F-18-FDG PET/CT for Monitoring Treatment Responses to the Epidermal Growth Factor Receptor Inhibitor Erlotinib
ABSTRACT Response rates of unselected non-small cell lung cancer (NSCLC) patients to the epidermal growth factor receptor inhibitor erlotinib are low and range from 10% to 20%. Early response assessments are needed to avoid costs and side effects of inefficient treatments. Here we determined whether early changes in tumor uptake of (18)F-FDG can predict progression-free and overall survival in NSCLC patients who are treated with erlotinib.
Twenty-two patients (6 men, 16 women; mean age ± SD, 64 ± 13 y) with stage III or stage IV NSCLC who received erlotinib treatment were enrolled prospectively. (18)F-FDG PET/CT was performed before the initiation of treatment (n = 22), after 2 wk (n = 22), and after 78 ± 21 d (n = 11). Tumor maximum standardized uptake values were measured for a maximum of 5 lesions for each patient. Tumor responses were classified using modified PET Response Criteria in Solid Tumors (use of maximum standardized uptake values). Median overall survival by Kaplan-Meier analysis was compared between groups using a log-rank test.
The overall median time to progression was 52 d (95% confidence interval, 47-57 d). The overall median survival time was 131 d (95% confidence interval, 0-351 d). Patients with progressive metabolic disease on early follow-up PET showed a significantly shorter time to progression (47 vs. 119 d; P < 0.001) and overall survival (87 vs. 828 d; P = 0.01) than patients classified as having stable metabolic disease or partial or complete metabolic response.
These data suggest that (18)F-FDG PET/CT performed early after the start of erlotinib treatment can help to identify patients who benefit from this targeted therapy.
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ABSTRACT: Targeted therapeutic agents are indicated in metastatic lung cancers. These being receptor specific therapies, manifestation of response can be best assessed by estimating the metabolic activity of tumor, rather than the size. This retrospective analysis studied metabolic and morphological response on Positron Emission Tomography (PET) and Computed Tomography (CT), respectively to these agents. Thirty-one patients (23 males, 8 females with an age range of 42-77 years) with Epidermal Growth Factor Receptor (EGFR) positive metastatic lung cancer on Gefitinib, who underwent PET/CT, at baseline and at 4-6 weeks, were assessed by Response Evaluation Criteria In Solid Tumors [RECIST] 1.1 and European Organization for Research and Treatment of Cancer (EORTC) criteria. Concordance between RECIST 1.1 and EORTC was seen in 26 (83.7%) patients. Discordance was seen in 5 (16.3%) patients. In patients with discordance, the results were confirmed by follow-up imaging. Metabolic EORTC criteria changed the disease status from stable disease to partial response (3 out of 5) and progressive disease (2 out of 5) in these five patients. Metabolic criteria using PET/CT could accurately predict response as well as disease progression early in the course of targeted therapy, compared to morphologic criteria. In addition, early metabolic response assessment can predict refractoriness of therapy.
Article: Imaging of Thoracic Cavity Tumors[Show abstract] [Hide abstract]
ABSTRACT: Computed tomography (CT) is the primary imaging modality for the diagnosis, staging, and follow-up of most thoracic cavity tumors. Fluorine-18 fluorodeoxyglucose positron emission tomography/CT has established itself as a supplementary tool to CT in lung cancer staging and in the assessment for distant metastases of many thoracic tumors. Magnetic resonance imaging is an important adjunctive imaging modality in thoracic oncologic imaging and is used as a problem-solving tool to assess for chest wall invasion, intraspinal extension, and cardiac/vascular invasion. Imaging can facilitate minimally invasive biopsy of most thoracic tumors and is vital in the pretreatment planning of radiation therapy.Surgical Oncology Clinics of North America 10/2014; DOI:10.1016/j.soc.2014.06.005 · 1.67 Impact Factor
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ABSTRACT: Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%-15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later.12/2014; 6(4):1821-1889. DOI:10.3390/cancers6041821