Topological methods for the comparison of structures using LDR-brachytherapy of the prostate as an example.

The dose coverage of low dose rate (LDR)-brachytherapy for localized prostate cancer is monitored 4-6 weeks after intervention by contouring the prostate on computed tomography and/or magnetic resonance imaging sets. Dose parameters for the prostate (V100, D90 and D80) provide information on the treatment quality. Those depend strongly on the delineation of the prostate contours. We therefore systematically investigated the contouring process for 21 patients with five examiners. The prostate structures were compared with one another using topological procedures based on Boolean algebra. The coincidence number C(V) measures the agreement between a set of structures. The mutual coincidence C(i, j) measures the agreement between two structures i and j, and the mean coincidence C(i) compares a selected structure i with the remaining structures in a set. All coincidence parameters have a value of 1 for complete coincidence of contouring and 0 for complete absence. The five patients with the lowest C(V) values were discussed, and rules for contouring the prostate have been formulated. The contouring and assessment were repeated after 3 months for the same five patients. All coincidence parameters have been improved after instruction. This shows objectively that training resulted in more consistent contouring across examiners.

Prognostic factors in urothelial renal pelvis and ureter tumours: a multicentre Rare Cancer Network study.

To assess the prognostic factors in patients with transitional-cell carcinoma of the renal pelvis and/or ureter, a series of 138 patients with transitional-cell carcinoma of the renal pelvis and/or ureter was collected in a retrospective multicentre study. 12 patients with distant metastases were excluded from the statistical evaluation. All but 3 patients underwent radical surgery: nephroureterectomy (n = 71), nephroureterectomy and lymphadenectomy (n = 20), nephroureterectomy and partial bladder resection or transurethral resection (n = 20), nephrectomy (n = 10), and ureterectomy (n = 5). Sixty-one per cent (n = 77) of the tumours were located in the renal pelvis, and 21% (n = 27) in the ureter (both in 22 [17%]). Following surgery, residual tumour was still present in 33 patients (16 microscopic and 17 macroscopic). Postoperative radiotherapy was given to 45 (36%) patients. The median follow-up period was 39 months. In a median period of 9 months, 66% of the patients relapsed (34 local, 7 locoregional, 16 regional, and 24 distant). The 5- and 10-year survival were 29% and 19%, respectively, in all patients. In univariate analyses, statistically significant factors influencing the outcome were Karnofsky index, pT-classification, pN-classification, tumour localisation, grade, and residual tumour after surgery. Multivariate analysis revealed that independent prognostic factors influencing outcome were pT-classification, the existence of residual tumour, and tumour localisation. In patients with urothelial renal pelvis and/or ureter tumours, a radical surgical attitude is mandatory; and the presence of tumour in the ureter is associated with a poorer prognosis.

Pediatric medulloblastoma: radiation treatment technique and patterns of failure.

PURPOSE: In this study factors are analyzed that may potentially influence the site of failure in pediatric medulloblastoma. Patient-related, disease-related, and treatment-related variables are analyzed with a special focus on radiotherapy time-dose and technical factors. METHODS AND MATERIALS: Eighty-six children and adolescents with a diagnosis of medulloblastoma were treated in Switzerland during the period 1972-1991. Postoperative megavoltage radiotherapy was delivered to all patients. Simulation and portal films of the whole-brain irradiation (WBI) fields were retrospectively reviewed in 77 patients. The distance from the field margin to the cribiform plate and to the floor of the temporal fossa was carefully assessed and correlated with supratentorial failure-free survival. In 19 children the spine was treated with high-energy electron beams, the remainder with megavoltage photons. Simulation and port films of the posterior fossa fields were also reviewed in 72 patients. The field size and the field limits were evaluated and correlated with posterior fossa failure-free survival. RESULTS: In 36 patients (47%) the WBI margins were judged to miss the inferior portion of the frontal and temporal lobes. Twelve patients failed in the supratentorial region and 9 of these patients belonged to the group of 36 children in whom the inferior portion of the brain had been underdosed. On multivariate analysis only field correctness was retained as being significantly correlated with supratentorial failure-free survival (p = 0.049). Neither the total dose to the spinal theca nor the treatment technique (electron vs. photon beams) were significantly correlated with outcome. Posterior fossa failure-free survival was not influenced by total dose, overall treatment time, field size, or field margin correctness. Overall survival was not influenced by any of the radiotherapy-related technical factors. CONCLUSION: A correlation between WBI field correctness and supratentorial failure-free survival was observed. Treatment protocols should be considered that limit supratentorial irradiation mainly to subsites at highest risk of relapse. Optimized conformal therapy or proton beam therapy may help to reach this goal. Treating the spine with electron beams was not deletereous. A significant correlation between local control and other technical factors was not observed, including those relating to posterior fossa treatment. The use of small conformal tumor bed boost fields may be prefered to the larger posterior fossa fields usually considered as the standard treatment approach.

