Qualitative and quantitative scintigraphy in sialorrhea before and after botulinum toxin injection.

OBJECTIVES/HYPOTHESIS: Sialorrhea is excessive saliva production and its usual escape of from the oral cavity. The use of botulinum toxin has been preconized, but its effectiveness until now has been unreliably measured. Our objective was to qualitatively and quantitatively determine the effectiveness of botulinum toxin injection in the reduction of saliva production by the parotid gland. STUDY DESIGN: Outcomes research. METHODS: Patients with moderate-to-critical sialorrhea had one of the parotid glands injected with 50 U of botulinum toxin, leaving the other as the control. Fifteen days after the toxin injection, they underwent scintigraphic analyses with intravenous injection of 10 mCi (37 MBq) of Tc-99 m (sodium pertechnetate). After this, the noninjected gland was treated for therapeutic complementation. RESULTS: The glands injected with botulinum toxin showed uptake reduction in 100% of patients. The uptake reduction in counts per second varied from 8% to 36%. The Wilcoxon paired test comparing the control glands with those injected showed a significant difference for the action of botulinum toxin (P = .0039). CONCLUSIONS: The scintigraphic study of parotid glands shows that botulinum toxin is effective in reducing sodium pertechnetate uptake. LEVEL OF EVIDENCE: 2c Laryngoscope, 129:2521-2526, 2019.

Medical exposure of the population from diagnostic use of ionizing radiation in luxembourg between 1994 and 2002.

A national evaluation on radiation doses from diagnostic procedures (x rays and nuclear medicine) was conducted in Luxembourg for the period 1994-2002 aiming at the estimation of the annual collective dose. The calculations were based on a survey of frequencies of more than 250 types of radiological examinations and included more than 425,000 patients. This evaluation ensured the practical implementation of Article 12 of the European Directive 97/43/EURATOM, which obliges the Member States to determinate the population dose from medical exposure. The results show an increase of the annual effective dose per capita from 1.59 mSv in 1994 to 1.98 mSv in 2002. The impact of computed tomography to dose received from medical use of radiation has dramatically increased in this time period. Luxembourg has one of the highest computed tomography examination rates compared to other health care level I countries. The following measures to minimize medical exposures were proposed in the study: medical physicists should have a more central role to play in patient dosimetry in interventional and diagnostic radiology, especially concerning computed tomography. Also, the implementation of an electronic "X-ray patient card" for all irradiated patients--except dental--and the use of the European referral criteria that give guidance and recommend investigations in various clinical settings can both help to decrease medical radiation exposures.

Thermosetting gels with modulated gelation temperature for ophthalmic use: the rheological and gamma scintigraphic studies.

For ophthalmic drug delivery, Pluronic F127 solutions have a phase transition temperature too low for them to be instilled into the eye at room temperature. Refrigerator storage is usually required to make administration easier, whereas the potential irritation of cold to the sensitive ocular tissues may result in poor topical bioavailability. The purpose of this study is to develop a thermosetting gel with a suitable phase transition temperature by combining Pluronic analogs and to examine the influence of incorporating mucoadhesive polysaccharide, sodium hyaluronate (HA-Na), on the ocular retention of the gel. Dynamic rheological method and single photon emission computing tomography (SPECT) technique were used to ex/in vivo evaluate the thermosetting gels, respectively. An optimized formulation containing 21% F127 and 10% F68 increased the phase transition temperature by 9 degrees C as evaluated by elasticity modulus compared to that of individual 21% F127 solution. Rheological behaviors of the Pluronic solutions showed that the combined Pluronic formulation was free flowing liquid below 25 degrees C and converted to a firm gel under the physiological condition. Furthermore, this formulation possessed the highest viscosity both before and after tear dilution at 35 degrees C. Gamma scintigraphic data demonstrated that the clearance of the thermosetting gel labeled with 99mTc-DTPA was significantly delayed with respect to the phosphate buffered solution, and at least a threefold increase of the corneal residence time was achieved. However, no further improvement in the ocular retention was observed when adding HA-Na into the thermosetting gel due to the substantially decreased gel strength.

