Quality control of 99Mo/99Tcm generators: results of a survey of the Radiopharmacy Working Group of the Italian Association of Nuclear Medicine (AIMN).

A multicentre survey of the quality control of 99Tcm generators has been completed: 245 generators from seven different commercial sources were tested over a period of 2 years. The results indicate that the mean pH of the eluates was 5.8 +/- 0.6; the aluminium contents were typically < 10 ppm; the radiochemical purity was 99.8 +/- 0.4% and the median 99Mo content was 3.8 x 10(-4) percent. The elution profiles gave a volume of 1.9 ml to obtain 50% of the total eluted activity and of 4.9 ml to obtain 95%. Other radionuclide impurities and heavy metal breakthrough were evaluated by graphite furnace absorption spectrometry and inductively coupled plasma mass spectrometry. National guidelines for the standardization of radiopharmacy procedures are currently being compiled.

[Comparison between measured and computed absorbed dose values in the tangential treatment of the breast]. / Confronto tra i valori misurati e calcolati della dose assorbita nel trattamento tangenziale della mammella.

The calculated absorbed dose values to the reference point of the breast tangential irradiation, obtained by 2-dimensional (2D) Treatment Planning Systems (TPS), were compared with the measured absorbed dose values obtained with a ionization chamber in an anthropomorphic phantom treated with two opposed photon beams of 60Co, 6 MV and 10 MV. This comparison was aimed at assessing the 2D algorithm dose overestimation due to the effect of missing tissue in the irradiated field. The ratio between the computed dose, Dc, and the measured dose, Dm, reached 1.08 for 60Co beams and 1.04 for X-ray beams of linacs. The Clarkson method gives an adequate correction factor for the calculated absorbed dose value in the reference point. The portal films of some patients were studied to estimate the correction factor for the treatment time or monitor units evaluated by TPS using tomographic breast central plane. The values of the correction factors reached 1.10 for 60Co photon beams and 1.04 for X-ray beams. The measurements were carried out with TLDs positioned in the central plane of the breast, covered by a special bolus, of a second anthropomorphic phantom. The dose homogeneity as well as the accuracy of the relative computed dose values in the breast phantom irradiated with 10 MV X-ray beams were assessed.

Ionizing radiation-induced apoptosis and DNA repair in murine erythroleukemia cells.

A morphological study of DNA repair and apoptotic patterns in relationship with cell cycle events was performed on murine erythroleukemia cells. The presence and distribution of DNA replicon sites were evaluated through the BrdU-anti BrdU immunofluorescence and immunogold techniques in light and electron microscopy. Different patterns of labelling and percentages of BrdU positive cells were observed depending on irradiation dose (up to 60 Gy) and time in post-irradiation culture (up to 24 hours). An enlargement of the S phase of the cell cycle was evidenced 18 hours post-irradiation as determined by flow cytometry analysis. The high resolution approach showed that, in spite of several morphological alterations, BrdU labelling was present even in cells displaying early and late apoptotic features.

[The echo-Doppler evaluation of the effects of glucagon on the portal flow in normal subjects. The premise for the loading test in portal hypertension]. / Valutazione con eco-Doppler degli effetti del glucagone sul flusso portale nei soggetti normali. Premessa per la prova da carico nell'ipertensione portale.

This study was aimed at evaluating the capabilities of Doppler US in the quantitative study of portal blood flow after glucagon administration in normal subjects. While its role in the qualitative study of portal hemodynamics is well known, it remains questionable whether Doppler US may be a valuable tool for the quantitative study of portal blood velocity. This may be solved by introducing, on a routine basis, meal tests which may provide a relative evaluation of the data. To date, these tests were based on the evaluation of blood flow velocity before and after a complete meal. For a more reliable test, we suggest that the meal be substituted with the i.v. administration of glucagon, which is known to play a major role in splanchnic hemodynamics during digestion. We examined 30 healthy volunteers and showed the possibility of a statistically significant evaluation of portal blood flow velocity before and after glucagon administration. After glucagon administration, blood flow velocity increased by 31.3% in 10 minutes, on the average, in all the healthy subjects.

[Profitability of the radiological examination of the thorax. Development of thoracic radiology, administered dose, quality control and role of the clinic]. / Rendimento degli esami radiologici del torace. Evoluzione della radiologia toracica, dosi somministrate, controllo di qualità, e ruolo della clinica.

The considerable spreading of chest X-ray (about 50% of all radiological examinations--WHO official report No. 698), and its biological and economic high cost, make interesting the cost/benefit evaluation of this simple and world-wide X-ray examination. The evaluation, highly important although very complex, is concerned with many different problems. The different problems, such as the development of radiological diagnosis in pulmonary diseases, dose of exposure, quality assurance and clinical role are analyzed.

[Image diagnosis and Doppler ultrasound in the functional study of portal circulation]. / Diagnostica per immagini ed Eco-Doppler nello studio funzionale del circolo portale.

The authors, after mentioning physiologic appearance of portal circulation and physical principles governing the interrelationship of pressure, flow and flow velocity in blood vessels, report the results of a study about trend of haemodynamic values in 23 normal subjects and 13 cirrhotic patients. Values of portal blood flow and fluid speed were measured using a pulsed "Linear-Doppler" system, before and after dinner. Statistical analysis of results proves the diagnostic value of examination that appears qualified as the method of first choice in the patients with suspected changes of portal circulation.