Purpose:To evaluate 1 novel MRI, neuro-cognitive and quality of life endpoints in preparation of their use in a prospective, randomized Phase III trial and 2. to obtain additional safety and efficacy data in 25 patients when the radiation enhancer XCYTRINTM (motexafin gadolinium, also known as gadolinium texaphyrin) is administered with whole brain radiation therapy (WBRT). Materials & Methods:In a prospective, multi-center, international trial, patients with brain metastases were treated with XCYTRIN (5 mg/kg/d IV) prior to each often 3Gy fractions of WBRT.Patients with unresected and previously unirradiated brain metastases and KPS 2 70 were eligible.Patients were evaluated by MRI, FACT-BR, and a battery of neuro-cognitive tests (Trail Making A&B.Grooved Pegboard Test, Hopkins Verbal Learning Test, Controlled Oral Word Association Test) before WBRT and at regularly scheduled follow-up time points.

To investigate the influence of implementing three-dimensional treatment planning on staffing needs, valid questionnaire responses from 22 radiotherapy institutions have been evaluated. Average time requirements per plan rise from 213 to 439 min upon implementation, but with experience decrease to 317 min. No institution reports additional staff positions according to estimated requirements.

Purpose: To assess the accuracy of field alignment in patients undergoing three-dimensional (3D) conformal radiotherapy of brain tumors, and to evaluate the impact on the definition of planning target volume and control procedures.Methods and Materials: Geometric accuracy was analyzed in 20 patients undergoing fractionated stereotactic conformal radiotherapy for brain tumors. Rigid head fixation was achieved by using cast material. Transfer of stereotactic coordinates was performed by an external positioning device. The accuracy during treatment planning was quantitatively assessed by using repeated computed tomography (CT) examinations in treatment position (reproducibility of isocenter). Linear discrepancies were measured between treatment plan and CT examination. In addition, for each patient, a series of 20 verifications were taken in orthogonal projections. Linear discrepancies were measured between first and all subsequent verifications (accuracy during treatment delivery).Results: For the total group of patients, the distribution of deviations during treatment setup showed mean values between -0.3-1.2 mm, with standard deviations (SD) of 1.3-2.0 mm. During treatment delivery, the distribution of deviations revealed mean values between 0.7-0.8 mm, with SDs of 0.5-0.6 mm, respectively. For all patients, deviations for the transition to the treatment machine were similar to deviations during subsequent treatment delivery, with 95% of all absolute deviations between less than 2.8 and 4.6 mm.Conclusion: Random fluctuations of field displacements during treatment planning and delivery prevail. Therefore, our quantitative data should be considered when prescribing the safety margins of the planning target volume. Repeated CT examination are useful to detect operator errors and large random or systematic deviations before start of treatment. Control procedures during treatment delivery appear to be of limited importance. In addition, our findings should help to determine "cut-off points" for corrective actions in stereotactic conformal radiotherapy of brain tumors. (C) 1999 Elsevier Science Inc.

PROBLEM:HDR brachyradiotherapy has minimized the exposure to radiation of the personnel working in this field. Nonetheless there are periodically reported troubles with afterloading units concerning the retraction of sources that require immediate action for the limitation of possible damage. LEGAL PRINCIPLES ACCORDING TO THE GERMAN REGULATION CONCERNING PROTECTION AGAINST RADIATION (STRAHLENSCHUTZVERORDNUNG = STRLSCHV): If in afterloading brachyradiotherapy the radiation source remains extended through malfunction we deal with an emergency according to the StrlSchV. The rescue personnel should be chosen in accordance with section 50 StrlSchV (Table 1).ORGANIZATION OF THE RESCUE OF THE PATIENT:The quickest possible rescue of a patient in an emergency demands an unequivocal definition of responsibilities. Our recommendations in this instance: the physicist is responsible for the organization of the emergency rescue. The radiation oncologist in charge informs himself about the necessary emergency measures before starting the treatment and carries out the emergency rescue. If the physicist diagnoses a failure in the retraction of the source he tries to remove the failure. If he doesn't succeed in retracting the source the radiation oncologist carries out the rescue of the patient. The organizational structure of the clinic allowing, the emergency physician should invariably be the physician who placed the applicator. In the emergency rescue the radiation oncologist should be protected by a lead barrier (Figure 1, Table 2) and use manipulators (Figure 1).DOSE ASSESSMENT IN PERSONNEL AND PATIENT:The radiation exposure of the rescue personnel is calculated from the photon-equivalence dose HX with the help of the dose-rate constant of 192Ir (Table 3). According to the same procedure there can be evaluated the local radiation exposure of the patient concerned (Table 3).CONCLUSIONS:Generally speaking, all considerations regarding the topic of emergency rescue should always start out from a worst-case scenario. Of all the people involved the patient is the one who is most exposed if the radiation source is located inside his or her body. If an emergency rescue is necessary the radiation exposure of patient and personnel can only be minimized by a quick rescue. This end requires a properly equipped emergency workplace, good training of all the people concerned, and regular exercises of the rescue procedures. A well-practiced emergency management can be of life-saving importance for the patient.