Analytical modeling of worldwide medical radiation use.

An analytical model was developed to estimate the availability and frequency of medical radiation use on a worldwide basis. This model includes medical and dental x-ray, nuclear medicine, and radiation therapy. The development of an analytical model is necessary as the first step in estimating the radiation dose to the world's population from this source. Since there is no data about the frequency of medical radiation use in more than half the countries in the world and only fragmentary data in an additional one-fourth of the world's countries, such a model can be used to predict the uses of medical radiation in these countries. The model indicates that there are approximately 400,000 medical x-ray machines worldwide and that approximately 1.2 billion diagnostic medical x-ray examinations are performed annually. Dental x-ray examinations are estimated at 315 million annually and approximately 22 million in-vivo diagnostic nuclear medicine examinations. Approximately 4 million radiation therapy procedures or courses of treatment are undertaken annually.

Cancer risks from medical radiation.

About 15% of the ionizing radiation exposure to the general public comes from artificial sources, and almost all of this exposure is due to medical radiation, largely from diagnostic procedures. Of the approximately 3 mSv annual global per caput effective dose estimated for the year 2000, 2.4 mSv is from natural background and 0.4 mSv from diagnostic medical exams. Diagnostic and therapeutic radiation was used in patients as early as 1896. Since then, continual improvements in diagnostic imaging and radiotherapy as well as the aging of our population have led to greater use of medical radiation. Temporal trends indicate that worldwide population exposure from medical radiation is increasing. In the United States, there has been a steady rise in the use of diagnostic radiologic procedures, especially x rays. Radiotherapy also has increased so that today about 40% of cancer patients receive some treatment with radiation. Epidemiologic data on medically irradiated populations are an important complement to the atomic-bomb survivors' studies. Significant improvement in cancer treatment over the last few decades has resulted in longer survival and a growing number of radiation-related second cancers. Following high-dose radiotherapy for malignant diseases, elevated risks of a variety of radiation-related second cancers have been observed. Risks have been particularly high following treatment for childhood cancer. Radiation treatment for benign disease was relatively common from the 1940's to the 1960's. While these treatments generally were effective, some resulted in enhanced cancer risks. As more was learned about radiation-associated cancer risks and new treatments became available, the use of radiotherapy for benign disease has declined. At moderate doses, such as those used to treat benign diseases, radiation-related cancers occur in or near the radiation field. Cancers of the thyroid, salivary gland, central nervous system, skin, and breast as well as leukemia have been associated with radiotherapy for tinea capitis, enlarged tonsils or thymus gland, other benign conditions of the head and neck, or benign breast diseases. Because doses from diagnostic examinations typically are low, they are difficult to study using epidemiologic methods, unless multiple examinations are performed. An excess risk of breast cancer has been reported among women with tuberculosis who had multiple chest fluoroscopies as well as among scoliosis patients who had frequent diagnostic x rays during late childhood and adolescence. Dental and medical diagnostic x rays performed many years ago, when doses were presumed to be high, also have been linked to increased cancer risks. The carcinogenic effects of diagnostic and therapeutic radionuclides are less well characterized. High risks of liver cancer and leukemia have been demonstrated following thorotrast injections, and patients treated with radium appear to have an elevated risk of bone sarcomas and possibly cancers of the breast, liver, kidney, thyroid, and bladder.

[Statistical analysis of nuclear medicine in the Higashi Nippon Gakuen University Dental Hospital].

The number of radionuclide in vivo tests carried out at the Higashi Nippon Gakuen University Dental Hospital was statistically analyzed and discussed. The subjects were all patients admitted to the Division of Nuclear Medicine during the seven years between 1981 and 1989. The total number of the patients included those introduced through medical facilities in Toubetsu-cho and others. The results of this analysis were as follows: 1) The proportion of the first time patients admitted to the Higashi Nippon Gakuen University Dental Hospital was only 11 percent of all patients. 2) Cases of radionuclide in vivo tests at the Higashi Nippon Gakuen University Dental Hospital decreased in number, annually. However the proportion of tumor scintigraphy and bone scintigraphy increased gradually.