(18)F-fluorodeoxyglucose positron emission tomography versus computed tomography in predicting histopathological response to epidermal growth factor receptor-tyrosine kinase inhibitor treatment in resectable non-small cell lung cancer.

PURPOSE: To prospectively evaluate diagnostic computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for identification of histopathologic response to neoadjuvant erlotinib, an epidermal growth factor receptor-tyrosine kinase inhibitor in patients with resectable non-small cell lung cancer (NSCLC). METHODS: This study was designed as an open-label phase 2 trial, performed in four hospitals in the Netherlands. Patients received preoperative erlotinib 150 mg once daily for 3 weeks. CT and FDG-PET/CT were performed at baseline and after 3 weeks of treatment. CT was assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. FDG-PET/CT, tumor FDG uptake, and changes were measured by standardized uptake values (SUV). Radiologic and metabolic responses were compared to the histopathological response. RESULTS: Sixty patients were enrolled onto this study. In 53 patients (22 men, 31 women), the combination of CT, FDG-PET/CT, and histopathological evaluation was available for analysis. Three patients (6 %) had radiologic response. According to European Organisation for Research and Treatment of Cancer (EORTC) criteria, 15 patients (28 %) showed metabolic response. In 11 patients, histopathologic response (≥50 % necrosis) was seen. In predicting histopathologic response, relative FDG change in SUVmax showed more SUVmax decrease in the histopathologic response group (-32 %) versus the group with no pathologic response (-4 %) (p = 0.0132). Relative change in tumor size on diagnostic CT was similar in these groups with means close to 0. CONCLUSIONS: FDG-PET/CT has an advantage over CT as a predictive tool to identify histopathologic response after 3 weeks of EGFR-TKI treatment in NSCLC patients.

Feasibility of pathology-correlated lung imaging for accurate target definition of lung tumors.

PURPOSE: To accurately define the gross tumor volume (GTV) and clinical target volume (GTV plus microscopic disease spread) for radiotherapy, the pretreatment imaging findings should be correlated with the histopathologic findings. In this pilot study, we investigated the feasibility of pathology-correlated imaging for lung tumors, taking into account lung deformations after surgery. METHODS AND MATERIALS: High-resolution multislice computed tomography (CT) and positron emission tomography (PET) scans were obtained for 5 patients who had non-small-cell lung cancer (NSCLC) before lobectomy. At the pathologic examination, the involved lung lobes were inflated with formalin, sectioned in parallel slices, and photographed, and microscopic sections were obtained. The GTVs were delineated for CT and autocontoured at the 42% PET level, and both were compared with the histopathologic volumes. The CT data were subsequently reformatted in the direction of the macroscopic sections, and the corresponding fiducial points in both images were compared. Hence, the lung deformations were determined to correct the distances of microscopic spread. RESULTS: In 4 of 5 patients, the GTV(CT) was, on average, 4 cm(3) ( approximately 53%) too large. In contrast, for 1 patient (with lymphangitis carcinomatosa), the GTV(CT) was 16 cm(3) ( approximately 40%) too small. The GTV(PET) was too small for the same patient. Regarding deformations, the volume of the well-inflated lung lobes on pathologic examination was still, on average, only 50% of the lobe volume on CT. Consequently, the observed average maximal distance of microscopic spread (5 mm) might, in vivo, be as large as 9 mm. CONCLUSIONS: Our results have shown that pathology-correlated lung imaging is feasible and can be used to improve target definition. Ignoring deformations of the lung might result in underestimation of the microscopic spread.

Fluorescence detection of pleural malignancies using 5-aminolaevulinic acid.

