Anne Devillers

PURPOSE: This study aimed to assess prospectively the efficacy of sequential [18F]fluorodeoxyglucose positron emission tomography (FDG PET) to evaluate early response to neoadjuvant chemotherapy in stage II and III breast cancer patients. PATIENTS AND METHODS: Images were acquired with a PET/computed tomography scanner in 64 patients after administration of FDG (5 MBq/kg) at baseline and after the first, second, third, and sixth course of chemotherapy. Ultrasound and mammography were used to assess tumor size. Decrease in the standardized uptake value (SUV) with PET was compared with the pathologic response. RESULTS: Surgery was performed after six courses of chemotherapy and pathologic analysis revealed gross residual disease in 28 patients and minimal residual disease in 36 patients. Although SUV data did not vary much in nonresponders (based on pathology findings), they decreased markedly to background levels in 94% (34 of 36) of responders. When using 60% of SUV at baseline as the cutoff value, the sensitivity, specificity, and negative predictive value of FDG PET were 61%, 96%, and 68% after one course of chemotherapy, 89%, 95%, and 85% after two courses, and 88%, 73%, and 83% after three courses, respectively. The same parameters with ultrasound (US) and mammography were 64%, 43%, and 55%, and 31%, 56%, and 45%, respectively. Assessment of tumor response with US or mammography was never significant whatever the cutoff. CONCLUSION: Pathologic response to neoadjuvant chemotherapy in stage II and III breast cancer can be predicted accurately by FDG PET after two courses of chemotherapy.

The treatment of metastatic neuroendocrine tumors depends on the aggressiveness of the disease. We wanted to know whether ¹⁸F-FDG PET and somatostatin receptor scintigraphy (SRS) can predict early disease progression and patient survival. <b>Methods:</b> We undertook a prospective study of patients with metastatic neuroendocrine tumor diagnosed between September 2003 and January 2006. After obtaining signed informed consent from the patients, we performed CT, SRS, and ¹⁸F-FDG PET and reviewed histologic data. CT was repeated every 3 mo to assess the risk of early progressive disease (first 6 mo), progression-free survival, and overall survival. <b>Results:</b> Thirty-eight patients (mean age, 60 ± 15 y) were included. Histologically, 4 patients had a high-grade and 34 a low-grade tumor. The results of ¹⁸F-FDG PET and SRS were positive in 15 and 27 patients. The 2-y overall survival and progression-free survival were 73% and 45%; 16 patients had early progressive disease. Most ¹⁸F-FDG PET–positive patients had early progressive disease (14/15, vs. 2/23 ¹⁸F-FDG PET–negative patients), and most SRS-negative patients had early progressive disease (9/11, vs. 7/27 SRS-positive patients); ¹⁸F-FDG PET gave excellent negative and positive predictive values of 91% and 93%; ¹⁸F-FDG PET results correlated with progression-free survival (<i>P</i> &lt; 0.001) and overall survival (<i>P</i> &lt; 0.001) even when only low-grade tumors were considered. SRS was associated with progression-free survival (<i>P</i> &lt; 0.001) and overall survival (<i>P</i> &lt; 0.03). At multivariate analysis, only ¹⁸F-FDG PET was predictive of progression-free survival. <b>Conclusion:</b>¹⁸F-FDG PET exhibits excellent predictive values for early tumor progression. ¹⁸F-FDG PET and SRS results correlate with progression-free survival and overall survival even for histologically low-grade tumors. These explorations could be included in the initial work-up for metastatic neuroendocrine tumor.

