Apport d’un nouveau score visuel en TEP/TDM au 18Fluorodeoxyglucose (18FDG) lors des récidives ganglionnaires de cancer ORL après traitement initial

New visual score in PET/CT 18Fluorodeoxyglucose (¹⁸FDG) to evaluate lymph node recurrence of head and neck cancer after initial treatment. Neck dissection for node recurrence of head and neck cancer is known for important morbidity after initial radiation therapy. ¹⁸FDG PET/CT in this situation looks interesting but needs standardized interpretation. Our objective was to develop a PET/CT interpretation method in suspicious locoregional head and neck recurrence. Twenty-seven patients with suspicious lymph node recurrence after initial radiation ± chemotherapy for head and neck cancer were retrospectively included. ¹⁸FDG PET/CT was performed before neck dissection and histological data. Initial PET records, binary visual scale, five-point visual scale “Deauville like” and semi-quantitative index were assessed by 2 reviewers. A lymph node recurrence was confirmed in 19 patients (70%) based on histological results. PET records analysis found 6 false positive (FP), 2 true negative (TN) and 19 true positive (TP), with a sensibility (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of 100%, 25%, 76% and 100%, respectively. Binary visual scale reclassified 1/6 FP. “Deauville like” criteria, reclassified 4/6 FP with the first reviewer (P < 0.001) and 5/6 with the second (P < 0.002), improving Sp and PPV of 66% and 95%, respectively. Kappa concordance coefficient for “Deauville like” scale was 0.88. Semi-quantitative index like SUVmax, SUVmean, SUVpeak, MTV, TLG and SAM showed no statistical value. Those preliminary results warrant a standardized visual scale, particularly the “Deauville like” criteria for ¹⁸FDG PET/CT interpretation in suspected lymph node recurrence of head and neck cancer.     

Comparaison de deux méthodes de mesure des TLG en TEP au 18-FDG dans le mélanome métastatique

IntroductionThere are many automated segmentation softwares in PET-CT, but none of them is used as gold standard. The aim of this study is to compare two segmentation softwares, one based on maximum intensity projection (MIP-based) and the second: PETVCAR^®, to measure TLG in patients with metastatic melanoma treated by vemurafenib.Materials and methodsSixteen patients were assessed by PET using 18-fluorodesoxyglucose (18-FDG) before and during the treatment with vemurafenib. TLG were measured by MIP-based and PETVCAR^® and then analysed in initial PET, all PET, by organ and added for each PET.ResultsThere is a good correlation between TLG in each method (r = 0.96 with P = 0 on 439 lesions on all PET). The mean difference between TLG PETVCAR^® and TLG MIP-based is negative. Segmentations are larger with MIP-based than with PETVCAR^® with discrepancies observed for larger and heterogeneous lesions. SUV_max doesn’t seem to be the factor causing these discrepancies. Correlation between the difference of TLG and their mean is also strong especially in bones, nodes and subcutaneous lesions.ConclusionBoth methods have a good correlation in spite of discrepancies observed for large or heterogeneous lesions. These lesions segmentations are larger with the method based on MIP than with PETVCAR^®.     

Comparison of the Prognostic Value of F-18 Pet Metabolic Parameters of Primary Tumors and Regional Lymph Nodes in Patients with Locally Advanced Cervical Cancer Who Are Treated with Concurrent Chemoradiotherapy

Objective

This study investigated the metabolic parameters of primary tumors and regional lymph nodes, as measured by pre-treatment F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) to compare the prognostic value for the prediction of tumor recurrence. This study also identified the most powerful parameter in patients with locally advanced cervical cancer treated with concurrent chemoradiotherapy.

Methods

Fifty-six patients who were diagnosed with cervical cancer with pelvic and/or paraaortic lymph node metastasis were enrolled in this study. Metabolic parameters including the maximum standardized uptake value (SUVmax), the metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumors and lymph nodes were measured by pre-treatment F-18 FDG PET/CT. Univariate and multivariate analyses for disease-free survival (DFS) were performed using the clinical and metabolic parameters.

