Positron emission tomography with [18F]FDOPA and [18F]FDG in the imaging of small cell lung carcinoma: preliminary results

Abstract

Small cell lung carcinomas (SCLC) express neuroendocrine markers, and dihydroxyphenylalanine (DOPA) is known to accumulate in neuroendocrine tumours. This study was performed with the aim of evaluating the uptake of 3,4-dihydroxy-6-(18)F-fluoro-phenylalanine ([(18)F]FDOPA) by SCLC, based on comparison with the results of fluorine-18 fluorodeoxyglucose ([(18)F]FDG) positron emission tomography (PET) and standard imaging procedures. [(18)F]FDG PET and [(18)F]FDOPA PET were performed on four patients with newly diagnosed SCLC. There was agreement between the results of [(18)F]FDOPA PET and [(18)F]FDG PET in four tumoural sites out of 11, whereas [(18)F]FDG PET and standard imaging procedures were in full agreement. A semi-quantitative analysis based on standardised uptake values (SUVs) was performed in order to compare [(18)F]FDG and [(18)F]FDOPA tumour uptake. The median [(18)F]FDG SUV(max) was 5.9 (with a 95% confidence interval from 4.4 to 9.2), while the median [(18)F]FDOPA SUV(max) was 1.9 (with a 95% confidence interval from 1.6 to 3.8). The difference between [(18)F]FDG SUV(max) and [(18)F]FDOPA SUV(max) was significant ( P<0.01). [(18)F]FDOPA PET appeared less sensitive than [(18)F]FDG PET and standard imaging procedures in the staging of SCLC. No clear relation between [(18)F]FDOPA uptake and positivity of neuroendocrine markers on immunohistochemistry emerged from these preliminary results; however, since [(18)F]FDOPA uptake may reflect better differentiation of the tumour, and possibly a better prognosis, this point warrants clarification in a larger study.

18F-Dihydroxyphenylalanine PET in Patients with Biochemical Evidence of Medullary Thyroid Cancer: Relation to Tumor Differentiation

“…This is in line with findings on other aggressive (dedifferentiated?) neuroendocrine tumors, such as small cell lung cancer and metastatic paraganglioma in patients with a SDHB gene mutation, in which 18 F-FDG PET has a very high sensitivity for the detection of tumor lesions, whereas more ''specialized'' tracers, such as 18 F-DOPA and 18 Fdopamine show only marginal tumoral uptake (21,22). It is important to distinguish between local disease recurrence, which may be surgically curable, and systemic disease, in which case the aim is palliation.…”

6-[F-18]Fluoro-l-DOPA Positron Emission Tomography in the Imaging of Merkel Cell Carcinoma: Preliminary Report of Three Cases with 2-Deoxy-2-[F-18]Fluoro-d-Glucose Positron Emission Tomography or Pentetreotide-(111In) SPECT Data

“…However, FDOPA-PET did not show more lesions than FDG-PET in the two true-positive patients and the contrast of the images was lower. We already observed this lower contrast with FDOPA-PET, as compared with FDG-PET, in small-cell lung cancer, another aggressive tumor of endocrine origin [14]. One potential advantage of FDOPA-PET over FDG-PET is its ability to detect brain metastases of MCC that are rare but should not be overlooked [18].…”

“…Becherer et al [15], who recently drew the same conclusion, reported that FDOPA-PET performs better than SRS in a series of 57 neuroendocrine lesions, mostly digestive carcinoid tumors. FDOPA is also taken up by small-cell carcinoma of the lung [14] and by cutaneous melanoma [17], both of which share similarities with MCC. The present case reports demonstrate that FDOPA is also taken up by MCC.…”

6-l-18F-Fluorodihydroxyphenylalanine PET in Neuroendocrine Tumors: Basic Aspects and Emerging Clinical Applications

“…Because this tumor type may express neuroendocrine markers, Jacob et al performed a very small study in 4 patients with small cell lung cancer and compared 18 F-FDG and 18 F-DOPA imaging (54). The performance of 18 F-DOPA was relatively poor compared with that of 18 F-FDG PET and conventional imaging, because FIGURE 10.…”