Effect of dose and dose-distribution in damage to the kidney following abdominal radiotherapy.

PURPOSE: To define the effects of abdominal radiotherapy on the kidney with regard to dose-distribution parameters. MATERIALS AND METHODS: Ninety-one patients with abdominal radiotherapy were included in the study, and the minimum follow-up was 1 year. Conventional fractionation, 5 x 1.8-2.0 Gy week(-1) to total doses of 30.6-62.5 Gy, was employed. Assessment of organ function was performed before, immediately after, and at 6 months and 1 year after radiotherapy. In cases with a significant radiation response at 1 year, subsequent follow-ups were done at 6-month intervals. Documented parameters included clinical examination, static and sequential scintigraphy of the kidneys, abdominal computed tomography, and sonography. RESULTS: Twenty-one patients (23%) developed a reduction in kidney function detected by static scintigraphy. Only in 15 of these patients was impairment of renal function observed by sequential scintigraphy. The contribution of the irradiated kidney to overall renal function decreased progressively to 34-40% by the third year after treatment. Hypertension was seen in two patients. No changes were found in laboratory parameters. ED(50) for scintigraphic changes decreased from 27 Gy for 10% of the volume to 7.6 Gy for 100%. ED(5) were in the range of 3-6 Gy, and this was independent of volume. CONCLUSIONS: Sophisticated imaging techniques allow the identification of radiation effects in partial volumes of the kidneys. A dose-response relationship in relation to the volume of kidney irradiated can thus be established for scintigraphic changes. As in a number of other organs, such changes do not relate directly to loss of renal function due to the reserve capacity of unirradiated kidney tissue.

[Prevention of radiation-induced diarrhea by smectite. Results of a double-blind randomized, placebo-controlled multicenter study]. / Prophylaxe der strahleninduzierten Diarrhö durch Smektit. Ergebnisse einer doppelblind randomisierten, plazebokontrollierten Multicenterstudie.

PURPOSE: Diarrhea and abdominal pain are well-known side effects abdominal or pelvic of radiation therapy that may lead to interruption of treatment in serious cases. In recent trials the silicate smectite has proven a promising drug in the prophylaxis of these adverse events. The presented trial aimed at the verification of earlier studies and the evaluation of a dose-effect relationship. PATIENTS AND METHODS: Between April 1994 and May 1995, a total of 176 patients obtaining radiotherapy of the pelvis or the abdomen were evaluated in a double-blind, randomized placebo-controlled investigation regarding the prophylactic effect of smectite (= Colina) against radiotherapy-induced diarrhea. During the whole period of radiotherapy 85 patients obtained 2 x 6 g smectite daily and 91 patients received 2 x 6 g placebo. The primary end point of the analysis was the time to the first appearance of diarrhea (> or = 3 pappy stools). RESULTS: All 176 patients were evaluated according to an intent-to-treat analysis. There was no significant difference between the prophylactic effects of smectite and placebo. For an explorative post-hoc analysis the total study group was split up into 2 subgroups, one with an irradiated small bowel volume < or = 837.5 ml, the other with a small bowel volume > 837.5 ml (median); the analysis indicated that the first subgroup showed a benefit for the smectite-treated patients in contrast to the placebo treatment (32 vs. 18 calendar days to the first appearance of diarrhea). This benefit was statistically not significant. CONCLUSION: Prophylactic application of smectite during irradiation of the pelvis and the abdomen can delay the development of radiotherapy-induced diarrhea, a statistical significance could not be verified neither in the total study group nor in the post-hoc subgroup analysis.

[D-xylose test of resorption as a method to determine radiation side effects in the small intestine]. / D-Xylose-Resorptionstest als Methode zur Erfassung der Strahlenreaktion des Darms.

