Role of FDG PET-CT in the treatment management of Hodgkin lymphoma

Fluorodeoxyglucose (FDG) positons emission tomography (PET)-computed tomography (CT) is used in many ways at baseline and during the treatment of patients with Hodgkin lymphoma. Many properties of the technique are used in the different steps of patient's management. Initial staging with PET-CT is more accurate than conventional imaging and PET-CT also became the gold standard imaging at the end of treatment with a negative PET-CT mandatory for reaching a complete remission. Early assessment of response by PET-CT is one of the most powerful prognostic factors for progression-free survival of patients with localized and advanced stages and allows guiding treatment. Conversely, previous studies showed that there is no role of FDG PET-CT for the patient's follow-up.

Abstract P4-01-05: 3’-deoxy-3’-[18F]fluoro-thymidine (18F-FLT) positron emission tomography (PET): An accurate and effective tool for assessing tumor response in breast cancer

Objectives : A French multicenter study was promoted by the national French cancer federation (Unicancer R&D) to assess the potential of [18F]FLT (positron emission tomography (PET) biomarker of proliferation)to manage breast cancer neoadjuvant chemotherapy (NAC). The main objective was to compare changes in tumor [18F]FLT uptake to histopathological changes induced by NAC, assuming an arrest of tumor growth related to the effectiveness of NAC.

Methods : 97 patients (age 48.6 +/- 10.2 y.) were included in 13 nuclear medicine centers. All patients were eligible to anthracycline-based NAC for a de novo unifocal breast cancer (ductal n = 84, lobular = 11, other type = 2; stage II n = 75, stage III n = 21 et stage IV n = 1). 90 patients underwent a baseline PET before the onset of NAC (PET1) and a final PET after the end of NAC and before surgery (PET3). PET acquisitions were performed 60±7min after FLT injection. SUVmax (maximum standardized uptake value), SUVpeak (1 cm3 ROI including pixel max) and SUV41 (isocontour 41% of pixel max) were computed. Changes in SUV on PET3 vs PET1 were analyzed in relation to histopathological findings at the end of NAC (Sataloff criteria).

Results : Tumor FLT uptake decreased markedly between TEP1 and TEP3 (SUVmax = 6.2±4.8 vs 1.3±1.2 respectively; SUVpeak = 4.6±3.2 vs 0.9±0.9; SUV41 = 3.6±2.8 vs 0.8±0.7). Total or near-total therapeutic effect (grade A) were obtained in 20 patients, more than 50% therapeutic effect but less than total or near-total effect (grade B) in 37 patients, less than 50% therapeutic effect but visible effect (grade C) in 22 patients, or no therapeutic effect (grade D) in 11 patients. SUVmax decreased dramatically (87.5%) to background levels in all patients with a complete response (grade A). Overall, changes in SUV differed depending on the type of histological response (p<0.01) i.e. SUVmax changes were more pronounced as pathological responses were good: 61% for grade D; 65.7% grade C and 69.8% grade B. The same results were obtained with the two other SUV types.

Conclusions : Pathologic response to NAC in breast cancer can be assessed accurately by FLT.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-01-05.

Changes in 18F-FDG tumor metabolism after a first course of neoadjuvant chemotherapy in breast cancer: influence of tumor subtypes

BACKGROUND

The aim of this study is to evaluate the impact of the different breast cancer subtypes on the tumor (18)F-FDG uptake at baseline and on its changes after the first course of neoadjuvant chemotherapy (NAC).

PATIENTS AND METHODS

One hundred and fifteen women with newly diagnosed, large or locally advanced breast cancer undergoing NAC were included. Estrogen receptor (ER), progesterone receptor (PR) and HER2 status were used to define three major tumor subtypes: triple negative (TN) (ER-/PR-/HER2-), luminal (ER+ and/or PR+; HER2-) and HER2 positive (HER2+). Using Fluorine-18 fluorodeoxyglucose positron emission tomography, the tumoral standard uptake value (SUV) maximal index was measured at baseline and just before the second course of NAC.

RESULTS

TN tumors presented the highest baseline SUV (11.3 ± 8.5; P < 0.0001). The decrease of SUV after the first course of NAC (ΔSUV) was significantly higher in TN and HER2-positive subtypes (-45% ± 25% and -57% ± 30%, respectively) than in luminal one (-19% ± 35%; P < 0.0001). ΔSUV was a predictive factor of the pathological complete response only in HER2-positive tumors (cut-off = -75%; P < 0.03) with an accuracy of 76%.

CONCLUSION

The baseline (18)F-FDG tumoral uptake but also its early response to NAC is different according to the immunohistological subtypes of breast cancer.

