[Advantages of PET-CT in the work-up of cervical cancer]. / Intérêts de la TEP-TDM pour le cancer du col de l'utérus.

The present paper addresses the advantages and limits of PET-CT in the work-up of cervical cancer. PET-CT is not to be overlooked in initial staging. It is useful to assess involvement of pelvic and lumbar lymph nodes. It can improve staging accuracy and help guide initial treatment such as optimisation of radiation therapy fields. Given its limited spatial resolution however, PET does not seem so adequate to document tumours less than 5 mm in diameter. It is not warranted for staging carcinoma in situ (FIGO stage 0) or preclinical carcinoma (FIGO stage 1A1 and 1A2). Furthermore MRI performances are best as far as local extension and tumour volume measurement are concerned. PET brings prognostic information. High initial uptake in tumour tissue or persistent increased uptake at completion of treatment indicates rather poor prognosis. PET is useful to evaluate therapy, but its exact role in this issue remains to be further refined. Finally, PET-CT can document early recurrence of disease.

Upper retropharyngeal node involvement in differentiated thyroid carcinoma demonstrated by 131I scintigraphy.

We report four patients with papillary thyroid cancer who had upper retropharyngeal node involvement demonstrated by 131I scintigraphy. Three patients presented with a thyroid nodule and enlarged jugular nodes. Total thyroidectomy was performed with node dissection. Pathology demonstrated papillary carcinoma with several metastatic nodes. 131I scanning 4 weeks after surgery demonstrated increased uptake in an upper retropharyngeal node. In one patient, thyroidectomy had been performed 21 years previously. Increased thyroglobulin level led to 131I scanning, which showed focal retropharyngeal uptake. All four patients had asymmetrical uptake at mouth level with focal uptake close to the sagittal plane. A lateral projection showed focal uptake between the base of the skull and the mandibular angle, behind the region of the mouth and nose. CT in all cases and MRI in one case confirmed the presence of an enlarged node. The mass was removed surgically in two patients and pathology confirmed the papillary nature of the metastatic node. Two patients were treated by 131I. Focal uptake of 131I in the region of the mouth is ambiguous, since salivary uptake of 131I is a common finding on scintigraphy. In cases of asymmetrical uptake in the region of the mouth, a lateral projection of the head therefore allows the correct diagnosis.

Decreased uptake of therapeutic doses of iodine-131 after 185-MBq iodine-131 diagnostic imaging for thyroid remnants in differentiated thyroid carcinoma.

We performed a prospective random study to assess possible thyroid stunning by a 185-MBq iodine-131 dose used to diagnose thyroid remnants. Patients with differentiated thyroid carcinoma were included after total or near-total thyroidectomy. They were randomly assigned to two groups. In group 0 (G0, 32 patients), iodine-123 administration only was used to diagnose thyroid remnants and/or metastasis, so that no thyroid stunning by 131I would occur. In group 1 (G1, 19 patients), diagnostic imaging was performed with 123I and 185 MBq 131I. 123I imaging was less sensitive than 131I imaging in identifying thyroid remnants in both groups (94%). Thyroid uptake of 123I was measured in both groups (at 2 h) and was not significantly different between the groups. Patients with thyroid remnants who remained in the study (28/32 in G0, 17/19 in G1) were treated with 370 MBq 131I, 5 weeks after treatment (mean time, range 12-84 days). In 12/17 G1 patients thyroid uptake measurement was repeated immediately before treatment. Uptake was equal to 1.97% +/- 0.71% and significantly lower (P < 0.05) than the previous measurement (3.76% +/- 1.50%). Patients were imaged 7 days after administration of the therapeutic dose and the images were compared with the diagnostic images. In 28/28 G0 patients thyroid remnants were unchanged and clearly seen. In 5/17 G1 patients, however the remnants were hardly identified, although they had been clearly seen at the time of diagnosis. We conclude the following: (1) a diagnostic dose of 185 MBq 131I decreases thyroid uptake for several weeks after administration and can impair immediate subsequent 131I therapy; (2) 123I is slightly less sensitive than 131I in identifying thyroid remnants; and (3) the need to scan for thyroid remnants remains to be confirmed, since only 2/51 patients enrolled in this study were not treated with 131I.

