Impact of tumor size and tracer uptake heterogeneity in (18)F-FDG PET and CT non-small cell lung cancer tumor delineation.: 18F-FDG PET and CT tumor delineation in NSCLC

International audienceUNLABELLED: The objectives of this study were to investigate the relationship between CT- and (18)F-FDG PET-based tumor volumes in non-small cell lung cancer (NSCLC) and the impact of tumor size and uptake heterogeneity on various approaches to delineating uptake on PET images. METHODS: Twenty-five NSCLC cancer patients with (18)F-FDG PET/CT were considered. Seventeen underwent surgical resection of their tumor, and the maximum diameter was measured. Two observers manually delineated the tumors on the CT images and the tumor uptake on the corresponding PET images, using a fixed threshold at 50% of the maximum (T(50)), an adaptive threshold methodology, and the fuzzy locally adaptive Bayesian (FLAB) algorithm. Maximum diameters of the delineated volumes were compared with the histopathology reference when available. The volumes of the tumors were compared, and correlations between the anatomic volume and PET uptake heterogeneity and the differences between delineations were investigated. RESULTS: All maximum diameters measured on PET and CT images significantly correlated with the histopathology reference (r > 0.89, P < 0.0001). Significant differences were observed among the approaches: CT delineation resulted in large overestimation (+32% ± 37%), whereas all delineations on PET images resulted in underestimation (from -15% ± 17% for T(50) to -4% ± 8% for FLAB) except manual delineation (+8% ± 17%). Overall, CT volumes were significantly larger than PET volumes (55 ± 74 cm(3) for CT vs. from 18 ± 25 to 47 ± 76 cm(3) for PET). A significant correlation was found between anatomic tumor size and heterogeneity (larger lesions were more heterogeneous). Finally, the more heterogeneous the tumor uptake, the larger was the underestimation of PET volumes by threshold-based techniques. CONCLUSION: Volumes based on CT images were larger than those based on PET images. Tumor size and tracer uptake heterogeneity have an impact on threshold-based methods, which should not be used for the delineation of cases of large heterogeneous NSCLC, as these methods tend to largely underestimate the spatial extent of the functional tumor in such cases. For an accurate delineation of PET volumes in NSCLC, advanced image segmentation algorithms able to deal with tracer uptake heterogeneity should be preferred

A Phase I Study of Concurrent Individualized, Isotoxic Accelerated Radiotherapy and Cisplatin–Vinorelbine–Cetuximab in Patients With Stage III Non–Small-Cell Lung Cancer

Background:In this open-label phase I study, the maximum-tolerated dose of cetuximab with concurrent chemoradiotherapy (C-CRT) in stage III non–small-cell lung cancer together with individualized, isotoxic accelerated radiotherapy (RT) was investigated.Methods:Patients with stage III non–small-cell lung cancer, World Health Organization performance status 0–1, forced expiratory volume in 1 second more than 50%, carbon monoxide diffusing capacity more than 50%, weight loss less than 10%, and no severe comorbidity were enrolled. Patients without progression after one to two cycles of gemcitabine–carboplatin were included and treated with cetuximab 400 mg/kg d7 and 250 mg/kg weekly together with RT and cisplatin (50 mg/m2 d1, 8; 40 mg/m2 d22)–vinorelbine for 5 weeks. Vinorelbine was escalated in three steps; (1) 10 mg/m2 d1, 8 and 8 mg/m2 d22, 29; (2) 20 mg/m2 d1, 8 and 8 mg/m2 d22, 29; (3) 20 mg/m2 d1, 8; 15 mg/m2 d22, 29. An individualized prescribed RT dose based on normal tissue dose constraints was applied (e.g., mean lung dose 19 Gy). The primary endpoint was the maximum-tolerated dose 3 months after the end of C-CRT; secondary endpoints were toxicity and metabolic response as assessed by positron emission tomography.Results:Between September 2007 and October 2010, 25 patients (12 men, 13 women, mean age 59 years) were included. The mean RT dose was 62 ± 6.6 Gy. The vinorelbine dose could be escalated to dose level 3. Twelve of 25 patients experienced greater than or equal to grade 3 toxicity (esophagitis 3, rash 1, diarrhea 1, cough 1, dyspnea 1, vomiting 1, and pulmonary embolism 1). No dose-limiting toxicities were observed. One patient with a complete pathological response in dose level 3 developed a fatal hemoptysis 4 months after RT. Metabolic remissions were observed in 19 of 22 patients.Conclusion:C-CRT with cetuximab and cisplatin–vinorelbine is safe to deliver at full dose. The recommended phase II dose is therefore cetuximab 400 mg/m2 d7 and 250 mg/m2 weekly, cisplatin 50 mg/m2 d1, 8; 40 mg/m2 d22 and vinorelbine 20 mg/m2 d1, 8; 15 mg/m2 d22, 29 for 5 weeks together with RT

Radical Treatment of Non-Small-Cell Lung Cancer Patients with Synchronous Oligometastases Long-Term Results of a Prospective Phase II Trial (Nct01282450)

