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P Rigo

Publications and source records attributed to P Rigo.

At least 37 records · Page 2Linked to original sources
PubMed2000

Persistent tumor 18F-FDG uptake after a few cycles of polychemotherapy is predictive of treatment failure in non-Hodgkin's lymphoma.

BACKGROUND AND OBJECTIVE: Early recognition of the ineffectiveness of chemotherapy could result in lower cumulative drug toxicity and tumor burden at the start of salvage therapy, which might improve clinical outcome. Therefore, we studied the value of (18)F-FDG PET for early evaluation of response in patients with non-Hodgkin's lymphoma (NHL). DESIGN AND METHODS: We studied 28 patients by (18)F-FDG PET after a median of 3 cycles of polychemotherapy. The presence or absence of abnormal (18)F-FDG uptake was correlated to clinical outcome (median follow-up: 17.5 months, range 4-47 months). RESULTS: Five of 28 patients still had increased (18)F-FDG uptake in one or more sites previously shown to be involved by lymphoma at baseline evaluation. Only one of these five patients entered complete remission (CR), whereas among the 23 patients with negative (18)F-FDG PET studies, two died of toxicity during chemotherapy and all the others entered clinical CR (p<0.00001). All five patients with and 7/21 patients without residual abnormal (18)F-FDG uptake relapsed or reprogressed (positive predictive value for relapse: 100%, negative predictive value: 67%). By Kaplan-Meier analysis, progression-free survival (PFS) at 1 and 2 years was respectively 20+/-18% and 0% for (18)F-FDG PET positive patients and 81+/-9% and 62+/-12% for (18)F-FDG PET negative patients (p=0.0001). Overall survival (OS) at 1 and 2 years was respectively 20+/-18% and 0% for (18)F-FDG PET positive and 87+/-7% and 68+/-11% for (18)F-FDG PET negative patients (p<0.0001). INTERPRETATION AND CONCLUSIONS: Persistent tumoral (18)F-FDG uptake after a few cycles of polychemotherapy is predictive of CR, PFS and OS in NHL. Further studies are warranted to determine whether (18)F-FDG PET has a predictive value independent from conventional prognostic factors. However, the sensitivity of qualitative (18)F-FDG PET imaging in identifying patients with a poor outcome was insufficient. Earlier evaluation after only one cycle of chemotherapy and quantitative analysis might increase the sensitivity of 18F-FDG PET is predicting treatment failure.

Adult↗
PubMed2000

[How I explore ... value of isotopic techniques in the detection of sepsis in valvular prostheses].

Vascular graft infection is a rare but serious complication of vascular surgery. The diagnosis is frequently difficult. White blood cell imaging (111In or 99mTc-HMPAO) is an adequate technique for detecting vascular graft infection. This is a sensitive and specific method and has some advantages in the detection of perioperative or low grade infection in comparison to conventional imaging. The usefulness of other techniques like the 18FDG-PET scan is studied, but not yet evaluated. We compare the different methods actually used by illustrating three case reports of vascular graft infection for whom the diagnosis was formally made by isotopic imaging.

Aged↗
PubMed1999

Whole-body positron emission tomography using 18F-fluorodeoxyglucose for posttreatment evaluation in Hodgkin's disease and non-Hodgkin's lymphoma has higher diagnostic and prognostic value than classical computed tomography scan imaging.

A residual mass after treatment of lymphoma is a clinical challenge, because it may represent vital tumor as well as tissue fibrosis. Metabolic imaging by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) offers the advantage of functional tissue characterization that is largely independent of morphologic criteria. We compared 18F-FDG PET to computed tomography (CT) in the posttreatment evaluation of 54 patients with Hodgkin's disease (HD) or intermediate/high-grade non-Hodgkin's lymphoma (NHL). Residual masses on CT were observed in 13 of 19 patients with HD and 11 of 35 patients with NHL. Five of 24 patients with residual masses on CT versus 1 of 30 patients without residual masses presented a positive 18F-FDG PET study. Relapse occurred in all 6 patients (100%) with a positive 18F-FDG PET, 5 of 19 patients (26%) with residual masses on CT but negative 18F-FDG PET, and 3 of 29 patients (10%) with negative CT scan and 18F-FDG PET studies (P </=.0001). We observed a higher relapse and death rate in patients with residual masses at CT compared with patients without residual masses at CT (progression-free survival at 1 year: 62 +/- 10 v 88 +/- 7%, P =. 0045; overall survival at 1 year: 77 +/- 5 v 95 +/- 5%, P =.0038). A positive 18F-FDG PET study was even more consistently associated with poorer survival: compared with patients with a negative 18F-FDG PET study, the 1-year progression-free survival was 0% versus 86% +/- 5% (P <.0001) and the 1-year overall survival was 50% +/- 20% versus 92% +/- 4% (P <.0001). The detection of vital tumor by 18F-FDG PET after the end of treatment has a higher predictive value for relapse than classical CT scan imaging (positive predictive value: 100% v 42%). This could help identify patients requiring intensification immediately after completion of chemotherapy. However, 18F-FDG PET mainly predicts for early progression but cannot exclude the presence of minimal residual disease, possibly leading to a later relapse.

