal threshold curves could be fitted well with power law function. After cross validation the correlation between the effective tumour diameter in pathology and autosegmentation was 0.900 and 0.905 for the SUVmax and SUVpeak without background correction respectively and 0.913 and 0.908 for the SUVmax and SUVpeak with background correction respectively.

CONCLUSION

No benefit was shown on clinical data for the SUVpeak based segmentation method over a SUVmax based one. Both methods can be used to determine the tumour volumes in resected NSCLC tumours.

Pathways to Lung Cancer Diagnosis: A Qualitative Study of Patients and General Practitioners about Diagnostic and Pretreatment Intervals

RATIONALE

Pathways to lung cancer diagnosis and treatment are complex. International evidence shows significant variations in pathways. Qualitative research investigating pathways to lung cancer diagnosis rarely considers both patient and general practitioner views simultaneously.

OBJECTIVES

To describe the lung cancer diagnostic pathway, focusing on the perspective of patients and general practitioners about diagnostic and pretreatment intervals.

METHODS

This qualitative study of patients with lung cancer and general practitioners in Australia used qualitative interviews or a focus group in which participants responded to a semistructured questionnaire designed to explore experiences of the diagnostic pathway. The Model of Pathways to Treatment (the Model) was used as a framework for analysis, with data organized into (1) events, (2) processes, and (3) contributing factors for variations in diagnostic and pretreatment intervals.

RESULTS

Thirty participants (19 patients with lung cancer and 11 general practitioners) took part. Nine themes were identified during analysis. For the diagnostic interval, these were: (1) taking patient concerns seriously, (2) a sense of urgency, (3) advocacy that is doctor-driven or self-motivated, and (4) referral: "knowing who to refer to." For the pretreatment interval, themes were: (5) uncertainty, (6) psychosocial support for the patient and family before treatment, and (7) communication among the multidisciplinary team and general practitioners. Two cross-cutting themes were: (8) coordination of care and "handing over" the patient, and (9) general practitioner knowledge about lung cancer. Events were perceived as complex, with diagnosis often being revealed over time, rather than as a single event. Contributing factors at patient, system, and disease levels are described for both intervals.

CONCLUSIONS

Patients and general practitioners expressed similar themes across the diagnostic and pretreatment intervals. Significant improvements could be made to health systems to facilitate better patient and general practitioner experiences of the diagnostic pathway. This novel presentation of patient and general practitioner perspectives indicates that systemic interventions have a role in timely and appropriate referrals to specialist care and coordination of investigations. Systemic interventions may alleviate concerns about urgency of diagnostic workup, communication, and coordination of care as patients transition from primary to specialist care.

Histologic Grade Is Predictive of Incidence of Epidermal Growth Factor Receptor Mutations in Metastatic Lung Adenocarcinoma

Activating epidermal growth factor receptor (EGFR) mutations in metastatic non-small cell lung cancer (NSCLC) are associated with a high response rate to EGFR tyrosine kinase inhibitor (TKI). The current guidelines recommend routine EGFR mutational analysis prior to initiating first line systemic therapy. The clinical characteristics including smoking status, histologic type, sex and ethnicity are known to be associated with the incidence of EGFR mutations. We retrospectively analyzed 277 patients with metastatic NSCLC within Kaiser Permanente Northern California (KPNC); among these patients, 83 were positive for EGFR mutations. We performed both univariate and multivariable logistic regressions to identify predictors of EGFR mutations. We found that histologic grade was significantly associated with the incidence of EGFR mutation, regardless of ethnicity, sex and smoking status. In grade I (well differentiated) and II (moderately differentiated), histology was associated with significantly higher incidence of EGFR mutations compared to grade II–III (moderate-to-poorly differentiated) and III (poorly differentiated). Ever-smokers with grade III lung adenocarcinoma had 1.8% incidence of EGFR mutations. This study indicates that histologic grade is a predictive factor for the incidence of EGFR mutations and suggests that for patients with grade II–III or III lung adenocarcinoma, prompt initiation of first-line chemotherapy or immunotherapy is appropriate while awaiting results of EGFR mutational analysis, particularly for patients with history of smoking.

Timeliness of Care and Lung Cancer Tumor-Stage Progression: How Long Can We Wait?

BACKGROUND

Timely care of lung cancer is presumed critical, yet clear evidence of stage progression with delays in care is lacking. We investigated the reasons for delays in treatment and the impact these delays have on tumor-stage progression.