BackgroundStage IV non–small-cell lung cancer (NSCLC) patients with oligometastases (< 5 metastatic lesions) may experience long-term survival when all macroscopic tumor sites are treated radically, but no prospective data on NSCLCs with synchronous oligometastases are available.MethodsA prospective single-arm phase II trial was conducted. The main inclusion criteria were pathologically proven NSCLC stage IV with less than five metastases at primary diagnosis, amendable for radical local treatment (surgery or radiotherapy). The study is listed in clinicaltrials.gov, number NCT01282450.ResultsForty patients were enrolled, 39 of whom were evaluable (18 men, 21 women); mean age was 62.1 ± 9.2 years (range, 44–81). Twenty-nine (74%) had local stage III; 17 (44%) brain, seven (18%) bone, and four (10%) adrenal gland metastases. Thirty-five (87%) had a single metastatic lesion. Thirty-seven (95%) of the patients received chemotherapy as part of their primary treatment. Median overall survival (OS) was 13.5 months (95% confidence interval 7.6–19.4); 1-, 2-, and 3-year OS was 56.4%, 23.3%, and 17.5%, respectively. Median progression-free survival (PFS) was 12.1 months (95% confidence interval 9.6–14.3); 1-year PFS was 51.3%, and both 2- and 3-year PFS was 13.6%. Only two patients (5%) had a local recurrence. No patient or tumor parameter, including volume and 18F-deoxyglucose uptake was significantly correlated with OS or PFS. The treatment was well tolerated.ConclusionIn this phase II study, long-term PFS was found in a subgroup of NSCLC patients with synchronous oligometastases when treated radically. Identification of this favorable subgroup before therapy is needed

Treatment with curative intent of stage III non-small cell lung cancer patients of 75years: A prospective population-based study

AbstractBackgroundThere is little data on the survival of elderly patients with stage III non-small cell lung cancer (NSCLC).MethodsPatients with stage III NSCLC in the Netherlands Cancer Registry/Limburg from January 1, 2002 to December 31, 2008 were included.FindingsOne thousand and two patients with stage III were diagnosed, of which 237 were 75years or older. From 228 patients, co-morbidity scores were available. Only 33/237 patients (14.5%) had no co-morbidities, 195 (85.5%) had one or more important co-morbidities, 60 (26.3%) two or more co-morbidities, 18 (7.9%) three or more co-morbidities and 2 patients (0.9%) suffered from four co-morbidities. Forty-eight percent were treated with curative intent. No significant difference in Charlson co-morbidity, age or gender was found between patients receiving curative or palliative intent treatment. Treatment with curative intent was associated with increased overall survival (OS) compared to palliative treatment: median OS 14.2 months (9.6–18.7) versus 5.2months (4.3–6.0), 2-year OS 35.5% versus 12.1%, for curative versus palliative treatment.Patients who received only radiotherapy with curative intent had a median OS of 11.1months (95% confidence interval [95% CI] 6.4–15.8) and a 5-year OS of 20.3%; for sequential chemotherapy and radiotherapy, the median OS was 18.0months (95% CI 12.2–23.7), with a 5-year OS of 14.9%. Only four patients received concurrent chemo-radiation.InterpretationIn this prospective series treating elderly patients with stage III NSCLC with curative intent was associated with significant 5-year survival rates

Volumetric CT-based segmentation of NSCLC using 3D-Slicer

Accurate volumetric assessment in non-small cell lung cancer (NSCLC) is critical for adequately informing treatments. In this study we assessed the clinical relevance of a semiautomatic computed tomography (CT)-based segmentation method using the competitive region-growing based algorithm, implemented in the free and public available 3D-Slicer software platform. We compared the 3D-Slicer segmented volumes by three independent observers, who segmented the primary tumour of 20 NSCLC patients twice, to manual slice-by-slice delineations of five physicians. Furthermore, we compared all tumour contours to the macroscopic diameter of the tumour in pathology, considered as the “gold standard”. The 3D-Slicer segmented volumes demonstrated high agreement (overlap fractions > 0.90), lower volume variability (p = 0.0003) and smaller uncertainty areas (p = 0.0002), compared to manual slice-by-slice delineations. Furthermore, 3D-Slicer segmentations showed a strong correlation to pathology (r = 0.89, 95%CI, 0.81–0.94). Our results show that semiautomatic 3D-Slicer segmentations can be used for accurate contouring and are more stable than manual delineations. Therefore, 3D-Slicer can be employed as a starting point for treatment decisions or for high-throughput data mining research, such as Radiomics, where manual delineating often represent a time-consuming bottleneck

Power engineering challenges in Zambia

The paper presents a review of current power engineering challenges in Zambia in relevance to the required potential necessary for the country’s modern economic development. An outline of the energy sector is provided. The driving need for enhancing the development of the energy sector is highlighted, accounted by the country’s annual increase of GDP, leading to an increase in electricity demand. Possible mitigations are suggested, with the development of Zambia's rich potential in renewable energy, as well as upgrading the operating power plants and constructing more off-grid and on-grid generating facilities