STUDY OBJECTIVE: Although the use of video-assisted thoracoscopy has improved the diagnostic accuracy in patients presenting with pleural diseases, not all biopsies performed are conclusive and staging of the disease is not always optimal. Fluorescence diagnosis (FD) with 5-aminolaevulinic acid (5-ALA) has been used in the diagnostic workup for various malignancies. The impact of 5-ALA-mediated FD on diagnosis and staging during video-assisted thoracoscopy was examined. DESIGN: Prospective, single-center study. SETTING: National cancer center. PATIENTS: Twenty-six patients with nonconclusive pleural effusions who were scheduled for video-assisted thoracoscopy. INTERVENTION: Eligible patients were administered 1,500 to 2,500 mg po of 5-ALA before video-assisted thoracoscopy. After conventional inspection with white light, fluorescence inspection of the pleural cavity was performed (D-LIGHT Auto Fluorescent System; Karl Storz; Tuttlingen, Germany). Biopsy specimens of both normal and abnormal sites, as determined from white light and FD inspection, were obtained for histologic examination. RESULTS: One patient was ineligible, and two patients were not evaluable because of equipment failure. One postoperative death occurred due to preexisting myocardial disease. In another patient, an empyema developed; in another patient, a postoperative infection of the lung developed. Other toxicities were minimal. A definitive diagnosis was obtained in 24 of 25 cases, with malignant mesothelioma in 15 cases, other malignancies in 5 cases, one infection, and three benign diseases. Upstaging occurred in four patients (unsuspected tumor deposits) due to FD examination. In 23 patients, a total of 111 biopsy specimens could be analyzed. When correct findings of white light and FD were compared, FD had an additional value in 21 of 111 biopsies, compared to white light with 16 of 111 biopsies. CONCLUSIONS: FD using 5-ALA in the pleural cavity is feasible with limited side effects when used in addition to white light inspection. It improved visualization of abnormal lesions and led to upstaging in 4 of 15 mesothelioma patients.

Concentrations of Erlotinib in Tumor Tissue and Plasma in Non-Small-Cell Lung Cancer Patients After Neoadjuvant Therapy.

INTRODUCTION: Tumors might not optimally respond to systemic therapy if minimal effective levels are not reached within the tumor. Erlotinib has mainly been studied in the adjuvant or palliative setting and, therefore, little is known about erlotinib tumor penetration. The purpose of this exploratory study was to investigate lung tumor tissue erlotinib concentrations after neoadjuvant therapy for non-small-cell lung cancer. PATIENTS AND METHODS: Patients were treated preoperatively with erlotinib (150 mg once daily for 3 weeks) up to 48 hours before surgery. Plasma samples were collected during treatment. Surgical resection involved radical resection of the lung tumor and tumor biopsies were frozen directly after surgery. Erlotinib and O-desmethyl erlotinib concentrations in lung tumor tissue and predose plasma were determined using high performance liquid chromatography coupled with tandem mass spectrometry. RESULTS: Thirteen evaluable patients were included. The mean plasma and lung tumor tissue erlotinib levels were 1222 ng/mL (SD, 678) and 149 ng/g (SD, 153), respectively. In 2 individual patients, erlotinib and O-desmethyl erlotinib concentrations in lung tumor tissue were detectable up to 13 days and 7 days after erlotinib intake, respectively. Mean erlotinib tissue concentrations extrapolated to a time point directly after intake of erlotinib were approximated at > 200 ng/g tissue, which is greater than the reported half maximal inhibitory concentration (IC50) of wild type epidermal growth factor receptor (EGFR) (183 ng/mL). CONCLUSION: No strong accumulation of erlotinib in lung tumor tissue was observed. Nevertheless, extrapolated intratumoral concentrations during erlotinib therapy were greater than the IC50 of wild type EGFR.

Timing of metabolic response monitoring during erlotinib treatment in non-small cell lung cancer.

UNLABELLED: The purpose of this study was to prospectively evaluate the timing of metabolic response monitoring with (18)F-FDG PET of (neoadjuvant) erlotinib treatment in patients with early-stage non-small cell lung cancer. METHODS: This study was designed as an open-label phase II trial performed in 4 hospitals in The Netherlands. Patients received preoperative erlotinib (150 mg) once daily for 3 wk. Response evaluation was performed after 4-7 d and at 3 wk with (18)F-FDG PET/CT scans. Tumor (18)F-FDG uptake and changes were measured as standardized uptake values (SUVs). The metabolic response was classified on the basis of European Organization for Research and Treatment of Cancer criteria (>25% decrease in the maximum SUV) and was compared with histopathologic regression as observed in the resection specimen. RESULTS: From December 2006 to November 2010, 60 patients with non-small cell lung cancer eligible for surgical resection were enrolled in this study. For 43 patients (18 men and 25 women), baseline (18)F-FDG PET/CT scans as well as both monitoring scans and histopathologic response monitoring were available. A partial metabolic response on (18)F-FDG PET/CT scans was observed for 10 patients (23%) after 1 wk and for 14 patients (33%) after 3 wk. Histopathologic examination revealed regression (necrosis of >50%) in 11 patients (26%). In these patients, the maximum SUV decreased by a mean of 17% within 1 wk and a mean of 31% at 3 wk. Seven patients were identified as responders within 1 wk. CONCLUSION: Response monitoring with (18)F-FDG PET/CT within 1 wk after the start of erlotinib treatment identified approximately 64% of histopathologic responders on the basis of European Organization for Research and Treatment of Cancer criteria.