Results

The metabolic parameters of the primary tumors were not associated with DFS. However, DFS was significantly longer in patients with low values of nodal metabolic parameters than in those with high values of nodal metabolic parameters. A univariate analysis revealed that nodal metabolic parameters (SUVmax, MTV and TLG), paraaortic lymph node metastasis, and post-treatment response correlated significantly with DFS. Among these parameters, nodal SUVmax (hazard ratio [HR], 4.158; 95% confidence interval [CI], 1.1–22.7; p = 0.041) and post-treatment response (HR, 7.162; 95% CI, 1.5–11.3; p = 0.007) were found to be determinants of DFS according to a multivariate analysis. Only nodal SUVmax was an independent pre-treatment prognostic factor for DFS, and the optimal cutoff for nodal SUVmax to predict progression was 4.7.

Conclusion

Nodal SUVmax according to pre-treatment F-18 FDG PET/CT may be a prognostic biomarker for the prediction of disease recurrence in patients with locally advanced cervical cancer.     

Correlation between baseline 18F-FDG PET/CT features and pathological complete response after neoadjuvant chemotherapy in early triple negative breast cancer

Aim of the studyTo evaluate correlation between metabolic and textural parameters on baseline ¹⁸F-FDG PET/CT and pathological response after neoadjuvant chemotherapy in non-metastatic triple negative breast cancer (TNBC).MethodsAll consecutive non-metastatic TNBC women treated by neoadjuvant chemotherapy followed by breast surgery who underwent ¹⁸F-FDG PET/CT examination at diagnosis between 2012 and 2018 were retrospectively included. Metabolic parameters (SUVmax, SUVmean, SUVpeak, MTV, TLG) of the primary tumour and lymph nodes, and textural features (entropy, homogeneity, SRE, LRE, LGZE, HGZE) of the primary tumour were collected. Pathological response was defined according to Sataloff classification.ResultsSeventy-four patients were enrolled. In univariate analysis, metabolic and textural features of the primary breast lesion or metabolic parameters of regional lymph nodes were not predictive of pathological complete response after neoadjuvant chemotherapy.ConclusionMetabolic and textural features of baseline PET/CT do not seem to predict pathological response after neoadjuvant chemotherapy in non-metastatic triple negative breast cancer.     

Intérêt pronostique et prédictif de la TEP-TDM au 18F-FDG chez les patients atteints de léiomyosarcomes de stades avancés

PurposeAssessment of early therapeutic response is essential to guide therapeutic management in patients with advanced leiomyosarcoma (LMS). We compared the predictive values of various 18F-FDG PET-CT-derived metabolic parameters, SUVmax, SUVpeak, metabolic tumor volume (MTV) and total lesion glycolysis (TLG).MethodsA total of 64 patients with LMS who underwent FDG PET/CT before and 6 weeks after the initiation of treatment were retrospectively analyzed. We determined SUVmax, SUVpeak, MTV, and TLG by segmentation to compare their predictive value for 9-month progression-free survival and overall survival. These parameters were dichotomized using the optimal threshold according to the area under the ROC (Receiver Operation Characteristic) curve and evaluated using a Cox model. Overall and progression-free survival analyses were performed using the Kaplan Meier model.ResultsSUVmax showed greater accuracy than TLG or MTV in ROC analysis (area under the curve, AUC, 0.680, 0.677, and 0.675, respectively). The cutoff values derived from the AUC data were SUVmax 4.7, TLG 37.46, and MTV 25 cm³. After dichotomization by threshold values, MTV was the most significant predictor compared with SUVmax and TLG (P = 0.000165, P = 0.007, and P = 0.001, respectively). In early therapeutic evaluation at 6 weeks, delta SUVpeak and PERCIST metabolic response were significantly correlated with progression-free survival (P = 0.008 and 0.035, respectively).ConclusionBaseline SUVmax, MTV and TGL were predictive of overall survival, delta SUVpeak and PERCIST response obtained by functional imaging in early therapeutic evaluation were significantly correlated with progression-free survival in advanced leiomyosarcoma patients.     

