Conventional Morphological Imaging Research Articles

Correlation between Calcitonin Levels and [F18]FDG-PET/CT in the Detection of Recurrence in Patients with Sporadic and Hereditary Medullary Thyroid Cancer

Purpose. Measurement of serum calcitonin is important in the followup of patients with medullary thyroid carcinoma (MTC) and reliably reflects the presence of the disease. This is the largest study so far in bibliography investigating the diagnostic accuracy of combined [18F]FDG-PET/CT in patients with MTC and elevated calcitonin levels. Methods. Between February 2007 and February 2011, 59 [18F]FDG-PET/CT were performed on 51 patients with MTC and elevated calcitonin levels for localization of recurrent disease. Conventional morphologic imaging methods were negative or showed equivocal findings. Results. Among the 59 [18F]FDG-PET/CT, 29 were positive (26 had true-positive and 3 false-positive findings) and 30 negative. The overall per-patient sensitivity of [18F]FDG-PET/CT was 44.1%. Using as cut-off point the calcitonin value of 1000 pg/ml, in patients with calcitonin exceeding this value, sensitivity raised to 86.7%. The overall sensitivity of [18F]FDG-PET/CT was lower (23%) in patients with MEN IIA syndrome. Conclusion. The findings of this paper show that [18F]FDG-PET/CT is valuable for the detection of recurrence in patients with highly elevated calcitonin levels, >1000 pg/mL, but in patients with lower calcitonin levels, its contribution is questionable. Also, there is evidence that the sensitivity of [18F]FDG-PET/CT is lower in patients with MTC as part of MEN IIA syndrome.

Performances de la TEP-TDM à la 6-Fluoro-[18F]-L-Dihydroxyphénylalanine (FDOPA) et de l’imagerie radiologique conventionnelle dans la prise en charge des patients avec maladie tumorale endocrine dont le primitif est inconnu

IntroductionDespite the extensive diagnostic work-up performed by conventional morphologic and functional imaging in patients with endocrine metastatic malignancies, the primary tumor remains often unknown. Knowledge of the primary tumor improves patients’ management in case of metastatic disease, and allows curative surgical debulking. At present, few studies have focused on the detection of the primary lesion. AimsTo retrospectively assess the FDOPA PET/CT accuracy in the detection of primary endocrine tumors and to evaluate the incremental value of FDOPA PET/CT over conventional imaging. Patients and methodsFourteen patients with biopsy-proven or clinically and biologically suspected endocrine tumors underwent FDOPA PET/CT. Results were compared with conventional imaging, and related to a pathologic or follow-up gold standard. ResultsFDOPA PET/CT detected the primary tumor in four out of 14 patients. Conventional imaging detected the primary tumor in three out of 14 patients. The association of FDOPA PET/CT and morphologic imaging allowed the identification of five out of 14 primary tumors. On an organ-based analysis, FDOPA PET/CT detected more metastasis than morphologic imaging (respective sensitivities of 92% and 58%). ConclusionIn our study, FDOPA PET/CT seemed more sensitive than conventional imaging for the detection of primary endocrine tumors and metastatic spread assessment. Physiological pancreatic uptake hampers FDOPA PET/CT accuracy for the detection of islet cell primary malignancies. Moreover, some pathologic characteristics of the endocrine phenotype, such as cellular differentiation, may influence FDOPA tumoral uptake.

Differentiating treatment-induced necrosis from recurrent/progressive brain tumor using nonmodel-based semiquantitative indices derived from dynamic contrast-enhanced T1-weighted MR perfusion

Differentiating treatment-induced necrosis (TIN) from recurrent/progressive tumor (RPT) in brain tumor patients using conventional morphologic imaging features is a very challenging task. Functional imaging techniques also offer moderate success due to the complexity of the tissue microenvironment and the inherent limitation of the various modalities and techniques. The purpose of this retrospective study was to assess the utility of nonmodel-based semiquantitative indices derived from dynamic contrast-enhanced T1-weighted MR perfusion (DCET1MRP) in differentiating TIN from RPT. Twenty-nine patients with previously treated brain tumors who showed recurrent or progressive enhancing lesion on follow-up MRI underwent DCET1MRP. Another 8 patients with treatment-naive high-grade gliomas who also underwent DCET1MRP were included as the control group. Semiquantitative indices derived from DCET1MRP included maximum slope of enhancement in initial vascular phase (MSIVP), normalized MSIVP (nMSIVP), normalized slope of delayed equilibrium phase (nSDEP), and initial area under the time-intensity curve (IAUC) at 60 and 120 s (IAUC(60) and IAUC(120)) obtained from the enhancement curve. There was a statistically significant difference between the 2 groups (P < .01), with the RPT group showing higher MSIVP (15.78 vs 8.06), nMSIVP (0.046 vs 0.028), nIAUC(60) (33.07 vs 6.44), and nIAUC(120) (80.14 vs 65.55) compared with the TIN group. nSDEP was significantly lower in the RPT group (7.20 × 10(-5) vs 15.35 × 10(-5)) compared with the TIN group. Analysis of the receiver-operating-characteristic curve showed nMSIVP to be the best single predictor of RPT, with very high (95%) sensitivity and high (78%) specificity. Thus, nonmodel-based semiquantitative indices derived from DCET1MRP that are relatively easy to derive and do not require a complex model-based approach may aid in differentiating RPT from TIN and can be used as robust noninvasive imaging biomarkers.