BACKGROUND: The D-xylose test is the most important method to determine a disorder of carbohydrates resorption in proximal small intestine. The application is based on an impaired resorption due to pathological change of small intestine surface, leading to a decreased blood level or decreased excretion in urine. PATIENTS AND METHOD: D-xylose test was applied in 91 patients before, shortly after, 1/2 and 1 year after radiotherapy. All patients received an abdominal radiotherapy. We determined the blood level of D-xylose by a capillary blood sample 1 hour after oral D-xylose administration. RESULTS: A significant decrease of the mean blood level of D-xylose to 1.88 mmol/l was determined after radiotherapy in comparison with 2.17 mmol/l before radiotherapy. Half a year after radiotherapy the mean blood level of D-xylose returned to normal. Regarding a threshold value of D-xylose blood level of 1.70 mmol/l 29 patients (32%) showed a pathologically decreased D-xylose resorption after radiotherapy. Twenty out of the 29 patients already showed a normal resorption half a year after the determination of the resorption disorder, 5 patients after 1 year and 4 patients after 1 1/2 years. There was no correlation between the detection of a disorder of D-xylose resorption and of a loss of body weight. The acute clinical side effects seemed to be more marked in connection with a disorder of D-xylose resorption, but this correlation is not significant. Eleven or 14 of the 29 patients, respectively, with pathologically decreased D-xylose resorption only had complaints of lower or upper gastrointestinal tract, respectively, and 10 patients did not have abdominal complaints at all. CONCLUSIONS: The D-xylose test is an important and simple method for determination of radiogen induced carbohydrate malabsorption in proximal small intestine. By means of it radiation side effects on small intestine can also be determined in patients who are otherwise free of complaints.

[Radiation effects in the left kidney after irradiation of the spleen]. / Strahlenfolgen an der linken Niere nach Milzbestrahlung.

BACKGROUND: An important component of treatment of malignant lymphoma is the radiotherapy. If the spleen has to be included in the irradiation field, the left kidney has to be considered as a risk organ. PATIENTS AND METHOD: In 25 patients, splenic pedicle or spleen was included in the irradiation field. These patients were followed up at 6-monthly intervals clinically and by renal scintigram. For 21 out of 25 patients, a volume-dose-histogram of the kidneys was made. RESULTS: A decreased uptake of activity by the left kidney was found in the static renal scintigram of 13 out of the 25 patients and was seen 6 months to 1 year after radiotherapy for the first time at a moderate intensity. The decreased uptake improved in 1 patient, but was progressive in 8 patients until a storage defect or a shrinking of the whole left kidney appeared. The volume-dose-histogram showed that a decreased uptake was seen in the upper half or whole left kidney respectively if at least 40% of the volume or the whole organ was irradiated with at least 20 Gy. 40% of the volume of the left kidney were exposed to at least 20 Gy in only for 3 out of the 12 patients with no decreased uptake. By means of the renal sequence scintigram a reduced function of the left kidney was determined for 11 out of 13 patients. The functional contribution of the left kidney deteriorated to 16 to 37% of the total function of the 2 kidneys. One patient developed a hypertension 1 1/2 years after radiotherapy; all other patients showed no clinical symptoms. Retention of substances in blood was not observed. CONCLUSIONS: The static renal scintigram enables defined radiation-induced lesions of parenchyma of the left kidney to be determined after irradiation of the splenic pedicle or spleen. The changes are predominantly subclinical but possible long-term effects are unknown. In the treatment planning all possibilities should be used to minimize the irradiation volume of the left kidney. Furthermore, all patients should be followed up at regular intervals on a long-term basis.

[Therapy trends in the prevention of radiation-induced diarrhea after pelvic and abdominal irradiation. Results of a tricenter study]. / Therapieansätze zur Prophylaxe der strahleninduzierten Diarrhoe nach Becken- und Abdominalbestrahlung. Ergebnisse einer trizentrischen Untersuchung.

