Early prediction of endocrine responsiveness in ER+/HER2-negative metastatic breast cancer (MBC): Pilot study with 18F-Fluoroestradiol (18F-FES) CT/PET

BACKGROUND

18F-FES PET/CT is considered an accurate diagnostic tool to determine whole-body endocrine responsiveness. In the ET-FES trial, we evaluated 18F-FES PET/CT as a predictive tool in ER+/HER2- metastatic breast cancer (MBC).

METHODS

Eligible patients underwent a 18F-FES PET/CT at baseline. Patients with SUV≥2 received single agent ET until PD; patients with SUV<2 were randomized to single agent ET (Arm A) or chemotherapy (CT) (Arm B). Primary objective was to compare the activity of first line ET versus CT in patients with 18F-FES SUV <2.

RESULTS

Overall, 147 patients were enrolled; 117 presented with 18F-FES SUV≥2 and received ET; 30 pts with SUV<2 were randomized to ET or CT. After a median follow up of 62.4 months, 104 patients (73.2%) had disease progression and 53 died (37.3%). Median PFS was 12.4 months (95%CI 3.1-59.6) in patients with SUV <2 randomised to Arm A versus 23.0 months (95%CI 7.7-30.0) in Arm B, (HR = 0.71, 95%CI 0.3 - 1.7); median PFS was 18.0 months (95%CI 11.2-23.1) in patients with SUV≥2 treated with ET. Median OS was 28.2 months (95%CI 14.2-NE) in patients with SUV <2 randomized to ET (Arm A) versus 52.8 months (95%CI 16.2-NE) in Arm B (CT). Median OS was not reached in patients with SUV≥2. 60-month OS rate was 41.6% (95%CI 10.4-71.1%) in Arm A, 42.0% (95%CI 14.0-68.2%) in Arm B and 59.6% (95%CI 48.6-69.0%) in patients with SUV≥2. In patients with SUV≥2, 60-months OS rate was 72.6% if treated with aromatase inhibitors versus 40.6% in case of fulvestrant or tamoxifen (p<0.005).

CONCLUSIONS

The ET-FES trial demonstrated that ER+/HER2- MBC patients are a heterogeneous population, with different levels of endocrine responsiveness based on 18F-FES CT/PET SUV.

Navigating the nuances: comparative analysis and hyperparameter optimisation of neural architectures on contrast-enhanced MRI for liver and liver tumour segmentation

In medical imaging, accurate segmentation is crucial to improving diagnosis, treatment, or both. However, navigating the multitude of available architectures for automatic segmentation can be overwhelming, making it challenging to determine the appropriate type of architecture and tune the most crucial parameters during dataset optimisation. To address this problem, we examined and refined seven distinct architectures for segmenting the liver, as well as liver tumours, with a restricted training collection of 60 3D contrast-enhanced magnetic resonance images (CE-MRI) from the ATLAS dataset. Included in these architectures are convolutional neural networks (CNNs), transformers, and hybrid CNN/transformer architectures. Bayesian search techniques were used for hyperparameter tuning to hasten convergence to the optimal parameter mixes while also minimising the number of trained models. It was unexpected that hybrid models, which typically exhibit superior performance on larger datasets, would exhibit comparable performance to CNNs. The optimisation of parameters contributed to better segmentations, resulting in an average increase of 1.7% and 5.0% in liver and tumour segmentation Dice coefficients, respectively. In conclusion, the findings of this study indicate that hybrid CNN/transformer architectures may serve as a practical substitute for CNNs even in small datasets. This underscores the significance of hyperparameter optimisation.

Pre-treatment dosimetry in90Y-SIRT: Is it possible to optimise SPECT reconstruction parameters and calculation methods for accurate dosimetry?

PURPOSE

The aim of this study was (a) to optimise the99mTc-SPECT reconstruction parameters for the pre-treatment dosimetry of90Y-selective internal radiation therapy (SIRT) and (b) to compare the accuracy of clinical dosimetry methods with full Monte-Carlo dosimetry (fMCD) performed with Gate.

METHODS

To optimise the reconstruction parameters, two hundred reconstructions with different parameters were performed on a NEMA phantom, varying the number of iterations, subsets, and post-filtering. The accuracy of the dosimetric methods was then investigated using an anthropomorphic phantom. Absorbed dose maps were generated using (1) the Partition Model (PM), (2) the Dose Voxel Kernel (DVK) convolution, and (3) the Local Deposition Method (LDM) with known activity restricted to the whole phantom (WP) or to the liver and lungs (LL). The dose to the lungs was calculated using the "multiple DVK" and "multiple LDM" methods.

RESULTS

Optimal OSEM reconstruction parameters were found to depend on object size and dosimetric criterion chosen (Dmean or DVH-derived metric). The Dmean of all three dosimetric methods was close (≤ 10%) to the Dmean of fMCD simulations when considering large segmented volumes (whole liver, normal liver). In contrast, the Dmean to the small volume (∅=31) was systemically underestimated (12%-25%). For lungs, the "multiple DVK" and "multiple LDM" methods yielded a Dmean within 20% for the WP method and within 10% for the LL method.

CONCLUSIONS

All three methods showed a substantial degradation of the dose-volume histograms (DVHs) compared to fMCD simulations. The DVK and LDM methods performed almost equally well, with the "multiple DVK" method being more accurate in the lungs.

Performance of [18F]FDG-PET/CT Imaging in First Recurrence of Invasive Lobular Carcinoma

BACKGROUND

Invasive lobular carcinoma accounts for 10 to 15% of all breast cancers. The first objective of this retrospective study was to assess the diagnostic performance of FDG-PET/CT scanning in women previously treated for invasive lobular carcinoma with suspected first recurrence. The secondary objectives were to evaluate the impact of PET/CT in a change in treatment and its prognostic value on specific survival.