METHODS

We queried our retrospective database of 265 veterans who underwent cancer resection from 2005 to 2015. We extracted time intervals between nodule identification, diagnosis, and surgical resection; changes in nodule radiographic size over time; final pathologic staging; and reasons for delays in care. Pearson's correlation and Fisher's exact test were used to compare cancer growth and stage by time to treatment.

RESULTS

Median time from referral to surgical evaluation was 11 days (interquartile range, 8 to 17). Median time from identification to therapeutic resection was 98 days (interquartile range, 66 to 139), and from diagnosis to resection, 53 days (interquartile range, 35 to 77). Sixty-eight patients (26%) were diagnosed at resection; the remainder had preoperative tissue diagnoses. No significant correlation existed between tumor growth and time between nodule identification and resection, or between tumor growth and time between diagnosis and resection. Among 197 patients with preoperative diagnoses, 42% (83) had intervals longer than 60 days between diagnosis and resection. Most common reasons for delay were cardiac clearance, staging, and smoking cessation. Larger nodules had fewer days between identification and resection (p = 0.03).

CONCLUSIONS

Evaluation, staging, and smoking cessation drive resection delays. The lack of association between tumor growth and time to treatment suggests other clinical or biological factors, not time alone, underlie growth risk. Until these factors are identified, delays to diagnosis and treatment should be minimized.

Anatomic, functional and molecular imaging in lung cancer precision radiation therapy: treatment response assessment and radiation therapy personalization

This article reviews key imaging modalities for lung cancer patients treated with radiation therapy (RT) and considers their actual or potential contributions to critical decision-making. An international group of researchers with expertise in imaging in lung cancer patients treated with RT considered the relevant literature on modalities, including computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET). These perspectives were coordinated to summarize the current status of imaging in lung cancer and flag developments with future implications. Although there are no useful randomized trials of different imaging modalities in lung cancer, multiple prospective studies indicate that management decisions are frequently impacted by the use of complementary imaging modalities, leading both to more appropriate treatments and better outcomes. This is especially true of ¹⁸F-fluoro-deoxyglucose (FDG)-PET/CT which is widely accepted to be the standard imaging modality for staging of lung cancer patients, for selection for potentially curative RT and for treatment planning. PET is also more accurate than CT for predicting survival after RT. PET imaging during RT is also correlated with survival and makes response-adapted therapies possible. PET tracers other than FDG have potential for imaging important biological process in tumors, including hypoxia and proliferation. MRI has superior accuracy in soft tissue imaging and the MRI Linac is a rapidly developing technology with great potential for online monitoring and modification of treatment. The role of imaging in RT-treated lung cancer patients is evolving rapidly and will allow increasing personalization of therapy according to the biology of both the tumor and dose limiting normal tissues.

Staging of Non-Small-Cell Lung Cancer

Staging of lung cancer serves 2 purposes; it attempts to classify patients into groups where particular treatments are appropriate and defines those groups based on expected prognosis. The eighth edition of the International Association for the Study of Lung Cancer staging system deals with the issues raised by screening with fine cut computed tomography. Each phase of staging is a legitimate dataset on its own. Molecular profiling of lung cancer has led to the development of an increasing number of novel agents to treat systemic disease. Prognosis is increasingly determined by genetic susceptibility of the specific cancer.

Impact of Timing of Lobectomy on Survival for Clinical Stage IA Lung Squamous Cell Carcinoma

BACKGROUND

Because the relationship between the timing of surgery following diagnosis of lung cancer and survival has not been precisely described, guidelines on what constitutes a clinically meaningful delay of resection of early-stage lung cancer do not exist. This study tested the hypothesis that increasing the time between diagnosis and lobectomy for stage IA squamous cell carcinoma (SCC) would be associated with worse survival.

METHODS

The association between timing of lobectomy and survival for patients with clinical stage IA SCC in the National Cancer Data Base (2006-2011) was assessed using multivariable Cox proportional hazards analysis and restricted cubic spline (RCS) functions.

