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P Rigo

Publications and source records attributed to P Rigo.

At least 19 recordsLinked to original sources
PubMed2001

Whole-body positron emission tomography using 18F-fluorodeoxyglucose compared to standard procedures for staging patients with Hodgkin's disease.

BACKGROUND AND OBJECTIVES: Accurate staging is essential in order to determine appropriate treatment in Hodgkin's disease (HD). (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) offers the advantage of metabolic imaging that is largely independent of morphologic criteria. In the present study we evaluated the role of (18)F-FDG PET compared to routine procedures for the staging of patients with HD. DESIGN AND METHODS: Thirty-three patients with HD underwent standard staging procedures (clinical examination, laboratory screening, chest X-ray, computed tomography (CT) of the chest and abdomen and bilateral bone marrow biopsies) and a whole-body (18)F-FDG PET study. In clinical examination, an isolated lymph node > 1 cm or multiple lymph nodes > or = 1 cm in size were considered abnormal. Positive findings at both clinical examination or CT and (18)F-FDG PET were regarded as actual locations of disease. Negative findings with both methods were regarded as true negative (no involvement by HD). In cases of discrepancy, response to treatment and follow-up data were used to assess the overall accuracy of the patient's original evaluation. RESULTS: Completely concordant results in lymph node staging were observed in 20 patients. The two staging procedures indicated complementary information in 1 patient. Conventional staging indicated more pathologic lymph node areas in 6 patients (at least 1 false positive). (18)F-FDG PET showed more sites in 6 patients. The sensitivity of (18)F-FDG PET in detecting all known pathologic lymph nodes was 83% for peripheral lymph nodes, 91% for thoracic lymph nodes and 75% for abdominal and pelvic lymph nodes. Conventional staging procedures and (18)F-FDG PET indicated the same tumor stage in 26 patients. Based on (18)F-FDG PET, downstaging was suggested in 4 patients, including a biopsy-proven case. However in 1 of these cases this was incorrect. (18)F-FDG PET suggested upstaging in 3 patients. Based on conventional staging or (18)F-FDG PET the same treatment strategy was defined in 32 patients. In one patient (18)F-FDG PET downstaged disease extension (stage IIIA-->IIA) that would have suggested radiotherapy as a possible treatment option. INTERPRETATION AND CONCLUSIONS: (18)F-FDG PET provides an easy and efficient whole-body method for the evaluation of patients with HD. (18)F-FDG PET never missed tumor masses >1 cm. (18)F-FDG PET detected additional sites of disease not seen by conventional procedures and identified absence of disease in some sites suspected to be involved. However, in our patients this did not translate into changes in treatment strategy.

Adolescent↗
PubMed2000

Automatic quantification of defect size using normal templates: a comparative clinical study of three commercially available algorithms.

Infarct size assessed by myocardial single-photon emission tomography (SPET) imaging is an important prognostic parameter after myocardial infarction (MI). We compared three commercially available automatic quantification algorithms that make use of normal templates for the evaluation of infarct extent and severity in a large population of patients with remote MI. We studied 100 consecutive patients (80 men, mean age 63 +/- 11 years, mean LVEF 47% +/- 15%) with a remote MI who underwent resting technetium-99m tetrofosmin gated SPET study for infarct extent and severity quantification. The quantification algorithms used for comparison were a short-axis algorithm (Cedars-Emory quantitative analysis software, CEqual), a vertical long-axis algorithm (VLAX) and a three-dimensional fitting algorithm (Perfit). Semiquantitative visual infarct extent and severity assessment using a 20-segment model with a 5-point score and the relation of infarct extent and severity with rest LVEF determined by quantitative gated SPET (QGS) were used as standards to compare the different algorithms. Mean infarct extent was similar for visual analysis (30% +/- 21%) and the VLAX algorithm (25% +/- 17%), but CEqual (15% +/- 11%) and Perfit (5% +/- 6%) mean infarct extents were significantly lower compared with visual analysis and the VLAX algorithm. Moreover, infarct extent determined by Perfit was significantly lower than infarct extent determined by CEqual. Correlations between automatic and visual infarct extent and severity evaluations were moderate (r = 0.47, P < 0.0001 to r = 0.62, P < 0.0001) but comparable for all three algorithms. Correlations between LVEF and visual evaluation of infarct extent (r = -0.80, P < 0.0001) and severity (r = -0.82, P < 0.0001) were good but correlations were significantly lower for all three algorithms (r = -0.48, P < 0.0001 to r = -0.65, P < 0.0001). Systematically lower correlations were found in non-anterior infarctions (n = 69) and obese patients (BMI > or = 30 kg/m2, n = 32) compared with anterior infarctions and non-obese patients for all three algorithms. In this large series of post-MI patients, results of infarct extent and severity determination by automatic quantification algorithms that make use of normal templates were not interchangeable and correlated only moderately with semiquantitative visual analysis and LVEF.