Adolescent↗
PubMed1999

Whole-body 18F-FDG PET for the evaluation of patients with Hodgkin's disease and non-Hodgkin's lymphoma.

Whole-body metabolic information provided by 18F-FDG PET could help in the evaluation of lymphoma patients at diagnosis and follow-up. We studied 60 patients, 42 at initial presentation and 18 for disease recurrence (23 aggressive non-Hodgkin's lymphoma, 21 low-grade non-Hodgkin's lymphoma and 16 Hodgkin's disease). All patients underwent a clinical examination, computed tomography (CT) and a non-attenuated PET scan within 1 week. The patients received 222-296 MBq (6-8 mCi) 18F-FDG intravenously and emission scans were recorded 45-90 min later. 18F-FDG PET detected more lymph nodes than the clinical examination or CT, but this rarely resulted in upstaging (two patients). The concordance between PET and CT for the evaluation of the spleen, liver and digestive tract was quite good. Discordance was noted in 12 patients for the evaluation of bone marrow infiltration, but confirmation by MRI or focal biopsy was not always obtained. We conclude that non-attenuated 18F-FDG PET is an easy and efficient whole-body method for the evaluation of patients with lymphomas. Compared with conventional techniques, however, it does not appear to offer much improvement for staging but provides a satisfactory base for follow-up.

Adolescent↗
PubMed1999

Value of FDG-PET in detecting residual or recurrent nonsmall cell lung cancer.

In order to evaluate the usefulness of 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) in the assessment of therapeutic effects, a study was performed before and after therapy in 126 patients with non-small cell lung cancer (NSCLC) codified stage I to stage IIIB. Treatment with an early curative result was given in 58 patients, whereas in 68 cases it was limited to palliation. During the treatment follow-up period (8-40 months), each patient was evaluated every 3 months by clinical examination and < or =6 months by imaging techniques (PET and computed tomography (CT)). A diagnosis of persistent or recurrent tumour was established by means of pathological analysis in 31 patients and by clinical evolution and subsequent imaging progression in 29 other patients. PET showed increased FDG uptake in all cases (n = 60) of persistent or recurrent tumour, whereas CT was nonspecific in 17 cases. Conversely, there were five false positive cases via PET imaging and three via CT. In detecting residual or recurrent NSCLC, PET had a sensitivity of 100% and specificity of 92%, whereas CT had a sensitivity and specificity of 71% and 95% respectively. In conclusion, 18-fluorodeoxyglucose positron emission tomography correctly identified response to therapy in 96% (121 of 126) of patients. Positron emission tomography appears to be more accurate (p = 0.05) than conventional imaging in distinguishing persistent or recurrent tumour from fibrotic scar in patients undergoing treatment for non-small cell lung cancer.

Adult↗
PubMed1999

[Clinical value of positron emission tomography in the detection and staging of recurrent colorectal cancer].

BACKGROUND: Positron emission tomography (PET) has been shown useful for the staging of patients with various carcinomas. METHODS: We have applied this technique to 54 cases of colorectal carcinoma and compared it to conventional imaging techniques. RESULTS: PET had moderately higher sensitivity and specificity than conventional techniques to detect individual lesion sites (75% vs 70.8% and 63% vs 21% respectively). It detected the same number of patients with recurrences (35/39) but overestimated disease less frequently (5 cases vs 12). PET favorably influenced therapeutic management in 17 patients, indicating different or additional surgery in 9 while avoiding surgery with curative intent or unnecessary surgery in 8. In 5 cases, erroneous information provided by PET could be corrected by conventional imaging techniques. CONCLUSION: We conclude that PET appears to provide complementary information useful for staging patients with colorectal carcinomas. It can significantly modify patients management. These data should be confirmed by a prospective study.

Adult↗
PubMed1999

[Role of positron emission tomography is the evaluation of digestive tract tumors].