METHODS

Patients in whom a PET/CT scan was performed from January 2011 to July 2019 in our Cancer Research Center were enrolled. Recurrence was suspected based on clinical symptoms, abnormal findings on conventional imaging, and/or elevated tumor markers. The diagnosis of recurrence was established by the oncologist after integration of all clinical, biological, histological, imaging, and follow-up data. Prognostic factors of recurrence as predicted by PET were determined using univariate logistic regression. KI67, mitotic index, or grade of mitosis were tested. Survival curves were compared using the log-rank test. Sixty-four patients (mean age: 60.3; SD = 12.4 years) were enrolled. The average time from initial diagnosis of the primary tumor to suspicion of recurrence was 5.2 ± 4.1 years. Forty-eight patients (75%) were judged to have recurrence by the oncologist: 7 local and 41 metastatic, with mainly bone (n = 24), lymph node (n = 14) and liver (n = 10) metastases.

RESULTS

Sensitivity, specificity, and positive and negative predictive values of PET/CT to predict recurrence were, respectively: 87%, 87%, 95%, and 70%. SUVmax at recurrence sites was generally high (mean: 6.4; SD = 2.9). False negative PET/CT results occurred with local (n = 2), peritoneal (n = 2), meningeal (n = 1), or bladder (n = 1) recurrences. In 40 patients with available histopathological data from suspected sites of recurrence, 30 PET/CT were true positive. In four patients, primary lung (n = 1) or gastric (n = 1) tumors or lymphomas (n = 2) were found. The detection of a recurrence resulted in a change in treatment in 44/48 patients (92%). No association between recurrence predicted by PET and biological biomarkers was found. Median specific survival appears shorter in patients with metastatic recurrence versus patients with local or no recurrence on PET/CT (p = 0.067).

CONCLUSIONS

FDG-PET/CT is an effective and reliable tool for the detection of invasive lobular carcinoma recurrence, although certain recurrence sites specific to this histological type can impair its diagnostic performance.

PET/CT of cranial arteries for a sensitive diagnosis of giant cell arteritis

OBJECTIVES

To investigate the performance of cranial PET/CT for the diagnosis of giant cell arteritis (GCA).

METHODS

All patients with a suspected diagnosis of GCA were prospectively enrolled in this study and had a digital PET/CT with evaluation of cranial arteries if they had not started glucocorticoids more than 72 hours previously. The diagnosis of GCA was retained after at least 6 months of follow-up if no other diagnosis was considered by the clinician and the patient went into remission after at least 6 consecutive months of treatment. Cranial PET/CT was considered positive if at least one arterial segment showed hypermetabolism similar to or greater than liver uptake.

RESULTS

For cranial PET/CT, sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) were 73.3%, 97.2%, 91.7% and 89.7%, respectively. For extracranial PET/CT, diagnostic performance was lower (Se = 66.7%, Sp = 80.6%, PPV = 58.8%, NPV = 85.3%). The combination of cranial and extracranial PET/CT improved overall sensitivity (Se = 80%) and NPV (NPV = 90.3%) while decreasing overall specificity (Sp = 77.8%) and PPV (PPV = 60%).

CONCLUSION

Cranial PET/CT can be easily combined with extracranial PET/CT with a limited increase in examination time. Combined cranial and extracranial PET/CT showed very high diagnostic accuracy for the diagnosis of GCA.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT05246540.

Early metabolic response of breast cancer to neoadjuvant endocrine therapy: comparison to morphological and pathological response

Background

Neoadjuvant endocrine therapy (NET) has shown efficacy in terms of clinical response and surgical outcome in postmenopausal patients with estrogen receptor-positive / HER2-negative breast cancer (ER+/HER2- BC) but monitoring of tumor response is challenging. The aim of the present study was to investigate the value of an early metabolic response compared to morphological and pathological responses in this population.

Methods

This was an ancillary study of CARMINA 02, a phase II clinical trial evaluating side-by-side the efficacy of 4 to 6 months of anastrozole or fulvestrant. Positron Emission Tomography/Computed Tomography using 2-deoxy-2-[¹⁸F]fluoro-D-glucose (FDG-PET/CT) scans were performed at baseline (M0), early after 1 month of treatment (M1) and pre-operatively in 11 patients (74.2 yo ± 3.6). Patients were classified as early “metabolic responders” (mR) when the decrease of SUVmax was higher than 40%, and “metabolic non-responders” (mNR) otherwise. Early metabolic response was compared to morphological response (palpation, US and MRI), variation of Ki-67 index, pathological response according to the Sataloff classification and also to Preoperative Endocrine Prognostic Index (PEPI) score. It was also correlated with overall survival (OS) and recurrence-free survival (RFS).

Results

Tumor size measured on US and on MRI was smaller in mR than mNR, with the highest statistically significant difference at M1 (p = 0.01 and 7.1 × 10^− 5, respectively). No statistically significant difference in the variation of tumor size between M0 and M1 assessed on US or MRI was observed between mR and mNR. mR had a better clinical response: no progressive disease in mR vs 2 in mNR and 2 partial response in mR vs 1 partial response in mNR. One patient with a pre-operative complete metabolic response had the best pathological response. Pathological response did not show any statistically significant difference between mR and mNR. mR had better OS and RFS (Kaplan-Meier p = 0.08 and 0.06, respectively). All cancer-related events occurred in mNR: 3 patients died, 2 of them from progressive disease.

Conclusions

FDG-PET/CT imaging could become a “surrogate marker” to monitor tumor response, especially as NET is a valuable treatment option in postmenopausal women with ER+/HER2- BC.

Dual time point [18F]FLT-PET for differentiating proliferating tissues vs non-proliferating tissues

Purpose

For differentiating tumor from inflammation and normal tissues, fluorodeoxyglucose ([¹⁸F]FDG) dual time point PET could be helpful. Albeit [¹⁸F]FLT is more specific for tumors than [¹⁸F]FDG; we explored the role of dual time point [¹⁸F]FLT-PET for discriminating benign from malignant tissues.