RESULTS

The 5-year overall survival of 4,984 patients who met study inclusion criteria was 58.3% (95% CI, 56.3-60.2). Surgery was performed within 30 days of diagnosis in 1,811 (36%) patients, whereas the median time to surgery was 38 days (interquartile range, 23, 58). In multivariable analysis, patients who had surgery 38 days or more after diagnosis had significantly worse 5-year survival than patients who had surgery earlier (hazard ratio, 1.13 [95% CI, 1.02-1.25]; P = .022). Multivariable RCS analysis demonstrated the hazard ratio associated with time to surgery increased steadily the longer resection was delayed; the threshold time associated with statistically significant worse survival was ∼90 days or greater.

CONCLUSIONS

Longer intervals between diagnosis of early-stage lung SCC and surgery are associated with worse survival. Although factors other than the timing of treatment may contribute to this finding, these results suggest that efforts to minimize delays beyond those needed to perform a complete preoperative evaluation may improve survival.

Does timeliness of care in Non-Small Cell Lung Cancer impact on survival?

OBJECTIVES

To measure time intervals in the management of Non-Small Cell Lung Cancer (NSCLC) patients, identify factors associated with this and evaluate the impact of timeliness of care on survival.

MATERIALS AND METHODS

A retrospective cohort of South Western Sydney (SWS) patients with newly diagnosed NSCLC from 2006 to 2012 was identified from the SWSLHD Clinical Cancer Registry. Time intervals evaluated in days were "Diagnosis to Initial Treatment" and "Referral to Initial Treatment". Treatment included surgery, radiotherapy, systemic therapy and palliative care. Negative binomial regression and Cox regression were used to identify factors associated with timeliness of care and survival respectively.

RESULTS

1926 NSCLC patients were identified of whom 1729 had initial treatment recorded. Initial treatment was palliative care in 35% (n=611), radiotherapy in 29% (n=498), surgery in 18% (n=314) and systemic therapy in 18% (n=306). Median time from diagnosis to treatment was 32days (IQR 15-58). Median time from specialist referral to treatment was 35days for surgery (IQR 21-49), 21days for radiotherapy (IQR 13-32) and 25days (IQR 15-35) for systemic therapy. On multivariable analysis, age between 70 and 79 years, ECOG performance status 0-1, Stage I-III NSCLC and systemic treatment were associated with longer Diagnosis to Treatment: intervals. Diagnosis to Treatment: interval was not associated with mortality in Stage I & II NSCLC. A longer interval was associated with reduced mortality in Stage III (HR 0.99, 95%CI 0.99-1.0, p=0.03) and Stage IV NSCLC (HR=0.99, 95% CI 0.99-0.99, p=0.0008).

CONCLUSIONS

At the population level, longer Diagnosis to Treatment: time intervals were not associated with adverse survival outcomes in NSCLC. However, delays to treatment may impact on other outcomes such as patient's psychological wellbeing and quality of life which were not measured in this study.

The role of PET/CT as a prognosticator and outcome predictor in lung cancer

Positron emission tomography/computed tomography (PET/CT) is an important imaging tool for management of lung cancer and can be utilized in diagnosis, staging, restaging, treatment planning and evaluating treatment response. In the past decade PET/CT has proven to be beneficial for the prediction of prognosis and outcome. PET findings before and after treatment, the quantitative PET parameters such as standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) as well as delayed PET/CT imaging can be used to determine patient prognosis and outcome. Other tracers such as hypoxia and proliferation marker tracers may be used for prognostication. The prognostic factors derived from PET/CT imaging help early development of risk-adapted treatment strategies, which provides cost-effective treatment and leads to improved patient management. Here, we discuss findings of studies related to application of PET/CT in lung cancer as well as some technical updates on quantitative PET/CT in lung cancer.

The Impact of Diffusion-Weighted MRI on the Definition of Gross Tumor Volume in Radiotherapy of Non-Small-Cell Lung Cancer

Objective

The study was designed to evaluate diffusion-weighted magnetic resonance imaging (DWI) vs. PET-CT of the thorax in the determination of gross tumor volume (GTV) in radiotherapy planning of non-small-cell lung cancer (NSCLC).

