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C Landoni

Publications and source records attributed to C Landoni.

At least 19 recordsLinked to original sources
PubMed2005

Feasibility of [18F]FDG-PET and coregistered CT on clinical target volume definition of advanced non-small cell lung cancer.

AIM: To prospectively evaluate the impact of coregistered positron emission tomography (PET) and computed tomography (CT) in 3D conformal radiotherapy (3D-CRT) planning in patients with non-small lung cancer (NSCLC). METHODS: Twenty-one patients (median age: 57 years; range: 42-80 years) referred to 3D-CRT for NSCLC were recruited. Positron emission tomography with 18F-fluorodeoxyglucose ([18F]FDG-PET) and conventional CT images were coregistered (PET/CT images) using a commercial software package based on surface matching technique. Neoplastic areas were contoured on [18F]FDG-PET images with the aid of the correspondent CT image by a nuclear medicine physician. CT images and their relative PET contours were then transferred to treatment planning system. A radiation oncologist firstly contoured clinical target volumes (CTV) on CT scan alone (CTV-CT), and then on coregistered PET/CT images (CTV-PET/CT). CTV-CT and CTV-PET/CT were compared for each patient; a difference higher than 25% was considered of clinical relevance. RESULTS: Three patients were shifted to palliative radiotherapy for metastatic disease or very large tumor size, showed by [18F]FDG-PET. Of the remaining 18 patients a CTV change, after inclusion of PET/CT data, was observed in 10/18 cases (55%): larger in 7/18 (range 33-279%) and smaller in 3/18 patients (range 26-34%), mainly due to inclusion or exclusion of lymph-nodal disease and to better definition of tumor extent. CTV changes smaller than 25% occurred in the remaining 8/18 patients. CONCLUSIONS: [18F]FDG-PET and CT images co-registration in radiotherapy treatment planning led to a change in CTV definition in the majority of our patients, which may significantly modify management and radiation treatment modality in these patients.

Adult↗
PubMed2005

Automatic registration of PET and CT studies for clinical use in thoracic and abdominal conformal radiotherapy.

AIM: Implementation and validation of an automatic registration method based on mutual information (MI) for the integration of thoracic and abdominal positron emission tomography (PET)/computed tomography (CT) studies, with the purpose to facilitate in a clinical context the inclusion of PET metabolic information in conformal radiotherapy (RT). METHODS: Registration was obtained by modeling a rigid spatial transformation between CT and PET transmission studies. The registration method was based on Normalized Mutual Information (NMI), by iteratively transforming the PET volume, until its optimal alignment to the CT study is achieved, in correspondence of the maximum of NMI. To avoid entrapment in local maxima and to improve convergence speed we introduced a multiresolution scheme. Accuracy of the proposed approach was investigated in experimental data, relative to phantom and patient studies, acquired in conditions similar to clinical situations. RESULTS: In phantom studies the mean error in the 3D space is 3.6 mm (range 3-4 mm) in thoracic region and 3.2 mm (range 2.9-3.7 mm) in abdominal region, considerably less than PET spatial resolution. In patient studies the spatial mean error increases with respect to phantom studies (5.4 mm and 5.2 mm for thorax and abdomen, respectively) but remains comparable to the PET spatial resolution. The accuracy of spatial realignment was thus found adequate for the registration of PET/CT registration, if good patient repositioning was adopted. CONCLUSIONS: The proposed registration method, based on MI, was validated for the integration of PET/CT studies of patients candidate for thoracic and abdominal conformal RT. The method is automatic and provided with a user interface, thus suitable for clinical use.

Abdominal Neoplasms↗
PubMed2004

Multi-modal medical image integration to optimize radiotherapy planning in lung cancer treatment.

This work presents a method for CT and PET image registration, and multi-modal analysis, to optimize radiotherapy planning in lung cancer treatment. The method relies on an image registration technique based on fiducial external markers to realign, spatially, PET images with the CT spatial reference system. The method was set up for clinical use in radiotherapy, allowing minimal modifications to be introduced in the management of patients undergoing radiation treatment. The accuracy of the registration technique was evaluated on patient studies in terms of Target Registration Error and was found to be less than 6.40 mm. The method was applied in the treatment planning of five patients affected by non-small-cell lung cancer, revealing the usefulness of PET/CT integration in delineating the extension of both the tumor mass and the tissues involved in the neoplastic process. Moreover, the functional information provided by PET often led to alterations in the treatment planning, changing the size and/or direction of radiation portals. The proposed method for PET/CT integration has been confirmed as being useful for optimizing radiotherapy planning in lung cancer treatment.

Algorithms↗
PubMed2004

PET/CT in diagnostic oncology.