Enalapril plus frusemide MAG3 scintigraphy in hypertensive patients with atherosclerosis and moderate renal insufficiency.

We performed a retrospective study on 26 patients with moderate renal failure (mean GFR = 51 +/- 21 ml min-1 1.73 m-2), hypertension and atherosclerosis. Apart from three patients who had completely normal renal Doppler ultrasonography, all patients underwent renal angiography. Three groups of kidneys with different atherosclerotic renal artery involvement were identified: Group 1, 24 kidneys with no renal artery stenosis (RAS); Group 2, 18 kidneys with mild (> 25% and < 50% diameter) RAS; and Group 3, 10 kidneys with moderate (> 50% diameter) RAS. We used a two-day protocol with frusemide plus enalapril 99Tcm-MAG3 scintigraphy. The mean parenchymal transit time (MPTT), time to the maximum activity (time to peak) of the renal curve (Tmax), residual activity and split renal uptake were evaluated. The measured parameters did not differ before and after enalapril in Group 1 or in Group 2. In Group 3, MPTT and residual activity differed significantly (P < 0.025) before and after enalapril. The Tmax before and after enalapril, MPTT before and after enalapril and residual activity after enalapril differed significantly (P < 0.05) between Groups 1 and 3 and between Groups 2 and 3. Threshold values were obtained to maximize diagnostic accuracy. The Tmax, MPTT and residual activity after enalapril gave satisfactory results, and MPTT performed best with a 75% positive predictive value and a 98% negative predictive value for the diagnosis of renal artery stenosis. We conclude that MPTT, measured after enalapril administration, is a useful parameter to detect renal artery stenosis in patients with hypertension, atherosclerosis and moderate renal insufficiency.

Evaluation of single-photon emission tomography imaging of supratentorial brain gliomas with technetium-99m sestamibi.

Single-photon emission tomography (SPET) with technetium-99m sestamibi (MIBI) was carried out in 61 adult patients with supratentorial expanding brain lesions. Thirty-one patients had pathologically proven malignant glioma. Ten patients had pathologically proven low-grade glioma, while another 12 patients had a clinical diagnosis of low-grade glioma. The other eight patients had a variety of lesions including radiation necrosis (3), abscess (2), ischaemic stroke (2) and primary brain lymphoma (1). SPET was performed 15 min after administration of 740-930 MBq MIBI and transverse, sagittal and coronal views were reconstructed. Using computed tomography or magnetic resonance imaging guidance, a MIBI uptake index was computed as the ratio of counts in the lesion to counts in the contralateral homologous region. In high-grade gliomas, the MIBI index ranged from 1.9 to 6.6 (mean 3.6 +/- 1.4) whereas it ranged from 0.8 to 1.7 (1.1 +/- 0.2) in the pathologically proven low-grade group (P < 0.01). No significant difference was found between the two low-grade groups (1.1 +/- 0.2 vs 1.1 +/- 0.2). No overlap was found between high-grade and low-grade glioma index values. Patients with suspected radiation necrosis, cerebral abscess or ischaemic stroke did not demonstrate high MIBI uptake (0.9-2.2), whereas one patient with brain lymphoma did (3.9). This study suggests that MIBI SPET imaging is of value in distinguishing low-from high-grade supratentorial gliomas in adults.

99mTc-MAG3 and 99mTc-DMSA in the detection and assessment of pyelonephritis.

In this report, we present the case of a patient suffering from recurrent acute pyelonephritis and who had a hypertrophic right kidney following left nephrectomy. 99mTc-dimercaptosuccinic acid (DMSA) scan is known to be of value in the diagnosis of pyelonephritis, based on the detection of parenchymal abnormalities. The kidney accumulation of 99mTc-mercaptoacetyl-glycylglycylglycine (MAG3) at 2-3 minutes also proves to supply useful information on cortical function. This case illustrates that 99mTc-MAG3 study may be an efficient complementary examination to 99mTc-DMSA scan in the detection and assessment of pyelonephritis.

Simultaneous technetium-99m MIBI angiography and myocardial perfusion imaging.