Materials and Methods

Eligible patients with NSCLC who were supposed to receive definitive radio(chemo)therapy were prospectively recruited. For MRI, a respiratory gated T2-weighted sequence in axial orientation and non-gated DWI (b = 0, 800, 1,400 and apparent diffusion coefficient map [ADC]) were acquired on a 1.5 Tesla scanner. Primary tumors were delineated on FDG-PET/CT (stGTV) and DWI images (dwGTV). The definition of stGTV was based on the CT and visually adapted to the FDG-PET component if indicated (e.g., in atelectasis). For DWI, dwGTV was visually determined and adjusted for anatomical plausibility on T2w sequences. Beside a statistical comparison of stGTV and dwGTB, spatial agreement was determined with the “Hausdorff-Distance” (HD) and the “Dice Similarity Coefficient” (DSC).

Results

Fifteen patients (one patient with two synchronous NSCLC) were evaluated. For 16 primary tumors with UICC stages I (n = 4), II (n = 3), IIIA (n = 2) and IIIB (n = 7) mean values for dwGTV were significantly larger than those of stGTV (76.6 ± 84.5 ml vs. 66.6 ± 75.2 ml, p<0.01). The correlation of stGTV and dwGTV was highly significant (r = 0.995, p<0.001). Yet, some considerable volume deviations between these two methods were observed (median 27.5%, range 0.4–52.1%). An acceptable agreement between dwGTV and stGTV regarding the spatial extent of primary tumors was found (average HD: 2.25 ± 0.7 mm; DC 0.68 ± 0.09).

Conclusion

The overall level of agreement between PET-CT and MRI based GTV definition is acceptable. Tumor volumes may differ considerably in single cases. DWI-derived GTVs are significantly, yet modestly, larger than their PET-CT based counterparts. Prospective studies to assess the safety and efficacy of DWI-based radiotherapy planning in NSCLC are warranted.

Application of novel quantitative techniques for fluorodeoxyglucose positron emission tomography/computed tomography in patients with non-small-cell lung cancer

AIM

Flurodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is routinely used in non-small-cell lung cancer. This study aims to assess the prognostic value of quantitative FDG-PET/CT parameters including standard uptake value (SUV), metabolic tumor volume (MTV) and total lesional glycolysis (TLG) in non-small-cell lung cancer.

METHODS

A retrospective review of 92 nonsurgical patients with pathologically confirmed stage I-III non-small-cell lung cancers treated with radical dose radiotherapy (≥50 Gy) was conducted. Metabolically active tumor regions on FDG-PET/CT scans were contoured manually. SUV, MTV and TLG were calculated for primary, nodal and whole-body disease. Univariate and multivariate (adjusting for age, sex, disease stage and primary tumor size in centimeters) Cox regression modeling were performed to assess the association between these parameters and both overall and progression-free survival (PFS).

RESULTS

On univariate analysis, overall survival (OS) was significantly associated with primary MTV (P = 0.03), whole-body MTV (P = 0.02), whole-body maximum SUV (P = 0.05) and whole-body TLG (P = 0.03). PFS was significantly associated with primary MTV (P = 0.01), primary TLG (P = 0.04), whole-body MTV (P < 0.01) and whole-body TLG (P = 0.01). On multivariate analysis, OS was significantly associated with whole-body MTV (P = 0.05). PFS was significantly associated with whole-body MTV (P = 0.02) and whole-body TLG (P = 0.05).

CONCLUSIONS

Whole-body MTV was significantly associated with overall and PFS, and whole-body TLG was significantly associated with PFS on multivariate analysis. These two parameters may be significant prognostic factors independent of other factors such as stage. SUV was not significantly associated with survival on multivariate analysis.

Defining a standard set of patient-centred outcomes for lung cancer

In lung cancer, outcome measurement has been mostly limited to survival. Proper assessment of the value of lung cancer treatments, and the performance of institutions delivering care, requires more comprehensive measurement of standardised outcomes.

The International Consortium for Health Outcomes Measurement convened an international, multidisciplinary working group of patient representatives, medical oncologists, surgeons, radiation oncologists, pulmonologists, palliative care specialists, registry experts and specialist nurses to review existing data and practices. Using a modified Delphi method, the group developed a consensus recommendation (“the set”) on the outcomes most essential to track for patients with lung cancer, along with baseline demographic, clinical and tumour characteristics (case-mix variables) for risk adjustment.

The set applies to patients diagnosed with nonsmall cell lung cancer and small cell lung cancer. Our working group recommends the collection of the following outcomes: survival, complications during or within 6 months of treatment and patient-reported domains of health-related quality of life including pain, fatigue, cough and dyspnoea. Case-mix variables were defined to improve interpretation of comparisons.