In the last years positron emission tomography (PET) with 18F-fluorodeoxyglucose ([18F]FDG) has become an established technique for the staging and follow-up of a wide variety of neoplasms. As PET imaging is based on the physiological mediated distribution of the administered tracer, rather than on anatomic and structural characteristics of tissue, the addition of CT imaging to PET improves the interpretation of PET images. Recently, integrated PET/CT scanners have been developed that can produce directly functional PET and anatomical CT data 1 session, without moving the patient and with minimal delay between the reconstruction and fusion of the 2 image data sets. In addition, CT images are also being used for attenuation correction in the reconstruction process of the PET emission data. A brief review of the most relevant technical characteristics of 3 PET/CT systems, which represent the state of the art of this technology, are described. Furthermore an overview of PET/CT acquisition protocols and clinical applications of PET/CT in oncology are described. Overall, advantages of PET/CT over PET that may influence the clinical routine, have been identified as a) the shorter image acquisition time with benefit on patients throughput and on patient compliance, b) the better accuracy in anatomically localizing focal areas of abnormal tracer uptake and defining tumor extent and c) the possibility to stage a disease in 1 single step.

Fluorodeoxyglucose F18↗
PubMed2003

Fluorodeoxyglucose positron emission tomography improves preoperative staging of resectable lung metastasis.

OBJECTIVE: F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is now a procedure of proven clinical value in the staging of primary lung cancer. This study evaluated the role of PET in the preoperative assessment of resectable lung metastases. METHODS: Eighty-six patients with previously treated malignancy and proven or suspected lung metastases, deemed resectable at computed tomography scan, were investigated with 89 preoperative PET procedures. Primary tumor sites were: gastrointestinal in 32 cases, sarcoma in 13, urologic in 14, breast in 8, head and neck in 7, gynecologic in 5, thymus in 5, other in 5. Seventy lung resections were performed in 68 patients of whom only 54 proved to be lung metastasis, 7 were primary lung tumors, and 9 were benign lesions. RESULTS: In 19 cases (21%) lung surgery was excluded on the basis of PET scan results due to extrapulmonary metastases (11 cases), primary site recurrence (2), mediastinal adenopathy (2), or benign disease (4). All mediastinal node metastases (7 cases) were detected by PET with a sensitivity, accuracy, and negative predictive value for mediastinal staging of 100%, 96%, and 100%, respectively, versus 71%, 92%, and 95% of the computed tomography scan. In the group of patients who underwent lung resection, PET sensitivity for detection of lung metastasis was 87%. CONCLUSIONS: PET scan proved to be a valuable staging procedure in patients with clinically resectable lung metastasis and changed the therapeutic management in a high proportion of cases.

Female↗
PubMed2003

Value of [11C]choline-positron emission tomography for re-staging prostate cancer: a comparison with [18F]fluorodeoxyglucose-positron emission tomography.

PURPOSE: We compared [11C]choline-positron emission tomography (PET) with [18F]fluorodeoxyglucose-PET for re-staging prostate cancer in a group of 100 patients. MATERIALS AND METHODS: A total of 100 consecutive patients referred for whole body [18F]fluorodeoxyglucose-PET for clinical prostate re-staging after radical treatment for prostate cancer were retrospectively included in the study. Mean prostate specific antigen (PSA) was 6.57 ng./ml. In all cases [11C]choline-PET was also performed. PET studies were done with a multiring device 5 minutes after intravenous injection of approximately 370 MBq. [11C]choline and 60 minutes after injection of approximately 370 MBq. [18F]fluorodeoxyglucose. PET findings were compared with those obtained with different conventional imaging and with PSA assessed at the time of PET and 1 year later. RESULTS: Areas of abnormal focal increases were noted in 47% of patients on [11C]choline-PET and in 27% on [18F]fluorodeoxyglucose-PET. Of the 100 patients 49 had positive conventional imaging findings. All except 14 [11C]choline-PET findings were concordant with conventional imaging, including 6 negative and 8 positive conventional imaging results. All except 1 [11C]choline-PET negative cases also had negative conventional imaging after 1 year. PSA at 1 year remained stable or decreased in 80% and 62% of [11C]choline-PET negative and positive cases, respectively. CONCLUSIONS: [11C]choline-PET seems to be useful for re-staging prostatectomy cases with increasing serum PSA levels. It is superior to [18F]fluorodeoxyglucose-PET and complementary to conventional imaging but with the advantage of staging disease at a single step.

Aged↗
PubMed2003

Advanced ovarian carcinoma: usefulness of [(18)F]FDG-PET in combination with CT for lesion detection after primary treatment.