Adding Maximum Standard Uptake Value of Primary Lesion and Lymph Nodes in 18F-Fluorodeoxyglucose PET Helps Predict Distant Metastasis in Patients with Nasopharyngeal Carcinoma

Objective

To find out the most valuable parameter of ¹⁸F-Fluorodeoxyglucose positron emission tomography for predicting distant metastasis in nasopharyngeal carcinoma.

Methods

From June 2007 through December 2010, 43 non-metastatic NPC patients who underwent ¹⁸F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) before radical Intensity-Modulated Radiation Therapy were enrolled and reviewed retrospectively. PET parameters including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glucose (TLG) of both primary tumor and cervical lymph nodes were calculated. Total SUVmax were recorded as the sum of SUVmax of primary tumor and cervical lymph nodes. Total SUVmean, Total MTV and Total TLG were calculated in the same way as Total SUVmax.

Results

The median follow-up was 32 months (range, 23–68 months). Distant metastasis was the main pattern of treatment failure. Univariate analysis showed higher SUVmax, SUVmean, MTV, and TLG of primary tumor, Total SUVmax, Total MTV, Total TLG, and stage T3-4 were factors predicting for significantly poorer distant metastasis-free survival (p = 0.042, p = 0.008, p = 0.023, p = 0.023, p = 0.024, p = 0.033, p = 0.016, p = 0.015). In multivariate analysis, Total SUVmax was the independent predictive factor for distant metastasis (p = 0.046). Spearman Rank correlation analysis showed mediate to strong correlationship between Total SUVmax and SUVmax-T, and between Total SUVmax and SUVmax-N(Spearman coefficient:0.568 and 0.834;p = 0.000 and p = 0.000).

Conclusions

Preliminary results indicated that Total SUVmax was an independently predictive factor for distant metastasis in patients of nasopharyngeal carcinoma treated with Intensity-Modulated Radiation Therapy.     

Multimodality Imaging to Predict Response to Systemic Treatment in Patients with Advanced Colorectal Cancer

Aim

Aim of this study was to investigate the potential of ¹⁸F-FDG PET, diffusion weighted imaging (DWI) and susceptibility-weighted (T2*) MRI to predict response to systemic treatment in patients with colorectal liver metastases. The predictive values of pretreatment measurements and of early changes one week after start of therapy, were evaluated.

Methods

Imaging was performed prior to and one week after start of first line chemotherapy in 39 patients with colorectal liver metastases. ¹⁸F-FDG PET scans were performed on a PET/CT scanner and DWI and T2* were performed on a 1.5T MR scanner. The maximum standardized uptake values (SUV), total lesion glycolysis (TLG), apparent diffusion coefficient (ADC) and T2* value were assessed in the same lesions. Up to 5 liver metastases per patient were analyzed. Outcome measures were progression free survival (PFS), overall survival (OS) and size response.

Results

Pretreatment, high SUV_max, high TLG, low ADC and high T2* were associated with a shorter OS. Low pretreatment ADC value was associated with shorter PFS. After 1 week a significant drop in SUV_max and rise in ADC were observed. The drop in SUV was correlated with the rise in ADC (r=-0.58, p=0.002). Neither change in ADC nor in SUV was predictive of PFS or OS. T2* did not significantly change after start of treatment.

Conclusion

Pretreatment SUV_max, TLG, ADC, and T2* values in colorectal liver metastases are predictive of patient outcome. Despite sensitivity of DWI and ¹⁸F-FDG PET for early treatment effects, change in these parameters was not predictive of long term outcome.     