PURPOSE: Radiotherapy induced diarrhea and convulsive pain are severe side-effects of irradiation of the pelvis and the abdomen leading often to an interruption of the treatment. Up to now these side-effects were only treated symptomatically, prophylactic therapies are not known. PATIENTS AND METHODS: During the years 1992 and 1993 174 patients who obtained radiotherapy in the pelvis or the abdomen because of different malignancies were observed referring to the diarrhea-prophylactic effect of Smectite (= Skilpin). 80 patients received Smectite at the beginning of radiotherapy, 94 patients of the control group were treated with motility modifying drugs when diarrhea appeared. The following parameters were compared: Frequency, consistence and incontinence of stool, tenesmus and the onset of diarrhea. RESULTS: 67.0% (n = 63) of the patients in the control group developed diarrhea, whereas in the pretreated Smectite-group only 37.5% of the cases (n = 30) developed diarrhea. The first appearance of diarrhea was at day 17 in the pretreated group and averagely at day 11 in the control group. 44% of the patients in the control group suffered from tenesmus versus 25% in the Smectite-group. CONCLUSION: In comparison to the symptomatic treatment of radiation enteritis the prophylactic application of Smectite is able to reduce the diarrhea from the beginning of radiotherapy or at least to reduce the pathological frequency of stool and therefore to increase the quality of life.

[CT-guided manual afterloading with 198-gold seeds in intracerebral tumors]. / CT-gestütztes manuelles Afterloading mit 198-Gold-Seeds bei intrazerebralen Tumoren.

Interstitial brachytherapy of intracerebral tumours was stimulated through the introduction of computed tomography and afterloading technique. Biopsies for their histologic verification as well as the stereotactic implantation of plastic tubes and adjusted to the extent of the tumour can be carried out with a high degree of exactitude by means of CT-supported localization and puncture. The small-sized 198-gold seeds are then introduced according to the manual afterloading technique and remain in situ until the planned dose in the target volume of 50 Gy is achieved. Report on our manual afterloading brachytherapy in high-grade astrocytomas III and IV and in adenomas of the hypophysis. Indications of the diagnostic and therapeutic procedure, irradiation planning, calculation of the dose and discussion of our tentative clinical experience are explained.

[The results of percutaneous transvascular sclerotherapy of varicoceles]. / Ergebnisse der perkutanen transvasalen Varikozelenverödung.

The indications, techniques, complications and results of percutaneous sclerotherapy or embolization of gonadal veins for varicocele are discussed. Of our 93 patients, sclerotherapy of varicocele was technically possible in 81 cases. Sclerotherapy or embolization can be effected by different materials, such as: Histoacryl and Lipidiol mixed 1:2 to 1:4 and Aethoxysklerol, applied by a coaxial catheter system or end-opened F 6-catheter. Today the percutaneous transluminal sclerotherapy of gonadal veins is the treatment of choice for varicocele.

High-dose-rate afterloading and the LQ-model--evaluation of efficacy in cervix cancer therapy.

For short-time afterloading with high dose rates at irradiation treatment of gynecological tumors an adequate fractioning with reduced total dose is necessary considering the basically changed dose-time relation opposite to the common long-time brachytherapy. In addition to the careful clinical control of empiric found fractioning regimes for the primary and postoperative intrauterine and intravaginal afterloading therapy in cervix carcinoma and endometrium carcinoma, at which the surroundings reactions of the urine bladder, rectum and sheath, and also the tumor regression and relapses were investigated, a calculation of equivalent doses seems to be recommendable by means of mathematically formulated model conception according to the NSD formula and the LQ model. Changed exponents p for the fractioning rate N depending on the total treatments time were used for the rate calculations at slowly fractionated small-volume irradiation opposite to a higher fractionated percutaneous great-volume irradiation NSD conception was developed for. In LQ-model calculation changed coefficients mu for the repair half-life-time T in connection to the changed repair capacity in small volume brachytherapy were used. Knowing the compatibility and tumor efficiency of the rate-values and the alpha/beta-ratio for different fraction regimes were calculated and compared concerning their radiobiological equivalence and practical use. The calculations show a good clinical correspondence for single and total dosage in fractionated high dose rate afterloading of gynecological tumors.

[Automatic adaptation of stationary field dose distributions to the individual geometry of the patient. I: Calculation of dose distributions]. / Automatische Anpassung von Stehfelddosisverteilungen an die individuelle Patientengeometrie. Teil I: Bewertung von Dosisverteilungen.