Imaging and endoscopic techniques have taken an increasing part in the management of gastroenterological disorders. Among these techniques, FDG-PET imaging has emerged as a powerful tool in the management of several cancer diseases, including tumors of the digestive tract. In particular, the role of PET for diagnosing and staging recurrent colorectal cancers, and for differentiating mass forming pancreatitis from carcinoma is now well established. In this review, we will briefly discuss the place of PET imaging in the work-up of the tumors of the digestive tract.

Colorectal Neoplasms↗
PubMed1998

Fluorine-18 deoxyglucose positron emission tomography for the detection of bone metastases in patients with non-small cell lung cancer.

Despite advances in morphological imaging, some patients with lung cancer are found to have non resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using bone scintigraphy, which has a high sensitivity but a poor specificity. We have attempted to evaluate the utility of the fluorine-18 deoxyglucose positron emission tomography (FDG PET) for the detection of bone metastasis. One hundred and ten consecutive patients with histological diagnosis of non-small cell lung cancer (NSCLC) who underwent both FDG PET and bone scintigraphy were selected for this review. In this group, there were 43 patients with metastatic disease (stage IV). Among these, 21 (19% of total group) had one or several bone metastases confirmed by biopsy (n = 8) or radiographic techniques (n = 13). Radionuclide bone scanning correctly identified 54 out of 89 cases without osseous involvement and 19 out of 21 osseous involvements. On the other hand, FDG PET correctly identified the absence of osseous involvement in 87 out of 89 patients and the presence of bone metastasis in 19 out of 21 patients. Thus using PET there were two false-negative and two false-positive cases. PET and bone scanning had, respectively, an accuracy of 96% and 66% in the evaluation of osseous involvement in patients with NSCLC. In conclusion, our data suggest that whole-body FDG PET may be useful in detecting bone metastases in patients with known NSCLC.

Aged↗
PubMed1998

Clinical evaluation of whole-body 18F-fluorodeoxyglucose positron emission tomography in the detection of liver metastases.

BACKGROUND: Assessment of metastatic involvement of the liver remains a diagnostic challenge. The objective of this study was to evaluate the potential role of FDG PET in the detection of liver metastases. PATIENTS AND METHODS: Sixty-four patients with malignancy and possible liver involvement were included. Liver metastases were present in 31 cases, demonstrated by histopathological analysis in 15 cases and by follow-up in 16 cases. The negative cases were confirmed by pathology in four cases, peroperative ultrasonography in 12 cases, and follow-up in 17 cases. Whole-body FDG PET was compared to CT (n = 53) and US (n = 43). RESULTS: PET demonstrated a 97% sensitivity, an 88% specificity and a 92% accuracy, compared to 93%, 75% and 85%, respectively, for CT (P = NS). Concordant results were obtained in 44 of 64 patients (69%: 19 TP. 25 TN). PET provided new and accurate information in 15 of 64 patients (23.4%). PET demonstrated liver metastases in 11 patients in whom conventional methods yielded negative (two cases) or doubtful (nine cases) results. Four patients free of liver involvement were correctly staged with PET, while CT/US were equivocal. PET was erroneous in five of 64 cases (7.8%, four FP, one FN). CONCLUSIONS: FDG PET allows an accurate screening of liver involvement in patients with malignancy. Combined with CT, it provides additional diagnostic information that could directly affect the management of these patients.

Adult↗
PubMed1998

18FDG-PET for the assessment of primary head and neck tumors: clinical, computed tomography, and histopathological correlation in 38 patients.

OBJECTIVES: To evaluate the clinical usefulness of FDG-PET (fluoro-2-deoxy-glucose-positron emission tomography) in the detection of lymph node involvement and recurrences in patients with head and neck cancer. STUDY DESIGN: Retrospective review of 38 patients with biopsy-proven head and neck cancers who underwent clinical, computed tomography (CT), and FDG-PET examinations. Twenty-five patients were studied prior to therapy and 13 patients were evaluated for disease recurrence. METHODS: All patients were operated and clinical data, CT, and FDG-PET results were correlated with histopathological findings. RESULTS: All primary tumors in 25 patients were detected, with the exception of one small superficial localization of the epiglottis. Histopathological examination showed lymph node involvement in 10 patients; PET detected lymph node involvement in five. FDG-PET found one case of nodal disease not identified by clinical and CT examination. With so few cases, this could be anecdotal. Five false-negative results (microscopic lymph node involvement) and two false positives were noted. Twelve of 13 patients with recurrent disease were correctly identified with FDG-PET. FDG-PET was the only imaging technique to identify local recurrence in two patients and lymph node involvement in two others. One false-positive result occurred in a patient with a foreign body granuloma. CONCLUSIONS: FDG-PET is a useful diagnostic modality for the detection of recurrent tumors and, in selected cases, precise lymph node involvement. The best way to further investigate the utility of clinical FDG-PET is in the follow-up of treated patients.