Intérêt pronostique et prédictif de la TEP-TDM au 18F-FDG au bilan initial des mélanomes de stade IIIB-C-D et IV avant traitement par anti-PD-1

PurposeThe advent of immunotherapy by checkpoint inhibitor has profoundly changed the prognosis of patients with metastatic melanoma. The objective of our study was to evaluate the prognostic and predictive performance of 18F-FDG PET/CT of the initial extension assessment of stage IIIB-C-D and IV melanomas.MethodsWe retrospectively included 57 patients who had 18F-FDG PET/CT prior to the introduction of anti-PD-1 immunotherapy. The parameters extracted were SUVmax, SUV peak, MTV and TLG of the lesion with highest uptake (MTV LM, TLG LM), as well as MTV total and TLG total, obtained by adaptive segmentation. The18F-FDG PET/CT were dichotomized using the optimal threshold measured according to the area under the curve in the ROC (Receiver Operation Characteristic) curves. These parameters were evaluated using a Cox model. Overall survival and progression-free survival analyses were performed using the Kaplan Meier model.ResultsThe median follow-up was 25.4 months, 38 patients had progressed or recurred, and 20 patients had died. TLG LM > 132.59 (P = 0.0011), MTV total > 12 cm³ (P = 0.0139), and TLG > 94.17 (P = 0.0084) were significantly associated with a shorter progression-free survival. TLG LM > 145.92 (P = 0.0062), MTV total > 10.16 cm³ (P = 0.0051), and a metastatic spread > 2 organs (P = 0.0001) were associated with a shorter overall survival.ConclusionWe confirm the potential prognostic interest of PET-TDM at 18FDG before immunotherapy of stage IIIB-C-D and IV melanomas on progression-free survival and overall survival. The combination of these metabolic markers reflecting tumor burden with clinical and biological prognostic factors could allow early identification of patients at high risk of anti-PD-1 failure.     

早期动态18F-FDG PET/CT成像在实体肿瘤评估中的应用

~(18)F-FDG PET/CT常规代谢成像反应肿瘤的葡萄糖代谢及乏氧情况,而~(18)F-FDG PET/CT早期动态成像能反映PET/CT成像早期肿瘤的灌注情况。由于肿瘤的异质性,在早期动态~(18)F-FDG PET/CT成像,即~(18)F-FDG PET/CT灌注成像中,存在独立于常规60 min~(18)F-FDG PET/CT代谢成像的SUVmax(最大标准摄取值)高摄取区。因此,在临床工作中应用~(18)F-FDG PET/CT早期动态成像,能够进一步对实体肿瘤的活性区域进行评估,能够更好评价患者预后、完善治疗方案。当前~(18)F-FDG早期动态成像已经应用在肝癌、肾癌以及膀胱癌等实体肿瘤诊断中。早期动态~(18)F-FDG PET/CT成像结合常规标准~(18)F-FDG PET/CT代谢成像,对实体肿块进行一站式成像方法,能够更好的对肿瘤进行评估。     

Prediction of Recurrence by Preoperative Intratumoral FDG Uptake Heterogeneity in Endometrioid Endometrial Cancer

PURPOSE: To investigate the prognostic value of preoperative intratumoral ¹⁸F-FDG uptake heterogeneity (IFH) derived from positron emission tomography (PET)/computed tomography (CT) in patients with endometrioid endometrial cancer. METHODS: We retrospectively evaluated clinicopathological data from patients with pathologically proven endometrioid endometrial cancer who had undergone ¹⁸F-FDG PET/CT scans before surgery. Patients were divided into two groups according to their IFH. The main outcome measure was disease-free survival (DFS). RESULTS: Between January 2010 and January 2015, data from 72 patients were available for analysis. The median duration of DFS was 23 months (range, 6 to 57 months), and 4 (5.6%) patients experienced recurrence. There were significant differences in tumor size, IFH, and DFS between patients with and without recurrence. In regression analysis, high IFH value [P = .007, hazard ratio (HR) 2.545, 95% confidence interval (CI) 1.468-8.674] was the only independent risk factor for recurrence. The Kaplan-Meier survival graphs showed that DFS significantly differed in groups categorized based on IFH (P < .001, log-rank test). CONCLUSIONS: Preoperative IFH measured by ¹⁸F-FDG PET/CT was associated with recurrence of endometrioid endometrial cancer. The finding supports evidence that FDG-based heterogeneity can be a novel and useful predictor of endometrioid endometrial cancer recurrence.     