Abstract P5-01-06: 18[F]-FDG Tumoral Uptake and Metabolic Response after 1 Cycle of Primary Chemotherapy According to Tumoral Phenotype of Breast Cancer

To compare the 18[F]-FDG-PET (PET) metabolic characteristics in triple-negative, luminal and positive HER2 breast cancer. Material and Methods: One hundred and forty-five patients with newly diagnosed locally advanced breast cancer were evaluated. Twenty one metastatic patients (discovered in baseline PET) were excluded and 9 patients were lost. One hundred and fifteen had undergone FDG PET before and after the first course of neoadjuvant chemotherapy. Breast cancer lesions were imaged at 80-90 minutes after administration of FDG. Maximum standardized uptake values (SUV) were measured at both time point (SUV1 and SUV 2). Metabolic response was measured by the relative decrease of SUV (ΔSUV). Using Immunohistochemistry as a surrogate for expression profiling, the tumours were classified as follows: triple negative defined by the lack of oestrogen receptors, progesterone receptors and human epidermal growth factor receptors 2 (HER2) expression, luminal (hormonal receptor positive, HER2 negative) and HER2 positive (overexpression of HER 2). Relationships between baseline [18F]-FDG uptake and clinical, histopathological and biological parameters were assessed by Mann-Whitney test. Relationships between SUV1, SUV2, ΔSUV and the tumoral phenotype were assessed by Kruskal-Wallis test.

Results: In the overall population the mean ±SD SUV1, SUV2 and ΔSUV values were 6.7± 5.9, 3.7± 3 and −36.7% ± 35.7%, respectively. Significant relationships were found between baseline FDG uptake and initial clinical and histopathological parameters : a high mitotic activity (p≥0.0001), a high nuclear pleomorphism (≥0.0002), a high tumour grading (p≥0.0001) and a negative oestrogen hormonal receptor status (p≥0.0001) were associated with a high baseline SUV. Patient age, lymph node involvement, architectural differentiation, progesterone hormonal receptor and HER2 status were not found to be related with SUV values.

Metabolic characteristics (mean ± SD) according to tumoral phenotype:

Conclusion: Our results show a significant positive relationship between the baseline FDG uptake and the proliferation markers, the tumour grading, the number of mitoses and the nuclear pleomorphism. A significant negative relationship was found between the baseline FDG uptake and the oestrogen hormonal receptor status. The triple negative phenotype was associated with higher baseline FDG uptake and higher residual FDG uptake after one course of chemotherapy commensurate with their aggressive biology. Luminal tumours showed a lower ΔSUV reflecting their lower chemosensibility.

Abstract P5-01-09: Evaluation of Tumor Blood Flow with Dynamic 18F-Fluorodeoxyglucose Positron Emission Tomography: Correlation with Microvessel Density

Background: Breast cancer is typically associated with an increase in tumor blood flow (due to angiogenesis) and tumor metabolism. Thus, these 2 key parameters are essential to characterize aggressiveness of breast tumors. Moreover, angiogenesis is a potential target for specific therapies. Positron Emission Tomography (PET) with 18F-Fluorodeoxyglucose (FDG) has become the gold standard for in vivo evaluation of tumor metabolism. A method for simultaneous measurement of blood flow and metabolism from a single injection of FDG may be an important addition for functional imaging of breast tumors. Unfortunately, there is no consensus on the validity of dynamic FDG acquisition for the evaluation of tumor blood flow.

Objective: to compare a new technique for simultaneous evaluation of tumor blood flow and metabolism, using a dynamic acquisition of FDG PET, with proliferation and endothelial cell markers. Material and methods: Twenty-eight patients with new diagnosed locally advanced breast cancer were included. In addition to diagnosis and tumor grading, biopsy samples of each tumor were used to assess the Ki-67 index of proliferation and the immuno-staining for CD31 (a panendothelial cell marker) and CD105 (a proliferation-related endothelial cell marker) (both expressed as number of labeled vessels counted on 10 consecutive high power fields, 400X magnification). All patients underwent FDG PET at least one week after sample biopsy and before any treatment. Dynamic 2 minutes acquisition was performed immediately after intravenous injection of 5 MBq/Kg of FDG; tumor Blood Flow (BF, in ml/min/g) was then calculated using a single compartiment kinetic model. Static acquisition was performed 60 minutes after injection for quantification of delayed FDG tumor uptake (“Standardized Uptake Value”, SUV), reflecting tumor metabolism.

Results: Pathologic and PET data were available for all patients. The SUV measured on delayed PET images was strongly positively correlated with the expression of Ki-67 (r=+0.693; P&lt;0.0001). In contrast, there was no significant correlation between SUV and endothelial markers (CD31 and CD105). Tumor BF was positively correlated with the expression of CD31 (r=+0.392; p=0.039) and CD105 (r=+0.470; p=0.016). In contrast, there was no significant correlation between BF and Ki-67. Patients were categorized according to low (inframedian) or high (supramedian) tumor BF. Patients with high tumor BF showed a higher mean CD31 expression (236±169 vs 124±47, p=0.025) and a higher mean CD105 expression (110±73 vs 51±14; p=0.006) when compared with low tumor BF. In contrast there was no significant difference concerning SUV and Ki-67.