Adult↗
PubMed2000

An appraisal of 18-fluorodeoxyglucose positron emission tomography for melanoma staging.

BACKGROUND: Positron emission tomography (PET scan) using fluorodeoxyglucose (FDG) is increasingly recognized as a reliable diagnostic method to detect metastases of malignant melanoma (MM). OBJECTIVE: To compare the diagnostic performance of 18-FDG PET scan to that of conventional imaging. METHODS: A total of 28 assessments were conducted in 24 patients at risk of metastatic MM. RESULTS: The diagnostic accuracy was over 80% and similar for PET scan and conventional imaging. CONCLUSION: Both the specificity and sensitivity of PET scan are high although not perfect. Confrontation of data with anatomical location and clinicopathological findings remains mandatory.

Humans↗
PubMed2000

[18FDG-PET imaging of pancreatic adenocarcinoma].

FDG-PET imaging non invasively studies the glucose metabolism which is usually increased in malignant lesions. We evaluated the clinical performance of PET for detecting pancreatic cancer and its recurrence. In our series of 24 studies, PET appears to complement other imaging modalities. As compared to CT, in particular, it demonstrated fewer false positive results in the pancreas and it was also more sensitive. Moreover, whole-body FDG-PET allows for the entire staging of the disease.

Adenocarcinoma↗
PubMed2000

[Diagnosis of primary hyperparathyroidism: role of scintigraphy].

We report a case of hyperparathyroidism whose diagnosis was suspected by a clinical history and confirmed by routine laboratory tests. Scintigraphy has permitted to localize a focalized lesion corresponding to an adenoma endocrinopathy. The new developments of this imaging technique will be discussed further. Some aspects of physiopathology will be briefly considered and a therapeutic algorithm will be proposed.

Adenoma↗
PubMed2000

[Contribution of positron emission tomography for the management of lung cancer].

18 FDG- PET is an imagining technique based on metabolic criteria rather than morphological criteria. (18) FDG- PET can demonstrate accelerated glycosis in cancer tissue related to increased transporter and glycolytic enzyme activity. Whole body PET is currently under validation in a growing number of indications during diagnostic and therapeutic assessment phases of cancer treatment. In the field of pulmonary oncology, (18) FDG- PET has already demonstrated its performance capacity to: 1) discriminate the malignant nature of a solitary pulmonary nodule, 2) improve sensitivity over CT for mediastinal assessment in small-cell lung cancer, 3) acquire whole body imaging to search for distant metastasis in patients with small-cell lung cancer; PET is particularly useful for evaluation of an adrenal mass, 4) complement CT imaging to better dissociate tumor residue or recurrence from post-therapeutic sequelae in small-cell lung cancer. Information provided by (18) FDG- PET is thus clinically relevant as it allows better dissociation of a benign process from a malignant process and better precision of small-cell lung cancer extension without necessitating systematic invasive exploration.

Bronchial Neoplasms↗
PubMed2000

[How I investigate ... a broncho-pulmonary cancer by metabolic imaging (PET-18-FDG)].

Continuing advances in PET imaging have resulted in an improved ability to evaluate thoracic malignancies. Published reports demonstrate that PET provides accurate noninvasive detection of malignancy that is useful in the characterization of a pulmonary solitary nodule and in the mediastinal or extrathoracic staging of known lung cancer. Preliminary studies suggest that PET may also be able to assess the therapeutic response after surgery or radiation therapy.

Diagnosis, Differential↗
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↗