Response to Treatment Series: Part 2, Tumor Response Assessment—Using New and Conventional Criteria

Conventional anatomic imaging biomarkers, including World Health Organization (WHO) criteria and Response Evaluation Criteria in Solid Tumors (RECIST), although effective, have limitations. This article will discuss the conventional and newer morphologic imaging biomarkers for the assessment of tumor response to therapy. Applying established methods of assessing tumor response to therapy allows consistency in image interpretation and facilitates communication with oncologists. Because of the new methods of treatment, assessment of necrosis and volumetric information will need to be incorporated into size-based criteria.

La TEP-TDM à la 18F-Dopa aurait-elle un rôle dans le suivi postopératoire des patients atteints de carcinome médullaire de la thyroïde ? Résultats préliminaires de l’expérience strasbourgeoise et revue de la littérature

Aim Retrospective study to assess the value of fluorine-18 dihydroxyphenylalanine ( 18F-Dopa) positron emission tomography (PET)/computed tomography (CT) in the post-surgical follow-up of patients with history of medullary thyroid carcinoma (MTC) and biological suspicion of disease relapse. A review of the literature was also performed. Patients and methods Ten patients (23–71 years) with MTC previously treated by surgery were examined by at least one 18F-Dopa PET/CT. All patients presented with elevated serum calcitonin (130–9076 ng/l) and/or CEA (1.2–518 ng/ml) levels. 3D whole body PET/CT was performed 45 and 120 minutes after intravenous injection of 4 MBq/kg of 18F-Dopa. Scintigraphic images were visually interpreted. For quantitative analysis, maximum standardized uptake value (SUV max) per focus was employed. PET results were compared with histological findings and/or with the results of all other imaging procedures. Results Seven patients (70%) had a positive 18F-Dopa PET/CT. Twenty-five focal tracer accumulations were described. Histopathological confirmation of metastatic disease was obtained in four of the seven patients with pathologic 18F-Dopa PET/CT. No scintigraphic abnormalities were evidenced in the three other patients, whose conventional morphological imaging procedures were also negatives. Delayed PET/CT examinations didn’t increase sensitivity. No correlation between 18F-Dopa PET/CT results and both serum calcitonin and CEA levels was achieved. Conclusion Our results are in accordance with the existing literature, showing the potential role of 18F-Dopa PET/CT in the clinical management of patients with history of MTC and biological suspicion of relapse during post-surgical follow-up. Prospective studies including larger patient series are necessary to confirm the future place of 18F-Dopa PET/CT in follow-up of MTC.

The role of biomarkers in thoracic imaging

Thoracic imaging plays an essential role in understanding and diagnosing chest disease. It has traditionally relied on conventional anatomic and morphologic imaging, but as technology evolves, novel diagnostic strategies have the potential to improve accuracy. This includes incorporation of biomarkers, which are an objective measure of a biological or pathological process. Biomarkers can be used in multiple different scenarios, and may complement current imaging studies, particularly in establishing a diagnosis, determining prognosis or predicting response to therapy. However, it is important to develop and validate clinically relevant biomarkers. This is a complex, multidisciplinary subject that requires knowledge of the clinical problem, an understanding of the technology and pathology, and significant resources. Ultimately, integration of biomarkers into patient evaluation must be cost effective and improve outcomes. This article will describe the potential roles and limitations of biomarkers in thorac...