Conclusion: Tumor BF quantified by dynamic FDG PET is related to tumor microvessel density evaluated by immunohistochemistry. Thus, dynamic FDG PET is a valuable tool to evaluate both tumor blood flow and metabolism. Further investigations are needed to confirm the respective role of these 2 key parameters for elaboration of therapeutic strategies and response assessment in locally advanced breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-01-09.

Abstract P5-01-05: Prognostic Value at 4 Years of FDG PET, after the First Course of Neoadjuvant Chemotherapy in Breast Cancer

FDG-PET may be a powerful examination to evaluate the effectiveness of neoadjuvant chemotherapy: it appears to be possible to predict the preoperative histological response after the first cycle of chemotherapy. The aim of this prospective study was to investigate the prognostic value of the early decrease of tumoral glucidic metabolism, evaluated with FDG-PET, after the first cycle of neoadjuvant chemotherapy in breast cancer. Material and methods: FDG-PET was performed before and after the first cycle of neoadjuvant chemotherapy in 92 patients with large or locally advanced, non inflammatory, breast cancer. The change of 18F-FDG tumoral uptake was calculated from the maximum Standard Uptake Value corrected for body surface and glycemia (ΔSUVmax). Disease free survival (DFS) was assessed, and the prognostic value of ΔSUVmax was first studied among all patients. Using immunohistochemistry as a surrogate for expression profiling, patients were then classified according to tumoral phenotypes as follow: triple negative (defined by the lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression), luminal (ER positive or PR positive, HER2 negative) and HER2 positive.

Results: The median follow-up was 46.3 months (range: 37–52 months). Twenty one patients had recurrent disease, 9 of whom died. Using univariate Cox regression analysis with all patients, DFS showed significant correlation with initial tumor size measured with ultrasound scan (p=0.03), and ΔSUVmax after the first cycle of neoadjuvant chemotherapy (cut-off = -45%, p=0.01). Using multivariate cox regression analysis, only ΔSUVmax remained an independent prognostic factor of DFS at four years (p=0.028). According to tumoral phenotypes, ΔSUVmax was a prognostic factor of DFS for the 50 patients with a luminal cancer : the risk of relapse was 8.7 times higher in women whose SUVmax decreased less than 24% after the first course of chemotherapy (p=0,04). No significant correlation between

ΔSUVmax and DFS was shown in the 22 triple negative phenotypes. For the 31 patients overexpressing HER2, a tumoral SUVmax lower than 1,8 after one cycle of chemotherapy tended to be a favorable prognostic factor with a lower risk of relapse (p = 0,058) but ΔSUVmax had no significant prognostic value (p=0.08).

Conclusion: Using immunohistochemistry, the change of tumoral FDG uptake after the first cycle of neoadjuvant chemotherapy in operable breast cancer patients appears to be an early surrogate marker of disease free survival for luminal tumors in this study. For HER2 positive tumors, FDG-PET seems to provide prognostic information but, as for the triple negative tumors, it was not statistically significant. FDG-PET might be useful to guide the early therapeutic choice for breast cancer treated with neoadjuvant chemotherapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-01-05.

Predicative value of [18F]-FDG PET scan for pathological complete response to neoadjuvant chemotherapy in breast cancer

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Background: To evaluate, in breast cancer patients treated by neoadjuvant chemotherapy, the early predictive value of the FDG uptake decrease for the assessment of the pathological complete response (pCR). Methods: Forty seven women with non metastatic with conventional imaging, non inflammatory, large or locally advanced breast cancer were included. Pathological tumour regression determined on surgical resection specimens served as the gold standard for the assessment of the neoadjuvant chemotherapy response. According to the Sataloff classification, patients were classified in two groups: patients with a pathological complete response (pCR) and patients with a pathological non complete response (non pCR). FDG uptake of breast lesions was evaluated before and after the first course of neoadjuvant chemotherapy, using Standard Uptake Value maximum (SUV) corrected by body surface area and glycaemia. Relations between baseline [18F]-FDG uptake and clinical, histopathological and biological parameters were assessed by Mann-Whitney test. Predictive value of the FDG decrease for the assessment of the pCR was studied with logistic regression analysis. Results: An elevated baseline SUV was found independently associated with a high mitotic activity (p<0.002), tumour grading (p<0.004), high score of nuclear pleomorphism (p= 0.03) and positive hormonal receptor status (p<0.005). After completion of chemotherapy, 11 (23%) of the 47 breast tumours examined at surgery showed a pCR while 36 (77%) showed a non pCR. The relative decrease (ΔSUV) after the first course of neoadjuvant chemotherapy was significantly greater in the pCR group than in the non pCR group (p< 10-4). A SUV decrease of 85.4% ± 21.9% in pCR patients versus 22.6% ± 36.6% in non pCR patients was found. ΔSUV<-60% predicted pCR with an accuracy of 87%. With multivariate logistic regression analyses, ΔSUV<-60% was the only predictive factor of the pCR Conclusions: In breast cancer patients treated by neoadjuvant chemotherapy, the FDG uptake decrease, after only one course of treatment, is an early and powerful predictor of the pCR.