AIM: To determine the additional value of [(18)F]FDG-PET in combination with computed tomography (CT) over CT used alone, for evaluating ovarian cancer patients after primary treatment. METHODS: Twenty-five women (mean age: 53.6 years) had primary debulking surgery followed by chemotherapy for histologically proven ovarian carcinoma. At initial diagnosis, the tumor types were papillary serous adenocarcinoma (n=20), endometroid carcinoma (n=3), mixed mullerian tumor (n=1), and granulosa cell tumor (n=1). All patients underwent [(18)F]FDG-PET and contrast enhanced CT examinations, within 30 days of the completion of chemotherapic treatment. [(18)F]FDG-PET images were interpreted with the knowledge of CT findings (PET+CT); conversely, CT images were evaluated with no knowledge of the [(18)F]FDG-PET results. Within 7 day of imaging studies, 2(nd)-look laparoscopy (n=7) or laparotomy (n=18) was performed for histological confirmation. In all cases, imaging findings were then correlated with results of histopathologic examination. RESULTS: Of the 23 neoplastic viable lesions, all histologically confirmed, 16 could be detected by CT alone and 19 by PET+CT. An inflammatory lymph-node was misdiagnosed as viable tumor with both PET+CT and CT alone; an area of scar tissue in the presacral region was also misinterpreted as malignant tissue with CT alone. Overall lesion-based sensitivity, specificity and accuracy in assessing focal areas of residual tumor were as follows: 69.56%, 83.33%, 74.28% for CT, and 82.60%, 91.67%, 85.71% for PET+CT. The negative predictive value of PET+CT was markedly higher (73.33%), compared to that of CT alone (58.82%). CONCLUSION: PET used in combination with CT allows to accurately assess tumor response. A major advantage of PET+CT over CT alone is in excluding the presence of residual viable lesions after treatment.

Adult↗
PubMed2003

Evaluation of the clinical performances of a large NaI(Tl) crystal 3D PET scanner.

AIM: This study was aimed at assessing the clinical performances of a NaI(Tl) crystal 3D PET scanner, C-PET (ADAC-UGM), using a multi-ring 2D BGO PET scanner (multi-ring PET), as a reference. METHODS: Thirty-seven oncological patients were studied in sequence with multi-ring PET and C-PET, within 30 days of a CT study. In order to assess the behaviour of C-PET in relation to acquisition count rate, patients were divided into 3 groups according to the count rate at the time of the C-PET scan acquisition. Group A (n=21): 3000-5000 kcounts/sec (recommended count rate range); Group B (n=8): <3000 Kcounts/sec and Group C (n=8): >5000 Kcounts/sec. RESULTS: The number of lesions detected by multi-ring PET and C-PET, classified according to size, was compared. For Group A and Group B there was a good agreement between C-PET and multi-ring PET in terms of lesion detectability (relative sensitivity: 99.9% and 96.0%, respectively), while for Group C the relative sensitivity of C-PET was 61.9%. CONCLUSION: Optimal performances of the C-PET scanner can thus be obtained at a count rate within or below the recommended range. Despite a lower lesion/background contrast resulting from a high scatter and random noise, the sensitivity of C-PET in detecting hypermetabolic lesions is comparable to that of multi-ring PET. These findings are discussed in relation to the physical performance of the two scanners and particularly in relation to the 3D vs 2D acquisition modality.

Adult↗
PubMed2002

Fluoro-deoxi-glucose uptake and angiogenesis are independent biological features in lung metastases.

Neoangiogenesis and enhanced glucose metabolism in neoplasms are likely to be activated by the same biochemical stimulus; hypoxia. A correlation between these two parameters has been postulated. The objective of this study was to evaluate the relationship between Fluoro-desoxi-glucose uptake at positron emission tomography scan and angiogenesis in lung metastasis. Fluoro-desoxi-glucose activity, expressed as a standard uptake value, and microvessel intratumoural density, were retrospectively calculated in a series of 43 lung metastasis resected in 19 patients. Primary sites were colorectal cancer in 16 metastases, sarcoma in eight, gynaecological in four and other sites in 15. The correlation between the two parameters was tested by logistic regression and multivariate analysis. Positron emission tomography scan was positive in 17 patients (sensitivity 89%). No correlation was observed between standard uptake value and microvessel intratumoural density in this series of lung metastasis. Positron emission tomography negative and positive nodules presented comparable value of microvessel intratumoural density (12.9 vs 11.3). Standard uptake value was significantly correlated with nodules size and was higher in colon cancer metastasis than in sarcoma ones. Microvessel intratumoural density was independent from nodule size but significantly higher in sarcoma than in colon cancer metastasis. The lack of correlation was confirmed by multivariate analysis after adjustment for tumour type and nodules size. The present study demonstrated that positron emission tomography scan is positive in a high proportion of patients regardless of microvessel density. Glucose uptake and angiogenesis appear to be independent biological features in lung metastasis. This observation may have implications for future antiangiogenic therapies.

Adult↗
PubMed2000

[Rapid increase of the use of PET in cancer investigation--but Sweden lags behind].