We defined an international consensus recommendation of the most important outcomes for lung cancer patients, along with relevant case-mix variables, and are working to support adoption and reporting of these measures globally.

#ICHOM Lung Cancer Standard Set of patient-centred outcomes: aligning global efforts to improve lung cancer carehttp://ow.ly/bFDR300EhY7

Risk factors and management of oligometastatic non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is an aggressive malignancy with close to half of all patients presenting with metastatic disease. A proportion of these patients with limited metastatic disease, termed oligometastatic disease, have been shown to benefit from a definitive treatment approach. Synchronous and metachronous presentation of oligometastatic disease have prognostic significance, with current belief that metachronous disease is more favorable. Surgical excision of intracranial and extracranial oligometastatic disease has been shown to improve survival, especially in patients with lymph node-negative disease, adenocarcinoma histology and smaller thoracic tumors. Definitive radiation to sites of oligometastatic disease and initial thoracic disease has also been shown to have a similar impact on survival for both intracranial and extracranial disease. Recent studies have reported on the use of targeted agents combined with ablative doses of radiation in the oligometastatic setting with promising outcomes. In this review, we present the historical and current literature describing surgical and radiation treatment options for patients with oligometastatic NSCLC.

An assessment of cone beam CT in the adaptive radiotherapy planning process for non-small-cell lung cancer patients

OBJECTIVE

To investigate the potential use of cone beam CT (CBCT) in adaptive radiotherapy (ART) planning process for non-small-cell lung cancer (NSCLC).

METHODS

17 retrospective patients with NSCLC Stage T1-T4, who had completed a course of radiotherapy with weekly CBCT imaging were selected for the study. The patients had been delineated and planned for three-dimensional (3D) conformal treatment (prescription: 55 Gy in 20 fractions) based on free-breathing four-dimensional CT data. Of these initial 17 patients, 12 had full quantitative data on gross tumour volume (GTV) position and volume throughout treatment. GTV delineation was carried out on weekly CBCT by a clinical oncologist. For each patient, mean percentage change in GTV and centre of mass (COM) displacement (based on 3D vectors) were calculated throughout treatment. Volume overlap between GTVs was calculated. Correlation of the COM displacement and planning GTV (pGTV) was assessed. A linear mixed model with patients as random effects was fitted to the data to assess potential benefit from using ART for these patients.

RESULTS

Comparison of CBCT-based GTV acquired prior to Fraction 1 (cbctGTV1) to pGTV showed mean 20 ± 19% volume increase using a related sample Wilcoxon signed rank test p = 0.04. Correlation was identified between volume reductions and dose delivered (beta = -0.003, p < 0.001)-a highly statistically significant association. Compared with cbctGTV1, the mean ratios ± standard deviation were cbctGTV2, 0.93 ± 0.08; cbctGTV3, 0.84 ± 0.12; and cbctGTV4, 0.75 ± 0.14. The dice similarity coefficient was 0.81 ± 0.14, 0.78 ± 0.17, 0.73 ± 0.19, respectively. The COM was consistent throughout treatment (mean 0.35 ± 0.24 cm). A fitted model predicts that a mean change of 30% volume relative to cbctGTV1 occurs at a dose of approximately 50 Gy.

CONCLUSION

Using a 30% reduction in volume, ART would not be of benefit for all radiotherapy-alone-treated patients with NSCLC assessed in this study. For individual patients and patients with atelectasis, CBCT imaging was able to identify volume change.

ADVANCES IN KNOWLEDGE

For patients treated with 55 Gy in 20 fractions, target volume changes throughout treatment have been demonstrated using CBCT and can be used to highlight patients who may benefit from ART.

Clinical and research priorities for combined modality therapy in stage III NSCLC

Stage III NSCLC comprises of a heterogeneous group of patients with regard to stage, extent of disease and prognosis. Disease presentation can often be complex in clinical practice, and the challenges are not well-defined in clinical trials or practice guidelines. In order to improve the therapeutic ratio of treatment, one needs to either increase the benefit of treatment or reduce toxicities, or both. Priorities in radiation therapy include dose escalation, imaging advances, improved target delineation, reduced planning target volume margin, intensity-modulated radiotherapy, image-guided radiotherapy, motion management and the use of cytoprotectants. Priorities in systemic therapy include the incorporation of molecularly targeted and immune-modulatory agents.