Prognostic Value of 18F-FDG PET/CT in Surgical Non-Small Cell Lung Cancer: A Meta-Analysis

Background

The identification of surgical non-small cell lung cancer (NSCLC) patients with poor prognosis is a priority in clinical oncology because of their high 5-year mortality. This meta-analysis explored the prognostic value of maximal standardized uptake value (SUV_max), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) on disease-free survival (DFS) and overall survival (OS) in surgical NSCLC patients.

Materials and Methods

MEDLINE, EMBASE and Cochrane Libraries were systematically searched until August 1, 2015. Prospective or retrospective studies that evaluated the prognostic roles of preoperative 18F-FDG PET/CT with complete DFS and OS data in surgical NSCLC patients were included. The impact of SUV_max, MTV or TLG on survival was measured using hazard ratios (HR). Sub-group analyses were performed based on disease stage, pathological classification, surgery only and cut-off values.

Results

Thirty-six studies comprised of 5807 patients were included. The combined HRs for DFS were 2.74 (95%CI 2.33–3.24, unadjusted) and 2.43 (95%CI: 1.76–3.36, adjusted) for SUV_max, 2.27 (95%CI 1.77–2.90, unadjusted) and 2.49 (95%CI 1.23–5.04, adjusted) for MTV, and 2.46 (95%CI 1.91–3.17, unadjusted) and 2.97 (95%CI 1.68–5.28, adjusted) for TLG. The pooled HRs for OS were 2.54 (95%CI 1.86–3.49, unadjusted) and 1.52 (95%CI 1.16–2.00, adjusted) for SUV_max, 2.07 (95%CI 1.16–3.69, unadjusted) and 1.91 (95%CI 1.13–3.22, adjusted) for MTV, and 2.47 (95%CI 1.38–4.43, unadjusted) and 1.94 (95%CI 1.12–3.33, adjusted) for TLG. Begg’s test detected publication bias, the trim and fill procedure was performed, and similar HRs were obtained. The prognostic role of SUV_max, MTV and TLG remained similar in the sub-group analyses.

Conclusions

High values of SUV_max, MTV and TLG predicted a higher risk of recurrence or death in patients with surgical NSCLC. We suggest the use of FDG PET/CT to select patients who are at high risk of disease recurrence or death and may benefit from aggressive treatments.     

Differences between TNM classification and 2-[18F]FDG PET parameters of primary tumor in NSCLC patients

BackgroundThe aim of the study was to compare the TNM classification with 2-[¹⁸F]FDG PE T biological parameters of primary tumor in patients with NSCLC.Materials and methodsRetrospective analysis was performed on a group of 79 newly diagnosed NSCLC patients. PET scans were acquired on Gemini TF PET/CT scanner 60–70 min after injection of 2-[¹⁸F]FDG with the mean activity of 364 ± 75 MBq, with the area being examined from the vertex to mid-thigh. The reconstructed PET images were evaluated using MIM 7.0 Software for SUV_max, MTV and TLG values.ResultsThe analysis of the cancer stage according to TNM 8^th edition showed stage IA2 in 8 patients, stage IA3 — 6 patients, stage IB — 4 patients, IIA — 3 patients, 15 patients with stage IIB, stage IIIA — 17 patients, IIIB — 5, IIIC — 5, IVA in 7 patients and stage IVB in 9 patients. The lowest TLG values of primary tumor were observed in stage IA2 (11.31 ± 15.27) and the highest in stage IIIC (1003.20 ± 953.59). The lowest value of primary tumor in SUV_max and MTV were found in stage IA2 (6.8 ± 3.8 and 1.37 ± 0.42, respectively), while the highest SUV_max of primary tumor was found in stage IIA (13.4 ± 11.4) and MTV in stage IIIC (108.15 ± 127.24).ConclusionTNM stages are characterized by different primary tumor 2-[¹⁸F]FDG PET parameters, which might complement patient outcome.     