Glucose consumption in tissue can be measured using positron emission tomography (PET) and 18F-deoxyglucose (18FDG). Malignant tumors rely largely on anaerobic glycolysis and show very rapid glucose consumption, and can therefore be imaged using PET and 18FDG. PET has been shown to be useful in the evaluation of patients with e.g. lung cancer, colo-rectal cancer, malignant melanoma and malignant lymphoma, in terms of both diagnostic accuracy and cost-effectiveness. The clinical use of PET for workup of cancer patients is increasing rapidly in North America as well as in the European Union, but Sweden is lagging behind.

Fluorine Radioisotopes↗
PubMed2000

[Rapid increase of the use of PET in cancer investigation--but Sweden lags behind].

Glucose consumption in tissue can be measured using positron emission tomography (PET) and 18F-deoxyglucose (18FDG). Malignant tumors rely largely on anaerobic glycolysis and show very rapid glucose consumption, and can therefore be imaged using PET and 18FDG. PET has been shown to be useful in the evaluation of patients with e.g. lung cancer, colo-rectal cancer, malignant melanoma and malignant lymphoma, in terms of both diagnostic accuracy and cost-effectiveness. The clinical use of PET for workup of cancer patients is increasing rapidly in North America as well as in the European Union, but Sweden is lagging behind.

Deoxyglucose↗
PubMed2000

18-FDG positron emission tomography in the evaluation of malignant pleural diseases - a pilot study.

OBJECTIVE: The diagnostic approach to pleural diseases may be difficult. The CT scan, which is the current diagnostic technique, has limited accuracy both in the differentiation between benign and malignant pleural diseases and in the diagnosis of primary and metastatic pleural neoplasms. Invasive procedures, such as thoracoscopy, are therefore frequently required to complete the diagnostic approach. The increasing incidence of malignant pleural mesothelioma has led to the development of new treatment strategies, which still need to be fully validated. There is, therefore, a need for new diagnostic techniques that can lead to a definite diagnosis and a satisfactory evaluation of the response to treatment. Encouraging results have been reported with the F-18-labeled analogue of 2-deoxyglucose (18-FDG) positron emission tomography (PET) in the evaluation of chest tumors such as lung cancer. The aim of this study was to evaluate the role of 18-FDG PET in the diagnostic assessment of pleural diseases. METHODS: Patients with CT scan evidence of pleural thickening, or fluid, entered a study to evaluate the accuracy of 18-FDG PET in diagnosing pleural diseases. Image analysis was performed both with visual interpretation and using a semiquantitative method, standardized uptake values (SUV), on coronal, sagittal and axial reconstructions. The results of PET imaging were compared to histological data. PET was also performed before and after treatment in patients who underwent chemotherapy to evaluate the accuracy of this technique in the assessment of the response. RESULTS: Fourteen patients entered the study. Histology demonstrated a malignant pleural disease in 13 patients; malignant pleural mesothelioma in ten patients, adenocarcinoma in two and liposarcoma in one. Benign pleural disease was diagnosed in the remaining patient. PET assessment demonstrated significant 18-FDG uptake in 12 of the 13 patients with a malignant disease, also revealing distant metastases in two of them. A false-negative result was observed in a patient with an epithelial mesothelioma. The overall accuracy was 92%. A benign pleural disease without significant uptake was correctly diagnosed in another patient. An aspecific uptake was observed in two patients who had undergone pleurectomy and intrapleural chemotherapy. A decreased tracer uptake was observed after chemotherapy in four patients. CONCLUSIONS: These preliminary results demonstrate that 18-FDG PET may have a great potential, both in the differential diagnosis of pleural diseases and in the evaluation of the response to treatment. At present, however, histological thoracoscopic diagnosis remains mandatory before planning treatment. Further studies in larger groups of patients are needed to draw definite conclusions on the role of PET in the assessment of pleural diseases.

Adenocarcinoma↗
PubMed1999

An automatic classification technique for attenuation correction in positron emission tomography.

In this paper a clustering technique is proposed for attenuation correction (AC) in positron emission tomography (PET). The method is unsupervised and adaptive with respect to counting statistics in the transmission (TR) images. The technique allows the classification of pre- or post-injection TR images into main tissue components in terms of attenuation coefficients. The classified TR images are then forward projected to generate new TR sinograms to be used for AC in the reconstruction of the corresponding emission (EM) data. The technique has been tested on phantoms and clinical data of brain, heart and whole-body PET studies. The method allows: (a) reduction of noise propagation from TR into EM images, (b) reduction of TR scanning to a few minutes (3 min) with maintenance of the quantitative accuracy (within 6%) of longer acquisition scans (15-20 min), (c) reduction of the radiation dose to the patient, (d) performance of quantitative whole-body studies.

Brain↗