Ratio of Lymph Node to Primary Tumor SUV on PET/CT Accurately Predicts Nodal Malignancy in Non-Small-Cell Lung Cancer

Thoracic lymph nodes with marginally elevated maximum standardized uptake value (SUVmax) on PET/CT a diagnostic challenge in staging non-small-cell lung cancer. We evaluated the ratio of lymph node to primary tumor SUVmax (SUVN/T) in predicting nodal malignancy among 132 sampled nodes from 85 patients both a primary tumor SUVmax > 2.5 and LN SUVmax 2.0 to 6.0. SUVN/T was more accurate than SUVmax for this subset of patients.

INTRODUCTION/BACKGROUND

Among non-small-cell lung cancers with appreciable functional activity, positron emission tomography/computed tomography (PET/CT) is the most accurate imaging modality for clinical staging. However, lymph nodes (LN) with marginally elevated standardized uptake value (SUV) present a diagnostic challenge. In this retrospective study, we hypothesized that normalizing the LN SUV by using the ratio of the LN to primary tumor SUVmax (SUVN/T) may be a better predictor of nodal malignancy than using SUVmax alone for nodes with low to intermediate SUV.

PATIENTS AND METHODS

We identified 172 patients with newly diagnosed non-small-cell lung cancer who underwent pathologic LN staging and PET/CT within 31 days before biopsy. Receiver operating characteristic curves with area under the curve (AUC) calculations were used to evaluate SUVmax and SUVN/T for their ability to predict nodal malignancy for both the entire cohort of 504 LNs and a subset of 132 LNs from 85 patients who had both primary tumor SUVmax > 2.5 and LN SUVmax 2.0 to 6.0.

RESULTS

In patients with primary tumor SUVmax > 2.5 and LN SUVmax 2.0 to 6.0, SUVN/T was significantly more accurate in predicting nodal malignancy (AUC, 0.846; 95% confidence interval, 0.775-0.917) than SUVmax (AUC, 0.653; 95% confidence interval, 0.548-0.759). The optimal cutoff value of SUVN/T to predict nodal malignancy was 0.28 (90% sensitivity, 68% specificity). Sensitivity was > 95% for SUVN/T < 0.21, whereas specificity was > 95% for SUVN/T > 0.50.

CONCLUSION

The ratio of LN SUV to primary tumor SUV on PET/CT is more accurate than SUVmax when assessing nodes of low to intermediate SUV.

Time to treatment as a quality metric in lung cancer: Staging studies, time to treatment, and patient survival

PURPOSE

Prompt staging and treatment are crucial for non-small cell lung cancer (NSCLC). We determined if predictors of treatment delay after diagnosis were associated with prognosis.

MATERIALS AND METHODS

Medicare claims from 28,732 patients diagnosed with NSCLC in 2004-2007 were used to establish the diagnosis-to-treatment interval (ideally ⩽35days) and identify staging studies during that interval. Factors associated with delay were identified with multivariate logistic regression, and associations between delay and survival by stage were tested with Cox proportional hazard regression.

RESULTS

Median diagnosis-to-treatment interval was 27days. Receipt of PET was associated with delays (57.4% of patients with PET delayed [n=6646/11,583] versus 22.8% of those without [n=3908/17,149]; adjusted OR=4.48, 95% CI 4.23-4.74, p<0.001). Median diagnosis-to-PET interval was 15days; PET-to-clinic, 5days; and clinic-to-treatment, 12days. Diagnosis-to-treatment intervals <35days were associated with improved survival for patients with localized disease and those with distant disease surviving ⩾1year but not for patients with distant disease surviving <1year.

CONCLUSION

Delays between diagnosing and treating NSCLC are common and associated with use of PET for staging. Reducing time to treatment may improve survival for patients with manageable disease at diagnosis.

