Changes in blood flow of growing experimental tumor determined by the clearance of 133Xe.

133Xe clearance method has been employed for measurement of the blood flow in 6C3HED lymphosarcoma implanted in flank of C3H mice. In small tumors (9-day old) the mean rate of blood flow was 9.4 +/- 5.0 ml/100g/min. but with progressing growth of tumors the rate of blood flow significantly decreased. In large tumors (14-day old) the mean rate of the blood flow was only 5.4 +/- 2.8. Our results demonstrate that this type of tumor, similarly as most of transplanted tumors are not well perfused and, that there is an inverse relationhip between the blood flow and the tumor size.

[Determination of glomerular filtration in children using 99mTc-DTPA and the sequential gammagraphy method]. / Urcovanie glomerulárnej filtrácie u detí 99mTc-DTPA metódou sekvencnej gamagrafie.

The method of sequence scintigraphy of the kidney with 99mTc-DTPA (diethylene triamine pentacetic acid) and subsequent determination of glomerular filtration rate by means of a gamma camera and computer were applied in examining 160 children with different diseases of the kidneys and urinary tract. By modifying the commercial computer program a study with quantitative evaluation of some functional parameters was designed, involving also the determination of the overall and of separate values of GF 99mTc-DTPA according to G. Gates. The main advantages of the applied method are its noninvasiveness, speed, safety, low radiation load, and its relatively broad use in diagnostic nephrological practice particularly in children.

Dynamic 99mTc-DTPA renal gammagraphy with glomerular filtration rate determination.

Using the method of 99mTc-DTPA (diethylenetriaminepentaacetic acid), sequential renal gammagraphy with subsequent glomerular filtration rate determination by means of a gamma-camera and computer, a total of 285 patients with suspected renal and urinary tract diseases, subjects after surgery on these organs or those serving as controls after drug therapy were examined. With the help of a modified computer user's program, a study was designed to perform quantitative evaluation of some functional parameters as well as determination of total and separate glomerular filtration rate values by 99mTc-DTPA according to Gates. The benefits of the method employed in our study are that it is non-invasive, rapid, atraumatic, with low exposure to radiation while offering a broad range of applications in routine diagnostic practice of nephrology, and especially so in paediatric patients.

Experiences with bone scanning in differential diagnosis of local bone lesions.

Because some primary tumours often metastasize to the skeleton, their early detection is essential for further therapy and prognosis. Radiographic examination is not sufficiently sensitive for early detection of bone metastases, because it can reveal the typical sign of metastases--decalcification--only after loss of 30-50% of the original amount of calcium from bone tissue (18). Bone scanning with bone-seeking radiopharmaceuticals represents a viable technique for early detection of bone lesions, especially early metastatic disease. The indication for this examination is undoubtedly in breast cancer, cancer of prostate, lung, thyroid gland, hypernephroma, melanoma, plasmocytoma and malignant lymphomas. After good clinical experience of the authors with bone scanning in detection of secondary bone tumours in known primary localisations (9, 14, 15, 10), they tried to elaborate in this paper indicative criteria for bone scanning in patients with suspicious secondary tumourous lesions by unknown primary localisations.