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Biomedical subjects

F Petersen

Publications and source records attributed to F Petersen.

At least 73 records · Page 4Linked to original sources
PubMed1983

[Postoperative radiotherapy and radiogold treatment of ovarian cancer].

At the Allgemeine Krankenhaus St. Georg, Hamburg, 240 patients with ovarian carcinomas were submitted to an adjuvant treatment between 1961 and 1973. The external therapy with telecobalt or by an 18 MeV betatron was dosed from 3000 to 4000 rads. Most of the patients received an additional single intraperitoneal application of 150 mCi gold-198. The five-year survival rate of all patients was 45%, whereas it was 71% for stage I, 47% for stage II, 21% for stage III, and 4% for stage IV. In 3% out of all cases, surgical procedure was necessary because of complications. Today, an indication for intraperitoneal therapy by radioactive isotopes is only adopted in case of a ruptured malignant ovarian tumor.

Adult↗
PubMed1982

[Reaction of autonomous and non-autonomous thyroid tissue to iodination blockers].

In the case of thyrostatic therapy of autonomous adenoma with iodinization blocker type drugs (here carbimazol), there is a relative increase of uptake of 99mTc-pertechnetate by the suppressed thyroid tissue before TSH becomes detectable by TRH testing (400 micrograms). As soon as endogenous TSH stimulation occurs (due to the decrease of thyroid hormone induced by the thyrostatic therapy), relatively more uptake of 99mTc-pertechnetate by the non-autonomous tissue is observed. 56 patients suspected of having autonomous thyroid adenoma were investigated. The activities in the regions of interest measured over autonomous and non-autonomous thyroid tissue before and after thyrostatic therapy were expressed in form of a double-ratio. 22 of the 56 patients were found to have an autonomous adenoma (double-ratio greater than or equal to 1.74). In 19 patients an adenoma was excluded with certainty (double-ratio less than or equal to 1.22). The remaining cases fell in-between and were difficult to classify. However, the gradual transition between the two groups so classified was harmonious. The different reactions of autonomous and non-autonomous thyroid tissue to thyrostatic therapy appear to be helpful in the differentiation between the two types of tissue.

Adenoma↗
PubMed1977

[Trisomy 22q-].

Explore the source record for details and available documents.

Adult↗
PubMed1977

[Comparison of scintigraphic and neurosurgical findings in brain tumors].

In 120 cases of operated brain tumors the neurosurgical findings are compared with the results of brain scintigraphy with 99mTc-pertechnetate. The study comprises only the frequent types of brain tumors such as meningeoma, astrozytoma, glioblastoma, oligodendroglioma, neurinoma and metastases. From the neurosurgical findinds were evaluated the localisation and size of the tumor, the extent of vascularity, of cysts and necroses. These data were related to the type or radioangiography and the degree of uptake in the scintigraphy. The tumors could be demonstrated by scintigraphy in 105 of the cases. Radioangiography was obviously superior to late scintigraphy in the diagnosis of the type of tumor. The size of the tumor appeared in the meningeomas greater and in the other types of tumor smaller than found by operation. The uptake in scintigraphy showed a correlation to vascularity. Otherwise there was found no correlation between vascularity and type of radioangiography in glioblastomas. This surprising result needs further investigatiion. Half of the cases with cysts and necroses showed an inhomogeneity in the uptake by the tumor.

Astrocytoma↗
PubMed1976

[Scintigraphic findings in amoebic abscess of the liver (author's transl)].

The accuracy, size, localization and course of liver scans of solitary or multiple amoebic liver abscesses was evaluated in 52 patients. The scintigraphic data were correlated with the clinical symptoms. In 47 of the 52 patients it was possible to demonstrate the liver abscess on the scintigram; the right lobe of the liver was involved more frequently than would have been expected simply on the basis of its volume. In most of the patients investigated the abscesses were solitary and in only 28% was it posssible to recognise two or three abscesses occurring simultaneously. Follow-up examinations showed rapid diminution in the size of the abscess furing medical treatment but complete return to normal during the first six months occurred in only 17% of cases. The results are discussed.

Diagnostic Errors↗
PubMed1976

[Dose-response relationship in radioiodine therapy of hyperthyroidism].

For the analysis of the dose-response relationship during radioiodine therapy, the effective dose was calculated based on measurements in 1171 patients in the course of treatment. Early results of the radioiodine therapy of these cases were checked up from six to nine months afterwards. The probability of incidence of a residual hyperthyroidism or of the induction of hypothyroidism respectively, in dependence on dosage, is represented by a dose-response curve. The dose-response curve for residual hyperthyreoses shows an exponential shape, whereas the curve of induced hypothyroidism is sigmoidally shaped. The results of experimental biophysics concerning dose-response curves allow the statement that there is no reactivity of the thyroid gland in cases of residual hyperthyroidism, whereas distinct compensation mechanisms are counteracting the induction of hypothyroidism. Thus, the conception of fractionated radioiodine therapy is supported by the shape of dose-response curves. The fractionation of the dose leads to accumulated inactivation effects on the hyperthyroidism, while the compensational mechanisms against hypothyroidism are strengthening by intermittent recovery and the rate of induced hypothyroidism is decreasing. The favorable effect of multiple treatment on the number of induced hypothyreoses could be verified by our own material. During the radioiodine therapy of hyperthyroidism, a defined interrelation is found between the effective dose, the thyroid mass and the effect of the dose. A formula of the isoeffective dose in dependence of the thyroid mass is derived analogically to percutaneous radiation therapy. The deviation of the effective dose from the dose previously calculated is represented as a distribution function. The mean value of this distribution function can be regarded as an expectation of the effective dose. Hence, a previous calculation of the dose is considered useful also in future. The isoeffective dose is proposed to be chosen in dependence on the thyroid mass according to a fifty-per-cent-probability of residual hyperthyroidism. Relative to the intensity of residual hyperthyroidism, a second treatment considering the same standards should be performed after four to nine months. The number of reiterated treatments needed depends on individual radiation sensitivity resulting from biological factors.

Dose-Response Relationship, Radiation↗