Methods

Before any treatment, 85 womens with de novo unifocal breast cancer underwent three PET acquisitions at 33.94 ± 8.01 min (PET30), 61.45 ± 8.30 min (PET60), and 81.06 ± 12.12 min (PET80) after [¹⁸F]FLT injection. Semiquantitative analyses of [¹⁸F]FLT uptake (SUV) were carried out on tumors, liver, bone marrow (4th thoracic vertebra (T4) and humeral head), descending thoracic aorta, muscle (deltoid), and contralateral normal breast. Repeated measures ANOVA tests and Tukey’s posttests were used to compare SUVmax of each site at the three time points.

Results

There was a significant increase in SUVmax over time for breast lesions (5.58 ± 3.80; 5.97 ± 4.56; 6.19 ± 4.42; p < 0.0001) (m ± SD for PET30, PET60, and PET80, respectively), and bone marrow (for T4, 8.21 ± 3.17, 9.64 ± 3.66, 10.85 ± 3.63, p < 0.0001; for humeral head, 3.36 ± 1.79, 3.87 ± 1.89, 4.39 ± 2.00, p < 0.0001). A significant decrease in SUVmax over time was observed for liver (6.79 ± 2.03; 6.24 ± 1.99; 5.57 ± 1.74; p < 0.0001), muscle (0.95 ± 0.28; 0.93 ± 0.29; 0.86 ± 0.20; p < 0.027), and aorta (1.18 ± 0.34; 1.01 ± 0.32; 0.97 ± 0.30; p < 0.0001). No significant difference was observed for SUVmax in contralateral breast (0.8364 ± 0.40; 0.78 ± 0.38; 0.80 ± 0.35).

Conclusion

[¹⁸F]FLT-SUVmax increased between 30 and 80 min only in proliferating tissues. This could be helpful for discriminating between residual tumor and scar tissue.

Good clinical practice recommendations for the use of PET/CT in oncology

Positron emission tomography/computed tomography (PET/CT) is a nuclear medicine functional imaging technique with proven clinical value in oncology. PET/CT indications are continually evolving with fresh advances made through research. French practice on the use of PET in oncology was framed in recommendations based on Standards-Options-Recommendations methodology and coordinated by the French federation of Comprehensive Cancer Centres (FNLCC). The recommendations were originally issued in 2002 followed by an update in 2003, but since then, a huge number of scientific papers have been published and new tracers have been licenced for market release. The aim of this work is to bring the 2003 version recommendations up to date. For this purpose, a focus group was set up in collaboration with the French Society for Nuclear Medicine (SFMN) to work on developing good clinical practice recommendations. These good clinical practice recommendations have been awarded joint French National Heath Authority (HAS) and French Cancer Institute (INCa) label status-the stamp of methodological approval. The present document is the outcome of comprehensive literature review and rigorous appraisal by a panel of experts, organ specialists, clinical oncologists, surgeons and imaging specialists. These data were also used for the EANM referral guidelines.

Multimodal In Vivo Imaging of Tumorigenesis and Response to Chemotherapy in a Transgenic Mouse Model of Mammary Cancer

Purpose

Transgenic mice expressing the polyoma middle T oncoprotein (PyMT) in the mammary epithelium were explored by multimodal imaging to monitor longitudinally spontaneous tumor growth and response to chemotherapy.

Procedures

Positron emission tomography (PET) with 2-deoxy-2-[¹⁸F]fluoro-d-glucose ([¹⁸F]FDG) and 3'-deoxy-3'-[¹⁸F]fluorothymidine ([¹⁸F]FLT), single photon emission tomography (SPECT) with [^99mTc]TcO₄ ([^99mTc]TEC), X-ray computed tomography, and fluorescent confocal endomicroscopy (FCE) images were acquired during tumor progression in female PyMT mice. Imaging with [¹⁸F]FDG and [^99mTc]TEC was also performed in untreated, doxorubicin-treated, and docetaxel-treated PyMT mice. Total tumor volumes were quantified. Tumors were collected and macroscopic and histological examinations were performed.

Results

All PyMT mice developed multifocal tumors of the mammary epithelium that became palpable at 8 weeks of age (W8). Computed tomography (CT) detected tumors at W14, while a clear tumoral uptake of [^99mTc]TEC and [¹⁸F]FDG was present as early as W6 and W8, respectively. No contrast between mammary tumors and surrounding tissue was observed at any stage with [¹⁸F]FLT. FCE detected an angiogenic switch at W10. Lung metastases were not clearly evidenced by imaging. Doxorubicin and docetaxel treatments delayed tumor growth, as shown by [¹⁸F]FDG and [^99mTc]TEC, but tumor growth resumed upon treatment discontinuation. Tumor growth fitted an exponential model with time constant rates of 0.315, 0.145, and 0.212 week⁻¹ in untreated, doxorubicin, and docetaxel groups, respectively.

Conclusions

Molecular imaging of mammary tumors in PyMT is precocious, precise, and predictive. [¹⁸F]FDG-PET and [^99mTc]TEC SPECT monitor tumor response to chemotherapy.

Electronic supplementary material

The online version of this article (doi:10.1007/s11307-015-0916-7) contains supplementary material, which is available to authorized users.

Abstract P4-01-03: Predictive value of FDG-PET/CT after neoadjuvant endocrine treatment in breast cancer

Background: Neaodjuvant endocrine therapy (NET) has demonstrated efficacy in terms of clinical response and outcome in hormone-receptor positive (HR+) post-menopausal patients (pts) with breast cancer (BC) not eligible for primary breast conservative surgery (BCS). However, the monitoring of tumor response to NET is challenging and clinical response is the current gold standard. The aim of the present study was to investigate the contribution of the early metabolic response (eMR) at one month in FDG-PET/CT in a NET setting for post-menopausal pts with HR+, HER2- BC compared to morphological and pathological responses. We also aimed to evaluate the prognostic value of eMR.