Prognosis of human chorionic gonadotropin-producing seminoma treated by postoperative radiotherapy.

PURPOSE: To clarify the controversy about the management and prognosis of human chorionic gonadotropin-producing seminoma, the records of 132 patients with abnormal human chorionic gonadotropin values treated with radiotherapy were analyzed. METHODS AND MATERIALS: The records of 1169 patients with pure seminoma treated in 10 institutions were screened for serum or urinary human chorionic gonadotropin. One hundred and thirty two patients with elevated human chorionic gonadotropin were found: 96 Stage I, 20 IIA, 7 IIB, 8 III and 1 IV. Median age was 34 y., mean follow-up was 5.0 years [range 1-12 y]. All received infradiaphragmatic radiotherapy (median dose 30 Gy), 25 (2 Stage I, 11 IIA, 5 IIB and 7 III) supradiaphragmatic radiotherapy (median dose: 28.5 Gy) and 10 had also initial chemotherapy (3 Stage IIB 6 III and 1 IV). Patients were allocated to three groups according to human chorionic gonadotropin values: (a) moderate elevation: up to 10 times (104 pts), (b) high elevation: 10 to 100 times (20 pts), (c) very high elevation: over 100 times the upper limit of normal value (8 pts). RESULTS: The proportion of Stage I, II and III was 76%, 19%, 5% in the ME group versus 50%, 35%, 15% in the high elevation group (p < 0.05). In the very high elevation group there were 7 Stage I and 1 Stage IV. Of 132 patients, six died (three dead of disease, two suicides, one acquired immunodeficiency syndrome). The 5 years overall survival probability was 94%. There were seven recurrences (initial stage: 1 Stage I, 2 IIB, 3 III and 1 IV). Of these, there were one in-field recurrence, 3 out of field and 3 in both sites. In 5 of 7, the human chorionic gonadotrophin level was again elevated at recurrence. The 5 years recurrence-free-survival probability was 94% (98% for Stage I, 100% for Stage IIA and 65% for Stage IIB and III [p < 0.001 between I and IIB + III, p < 0.05 between IIA and IIB + III]). Four of the 7 recurrences were salvaged by chimiotherapy +/- radiotherapy. In the high elevation and very high elevation groups, the 5 years recurrence-free-survival was 88%, vs. 96% for the moderate elevation group (p = 0.10). CONCLUSION: Based on this series of patients, human chorionic gonadotropin production is not an unfavorable prognostic factor in pure seminoma. Even in the subgroups with high or very high human chorionic gonadotropin levels (who had a higher proportion of advanced stages), the prognosis remained excellent. In Stage I and IIA seminoma with abnormal human chorionic gonadotropin levels, recurrence rate after post-operative radiotherapy alone is extremely low.

Restoration of pharyngoesophageal continuity with a replaceable prosthetic conduit: a new method.

Treatment of carcinomas of the upper aerodigestive tract by high dose radiation and wide surgical resection result in large tissue defects. When the inferior pharyngeal constrictor and the cricopharyngeus muscles are removed, a replaceable prosthetic conduit can be used effectively to reestablish pharyngoesophageal continuity. This prosthesis can be readily fabricated and obviates the need for extensive reconstructive operations in suitable candidates.

Computed tomographic demonstration of venous thrombosis of different etiologies.

Typical computed tomographic signs of venous thrombosis include the demonstration of the hypodense center (20 to 45 HU) in the involved blood vessel with a hyperdense margin surrounding it. CT represents a reliable method of diagnosis complimentary to that achieved by venography. CT examination allows the visualisation of the proximal end of the thrombus and gives the etiology of the thrombus. Venous thromboses occurring for the first time demonstrate a well defined borderline around the vein with a lack of reaction in the surrounding tissue. On the other hand, recurrent venous thrombosis is characterized by an inhomogenous zone of higher density in the perivascular region. A similar image can be obtained in secondary thrombosis due to inflammatory changes from adjacent tumours. In cases of thrombosis with tumour involvement, the tumour can be demonstrated.

[Value and possibilities for the improvement of hysterosalpingography]. / Stellenwert und Optimierungsmöglichkeiten der Hysterosalpingographie.