Resting first-pass radionuclide angiography (FPRNA) was performed with the myocardial perfusion agent technetium-99m MIBI. In 27 patients, it was compared with technetium-99m diethylenetriamine pentaacetic acid FPRNA. A significant correlation was present in left (r = 0.93, p less than 0.001) as well as right (r = 0.92, p less than 0.001) ventricular ejection fraction measured with both radiopharmaceuticals. In 13 patients, MIBI derived segmental wall motion was compared with contrast ventriculography. A high correlation was present (p less than 0.001), and qualitative agreement was found in 38/52 segments. In 19 patients with myocardial infarction a significant correlation was present between MIBI segmental wall motion and perfusion scores (p less than 0.001). In ten patients with a history of myocardial infarction, 18 myocardial segments demonstrated diseased coronary vessels and impaired wall motion at contrast angiography. These segments were all identified by the MIBI wall motion and perfusion study. We conclude that MIBI is a promising agent for simultaneous evaluation of cardiac function and myocardial perfusion at rest.

Radio high-performance liquid chromatographic determination of 14C-labelled LF 2-0254, A 1,4-dihydropyridine calcium antagonist, in rat and dog plasma using off-line liquid scintillation counting.

LF 2-0254 is a 1,4-dihydropyridine calcium antagonist with a slow onset of action. The pharmacokinetics of [14C]LF 2-0254 were studied in rats and dogs. A sensitive high-performance liquid chromatographic method using liquid scintillation counting was developed for the quantitation of labelled LF 2-0254 in plasma. The peak height of the internal standard in the chromatogram was measured by UV detection and the mobile phase containing the chromatographic peak of [14C]LF 2-0254 was collected and counted for radioactivity. The concentration of labelled drug in the plasma was then determined using a calibration graph constructed from the determination of [14C]LF 2-0254 of known specific activities. The limit of determination was dependent on the specific activity of the drug administered. This method permits the measurement of the radioactive drug in biological fluids.

Evaluation of allograft perfusion by radionuclide first-pass study in renal failure following renal transplantation.

To assess the diagnostic value of indices measured on a first-pass curve, we performed 72 radionuclide renal first-pass studies (RFP) in 21 patients during the early weeks following renal allograft transplantation. The diagnosis was based on standard clinical and biochemical data and on fine needle aspiration biopsy (FNAB) of the transplant. Aortic and renal first-pass curves were filtered using a true low-pass filter and five different indices of renal perfusion were computed, using formulae from the literature. Statistical analysis performed on the aortic and renal indices indicated excellent reproducibility of the isotopic study. Although renal indices presented a rather large scatter, they all discriminated well between normal and rejection. Three indices have a particularly good diagnostic value. In the discrimination between rejection and Acute Tubular Necrosis (ATN), only one index gave satisfying results. The indices, however, indicate that there are probably ATN with an alternation of renal perfusion and rejection episodes where perfusion is almost intact. We conclude that radionuclide first-pass study allows accurate and reproducible quantitation of renal allograft perfusion. The measured parameters are helpful to followup the course of a post-transplantation renal failure episode and to gain more insight into renal ischemia following transplantation.

[Renal scintigraphy under hyperdiuresis in upper urinary tract dilatations]. / La scintigraphie rénale sous-hyperdiurèse dans les dilatations du haut appareil urinaire.

Emphasis is placed on the existence of two types of dilatation of the upper excretory tract: obstructive and non-obstructive lesions. Renal scintigraphy with technetium-labelled DTPA combined with a Lasilix test was performed in 34 patients (26 operated and 8 treated medically) with a total of 41 dilated renal units. Intra-operative exploration in the 17 reno-ureteral units assessed as being the site of obstruction on scintigraphy confirmed the lesion in the 14 cases of anomalies of the pyelo-ureteral junction and the 3 mega-ureters. For as long as the obstructed zone is not resected the dilated urinary tract fails to empty. In the other 12 units, the scintigraphy diagnosis of non-obstructive hypotony was confirmed by the operation and the subsequent course (notably in the 10 cases of reflux in the wide ureters reimplanted with a good result without resection of end of ureter).

Pulmonary calcifications in children on dialysis.