FDG-PET probe-guided surgery for recurrent retroperitoneal testicular tumor recurrences

Aim Tumor marker based recurrences of previously treated testicular cancer are generally detected with CT scan. They sometimes cannot be visualized with conventional morphologic imaging. FDG-PET has the ability to detect these recurrences. PET probe-guided surgery, may facilitate the extent of surgery and optimize the surgical resection. Methods Three patients with resectable 2nd or 3rd recurrent testicular cancer based on elevated tumor markers after previous various chemotherapy schedules and resections of residual retroperitoneal tumor masses were included in this study. A diagnostic FDG-PET was performed and a hotspot in previously operated area of the retroperitoneal space in all three patients was visualized. PET probe-guided surgery was performed using a high-energy gamma probe 3 h post-injection of 500 MBq FDG. Results All patients showed extended adhesions and scar tissue in the retroperitoneal area due to the previous surgeries. Pre-operative PET/CT scan showed a good correlation with intra-operative PET probe-guided detection of recurrent lesions. There was a high target to background ratio (TGB) of 5:1 during the procedure. In one patient, a 2 cm large lesion, which did not show on pre-operative FDG-PET scan, was detected with the PET probe. Histopathologic tissue evaluation demonstrated recurrent vital tumor in all PET probe positive lesions. Conclusions PET probe-guided surgery seems to be a promising tool to localize FDG-PET positive lesion in recurrent testicular cancer in hardly accessible surgical locations. PET probe-guided surgery might be a useful technique in surgical oncology for recurrent testicular cancer and has the potential to be applied in surgery of other malignant diseases.

Radionuclide and hybrid imaging of recurrent prostate cancer

Prostate cancer is one of the most common cancers in men, leading to substantial morbidity and mortality. After definitive therapy with surgery or radiation, many patients have biochemical relapse of disease--ie, an increase in their prostate-specific antigen level--which often precedes clinically apparent disease by months or even years. Therefore, imaging of the site and extent of tumour recurrence (local, regional, distant, or a combination) is of great interest. Conventional morphological imaging methods showed limited accuracy for assessment of recurrent prostate cancer; however, in recent years, functional and molecular imaging have offered the possibility of imaging molecular or cellular processes of individual tumours, often with more accuracy than morphological imaging. Hybrid imaging modalities (PET-CT, and single-photon emission CT [SPECT]-CT) have been introduced that combine functional and morphological data and allow whole-body imaging. Here, we review the contribution of radionuclide imaging and hybrid imaging for assessment of recurrent prostate cancer (local vs regional vs distant disease). We discuss available data on PET-CT and SPECT-CT, and provide an overview of experimental tracers and their preclinical and clinical development. Finally, we present a perspective on the potential of future hybrid magnetic resonance-PET imaging.

Treatment induced necrosis versus recurrent/progressing brain tumor: going beyond the boundaries of conventional morphologic imaging

Brain tumor patients undergo various combinations therapies, leading to very complex and confusing imaging appearances on follow up MR imaging and hence, differentiating recurrent or progressing tumors from treatment induced necrosis or effects has always been a challenge in neuro-oncologic imaging. This particular topic has become more relevant these days because of the advent of newer anti-angiogenic and anti-neoplastic chemotherapeutic agents as well as use of salvage radiation therapy. Various clinically available functional imaging modalities can provide additional physiologic and metabolic information about the tumors which could be useful in identifying viable tumor from treatment induced necrosis and hence, can guide treatment planning. In this review we will discuss various functional neuro-imaging modalities, their advantages and limitations and also their utility in treatment planning.

Imaging in clinical trials

Drug development continues to face challenges to successfully progress the most promising drug candidates through the stages of clinical trials. Given the increasing cost to develop a drug, methods are required to characterise early drug efficacy and safety. Imaging techniques are increasingly used in oncological clinical trials to provide evidence for decision making. With the application of conventional morphological imaging techniques and standardised response criteria based on tumour size measurements, imaging continues to be used to define key study end points. However, functional imaging techniques are likely to play an important role in the evaluation of novel therapeutics, although how these methods are to be optimally applied has yet to be clearly established. The specific challenges of standardising multi-centre imaging in the context of clinical trials are highlighted, including the processes for image acquisition, data analysis and radiological review.