In radiotherapy approved standard irradiation techniques are available for almost all tumor localizations that has to be adapted to individual anatomic situations with the concrete particular case. A possibility is shown that allows an anatomic adaptation of four types of parameters for four coplanar irradiation fields in maximum with permissible expenditure of time. During the dose adaptation process the estimation of the separate dose distribution is done for the target area and for risk organs according to given criteria by an added measure function value that is calculated from measure function values for the areas to be estimated.

[Automatic adaptation of stationary field dose distributions to the individual geometry of the patient. II: A model for adaptation of dose distributions]. / Automatische Anpassung von Stehfelddosisverteilungen an die individuelle Patientengeometrie. Teil II: Modell zur Anpassung von Dosisverteilungen.

Starting point for automatic adaptation of a dose distribution is a starting variant which parameters values are fixed as a matter of experience. On base of this starting variant a limited number of variants is produced and the "quality" of the attained dose distribution in each case is expressed by an added measure function value. A gradual improvement of adaptation of dose distribution to individual geometry of patients is done by pointed search of new parameter values for field breadths, field beginning points, field weights, and field insolation directions.

[Automatic adaptation of stationary field dose distributions to the individual geometry of the patient. III: Practical application]. / Automatische Anpassung von Stehfelddosisverteilungen an die individuelle Patientengeometrie. Teil III: Praktische Anwendung.

For the concrete case of a central bronchial carcinoma the method, explained in parts I and II, is applied for an automatic dose adaptation. In result a dose distribution is found which has a better adaptation of target area isodoses opposite the starting variant and results in a lower exposure of risk regions altogether.

[Percutaneous transvascular embolization as a palliative measure in bleeding gynecological malignancies of the pelvis]. / Die perkutane transvasale Embolisation als Palliativmassnahme bei blutenden gynäkologischen Malignomen des kleinen Beckens.

Between 1981 and 1983 48 patients with an average age of 54 years have had an arterial embolization of internal iliac artery. In 7 patients this was done preoperatively within a clinical study, in 41 ones because of profuse vaginal bleedings. In 6 patients there was a vital indication. In all cases survival time was 152 days. In two cases a re-embolization was necessary. In these two patients survival time was on average 338 days. The manoeuvre was done with particles of gelatin of different size suspended in contrast medium. One complication could be observed, but was not caused directly by embolization. In cases of profuse or vital bleedings which conservatively cannot be stopped embolization is method of first choice with no contraindication.

Percutaneous transluminal angioplasty (dilatation) of carotid, vertebral, and innominate artery stenoses.

Over a period of 5 years, 51 stenoses of brachiocephalic arteries were successfully dilated, and one subclavian occlusion recanalized in 42 patients. Among 24 patients there were 21 stenoses of the internal carotid artery, two stenoses of the common carotid artery, two stenoses of the innominate artery, five stenoses at the origin of the vertebral artery, and four stenoses of the subclavian artery. There were 17 patients who had stenoses of the subclavian artery. In 12 cases several arteries were affected. In 9 patients multiple (2-3) stenoses in these supraaortic arteries were dilated. In 4 cases bilateral dilatation of internal carotid arteries was performed. There were transient, minor complications in 2 patients.

[Results of percutaneous transluminal dilatation of cerebral vascular stenoses]. / Ergebnisse der perkutanen transluminalen Dilatation (PTD) von Hirngefässstenosen.

The present paper is a review of 37 successful catheter dilatations of supra-aortic vascular stenoses. There were sixteen patients with a total of 21 stenoses of the internal carotid, vertebral artery or common carotid artery and sixteen patients with subclavian stenoses. Amongst the patients with stenoses of the cerebral vessels, there were ten with multiple lesions and six with a single stenosis. Three patients had successful dilatations of bilateral stenoses. The indications, technique, and complications of catheter dilatation of lesions of the cerebral vessels are described and discussed.