Adult↗
PubMed1998

Malignant melanoma staging using whole-body positron emission tomography.

The correct staging of potentially metastatic melanoma is essential for an appropriate therapeutic attitude. Current methods include computed tomography, magnetic resonance imaging, ultrasonography and scintigraphy. Another tool is whole-body positron tomography using the radiopharmaceutical 2-fluorine-18-fluoro-2-deoxy-D-glucose as an emitter because it accumulates inside neoplasms, especially melanoma. We report two cases of malignant melanoma in which computed tomography and magnetic resonance imaging suggested visceral metastatic spread. In contrast, whole-body positron emission tomography indicated the absence of metastases, and this was confirmed by histological examination of the organs where metastases were suspected. Whole-body positron emission tomography appears to have high specificity and sensitivity for clinical melanoma staging.

Aged↗
PubMed1997

Cardiac risk assessment before vascular surgery: a prospective study comparing clinical evaluation, dobutamine stress echocardiography, and dobutamine Tc-99m sestamibi tomoscintigraphy.

Preoperative evaluation for cardiac risk assessment before peripheral vascular surgery remains controversial. Between January and June 1994, a prospective open study was carried out in 156 patients scheduled for elective vascular procedures (63 carotid endarterectomies, 34 abdominal aortic aneurysms, 29 aortoiliac and 30 infrainguinal reconstructions) to compare the ability of clinical data, dobutamine stress echocardiography, and dobutamine Tc-99m sestamibi tomoscintigraphy to predict postoperative cardiac events. Pharmacological stress testing consisted of incremental dobutamine infusion (+/-1 mg atropine to achieve 85% of age-predicted maximal heart rate, with continuous echocardiographic monitoring, and injection of Tc-99m sestamibi after dobutamine infusion). Dobutamine echocardiography was abnormal in 36 patients (worsening resting wall motion abnormality in 11; new induced wall motion abnormality in 25). Dobutamine Tc-99m sestamibi tomoscintigraphy revealed a reversible perfusion defect in 34 patients, indicating the presence of myocardial ischaemia. As a result, eight patients underwent myocardial revascularization (n = 5) or the proposed operation was cancelled (n = 3). In the remaining 142 vascular procedures, there were eight (5.6%) adverse cardiac events: three myocardial infarctions (two fatal), three prolonged myocardial ischaemia, one acute congestive heart failure and one sustained ventricular arrhythmia in the post operative period. Univariate analysis selected unstable angina (relative risk (RR) 11.6), previous congestive heart failure (RR 6.4), Detsky's score of > or = 15 (RR 3.0), positive dobutamine stress echocardiography (RR 3.7), and positive dobutamine tomoscintigraphy (RR 7.4) as significant predictors of postoperative cardiac events. In patients without clinical markers of coronary artery disease (n = 66), non-invasive cardiac testing did not predict cardiac complications (n = 2; one prolonged myocardial ischaemia; one infarction). In the subset of 76 patients with definite clinical or electrocardiographic evidence of ischaemic heart disease, dobutamine stress testing provided additional information, and optimized risk stratification: five of six patients who suffered a cardiac complication had a pathologic dobutamine stress test. Furthermore, a negative dobutamine stress test was characterized by a high negative predictive value (0.96 for echocardiography; 0.97 for tomoscintigraphy). The study further demonstrated that the cardiac response (ischaemic versus non-ischaemic) to dobutamine stress was concordantly classified by echocardiographic and tomoscintigraphic techniques in 96% of cases. It is concluded that complementary non-invasive cardiac stress testing by dobutamine is indicated only in patients with clinically apparent coronary artery disease.

Aged↗
PubMed1997

Evaluation of pleural diseases with FDG-PET imaging: preliminary report.

BACKGROUND: Positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) is an accurate method for differentiating benign from malignant disease. The use of FDG-PET for the aetiological diagnosis of pleural disease was investigated in 25 patients. METHODS: PET was performed on each subject before invasive procedures were used to determine the aetiological diagnosis. The PET data were analysed by visual interpretation of coronal, sagittal, and transverse slices. RESULTS: Sixteen patients were found to have malignant pleural disease and nine had benign disease. All patients with histologically confirmed malignant disease showed FDG uptake within the pleural thickening which was intense in 14 cases and moderate in two. PET imaging showed the absence of FDG uptake and correctly categorised seven non-malignant lesions. Two patients with infectious pleural diseases showed a localised and moderate FDG uptake. CONCLUSION: Our preliminary results suggest that FDG-PET could be an effective tool for differentiating between benign and malignant pleural diseases.