Methods: This was a prospective and ancillary study of CARMINA 02, UCBG0609 (Cancer in press), a phase II clinical trial evaluating the efficacy of 4 to 6 months neoadjuvant anastrozole or fulvestrant. FDG-PET/CT exams were performed at baseline (M0), after 1 month of treatment (M1: eMR) and pre-Op (late metabolic response: lMR) in 11 pts (74.2 years ± 3.6) from 2007 to 2010. Pts were classified “metabolic responders” (mR) if SUVmax values decrease was ≥ 40% at M1 and “non-metabolic responders” (mNR) if otherwise; lMR was also assessed in mR and mNR groups defined at M1. We compared eMR to morphological response (clinical, breast US and MRI) at M1 and pre-op, to the pathological response according to Sataloff classification and to Ki67 score variation during treatment. Early metabolic response was also correlated with the PEPI (Preoperative Endocrine Prognostic Index) score and survival (overall survival, OS and relapse free survival, RFS).

Results: Main results are summarized in Table I. There was a significant difference between mR and mNR pts at M1 (eMR) and pre-op (lMR). One patient with a complete metabolic response at pre-op had the best pathological response (Sataloff TB). Also, mR pts had a better clinical response: 2 partial response (PR) in mR vs 1 in mNR group and 2 mNR patients were classified PD (progressive disease). There was a trend toward better survival for mR pts in OS and RFS (Kaplan-Meier p=0.18 and 0.06, respectively) and all the pejorative events occurred in the mNR group: 3 deaths and 3 metastatic progressions. Besides, no difference in eMR was observed regarding the histological subtype (ductal or lobular; p&gt;0.05) nor the treatment group (p&gt;0.05).

Table I: Metabolic, morphological and pathological response at M1, Pre-Op and on the surgical specimen.  MR : 5ptsmNR : 6ptsP valueM1SUVmax2.6±1.13.9±1.40.00017 Clinical size42.5mm±11.951.7mm±7.50.19 US size22.6mm±6.334.2mm±2.40.02 MRI size21.2mm±4.239.7mm±4.79.16 E-5 Ki 673.6%±1.98.2%±80.19Pre-OpSUVmax2±1.33.3±1.40.018 Clinical size31mm±12.448.3mm±10.80.035 US size18.5mm±7.331.3mm±9.50.07 MRI size17.9mm±7.134.8mm±7.70.003Surgical SpecimenSataloff (TA+TB vs TC+TD)20% vs 80%0 vs 100%1 PEPI score (I+II vs III)80% vs 20%33 vs 67%0.048 Ki 678.6%±9.812.3%±7.90.41

Conclusions: These preliminary results showed the value of the early metabolic response in FDG- PET/CT in a NET setting compared to the morphological or the pathological responses alone. Early metabolic responders patients had better OS, RFS and PEPI scores.

Citation Format: Boughdad S, Champion L, Becette V, Cherel P, Fourme E, Edeline V, Lemonnier J, Lerebours F, Alberini JL. Predictive value of FDG-PET/CT after neoadjuvant endocrine treatment in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-01-03.

Rate of Distant Metastases on 18F-FDG PET/CT at Initial Staging of Breast Cancer: Comparison of Women Younger and Older Than 40 Years

Women who have breast cancer and are younger than 40 y have a poorer outcome than older women. A higher rate of undetected metastases at the time of diagnosis in younger women has been proposed to account for this difference. Our main objective was to test this hypothesis by comparing the distant metastasis rate (DMR) on initial ¹⁸F-FDG PET/CT in a group of breast cancer patients younger than 40 y (<40 y group) with that in a group of breast cancer patients older than 40 y (≥40 y group). An assessment of associations between distant metastases and tumor characteristics was a second objective of the present study.

METHODS

A retrospective single-institution study was performed on women who had breast cancer and no prior malignancy, who were asymptomatic for metastatic lesions on initial clinical examination, and who had initial ¹⁸F-FDG PET/CT within 3 mo after pathologic breast cancer diagnosis and before initial treatment. On the basis of these criteria, data for 2 groups of women differing only in age (<40 y and ≥40 y) were extracted from the hospital information system of Curie Institute-Paris. ¹⁸F-FDG PET/CT examinations were reviewed, and the DMR was recorded for each clinical stage subgroup (stages I-III).

RESULTS

For each group (<40 y and ≥40 y), 107 patients were included, with the same number of patients in each clinical stage subgroup (12 stage I patients, 32 stage IIA patients, 30 stage IIB patients, and 33 stage III patients). The ages of the patients (mean ± SD) were 34.5 ± 4.0 y (<40 y group) and 56.0 ± 10.7 y (≥40 y group). No significant difference in DMRs was observed between the <40 y group and the ≥40 y group (DMRs, 21% and 22%, respectively; P = 1). The DMRs in patients not selected for age were 8% for stage I, 11% for stage IIA, 15% for stage IIB, and 44% for stage III.

CONCLUSION

The DMR was not significantly higher in younger breast cancer patients (<40 y) than in older breast cancer patients (≥40 y), ruling out the assumption that undetected metastases at diagnosis explain the poorer outcome of younger women. However, our results highlight the high yield of ¹⁸F-FDG PET/CT for initial breast cancer staging, even in stage II patients, whatever their age.

¹⁸F-FDG PET/CT for Staging and Restaging of Breast Cancer

Many studies have pointed out the role of (18)F-FDG PET/CT (or (18)F-FDG PET) in patients with clinical stage III or II breast cancer. (18)F-FDG PET/CT might advantageously replace other staging procedures, such as bone scanning and possibly contrast-enhanced CT of the thorax or abdomen-pelvis. We discuss the findings, locoregional or distant, that can be expected in different categories of breast cancer and their impact on prognosis and management. We also discuss the role of (18)F-FDG PET/CT in restaging and how (18)F-FDG PET/CT compares with conventional techniques in restaging for patients with suspected disease recurrence. We conclude with some recommendations for clinical practice and future research.

18F-FDG PET/CT to Predict Response to Neoadjuvant Chemotherapy and Prognosis in Inflammatory Breast Cancer

The aim of this prospective study was to assess the predictive value of (18)F-FDG PET/CT imaging for pathologic response to neoadjuvant chemotherapy (NACT) and outcome in inflammatory breast cancer (IBC) patients.