Tumor response and toxicity of neoadjuvant erlotinib in patients with early-stage non-small-cell lung cancer.

PURPOSE: The development of targeted therapy has introduced new options to improve treatment outcome in selected patients. The objective of this prospective study was to investigate the safety of preoperative erlotinib treatment and the (in vivo) response in patients with early-stage resectable non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: This study was designed as an open-label phase II trial, performed in four hospitals in the Netherlands, according to a Simon's minimax two-stage procedure. Initially, operable patients with early-stage NSCLC (n = 15) were entered from an enriched population (never-smoker, female sex, nonsquamous histology, or Asian ethnicity); thereafter, unselected patients were included to a total of N = 60. Patients received preoperative erlotinib 150 mg once daily for 3 weeks. Response to treatment was evaluated using [18F] fluorodeoxyglucose positron emission tomography (PET) and computed tomography (CT) scans during treatment and histologic examination of the resection specimen. Primary end points were toxicity and pathologic response. RESULTS: Sixty patients were included. Seven patients stopped treatment prematurely (12%). Skin toxicity was present in 37 patients (62%), and diarrhea was present in 21 patients (35%). PET evaluation revealed metabolic response (> 25% standardized uptake value decrease) in 16 patients (27%); CT evaluation using Response Evaluation Criteria in Solid Tumors (RECIST) showed response in three patients (5%). At surgery, no unexpected complications occurred. Pathologic examination showed more than 50% necrosis in 14 patients (23%), of whom three (5%) had more than 95% tumor necrosis. The response rate in the enriched population was 34% (10 of 29 patients). CONCLUSION: According to predefined criteria, neoadjuvant erlotinib has low toxicity and sufficient activity to deserve further testing in future studies in an enriched population.

Is 18F-FDG PET/CT useful for the early prediction of histopathologic response to neoadjuvant erlotinib in patients with non-small cell lung cancer?

UNLABELLED: Early prediction of treatment response is of value in avoiding the unnecessary toxicity of ineffective treatment. The objective of this study was to prospectively evaluate the role of integrated (18)F-FDG PET/CT for the early identification of response to neoadjuvant erlotinib, an epidermal growth factor receptor tyrosine kinase inhibitor. METHODS: From October 2006 to March 2009, 23 patients with non-small cell lung cancer eligible for surgical resection were evaluated for this study. Patients received preoperative erlotinib (150 mg) once daily for 3 wk. (18)F-FDG PET/CT was performed before and at 1 wk after the administration of erlotinib. Changes in tumor (18)F-FDG uptake during treatment were measured by standardized uptake values and assessed prospectively according to the criteria of the European Organization for Research and Treatment of Cancer. Patients with a decrease in standardized uptake values of 25% or more after 1 wk were classified as "metabolic responders." The metabolic response was compared with the pathologic response, obtained by histopathologic examination of the resected specimen. RESULTS: Following the (18)F-FDG PET/CT criteria of the European Organization for Research and Treatment of Cancer, 6 patients (26%) had a partial response within 1 wk, 16 patients (70%) had stable disease, and 1 patient (4%) had progressive disease. The median percentage of necrosis in the early metabolic responder group was 70% (interquartile range, 30%-91%), and the median percentage of necrosis in the nonresponder group was 40% (interquartile range, 20%-50%; P = 0.09). The kappa-agreement between the metabolic and pathologic responders was 0.55 (P = 0.008). CONCLUSION: The results of this study suggest that early during the course of epidermal growth factor receptor tyrosine kinase inhibitor therapy, (18)F-FDG PET/CT can predict response to erlotinib treatment in patients with non-small cell lung cancer.

[Diagnostic image. A woman with an abnormal screening mammogram]. / Een vrouw met een afwijking op het mammogram.

A 56-year-old woman had an abnormal mammogram and a palpable mass in the left breast. Cytological and histological examination revealed a pilomatrixoma of the breast.