Adult↗
PubMed1997

Whole-body 18FDG positron emission tomography in the staging of non-small cell lung cancer.

Despite advances in morphological imaging, some patients with lung cancer are found to have nonresectable disease at surgery or die of recurrence within yr of surgery. We performed a prospective study in 109 patients to compare the accuracy of whole-body positron emission tomography (PET) using fluorine-18 deoxyglucose (18FDG) and conventional imaging (CI) methods for the staging of non-small cell lung cancer (NSCLC). When CI or PET study suggested metastatic disease, confirmation was obtained by biopsy or follow-up information. As compared to CI, 18FDG-PET correctly changed the N stage in 22 patients (33%) and the M stage in 15 patients (14%). For the detection of distant metastases, PET study showed five false-positive sites and no false-negative cases. Currently, the accuracy of PET in the detection of M stage is 96%. Our study shows that visual interpretation of whole-body fluorine-18 deoxyglucose-positron emission tomography images can improve the diagnostic accuracy in the staging of non-small cell lung cancer. Further experience is needed to establish if metabolic imaging would be a cost-effective tool in the future management of lung cancer.

Carcinoma, Non-Small-Cell Lung↗
PubMed1997

[Positron emission tomography using 18F-fluorodeoxyglucose in oncology].

The use of 18FDG highlights biochemical disturbations present in cancerous tissues, in particular the accelerated glycolysis related to increased glucose transporters and to the increased activity of the enzymes of glycolysis. The recent availability of whole-body PET tomographs has opened the way to a variety of oncological applications. The usefulness of 18FDG-PET at various stages of diagnosis, staging and therapy follow-up has now been demonstrated. We demonstrate some of these indications, in particular in lung cancers, lymphomas and colorectal carcinomas.

Female↗
PubMed1996

Quantitative evaluation of myocardial single-photon emission tomographic imaging: application to the measurement of perfusion defect size and severity.

A new method is described for precise quantitative analysis of the relative three-dimensional distribution of myocardial tracers. The system uses a 360 degrees elliptical sampling of radial slices to create activity profiles. These are then positioned onto a common centre at the same angular coordinates as the corresponding radial slice reconstruction planes to generate a two-dimensional polar summary display. Abnormal distribution is then identified by automatic comparison of the patient polar map with the threshold of a normal database defined on a pixel by pixel basis as the normal mean -2.5 SD. Our stress and rest databases currently comprise 34 and 24 studies for sestamibi and tetrofosmin respectively. The present method differs from currently available software in two major respects. First, radial slices are used rather than short-axis slices to minimize operator intervention and to allow quantitative evaluation of the left ventricle volume independent of the heart size and without truncation, in particular near the apex and at the base. This sampling scheme also results in a more homogeneous and sampling-independent partial volume effect. Secondly, quantitative analysis is improved by calculating perfusion defect severity, extent and size in a precise manner. Severity is evaluated relative to a standardized background measurement and to the mean normal value rather than to the threshold value. This parameter was underestimated up to a defect extent of 32 cm2 in our phantom studies. Calculation of defect extent takes into account the surface distortion resulting from planar projection by using pixel by pixel weighted factors but it is otherwise overestimated as a result of the limited resolution of the imaging system. Integrating defect severity and extent, our hypoperfusion index appeared to accurately estimate the true defect size in our phantom model (r=0.993). The reproducibility of analysis was 6.24% in phantom studies and 3.10% in patient studies including repeated acquisitions. Applied to a well-documented population of 80 patients, this method resulted in an 86% sensitivity and a 78% specificity for overall coronary artery disease detection with reference to the angiographic data.

Coronary Disease↗
PubMed1996

Oncological applications of positron emission tomography with fluorine-18 fluorodeoxyglucose.

Positron emission tomography (PET) is now primarily used in oncological indication owing to the successful application of fluorine-18 fluorodeoxyglucose (FDG) in an increasing number of clinical indications at different stages of diagnosis, and for staging and follow-up. This review first considers the biological characteristics of FDG and then discusses methodological considerations regarding its use. Clinical indications are considered, and the results achieved in respect of various organs and tumour types are reviewed in depth. The review concludes with a brief consideration of the ways in which clinical PET might be improved.

Deoxyglucose↗