METHODS

Twenty-three consecutive patients (51 y ± 12.7) with newly diagnosed IBC, assessed by PET/CT at baseline (PET1), after the third course of NACT (PET2), and before surgery (PET3), were included. The patients were divided into 2 groups according to pathologic response as assessed by the Sataloff classification: pathologic complete response for complete responders (stage TA and NA or NB) and non-pathologic complete response for noncomplete responders (not stage A for tumor or not stage NA or NB for lymph nodes). In addition to maximum standardized uptake value (SUVmax) measurements, a global breast metabolic tumor volume (MTV) was delineated using a semiautomatic segmentation method. Changes in SUVmax and MTV between PET1 and PET2 (ΔSUV1-2; ΔMTV1-2) and PET1 and PET3 (ΔSUV1-3; ΔMTV1-3) were measured.

RESULTS

Mean SUVmax on PET1, PET2, and PET3 did not statistically differ between the 2 pathologic response groups. On receiver-operating-characteristic analysis, a 72% cutoff for ΔSUV1-3 provided the best performance to predict residual disease, with sensitivity, specificity, and accuracy of 61%, 80%, and 65%, respectively. On univariate analysis, the 72% cutoff for ΔSUV1-3 was the best predictor of distant metastasis-free survival (P = 0.05). On multivariate analysis, the 72% cutoff for ΔSUV1-3 was an independent predictor of distant metastasis-free survival (P = 0.01).

CONCLUSION

Our results emphasize the good predictive value of change in SUVmax between baseline and before surgery to assess pathologic response and survival in IBC patients undergoing NACT.

Role of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography in gastrointestinal cancers

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a routine imaging modality for many malignancies and its use is currently increasing. In the present review article, we will summarize the evidence for FDG-PET/CT use in digestive cancers (excluding neuroendocrine tumours), and review the existing recommendations. While PET/CT is nowadays considered to be an important tool in the initial workup of oesophageal and anal cancers, new data are emerging regarding its use in assessing therapeutic efficacy, radiotherapy treatment planning, and detection of recurrence in case of isolated tumour marker elevation. Moreover, PET/CT may help decision making by detecting distant metastatic sites especially in potentially resectable metastatic colorectal cancer and, to a lesser extent, in localized gastric and pancreatic cancers. Finally, incidental focal colonic FDG uptakes require exploration by colonoscopy, as they are often associated with premalignant or malignant lesions.

¹⁸F-FDG PET/CT imaging versus dynamic contrast-enhanced CT for staging and prognosis of inflammatory breast cancer

PURPOSE

Inflammatory breast cancer (IBC) is the most aggressive type of breast cancer with a poor prognosis. Locoregional staging is based on dynamic contrast-enhanced (DCE) CT or MRI. The aim of this study was to compare the performances of FDG PET/CT and DCE CT in locoregional staging of IBC and to assess their respective prognostic values.

METHODS

The study group comprised 50 women (median age: 51 ± 11 years) followed in our institution for IBC who underwent FDG PET/CT and DCE CT scans (median interval 5 ± 9 days). CT enhancement parameters were net maximal enhancement, net early enhancement and perfusion.

RESULTS

The PET/CT scans showed intense FDG uptake in all primary tumours. Concordance rate between PET/CT and DCE CT for breast tumour localization was 92%. No significant correlation was found between SUVmax and CT enhancement parameters in primary tumours (p > 0.6). PET/CT and DCE CT results were poorly correlated for skin infiltration (kappa = 0.19). Ipsilateral foci of increased axillary FDG uptake were found in 47 patients (median SUV: 7.9 ± 5.4), whereas enlarged axillary lymph nodes were observed on DCE CT in 43 patients. Results for axillary node involvement were fairly well correlated (kappa = 0.55). Nineteen patients (38%) were found to be metastatic on PET/CT scan with a significant shorter progression-free survival than patients without distant lesions (p = 0.01). In the primary tumour, no statistically significant difference was observed between high and moderate tumour FDG uptake on survival, using an SUVmax cut-off of 5 (p = 0.7 and 0.9), or between high and low tumour enhancement on DCE CT (p > 0.8).

CONCLUSION

FDG PET/CT imaging provided additional information concerning locoregional involvement to that provided by DCE CT on and allowed detection of distant metastases in the same whole-body procedure. Tumour FDG uptake or CT enhancement parameters were not correlated and were not found to have any prognostic value.

miRNA expression profiling of inflammatory breast cancer identifies a 5-miRNA signature predictive of breast tumor aggressiveness

IBC (inflammatory breast cancer) is a rare but very aggressive form of breast cancer with a particular phenotype. The molecular mechanisms responsible for IBC remain largely unknown. In particular, genetic and epigenetic alterations specific to IBC remain to be identified. MicroRNAs, a class of small noncoding RNAs able to regulate gene expression, are deregulated in breast cancer and may therefore serve as tools for diagnosis and prediction. This study was designed to determine miRNA expression profiling (microRNAome) in IBC. Quantitative RT-PCR was used to determine expression levels of 804 miRNAs in a screening series of 12 IBC compared to 31 non-stage-matched non-IBC and 8 normal breast samples. The differentially expressed miRNAs were then validated in a series of 65 IBC and 95 non-IBC. From a set of 18 miRNAs of interest selected from the screening series, 13 were differentially expressed with statistical significance in the validation series of IBC compared to non-IBC. Among these, a 5-miRNA signature comprising miR-421, miR-486, miR-503, miR-720 and miR-1303 was shown to be predictive for IBC phenotype with an overall accuracy of 89%. Moreover, multivariate analysis showed that this signature was an independent predictor of poor Metastasis-Free Survival in non-IBC patients.

Diagnostic and therapeutic imaging for cancer: therapeutic considerations and future directions

As cancer treatment cost soar and the mantra for "personalized medicine" grows louder, we will increasingly be searching for solutions to these diametrically opposed forces. In this review we highlight several exciting novel imaging strategies including MRI, CT, PET SPECT, sentinel node, and ultrasound imaging that hold great promise for improving outcomes through detection of lymph node involvement. We provide clinical data that demonstrate how these evolving strategies have the potential to transform treatment paradigms.