Pulmonary calcifications are known to occur in patients with chronic renal failure. Recently, scintigrams with bone-seeking radionuclides have been used to detect subclinical pulmonary calcium deposits. We studied 18 children on maintenance dialysis without evidence of pulmonary calcification on chest X-ray. Four children (22.2%) had a positive technetium 99m hydroxymethylene diphosphate scan (group 1), and 14 children had a negative scan (group 2). Mean serum aluminum levels were 2.68 +/- 0.30 mumol/l (mean +/- SD) in group 1 as compared to 1.66 +/- 0.72 in group 2 (p less than 0.01). No significant difference was found between the groups with respect to serum levels of calcium, phosphorus, bicarbonate, magnesium and the calcium-phosphorus product as well as parathyroid hormone and vitamin D levels. The patients with pulmonary calcifications were on dialysis a significantly longer time than those of group 2 (62 +/- 15 versus 35.7 +/- 23 months; p less than 0.01). These data show that pulmonary calcification occurs with high frequency in children undergoing long-term dialysis. They seem to be related to high serum aluminum levels. We propose that pulmonary scintigrams with bone-seeking radionuclides be used routinely for the diagnosis and follow-up of uremic pulmonary calcification.

[Radioisotopic quantification of kidney function using Tc-99m-DMSA. Comparison with creatinine clearance in children with a single kidney]. / Quantification radio-isotopique de la fonction rénale à l'aide de DMSA 99m Tc. Comparaison avec la clearance de la créatinine chez l'enfant porteur de rein unique.

To assess the accuracy of renal function quantification with Tc 99m-DMSA in children, we compared DMSA renal uptake and creatinine clearance in 16 cases of children with single kidney. The age of the patients ranged from two month to fourteen years. DMSA renal uptake was measured 7 hours after injection and was normalized in percent of the injected activity. A significant correlation was found between creatinine clearance and DMSA uptake (Pearson's r = 0.866, p less than 0.01). Normal creatinine clearance in children (80 to 120 ml/min-1 X 1.73 m-2) allowed determination of normal renal uptake (36 to 60%). This study indicates that in cases of asymmetrical renal impairment renal uptake reflects split renal creatinine clearance. Since the former is much easier to measure, DMSA should play an important role in the evaluation of differential renal function.

Quantitation of renal function with 99Tcm-DMSA. A comparison with creatinine clearance in children with single kidney.

To study the accuracy of renal function quantification with 99Tcm-DMSA we compared DMSA renal uptake and creatinine clearance in 16 cases of children with single kidney. The age of the patients ranged from two months to fourteen years. Creatinine clearance was normalized to 1.73 m2. DMSA uptake was measured 7 h after intravenous injection. Background subtraction was used and soft tissue attenuation was taken into account. The uptake was normalized in percentage of the injected activity. A significant correlation was found between creatinine clearance and DMSA uptake (rt = 0.866, p less than 0.01). Normal creatinine clearance range in children (80 to 120 ml min-1/1.73 m2) allowed determination of normal uptake range (36 to 60%). This study indicates that in case of asymmetrical renal impairment renal uptake will reflect split renal creatinine clearance. Since the former is much easier to measure, DMSA should play an important role in the evaluation of differential renal function.

[Radioisotopes in the exploration of upper urinary tract obstruction]. / Les radio-isotopes dans l'exploration des obstructions de la voie urinaire haute.

The authors describe the various possibilities offered by isotope studies in cases of obstruction of the upper urinary tract. This examination allows: -- exploration of the dilatation itself, -- and isotope study of renal function. The dilatation can be explored either by means of the nephrogram with hyperdiuresis or by measurement of the renal transit time. The nephrogram with hyperdiuresis will give a precise answer: definite obstruction or no obstruction. Intermediate forms are possible, in which a mathematical interpretation of the curves of decay of the renal radioactivity will help distinguish between hypotonia without obstruction and true obstruction with dilatation. A marked decrease in renal function or severe vesico-renal reflux can interfere with the interpretation of these curves. Measurement of the renal transit time with the mathematical calculation of deconvolution is a valuable application of isotopes, but it is less practical than the nephrogram with hyperdiuresis. The isotope study of renal function is a promising technique, as it is able to study the global clearance without the need for blood tests (this is true for both the glomerular filtration rate and for the measurement of renal blood flow). Furthermore, this technique should allow each kidney to be studied separately. Separate measurements do not provide an absolute value for each kidney, but evaluate the part played by each kidney in the global renal function, which can be measured simply by means of the isotope study.(ABSTRACT TRUNCATED AT 250 WORDS)