Value of 18FDG PET for prediction of therapeutic response in HER2+ breast cancer: Interim analysis

¹⁸F-FDG PET is recommended for the initial staging of locally advanced breast cancer. Studies have shown the prognostic value of ¹⁸F-FDG PET for staging, but its ability to predict pathological complete response remains uncertain. Our objective was to determine the predictive value of early therapeutic evaluation by ¹⁸F-FDG PET for HER2-positive breast cancer patients. We studied a subpopulation of the prospective and multicentric French NeoTOP trial, at interim analysis. All patients were eligible for neoadjuvant chemotherapy. A ¹⁸F-FDG PET was performed at baseline and then after one cycle of neoadjuvant treatment. ¹⁸F-FDG PET were studied by three conventional methods (two visuals and one quantitative) and by textural analysis. Complete pathological response on surgical samples corresponded to grades 1/2 of Chevallier's classification and no responders corresponded to grades 3/4 of Chevallier. Pathological results were available for 21 patients. SUV_max decreased by 55% after one cycle of chemotherapy. No difference between groups was found with visuals, conventional quantitative and textural analysis of tumour uptake evaluations. Early therapeutic evaluation by ¹⁸F-FDG PET for HER2-positive breast cancer was not predictive of pathological therapeutic response after neoadjuvant treatment, with conventional study or textural analyses in this interim analysis.     

Comparaison de différents indices métaboliques et de la méthode SULTAN dans l’évaluation de la réponse thérapeutique par TEP au 18FDG dans le cancer du sein métastatique

Objective18F-FDG PET is a valuable tool in the evaluation of therapeutic response in breast cancer. This retrospective study was designed to compare the performance of six metabolic indices and to define their optimal thresholds, in patients treated with chemotherapy or hormone therapy for metastatic breast cancer. The performances of a parametric analysis by SULTAN method were also evaluated.MethodsTwenty patients, who underwent from 2 to 7 PET during the follow-up were analyzed. For each target, six indices were measured: SUVmax (maximum Standardized Uptake Value), SUVpeak, SAM (Standardized Added Metabolic activity), metabolic volume (MV), SUVmean using an adaptive threshold, and TLG (total lesion glycolysis). The percentage change of each target between each PET was calculated. A method based on parametric imaging (SULTAN) was also applied to each patient. The results were compared to the gold standard, defined by clinical evaluation, biological and morphological imaging RECIST 1.1 criteria. A per-lesion and per-patient analysis were performed and the optimal thresholds for each indices were calculated.ResultsFor the per-lesion analysis, 61 targets and 111 evolutions with 67 responders (R) and 44 non-responders (NR) were studied. Using ROC curve analysis and intercomparison, SUVmax, SUVpeak and SUVmean were significantly better than SAM, TLG and VM (P < 0.05). Using the optimal thresholds of −21%, –21%, –34%, –48% and –23% for SUVmax, SUVpeak, SUVmean, SAM and TLG respectively, these five indices were significantly correlated with the gold standard. SUVmax, SUVpeak and SUVmean showed the best performances of sensitivity (88%, 87% and 78% respectively), specificity (93%, 93% and 98% respectively) and negative predictive value (NPV) (84%, 69% and 74% respectively). For the per-patient analysis, 42 pairs of PET with 22 R and 20 NR were studied. Only SUVmax and SUVpeak were correlated to gold standard with the 30%-PERCIST-threshold and with optimal thresholds with performances of sensitivity of 73% and 77%, specificity of 95% and NPV of 76% and 79%. Parametric analysis with SULTAN showed excellent performances in the per-lesion and per-patient analysis (sensitivity 84% and 82%, specificity 98% and 90%, NPV 80% and 82%, respectively).ConclusionSUVmax and SUVpeak appeared the best indices to evaluate metabolic response in metastatic breast cancer. The SULTAN method was a reliable method to assist interpretation.     