18F-Fluorodeoxyglucose positron emission tomography for the diagnosis of adrenocortical tumors: a prospective study in 77 operated patients

CONTEXT

Most adrenal incidentalomas are nonfunctioning adrenocortical adenomas (ACAs). Adrenocortical carcinomas (ACCs) are rare but should be recognized at an early stage.

OBJECTIVE

The objective of the study was to evaluate the usefulness of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) to predict malignancy in patients without a previous history of cancer.

DESIGN

This was a prospective, multicenter study from 2001 to 2006.

SETTING

The study was conducted at a network of seven university hospitals in Paris.

PATIENTS

Seventy-seven patients were included. All underwent surgery because of hypersecretory and/or growing benign lesions (n = 18), obvious ACCs (n = 21), or radiologically indeterminate lesions (n = 38).

MAIN OUTCOME MEASURE

The degree of (18)F-FDG PET uptake [maximum standardized uptake value (maxSUV)] was related to the pathological findings serving as a reference, and its diagnostic value was compared with that of computerized tomography (CT) scan.

RESULTS

Pathology eventually diagnosed 43 ACAs, 22 ACCs, and 12 nonadrenocortical lesions. Using a cutoff value above 1.45 for adrenal to liver maxSUV ratio, the sensitivity and specificity to distinguish ACAs from ACCs were, respectively, 1.00 (95% confidence interval 0.85-1.00) and 0.88 (95% confidence interval 0.75-0.96). Among the 38 indeterminate lesions at CT scan, we could analyze a subgroup of 16 adrenocortical tumors with high unenhanced density (>10 HU) and an inappropriate washout: (18)F-FDG PET correctly predicted the benignity in 13 of 15 ACAs.

CONCLUSIONS

In a multidisciplinary team approach, (18)F-FDG PET helps to manage suspicious CT scan lesions. An adrenal to liver maxSUV ratio less than 1.45 is highly predictive of a benign lesion.

Diagnosis and localization of renal cyst infection by 18F-fluorodeoxyglucose PET/CT in polycystic kidney disease

Renal cyst infection in polycystic kidney disease is a serious complication. Early diagnosis and localization of infected cyst are crucial and usually require conventional imaging modalities, including ultrasound and computed tomography (CT). However, their contribution is limited because of nonspecific results. We report on a patient with suspected renal cyst infection for which 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan allowed the exact localization of the infected cyst and guided a drainage procedure. FDG-PET/CT imaging could be a valuable tool for early identification of infected renal cyst infection, and may contribute to better patient management.

[The role of PET scan in gastrointestinal stromal tumors]

Abdominal CT is considered the imaging method of choice for the staging and treatment monitoring of Gastrointestinal Stromal Tumors (GIST). The role of Whole-body FDG-PET seems limited for staging because of the low rate of extra-abdominal tumoral involvement and lower sensitivity than CT. However, PET provides assessment of therapeutic response to imatinib as early as 8 days after treatment is begun. The decrease in the metabolic tumor activity is often marked and intense and it is easier to evaluate than changes in tumor shrinkage and density measured on CT. PET may also be useful when morphological findings are unclear, treatment efficacy uncertain or when progression is identified on CT scan, especially when these findings do not agree with clinical data. PET and CT are complementary and hybrid PET/CT systems have been shown to be useful in GIST. PET may be proposed for the assessment of treatment response in prospective studies with imatinib or other molecules. In patients with GIST, FDG-PET should be performed based on a pluridisciplinary decision.

High and typical 18F-FDG bowel uptake in patients treated with metformin

PURPOSE

This prospective and bi-centric study was conducted in order to determine the impact of antidiabetic treatments (AD) on (18)F-FDG bowel uptake in type 2 diabetic patients.

METHODS

Fifty-five patients with previously diagnosed and treated type 2 diabetes mellitus (group 1) were divided in two subgroups: AD treatment including metformin (n=32; group 1a) and AD treatment excluding metformin (n=23; group 1b). The 95 patients without diabetes mellitus made up controls (group 2). (18)F-FDG uptake in small intestine and colon was visually graded and semi-quantitatively measured using the maximum standardized uptake value.

RESULTS

(18)F-FDG bowel uptake was significantly increased in AD patients (group 1) as compared to controls (group 2) (p<0.001). Bowel uptake was significantly higher in AD patients including metformin (group 1a) as compared to AD patients excluding metformin (group 1b) (p<0.01), whose bowel uptake was not significantly different from controls (group 2). A metformin treatment was predictive of an increased bowel uptake in the small intestine (odds ratio OR=16.9, p<0.0001) and in the colon (OR=95.3, p<0.0001), independently of the other factors considered in the multivariate analysis. Bowel uptake pattern in the patients treated with metformin was typically intense, diffuse and continuous along the bowel, strongly predominant in the colon, in both the digestive wall and lumen.

CONCLUSION

This study emphasizes that metformin significantly increases (18)F-FDG uptake in colon and, to a lesser extent, in small intestine. It raises the question of stopping metformin treatment before an (18)F-FDG PET/CT scan is performed for intra-abdominal neoplasic lesion assessment.

Incidental colonic focal lesions detected by FDG PET/CT

OBJECTIVE

The aim of this study was to assess the performance of FDG PET/CT for the detection of colonic lesions, especially advanced neoplasms (villous or >10-mm adenomas, carcinomas). Because of 18F FDG accumulation in adenomatous polyps, PET using FDG can detect early premalignant colorectal lesions.

MATERIALS AND METHODS

FDG PET/CT studies performed for a 1-year period in 1,716 consecutive patients with various malignant diseases, except colorectal cancer, were retrospectively reviewed. PET images obtained 1 hr after FDG injection and non-contrast CT images used for attenuation correction were fused for analysis. Of 45 patients showing intense focal colonic FDG uptake, 20 patients (with 21 foci) underwent a colonoscopic investigation, and, when necessary, polyp resection. The intensity of FDG uptake was quantified using the standardized uptake value (SUV(max)).

