[Risk assessment of irradiation of tissue with metal implants]. / Odhad rizika ozarování tkáne s kovovými implantáty.

Authors examine the influence of metal implants on the distribution of ionizing radiation in tissue. In vivo measurements in a patient are seldom possible. The risk can be assessed with sufficient accuracy on the basis of various experimental dosimetric methods, histological changes in the irradiated volume and the tolerance to the physical stress, published in the available literature. The analysis shows that the risk of significant dose inhomogeneity or the treatment toxicity is minimal if mentioned principles are adhered to. Radiotherapy indications and dosage should not be markedly changed on the basis of the presence of metal in the irradiated volume.

[Radical radiotherapy of prostate carcinoma]. / Soucasné moznosti radikální radioterapie karcinomu prostaty.

Radiotherapy is an effective treatment modality of prostate carcinoma. Considering the limited radiosensitivity of this tumour it is necessary to use relatively high doses of radiation. Modern technology offers the possibility to perform high-dose radiotherapy with acceptable toxicity. The authors present various options of both external and internal irradiation. They point out that brachytherapy, previously considered less appropriate from the radiobiology aspect, is according to the current views and results a very suitable treatment modality of prostate cancer.

[Treatment of early stages of ovarian carcinoma. Evaluation of experience at the Institute of Radiation Oncology over a 10-year period (1983-1993)]. / Lécba casných stadií karcinomu ovaria. Zhodnocení zkuseností Ustavu radiacní onkologie za období deseti let (1983-93).

The authors evaluated in a retrospective study the therapeutic results of ovarian carcinoma stage FIGO I (68 patients) and FIGO II (28 patients) attained in the Institute of Radiation Oncology, Prague during the ten-year period from 1983-1993. Total survival and survival without relapse within five years are 77% in stage I and 74% in stage II. The corresponding values of five-year survival without relapse were 56% and 58% resp. Despite the fact that the therapeutic results are comparable with data in the literature, a great shortcoming is the inadequate documentation of the initial laparotomy and the very general histopathological finding, moreover without grading, in a great proportion of the patients. The authors emphasize that these shortcomings make a reliable indication of adjuvant therapy impossible, in particular in early stages of ovarian carcinoma. Despite repeated references to this shortcoming these mistakes have persisted for several decades.

Symmetrical multifocal liposarcoma.

Multiple liposarcomas are extremely rare. We report on a patient with liposarcoma of the right lower limb who had undergone surgery and radiotherapy 4 years previously for a liposarcoma in the left lower limb. An outline of the management is discussed and a short review of available literature is given.

Wavelength-tuning interferometry of intraocular distances.

We describe basic principles of wavelength-tuning interferometry and demonstrate its application in ophthalmology. The advantage of this technique compared with conventional low-coherence interferometry ranging is the simultaneous measurement of the object structure without the need for a moving reference mirror. Shifting the wavelength of an external-cavity tunable laser diode causes intensity oscillations in the interference pattern of light beams remitted from the intraocular structure. A Fourier transform of the corresponding wave-number-dependent photodetector signal yields the distribution of the scattering potential along the light beam illuminating the eye. We use an external interferometer to linearize the wave-number axis. We obtain high resolution in a model eye by slow tuning over a wide wavelength range. With lower resolution we demonstrate the simultaneous measurement of anterior segment length, vitreous chamber depth, and axial eye length in human eyes in vivo with data-acquisition times in the millisecond range.

Palliation of carcinoma of the oesophagus with brachytherapy and the Didcott dilator.

Forty-one patients with oesophageal cancer who developed strictures after high dose rate intraluminal brachytherapy were dilated using a slow continuous dilator (Didcott dilator). After dilatation, all patients were evaluated monthly for relief of dysphagia. At the end of the 1st month, 41 patients were evaluable: 28 had no dysphagia while 13 had improvement; at the end of the 2nd month, 40 were evaluable, 26 had no dysphagia while 14 had improvement; at the end of the 3rd month, 34 patients were evaluable, 24 had no dysphagia while 10 had improved. Three patients developed worsening of dysphagia owing to tumour recurrence among 32 patients who were evaluable at the end of the 4th month. Five patients developed worsening of dysphagia among the 26 patients who were evaluable at the 5th month due to tumour. These patients were dilated with the Didcott dilator and were treated with further brachytherapy. At the end of the 6th month, 14 patients were evaluable; seven had no dysphagia, while seven had improvement over their presenting dysphagia scores. Slow continuous dilatation using the Didcott dilator is very effective in the dilatation of strictures after high dose rate intraluminal brachytherapy. Dilatation is prolonged and sustained and a single dilatation is usually enough to maintain patency.