UNLABELLED: This study aimed to evaluate the long-term prognostic usefulness of (18)F-FDG PET for patients with metastatic gastroenteropancreatic neuroendocrine tumors (GEPNETs). METHODS: Thirty-eight patients with metastatic GEPNETs were prospectively enrolled. Initial check-up comprised CT scan, (111)In-pentetreotide scintigraphy (SRS), and (18)F-FDG PET. Only (18)F-FDG PET-positive lesions with a maximum standardized uptake value (SUVmax) greater than 4.5 or an SUV ratio (SUVmax tumor to SUVmax nontumoral liver tissue, or T/NT ratio) of 2.5 or greater were considered positive for prognosis-that is, indicating a poor prognosis. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Factors associated with survival were assessed with univariate and multivariate analyses, using the Cox regression model. RESULTS: Median PFS and OS were significantly higher for patients with a negative (18)F-FDG PET finding, with an OS of 119.5 mo (95% confidence interval [CI], 72-∞), than for patients with a positive (18)F-FDG PET finding (only 15 mo [95% CI, 4-27]) (P < 10(-3)). Median PFS and OS were significantly higher for the patient group that had a positive SRS than the group with a negative SRS (P = 0.0002). For patients with a positive SRS, PFS and OS were significantly shorter when the (18)F-FDG PET finding was positive: 19.5 mo (95% CI, 4-37) for PFS and 119.5 mo (95% CI, 81-∞) for OS (P < 10(-3)). In the patient group with a low-grade GEPNET and a positive SRS, PFS and OS were also significantly lower for patients with a positive (18)F-FDG PET. At 48-mo follow-up, 100% of patients who had a positive (18)F-FDG PET for disease progression (of which 47% were also SRS-positive) were deceased, and 87% of patients with a negative (18)F-FDG PET were alive (P < 0.0001). The T/NT ratio was the only parameter associated with OS on multivariate analysis. CONCLUSION: Overall, (18)F-FDG PET appears to be of major importance in the prognostic evaluation of metastatic GEPNET. A positive (18)F-FDG PET with an SUV ratio (T/NT) of 2.5 or greater was a poor prognostic factor, with a 4-y survival rate of 0%. A positive SRS does not eliminate the need for performing (18)F-FDG PET, which is of greater prognostic utility.

= not significant). R-CHOP alone is not inferior to R-CHOP followed by RT in patients with nonbulky limited-stage DLBCL. This trial was registered at www.clinicaltrials.gov as #NCT00841945.

The aim of this retrospective multicentric study was to develop and evaluate a prognostic ¹⁸F-FDG PET/CT radiomic signature in early-stage non–small cell lung cancer patients treated with stereotactic body radiotherapy (SBRT). <b>Methods:</b> Patients from 3 different centers (<i>n</i> = 27, 29, and 8) were pooled to constitute the training set, whereas the patients from a fourth center (<i>n</i> = 23) were used as the testing set. The primary endpoint was local control. The primary tumor was semiautomatically delineated in the PET images using the fuzzy locally adaptive Bayesian algorithm, and manually in the low-dose CT images. In total, 184 Image Biomarkers Standardization Initiative–compliant radiomic features were extracted. Seven clinical and treatment parameters were included. We used ComBat to harmonize radiomic features extracted from the 4 institutions relying on different PET/CT scanners. In the training set, variables found significant in the univariate analysis were fed into a multivariate regression model, and models were built by combining independent prognostic factors. <b>Results:</b> Median follow-up was 21.1 mo (range, 1.7–63.4 mo) and 25.5 mo (range, 7.7–57.8 mo) in training and testing sets, respectively. In univariate analysis, none of the clinical variables, 2 PET features, and 2 CT features were significantly predictive of local control. The best predictive models in the training set were obtained by combining one feature from PET (Information Correlation 2) and one feature from CT (flatness), reaching a sensitivity of 100% and a specificity of 96%. Another model combining 2 PET features (Information Correlation 2 and strength) reached sensitivity of 100% and specificity of 88%, both with an undefined hazard ratio (<i>P</i> &lt; 0.001). The latter model obtained an accuracy of 0.91 (sensitivity, 100%; specificity, 81%), with a hazard ratio undefined (<i>P</i> = 0.023) in the testing set; however, other models relying on CT radiomic features only or the combination of PET and CT features failed to validate in the testing set. <b>Conclusion:</b> We showed that 2 radiomic features derived from ¹⁸F-FDG PET were independently associated with local control in patients with non–small cell lung cancer undergoing SBRT and could be combined in an accurate predictive model. This model could provide local relapse-related information and could be helpful in clinical decision making.