RESULTS

The FDG colonic foci were associated with 18 colonoscopic abnormalities in 15 patients, with no colonic abnormality detected in five patients (false-positive [FP] results). Histopathologic findings revealed advanced neoplasms in 13 patients (13 villous adenomas and three carcinomas) and two cases of hyperplastic polyps. A difference in the mean SUV(max) was found between FP and true-positive colonic FDG foci but was not statistically significant (p = 0.14).

CONCLUSION

Presence of a focal colonic FDG uptake incidental finding on a PET/CT scan justifies a colonoscopy to detect (pre-)malignant lesions. The fusion of PET and CT images allows an accurate localization of the lesions. PET/CT is a useful tool to differentiate pathologic from physiologic FDG uptake.

[FDG (18 fluorodeoxyglucose) positron emission tomography and breast cancer]

Positron emission tomography (PET) is a metabolic radionuclide imaging method in which a tracer labeled with a positron emitter is detected with a dedicated system. 18F-fluorodeoxyglucose (FDG) accumulates in tumor cells because of their increased glycolytic activity, and is thus widely used as a tracer in oncology. This increased metabolic activity precedes morphologic modifications, making FDG-PET a very useful tool for detecting and staging cancer. It can also be used to characterize morphologic changes, differentiating not only between benign and malignant lesions, but also between viable tumor cells and areas of necrosis and/or fibrosis induced by treatments. Being a whole-body examination, it allows malignancies to be staged in a single procedure. Systems combining PET and CT (computed tomography) offer improved performance, providing both metabolic and anatomical data. This technique appears to be useful for initial breast cancer staging, especially of locally advanced forms and suspected recurrences (increase of isolated tumor marker). Early studies of PET evaluation of responses to hormonal and/or cytotoxic therapies have also given very promising results. However, this technique does not seem sufficiently sensitive to be included in the initial screening or diagnosis of primary tumors, owing to its limited resolution (about 5 mm) and its restricted availability. This approach is poorly sensitive when used for axillary assessment, but offers good specificity.

Association of peripheral multifocal choroiditis with sarcoidosis: a study of thirty-seven patients

OBJECTIVE

To assess the clinical spectrum of peripheral multifocal choroiditis (PMC) and its association with sarcoidosis.

METHODS

Thirty-seven patients examined between November 1997 and November 2001 who met all diagnostic criteria for PMC were included in this retrospective study. Patients were assessed for the following signs of sarcoidosis: typical changes on chest radiography or computed tomography; predominantly CD4 lymphocytosis in bronchoalveolar lavage fluid; elevated serum angiotensin-converting enzyme levels; elevated gallium uptake; and noncaseating granuloma on biopsy.

RESULTS

Most of the patients were female (30 of 37; 81%) and white (30 of 37; 81%). Mean +/- SD age at onset was 57.5 +/- 18.7 years. Seven (19%) of the 37 patients had biopsy-proven sarcoidosis and 18 patients (49%) with presumed sarcoidosis met at least 2 of the above-mentioned criteria for sarcoidosis but had normal biopsy results. Twelve patients (32%) had an indeterminate diagnosis. Patients with presumed sarcoidosis did not differ from those with proven sarcoidosis as regards the above-mentioned criteria, except for noncaseating granuloma, implying that more than two-thirds of patients (predominantly whites) had underlying sarcoidosis. Most patients with positive gallium scintigraphy had increased mediastinal uptake, as described in sarcoidosis. Patients with underlying sarcoidosis had more severe visual impairment due to cystoid macular edema (CME). Weekly methotrexate (0.3 mg/kg) seemed to control CME.

CONCLUSION

White patients with PMC should be considered to have sarcoidosis. The identification of sarcoidosis in patients with severe ocular disease can help with therapeutic choices.

Whole-body positron emission tomography using fluorodeoxyglucose in patients with metastases of unknown primary tumours (CUP syndrome)

The aim of this study was to evaluate the clinical performances of whole body 2-[18F]fluorodeoxyglucose positron emission tomography (FDG PET) imaging for the detection of the primary tumour in patients with metastases of unknown origin. Forty-one patients, without previous history of known cancer (18 women and 23 men; average age 64.1 years) with metastasis confirmed by histopathological analysis were included in a retrospective study. Results of PET were compared with those of techniques used in the current conventional diagnostic procedure. All known metastatic lesions were detected by PET. There were 26 true-positive and two false-negative results. Primary tumour remained undetermined in eight patients after conventional investigations and PET. PET was superior to conventional diagnostic procedure in 11 patients and led to modify treatment in 11 patients. Sensitivity of PET was superior than computed tomography in detecting abdominal primary tumours. FDG PET is useful in patients with unknown primary tumour because its sensitivity is good and it could modify the disease management. Otherwise, PET allows the evaluation of the extent of the disease and could be used to monitor treatment efficiency. Its contribution has to be evaluated particularly in patients with primary tumour with a specific treatment.