The diagnostic results of hysterosalpingography and laparoscopy were compared (30 patients). Agreement between the methods was found in 73%. In 17% of the women, findings seen on hysterosalpingography, could not be confirmed at laparoscopy. Conversely, in 10% of negative hysterosalpingograms, adhesions were found at laparoscopy. Possible causes for these differences are discussed. At present three different methods are used for hysterosalpingography. Compared with a metal cannula or a Foley catheter, the use of a baby's feeding tube resulted in a reduction of tubal spasm. A reduction in screening time and consequent decrease in gonadal radiation is possible without loss of diagnostic information.

[Radiotherapy of hypophyseal adenoma]. / Strahlentherapie der Hypophysenadenome.

The efficacy of radiotherapy alone for control of pituitary adenoma is well documented. Because of slow endocrinologic response and delayed shrinkage of the tumor, it is reserved for inoperable patients. Transsphenoidal surgery is generally regarded as the treatment of choice. It provides prompt reduction of tumor mass and hormone levels. Radiotherapy as an adjunct has been proven effective in gross residual disease and for post-operatively elevated hormone levels. It is also effective in treating recurrencies after surgery. Its value in an interdisciplinary approach is discussed.

[Case report on a myocardial ischemia due to medical tocolysis with ritodrin (pre-par) (author's transl)]. / Kasuistiche Mitteilung über das Auftreten einer Myokardischämie unter medikamentöser Tokolyse mit Ritodrin (Pre-Par).

In the 24 year old former competitive athelete tocolysis with ritodrin (pre-par) was started at 28 weeks gestation in her second pregnancy for premature labor. Diffuse cardiac ischemia occurred during the intravenous infusion of ritodrin. The betamimetic drug was the factor which started the myocardial ischemia as evidenced by the serial electrocardiograms. The importance of serial electrocardiograms during treatment with ritodrin is emphasized.

[Percutaneous radiotherapy of cervical cancer]. / Zur perkutanen Strahlentherapie des Zervixkarzinoms.

Whereas the local effect of radiotherapy in the postoperative treatment of uterine cervix cancer developing lymphogenic metastases may be regarded as clearly demonstrated, there is no evidence of its effect on the survival of patients. A definite answer to this question is only possible on the basis of prospective studies. In primary radiotherapy, more importance than in former days is given to percutaneous irradiation which allows a more homogeneous dose to the small pelvis. According to the present state of knowledge it is not justified to do without contact therapy except in cases of a very advanced disease.

[Initial experiences with interstitial brachycurietherapy (low dose rate I-125 seeds in carrier/vicryl and high dose rate Ir-192 afterloading system) in the palliative treatment of head and neck tumors]. / Erste Erfahrungen mit interstitieller Brachycurietherapie (low-dose-rate J-125-seeds in carrier/Vicryl bzw. high-dose-rate Ir-192-afterloading system) in der Palliativbehandlung von Kopf-Hals-Tumoren.

The local control rates for previously irradiated recurrent tumours of the head and neck is dose dependent. High dose percutaneous irradiation alone is associated with a high complication rate. On the other hand it is possible to apply high local doses by interstitial irradiation, whilst sparing the surrounding tissue. In the last 2 years we have used Iodine 125-seeds in carrier (Vicryl) and a high dose rate Iridium 192-source for the afterloading technique. Our first experiences with 12 patients show reasonable palliation, but not effect on survival.

A 5-year follow-up study for distance visual acuity after low dose radiation on subfoveal choroidal neovascularization in age-related macular degeneration.

In a prospective study with a 5-year follow-up, we assessed the effect of a single series of low-dose radiation on the distance visual acuity in eyes with angiographically confirmed subfoveal choroidal neovascularization (CNV) in age-related macular degeneration (ARMD). The posterior pole of 12 eyes was treated with 5 Gy (4 x 1.25 Gy), and 34 eyes treated with 8 Gy (4 x 2 Gy). The best corrected distance visual acuity was measured at the time of treatment, and annually thereafter for 5 years. The study obtained complete follow-up for 11 patients in the 5-Gy group (nine classic, two occult CNVs), and 29 patients in the 8-Gy group (12 classic, 17 occult CNVs). At baseline, the mean distance visual acuity of the treated eyes was 0.16 (20/125) in the 5-Gy group, and 0.2 (20/100) in the 8-Gy group. Five years later, an average loss of 3.2 lines was present in the 5-Gy group, and 4 lines in the 8-Gy group. After 5 years, an average loss of 2 lines was found in a control group consisting of 18 second eyes with low stage dry ARMD, with a mean distance visual acuity of 0.5 (20/40) at baseline. Statistical analyses with Wilcoxon and Mann-Whitney U-tests showed that a single series of low dose radiation with either 5 Gy or 8 Gy was not able to stabilize the distance visual acuity of eyes with subfoveal CNV in ARMD during a 5-year follow-up.