Integrated PET/CT in Evaluating Sarcomatous Transformation in Osteochondromas

To study the role of PET-CT in evaluating sarcomatous transformation in osteochondromas. This was a retrospective analysis of a prospective data base of 12 patients from 2005 to 2007 with a clinical diagnosis of an osteocartilaginous lesion who were referred for a FDG PET-CT study to evaluate for possible malignant transformation. Imaging was performed on a GE Discovery ST PET-CT system after intravenous injection of 370 MBq (10 mCi) of F-18 FDG. Seven patients with histopathological evidence of a sarcomatous transformation to grade II chondrosarcoma showed moderate to high FDG uptake (SUV 3.3-6.9), whereas 1 patient with a dedifferentiated chondrosarcoma showed a focus of very intense uptake (SUV 11.4). Four patients with histopathological and/or clinical or follow-up diagnosis of a benign osteocartilaginous lesion showed low grade FDG uptake (SUV 0.8-1.3). FDG uptake was also noted in an asymptomatic osteochondroma which on histopathology revealed a grade II chondrosarcoma. Whole body FDG PET-CT is an important adjunct to conventional morphologic imaging in evaluating suspected malignant transformation in osteochondromas. Increased glucose metabolism can help diagnose sarcomatous transformation at the suspected sites as well as detect early malignant change at clinically unsuspected sites. Moreover, its ability to detect a focus of dedifferentiation can be useful for prognostication and to plan adjuvant treatment. A small cohort limits statistically sound conclusions to be drawn from this study, however further prospective trials based on these findings can help explore the potential application of FDG PET-CT in this clinical condition.

Contribution of diffusion-weighted MR imaging for predicting benignity of complex adnexal masses

The purpose of this study was to prospectively assess the contribution of diffusion-weighted MR imaging (DWI) for characterizing complex adnexal masses. Seventy-seven women (22-87 years old) with complex adnexal masses (30 benign and 47 malignant) underwent MR imaging including DWI before surgery. Conventional morphological MR imaging criteria were recorded in addition to b(1,000) signal intensity and apparent diffusion coefficient (ADC) measurements of cystic and solid components. Positive likelihood ratios (PLR) were calculated for predicting benignity and malignancy. The most significant criteria for predicting benignity were low b(1,000) signal intensity within the solid component (PLR = 10.9), low T2 signal intensity within the solid component (PLR = 5.7), absence of solid portion (PLR = 3.1), absence of ascites or peritoneal implants (PLR = 2.3) and absence of papillary projections (PLR = 2.3). ADC measurements did not contribute to differentiating benign from malignant adnexal masses. All masses that displayed simultaneously low signal intensity within the solid component on T2-weighted and on b(1,000) diffusion-weighted images were benign. Alternatively, the presence of a solid component with intermediate T2 signal and high b(1,000) signal intensity was associated with a PLR of 4.5 for a malignant adnexal tumour. DWI signal intensity is an accurate tool for predicting benignity of complex adnexal masses.

MP-14.02: Initial experience of functional imaging of upper urinary tract urotherial carcinoma by diffusion-weighted MRI

Different from conventional morphological imaging, diffusion-weighted (DW) MRI provides functional information, which has been widely used in the diagnosis of acute cerebral stroke. We reported initial experience of this imaging technique of upper urinary tract (UUT) urothelial carcinoma (UC).

The Value of Imaging Methods with Emphasis on PET/CT in Head and Neck Tumours: a Comparison between a Novel Diagnostic Regime Using 18F‐FDG PET and Conventional Techniques – Own Results and Literature Review

SummaryHead and neck cancers are rising in incidence. In the diagnosis of malignant head and neck cancer, conventional morphological imaging methods, i.e. ultrasonography, radiography, computerised tomography (CT) and magnetic resonance imaging (MR) play a routine role besides clinical investigation. Despite these diverse techniques, the primary tumour often cannot be found. Furthermore, for staging purposes as well as for the detection of tumour recurrence after chemotherapy and/or radiotherapy, morphological examination techniques such as CT and MR are of limited accuracy. Due to promising results in the literature, 18F‐fluorodeoxyglucose‐positron emission tomography has been playing an increasing role in the assessment of malignant head and neck cancer. The authors present a literature review as well as their own data in comparison to conventional imaging methods.

Clear-PEM: A dedicated pet camera for improved breast cancer detection

Positron emission mammography (PEM) can offer a non-invasive method for the diagnosis of breast cancer. Metabolic images from PEM using 18F-fluoro-deoxy-glucose, contain unique information not available from conventional morphologic imaging techniques like X-ray radiography. In this work, the concept of Clear-PEM, the system presently developed in the frame of the Crystal Clear Collaboration at CERN, is described. Clear-PEM will be a dedicated scanner, offering better perspectives in terms of position resolution and detection sensitivity.