In vitro and in vivo evaluation of therapy targeting epithelial-cell adhesion-molecule aptamers for non-small cell lung cancer

Targeted, disease-specific delivery of therapeutic nanoparticles shows wonderful promise for transmitting highly cytotoxic anti-cancer agents. Using the reaction of non-small cell lung cancer (SK-MES-1 and A549 cell lines) as representative of other cancer types', the present study examines the effects of EpCAM-fluoropyrimidine RNA aptamer-decorated, DOX-loaded, PLGA-b-PEG nanopolymersomes that bond specifically to the extracellular domain of epithelial-cell adhesion molecules. Results demonstrate that EpCAM aptamer-conjugated DOX-NPs (Apt-DOX-NP) significantly enhance cellular nanoparticle uptake in SK-MES-1 and A549 cell lines and increase the cytotoxicity of the DOX payload as compared with non-targeted DOX-NP (P<0.05). Additionally, Apt-DOX-NP exhibits greater tumor inhibition in nude mice bearing SK-MES-1 non-small cell lung-cancer xenografts and reduces toxicity, as determined by loss of body weight, cardiac histopathology and animal survival rate in vivo. After a single intravenous injection of Apt-DOX-NP and DOX-NPs, tumor volume decreased 60.9% and 31.4%, respectively, in SK-MES-1-xenograft nude mice compared with members of a saline-injected control group. This study proves the potential utility of Apt-DOX-NP for therapeutic application in non-small cell lung cancer. In the future, EpCAM-targeted therapies might play a key role in treating non-small cell lung cancer, the most common type of lung cancer.

Lung cancer

(18)F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) plays a key role in the evaluation of undiagnosed lung nodules, when primary lung cancer is strongly suspected, or when it has already been diagnosed by other techniques. Although technical factors may compromise characterization of small or highly mobile lesions, lesions without apparent FDG uptake can generally be safely observed, whereas FDG-avid lung nodules almost always need further evaluation. FDG-PET/CT is now the primary staging imaging modality for patients with lung cancer who are being considered for curative therapy with either surgery or definitive radiation therapy.

Impact of pretreatment tumor growth rate on outcome of early-stage lung cancer treated with stereotactic body radiation therapy

PURPOSE

To determine the influence of pretreatment tumor growth rate on outcomes in patients with early-stage non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT).

METHODS AND MATERIALS

A review was conducted on 160 patients with T1-T2N0M0 NSCLC treated with SBRT at single institution. The patient's demographic and clinical data, time interval (t) between diagnostic and planning computed tomography (CT), vital status, disease status, and cause of death were extracted from a prospectively kept database. Differences in gross tumor volume between diagnostic CT (GTV1) and planning CT (GTV2) were recorded, and growth rate was calculated by use of specific growth rate (SGR). Kaplan-Meier curves were constructed for overall survival (OS). Differences between groups were compared with a log-rank test. Multivariate analyses were performed by use of the Cox proportional hazard model with SGR and other relevant clinical factors. Cumulative incidence was calculated for local, regional, and distant failures by use of the competing risk approach and was compared with Gray's test.

RESULTS

The median time interval between diagnostic and planning CT was 82 days. The patients were divided into 2 groups, and the median SGR was used as a cut-off. The median survival times were 38.6 and 27.7 months for the low and high SGR groups, respectively (P=.03). Eastern Cooperative Oncology Group performance status (P=.01), sex (P=.04), SGR (P=.03), and GTV2 (P=.002) were predictive for OS in multivariable Cox regression analysis and, except sex, were similarly predictive for failure-free survival (FFS). The 3-year cumulative incidences of regional failure were 19.2% and 6.0% for the high and low SGR groups, respectively (P=.047).

CONCLUSION

High SGR was correlated with both poorer OS and FFS in patients with early-stage NSCLC treated with SBRT. If validated, this measurement may be useful in identifying patients most likely to benefit from adjuvant therapy after SBRT.

Use of PET/CT for patient selection and radiation therapy target volume definition in patients with non-small-cell lung cancer

SUMMARY PET scanning is having an increasing impact on the treatment of non-small-cell lung cancer with radiation therapy (RT) and chemoRT. It has a powerful impact on staging, often revealing evidence of more advanced, frequently incurable, disease in patients who would otherwise be considered suitable for treatment with potentially curative definitive RT. Approximately a third of curative RT candidates are found to be unsuitable for this often highly toxic form of treatment after PET, thereby ensuring that this intensive treatment is only given to those patients who might benefit from it. If a patient remains suitable for treatment with RT after PET staging, PET can play a further critical role in the targeting of the RT. Without the use of PET in this way, a quarter of patients or more would experience geographic misses, in which some tumor regions would be either underdosed or excluded entirely from treatment, thereby compromising the chances of a successful outcome. There is emerging evidence that the overall results of treatment with RT can be improved by the appropriate use of PET in non-small-cell lung cancer.