No significant financial relationships to disclose.

Correlation between inter-ictal regional cerebral blood flow and sphenoidal electrodes--recorded inter-ictal spikes in mesial temporal lobe epilepsy

The objective of this study was to assess the reliability of the diagnosis of mesial temporal lobe epilepsy using EEG and sphenoidal electrodes. Inter-ictal 99 m Tc-HMPAO SPECT scans were registered in 21 patients with confirmed mesial temporal lobe epilepsy identified by scalp EEG and sphenoidal electrodes. Visual and quantitative SPECT analysis was performed blind to EEG data. An asymmetry index (AI) was measured from the ratio of two symmetrical regions of interest. A temporal lobe hypoperfusion was defined as an uptake reduced by 5% with respect to the contralateral region. Inter-ictal SPECT abnormalities were observed in 12 out of 21 patients (57%) from both visual and quantitative analysis (focal hypoperfusion in 11 cases, focal hyperperfusion in one case). In seven patients (33%) both visual and quantitative scintigraphy were normal. Abnormal AI was found in 11/15 patients with a high frequency of seizures and in 1/6 patients with a low frequency of seizures. The major data is that the probability to have an abnormal SPECT is statistically correlated to the frequency of the epileptic fits. The couple EEG recordings with sphenoidal electrodes and SPECT is sensitive and reliable in the diagnosis of mesial temporal lobe epilepsy.

Severe right ventricular contraction asynchronism revealing a large pericardial effusion

A gated blood-pool equilibrium radionuclide angiography was performed in a patient to determine the ejection fraction for doxorubicin cardiotoxicity evaluation. The phase image of the first harmonic of the Fourier analysis revealed a severe delay of the right ventricular contraction compared with that of the left ventricle. This right ventricular contraction asynchronism was due to a large pericardial effusion, confirmed by the presence of the halo sign on the summed gated images and by echocardiography. The phase delay moves towards normalization after pericardiocentesis. Although radionuclide angiocardiography is not the best method for identification of pericardial effusion, this diagnosis should be evoked when a severe homogenous delay of the right ventricular contraction is observed.

[Prognostic value of CA 125 initial half-life measured during first-line chemotherapy in 62 patients with epithelial ovarian cancer stage III or IV]

The prognostic value of CA 125 initial half-life in serum (Tb) during the first cycles of first-line chemotherapy was studied in 62 patients with stage III or IV ovarian cancer. The half-life was strongly correlated; 1) with the rate of biological remission (P < 0.001). This one was respectively equal to 94.7% when Tb was lower than 20 days, 66.6% when Tb was between 20 and 40 days and 7.7% when Tb was higher than 40 days; 2) with the rate of histological remission (P < 0.001) which was equal to 66.6% when Tb was lower than 13 days; 3) with the speed of recurrence growth measured by the doubling time (dT) of CA 125. The median of dT was equal to 182 days when Tb was lower than 13 days, 63 days when Tb was between 13 and 20 days (P < 0.02) and 38 days when Tb was higher than 20 days (P < 0.001); 4) with the duration of disease-free survival (DFS) (P < 0.001): the medians were equal to 23.9 months, 18.0 months, 12.0 months, and 5.5 months, respectively, when Tb was lower than 13 days, between 13 and 20 days; 20 and 40 days, and higher than 40 days; and 5) with the duration of overall survival (OS). The probability of survival at five years was equal to 48% when Tb was lower than 13 days. This probability falled to 13%, 12%, and 8%, when Tb was respectively between 13 and 20 days, 20 and 40 days and higher than 40 days. Multiple regression analysis showed that CA 125 half-life was the most important prognostic factor for DFS and OS. Analysis of correlation allowed to identify a relation between: 1) dT and Tb [dT = Tb/[-0.305 + (0.0388)(Tb)]; P < 10(-4)]; 2) the slope of CA 125 initial regression (P) and DFS [DFS = 201.9e (-16.64*P); P < 10(-8)]; 3) P and OS [OS = 285.0e(-17.00*P); P < 10(-7)]. The initial CA 125 half-life measured during the first cycles of first time chemotherapy seemed to be a critical predictor of response to therapy.