Positron-emission tomography for head and neck cancer

Positron-emission tomography (PET) is a functional imaging technology that has the potential to improve the staging and detection of tumor compared to more conventional morphologic imaging techniques. It is a noninvasive technique that can expose molecular processes in cells and biological characteristics of tumors. The use of PET for staging and early detection of recurrent or residual disease may allow additional intervention with more aggressive treatments that could improve outcomes for individual patients. Optimal scanning is very dependent on the technique of image acquisition and available technology. The most promising technological development is combination CT PET scanners that will allow exact anatomical correlation with areas of increased tracer uptake. New tracers may allow quantification of cellular processes such as apoptosis or hypoxia as well as identification of tumors that may respond to certain targeted therapies. This may enable tailoring treatment to molecular characteristics and improved outcomes for patients. This review summarizes the available literature for PET in patients with head and neck cancer.

Diagnostic of breast cancer: what do clinicians expect from PEM?

Early detection of breast cancer is crucial for efficient and effective treatment. Functional breast imaging could improve imaging of such lesions because it provides a non-invasive method in the screening of women for the presence of the disease, as well as for staging disease and tracking its response to therapy. Dedicated breast PET imaging, called positron emission mammography (PEM), is a new technique to obtain images of the breast for detection of radiopharmaceutical-avid tumours. Metabolic images from PEM contain unique information not available from conventional morphologic imaging techniques and aid in establishing the diagnosis of breast cancer. Therefore, PEM might be used for staging, characterising indeterminate lesions, and finding occult lesions in those patients who are difficult to scan with mammography. PEM promises to achieve low-cost directed functional examination of breast abnormalities, with the potential for performing X-ray correlation and image-guided biopsy. However, at present, published data on the use of PEM in breast cancer are still too limited for establishing the role of this particular technique.

Nuclear medicine imaging for the assessment of primary and recurrent head and neck carcinoma using routinely available tracers.

This article reviews the literature on the use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) and thallium-201, technetium-99m sestamibi and technetium-99m tetrofosmin single-photon emission tomography (SPET) for the diagnosis and staging of primary and recurrent squamous cell carcinoma of the head and neck (SCCHN). A search of the MEDLINE and CancerLit databases covering articles entered between 1989 and February 2003 was performed. In the case of FDG PET, only full-ring PET studies that included comparison with conventional morphological imaging were considered. Due to the wide variation in methodology, a straightforward meta-analysis of FDG PET literature was impossible. Instead, indicative summary receiver-operating curves of FDG PET and morphological imaging techniques were generated and a paired comparison of the sensitivities and specificities of FDG PET and morphological imaging performed. Compared with conventional morphological imaging, FDG PET proved as sensitive and specific for the detection of primary SCCHN but more sensitive and specific for the detection of cervical lymph node involvement (CLNI) and recurrence of SCCHN. Additional studies addressing the role of FDG PET in screening for distant metastases and synchronous primary tumours are mandatory. Following negative conventional evaluations, FDG PET identifies occult primary tumours in 20-50% of patients presenting with CLNI. As regards the use of 201Tl, 99mTc-sestamibi and 99mTc-tetrofosmin, more studies are required to define whether these imaging agents could form part of the current diagnostic armamentarium in SCCHN patients. It is concluded that FDG PET either is superior to or offers added value when compared with conventional morphological imaging techniques for the purpose of diagnosis and staging of primary and recurrent SCCHN.

Positron Emission Tomography in Non-Hodgkin's Lymphoma (NHL): Relationship Between Tracer Uptake and Pathological Findings, Including Preliminary Experience in the Staging of Low-Grade NHL

Advances in imaging techniques have allowed more precise staging and better evaluation of the effect of new treatment modalities. The limitations of conventional morphologic imaging techniques are well known. Positron emission tomography (PET) using fluorine-18–labeled fluorodeoxyglucose is now routinely used for Initials staging and re-evaluation during or after treatment of Hodgkin's disease and aggressive non-Hodgkin's lymphoma (NHL), but not in low-grade NHL. In the first part of this review, the relationship between glucose metabolism as measured by PET, pathological findings including histological grade and proliferative activity, and prognosis are analyzed. In the second part, the potential role of PET in the staging and follow-up of low-grade NHL is discussed. Published data indicate that PET may contribute to the management of low-grade follicular NHL.

Clear-PEM, a dedicated PET camera for mammography

Preliminary results suggest that Positron Emission Mammography (PEM) can offer a noninvasive method for the diagnosis of breast cancer. Metabolic images from PEM contain unique information not available from conventional morphologic imaging techniques and aid in expeditiously establishing the diagnosis of cancer. A dedicated machine seems to offer better perspectives in terms of position resolution and sensitivity. This paper describes the concept of Clear-PEM, the system presently developed by the Crystal Clear Collaboration at CERN for an evaluation of this approach. This device is based on new crystals introduced by the Crystal Clear as well as on modern data acquisition techniques developed for the large experiments in high energy physics experiments.