Intérêt de la tomographie par émission de positons (TEP) au 18FDG dans le suivi des patients traités pour carcinome épidermoïde des voies aérodigestives supérieures (VADS) en rémission clinique

IntroductionPosttreatment follow-up of head and neck squamous cell carcinoma (HNSCC) recurrence is a diagnostic challenge. Tissue distortions from radiation and surgery can obscure early detection of recurrence by conventional follow-up approaches such as physical examination (PE), computed tomography, and magnetic resonance imaging. A number of studies have shown that ¹⁸Fluoro-fluorodeoxyglucose (¹⁸FDG) Positron emission tomography (PET) may be an effective technique for the detection of persistent, recurrent, and distant metastatic HNSCC after treatment. The aim of this prospective study was to determine the benefits (sensitivity, specificity, predictive values, and accuracy) of ¹⁸FDG PET using hybrid PET–Computed tomography system (PET/CT) in the detection of HNSCC subclinical locoregional recurrence and distant metastases, in patients 12 months after curative treatment with a negative conventional follow up.Materials and MethodsNinety-one patients cured from head and neck squamous cell carcinoma (HNSCC) without any clinical element for recurrence were included. Whole-body ¹⁸FDG PET/CT examination was performed 11.6 ± 4.4 months after the end of the treatment. The gold standard was histopathology or 6 months imaging follow-up.ResultsThe whole-body ¹⁸FDG PET/CT of the 91 patients in this study consisted of 52 negative and 39 positive results. Nine of these patients who exhibited abnormal ¹⁸FDG uptake in head and neck area did not have subsequently proven recurrent HNSCC (false positive). Thirty had proven recurrence (true positive). All 52 patients with negative readings of ¹⁸FDG PET/CT remained free of disease at 6 months (true negative). The sensitivity and specificity of ¹⁸FDG PET/CT in this study for the diagnosis of HNSCC recurrence were 100% (30/30) and 85% (52/61) respectively. The positive predictive value was 77% (30/39). The negative predictive value was 100% (52/52). The overall accuracy was 90% (82/91).ConclusionThe results of our study confirm the high effectiveness of ¹⁸FDG PET/CT in assessment of HNSCC recurrence. It suggests that this modality is more accurate than conventional follow-up PE alone in the assessment of patient recurrence after previous curative treatment for HNSCC. Therefore, a PET study could be systematically proposed at 12 months after the end of the treatment.     

Metabolic Tumour Burden Measured by 18F-FDG PET/CT Predicts Malignant Transformation in Patients with Neurofibromatosis Type-1

Background

To investigate the diagnostic and prognostic performances of ¹⁸F-FDG PET/CT measures of metabolic tumour burden in patients with neurofibromatosis type-1 (NF1), suspect of malignant transformation.

Methods

This retrospective study included 49 patients (15–60 years old, 30 women) with a diagnosis of NF1, followed in our Reference Centre for Rare Neuromuscular Diseases, who presented clinical signs of tumour progression (pain, neurological deficit, tumour growth). Quantitative metabolic parameters were measured on 149 tumoral targets, using semi-automatic software and the best cut off values to predict transformation was assessed by Receiver Operating Characteristics (ROC) analysis. Prognostic value of PET/CT metabolic parameters was assessed by Kaplan-Meier estimates of overall survival.

Results

Lesions were histologically documented in 40 patients: a sarcomatous transformation was found in 16, a dysplastic neurofibroma (NF) in 7, and a benign NF in 17; in the remaining 9 patients, a minimal follow-up of 12 mo (median 59 mo) confirmed the absence of transformation. The optimal cut off values for detection of malignant transformation were, in decreasing order of area under the ROC curves, a tumour-to-liver (T/L) ratio >2.5, SUV_max > 4.5, total lesion glycolysis (TLG) > 377, total metabolic tumour volume (TMTV) > 88 cm³, and heterogeneity index (HI_suv) > 1.69. The best prognostic marker was the TLG: the 4-y estimates of survival were 97% [95% CI, 90% - 100%] in patients with TLG ≤ 377 vs. 27% [95% CI, 5% - 49%] in patients with TLG > 377 (P < 0.0001; χ² 27.85; hazard ratio 13.27 [95% CI, 3.72–47.35]). T/L ratio, SUV_max and TMTV demonstrated slightly lower performance to predict survival, with χ² ranging 14.41–19.12. The HI_suv index was not predictive of survival.