Somatostatin receptors 2 and 5 are the major somatostatin receptors in insulinomas: an in vivo and in vitro study

Somatostatin (SRIF) receptors (sst) are present on normal pancreatic endocrine beta-cells. However, the use of SRIF analogs in the scintigraphic imaging of insulinomas and in the medical management of these tumors seems to be restricted to a subgroup of patients. The aim of this study was to determine the prevalence of sst expression in vitro and characterize sst subtype binding in insulinomas and its correlation with in vivo sst receptor scintigraphy (SRS). In vitro studies were performed on 27 insulinomas from 25 patients: 22 with benign and three with malignant tumors. Semiquantitative RT-PCR of sst mRNAs was performed for 20 of these insulinomas. Sst2 and sst5 were expressed in 70%, sst1 in 50%, and sst3 and sst4 subtypes only in 15-20% of the tumors. (125)I-Tyr(0)DTrp(8)SRIF(14) binding was assessed by quantitative autoradiography in 18 insulinomas, and competition experiments were performed with SRIF(14) and L797-591, L779-976, L796-778, L803-087, L817-818, selective agonists of the five sst subtypes, and BIM23244, a selective agonist of sst2 and sst5. Significant specific binding was observed in 72% of the insulinomas. Displacement experiments with ligands of higher affinity for each of the sst receptors revealed significant binding with the sst2 and sst5 ligands in 72%, sst3 in 44%, sst1 in 44%, and sst4 in 28% of cases. All insulinomas displaying sst2 binding were also sst5 sensitive. However, the ratio of sst5/sst2 displacement was variable and only equal to that for SRIF(14) in experiments with the sst2/sst5 agonist BIM23244. SRS was performed 10 times in nine patients; it detected 60% of the tumors, including metastases of a malignant insulinoma. All the tumors detected by SRS displayed high levels of (125)I-Tyr(0)DTrp(8)SRIF(14) binding. The mechanisms underlying the loss of expression of sst2/sst5 in a third of insulinomas remains to be determined, but this loss of expression may be involved in beta-cell dysfunction.

Positron emission tomography imaging in nonmalignant thoracic disorders

The role of the fluorodeoxyglucose (FDG) technique positron emission tomography (PET) is well established in the management of patients with lung cancer. Increasingly, it is becoming evident that FDG-PET can be effectively employed to diagnose a variety of benign pulmonary disorders. Knowledge of such applications further expands the domain of this powerful modality and further improves the ability to differentiate benign from malignant diseases of the chest. We describe pertinent technical factors that substantially contribute to optimal imaging of the thoracic structures. Particularly, the complementary role of attenuation correction (AC) to that of non-AC images is emphasized. We further outline the need for and the state of the art for co-registration of PET and anatomic images for diagnostic and therapeutic purposes. We then review patterns of physiologic uptake of FDG in thoracic structures, including the lung, the heart, the aorta and large arteries, esophagus, thymus, trachea, thoracic muscles, bone marrow, and joints and alterations following radiation therapy to the thorax. A great deal of information is provided with regard to differentiating benign from malignant nodules and in particular, we emphasize the role of dual time point imaging and partial volume correction for accurate assessment of such lesions. Following a brief review of the diagnostic issues related to the assessment of mediastinal adenopathies, the role of FDG-PET imaging in environment-induced lung diseases, including pneumoconiosis, smoking, and asthma are described. A large body of information is provided about the role of this technology in the management of patients with suspected infection and inflammation of the lungs such as acquired immunodeficiency syndrome, fever of unknown origin, sarcoidosis, chronic granulomatous disease and monitoring the disease process and response to therapy. Finally, the value of FDG-PET in differentiating benign from malignant diseases of the pleura including asbestosis-related disorders is described at the conclusion of this comprehensive review.

Detection of occult disease in breast cancer using fluorodeoxyglucose camera-based positron emission tomography

An isolated increase of blood tumor marker CA 15.3 in breast cancer is considered a sensitive indicator for occult metastatic disease but by itself is not sufficient for initiating therapeutic intervention. We investigated the potential of camera-based positron emission tomography (PET) imaging using [18F]-fluorodeoxyglucose (FDG) to detect clinically occult recurrences in 132 female patients (age, 35-69 years) treated for breast cancer, all presenting with an isolated increase in blood tumor marker CA 15.3 without any other evidence of metastatic disease. FDG results were correlated to pathology results or to a sequentially guided conventional imaging method. One hundred nineteen patients were eligible for correlations. Positive FDG scans were obtained for 106 patients, including 89 with a single lesion and 17 with 2 or more lesion. There were 92 true-positive and 14 false-positive cases, 10 of which became true positive within 1 year. Among the 13 negative cases, 7 were false negative and 6 were true negative. Camera-based PET using FDG has successfully identified clinically occult disease with an overall sensitivity of 93.6% and a positive predictive value of 96.2%. The smallest detected size was 6 mm for a lymph node metastasis (tumor to nontumor ratio, 4:2). FDG camera-based PET localized tumors in 85.7% of cases suspected for clinically occult metastatic disease on the basis of a significant increase in blood tumor marker. A positive FDG scan associated with an elevated CA 15.3 level is most consistent with metastatic relapse of breast cancer.

Technetium-99m HMPAO-labeled leukocyte imaging compared with endoscopy, ultrasonography, and contrast radiology in children with inflammatory bowel disease

BACKGROUND

The purpose of this study was to evaluate retrospectively the value of leukocyte-labeled scintigraphy, ultrasonography, and contrast radiography compared with endoscopy in children suspected of having inflammatory bowel disease (IBD).

METHODS

Twenty-eight children (17 boys; mean age, 10.2 years) with IBD based on standard colonoscopic, histologic, and radiologic criteria (16 with Crohn's disease, 5 with ulcerative colitis, 5 with nonspecific colitis, I with granulomatous disease, and I with Beh,cet's disease) were included. Endoscopic, ultrasonographic, and contrast radiologic examinations were realized for 28, 23, and 19 children respectively.

RESULTS

Sensitivity and specificity were 75% and 92% for leukocyte-labeled scintigraphy, 39% and 90% for ultrasonography, and 58% and 83% for contrast radiography. The authors noted discontinuous uptake for 14 of 15 true-positive results for patients with Crohn's disease and continuous uptake for 4 of 4 true-positive results for patients with ulcerative colitis. A negative correlation between scan activity index and Lloyd-Still clinical score was found for 11 patients with Crohn's disease (r = -0.77).

CONCLUSIONS

Leukocyte-labeled scintigraphy, a noninvasive and reproducible technique, is a useful tool in the diagnosis and therapeutic strategy of IBD, and provides information on the presence, the intensity, and the extent of the disease, particularly in the terminal ileum. Leukocyte-labeled scintigraphy may not replace colonoscopy with biopsies for diagnosis confirmation. Its reliability seems higher than that of ultrasonography.