Conclusion

Our study demonstrates that TLG and TMTV, as PET/CT measures of metabolic tumour burden, may be used clinically to identify sarcomatous transformation in patients with NF1 and predict overall survival, with a higher specificity for the TLG. Conventional measures such as the SUV_max, and T/L ratio also demonstrate high prognostic value.     

Incidentalomes parotidiens en TEP-18F-FDG : prévalence,diagnostic et impact thérapeutique

Objective

Parotid gland incidentalomas are unexpected hypermetabolic foci in the parotid region that can be found when scanning the whole-body by PET/CT. The role of SUVmax is controversial to differentiate benign or malignant tumours in this indication. The aim of this study was to determine PET/CT features of malignant parotid incidentaloma, in order to improve medical care.

Intérêt de la TEP/TDM au 18FDG dans les sous-types histologiques agressifs de cancers thyroïdiens (oncocytaire et peu différencié)

IntroductionThe objective of our study was to evaluate the performance of ¹⁸FDG PET/CT in aggressive histological subtypes of differentiated cancer of the thyroid and its therapeutic impact.MethodThirty-three patients (22 Hürthle cell carcinoma and 11 poorly differentiated carcinoma) who underwent FDG PET/CT were retrospectively included. Nine scans have been performed for initial staging, 16 for suspicion of recurrence (with 11 having a rising Tg), 3 for the reassessment of metastatic disease under systemic treatment and 30 systematically during follow-up. The results of PET/CT were confronted with histological data and follow-up results.ResultsThirteen out of 18 positive scans were confirmed (8 locoregional recurrences and 5 distant metastases). The majority of them were performed for a suspicion of recurrence (8) or for initial staging (2). The sensitivity, specificity, PPV, and NPV were respectively 81.2%, 88.1%, 72.2% and 92.5%. For Hürthle cell carcinoma and poorly differentiated carcinoma, the sensitivity and specificity were respectively 100% vs. 57% and 86% vs. 93%. Systematic PET scans were most of the time negative (26/30) and in accordance with histological and follow-up results. It was the same in case of scans performed for undetectable initial Tg (16/22). PET/CT modified patient management in 14% of the cases.ConclusionThis study confirms the good performances of ¹⁸FDG PET/CT for initial staging and in case of elevated Tg during the follow-up of aggressive histological subtypes of thyroid cancer. It does not seem relevant in the absence of a suspicion of recurrence or in the case of undetectable initial Tg.     

DEAD/H (Asp–Glu–Ala–Asp/His) box polypeptide 3, X-linked is an immunogenic target of cancer stem cells

Accumulating evidence suggests that most solid malignancies consist of heterogeneous tumor cells and that a relatively small subpopulation, which shares biological features with stem cells, survives through potentially lethal stresses such as chemotherapy and radiation treatment. Since the survival of this subpopulation of cancer stem cells (CSC) plays a critical role in recurrence, it must be eradicated in order to cure cancer. We previously reported that vaccination with CD133⁺ murine melanoma cells exhibiting biological CSC features induced CSC-specific effector T cells. These were capable of eradicating CD133⁺ tumor cells in vivo, thereby curing the parental tumor. In the current study, we indicated that DEAD/H (Asp–Glu–Ala–Asp/His) box polypeptide 3, X-linked (DDX3X) is an immunogenic protein preferentially expressed in CD133⁺ tumor cells. Vaccination with DDX3X primed specific T cells, resulting in protective and therapeutic antitumor immunity. The DDX3X-primed CD4⁺ T cells produced CD133⁺ tumor-specific IFNγ and IL-17 and mediated potent antitumor therapeutic efficacy. DDX3X is expressed in various human cancer cells, including lung, colon, and breast cancer cells. These results suggest that anti-DDX3X immunotherapy is a promising treatment option in efforts to eradicate CSC in the clinical setting.