The advantage of external radiation therapy in renal cell carcinoma is controversial. High complication rates reported in previous trials of postoperative radiation therapy can now be avoided by using contemporary modern treatment techniques. Based on both prospective and retrospective data the following indications for adjuvant radiation therapy should be considered and tested in phase III trials: a) unresectable non-metastatic tumours (preoperative irradiation), b) incomplete resection with gross or macroscopically positive margins, c) locally advanced tumour with perinephric fat extension or adrenal invasion.

Purpose: To assist in the design of quality assurance activities of 3D treatment planning systems (TPSs), a postal survey has been carried out, addressing TPS users on quality characteristics and their relative importance in clinical routine planning.Material and Methods: The approach as described in ISO/IEC 9126 has been used to analyze TPS quality. Both TPS quality characteristics and how these may be used to establish a quality model are included. A questionnaire on ranking of these TPS quality characteristics has been sent out to the German DEGRO members in February 1997.Results: By the end of July 1997, 90 individual assessments (of 45 physicists, 35 physicians, and 10 radiographers) had been collected. On an importance scale from 1 (very important) to 6 (unimportant), weight factors of 1.71 (portability), 2.84 (maintainability), 3.18 (efficiency), 3.85 (usability), 4.52 (functionality) and 4.90 (reliability) have been determined from the data. From user satisfaction data also obtained from the questionnaire responses, baseline quality indices could be established from the quality model for the RTPs Cadplan, TMS Helax, and Voxelplan.Conclusion: The responses highlight the need for TPS quality assurance at the same time along the lines of safety-related, research-oriented, and interactive end-user software systems in radiotherapy treatment planning. Quality assurance activities must take this into account. Their effect can be monitored by using quality indices as derivable from the established quality model.

Die Segmentierung von Schnittbildserien spielt bei der Definition von Zielvolumen und Risikoorganen für die 3D-Bestrahlungsplanung eine große Rolle. In dieser Arbeit wird eine Methode zur Quantifizierung der rein technisch bedingten Ungenauigkeit bei der manuellen Bildsegmentierung beschrieben. Zur Validierung dieser Methode wurde ein Graustufenphantom mit verschiedenen geometrischen Figuren unterschiedlichen Kontrastes entwickelt. die von verschiedenen Versuchspersonen mit Hilfe des Segmentierungsprogramms TOMAS des Heidelberger VOXELPLAN-Systems konturiert wurden. Über die erzielten Ergebnisse wird berichtet.

PURPOSE:A multicenter prospective trial was conducted (Maligue Keimzelltümoren [MAKEI] 83/86/89) to assess outcome in intracranial germinoma after treatment with radiotherapy alone at reduced doses.PATIENTS AND METHODS:Between 1983 and 1993, 60 patients with histologically (n = 58) or cytologically (n = 2) confirmed germinoma were enrolled onto the study. Patients received radiotherapy alone (craniospinal axis/local boost). In the MAKEI 83/86 study (involving 11 patients), the dose to the craniospinal axis was 36 Gy and the dose to the tumor region was 14 Gy. In the MAKEI 89 study (involving 49 patients), doses were 30 and 15 Gy, respectively.RESULTS:Median patient age was 13 years (range, 6 to 31 years). Complete remission was achieved in all patients. The estimated (Kaplan-Meier) 5-year relapse-free survival rate was 91.0% +/- 3.9% at a mean follow-up of 59.5 months (range, 3 to 180 months); the estimated overall survival rate was 93.7% +/- 3.6%. Relapse occurred in five patients 10 to 33 months (mean, 18.4 months) after diagnosis (one patient developed a spinal canal metastasis and underwent salvage radiotherapy and chemotherapy; four patients had metastases outside the CNS and underwent salvage chemotherapy alone). Four patients died: one died from disease, two died from therapy-related complications, and one committed suicide. Acute complications with long-lasting sequelae were tumor or surgery related (three cases of blindness, six of reduced vision, two of hemiparesis). Psychosocial development was normal in the majority of patients.CONCLUSION:Radiotherapy directed toward the craniospinal axis or tumor site alone at decreased dose levels is effective. To reduce the risk of late side effects, further attempts to decrease total doses are justified. In cases of recurrent disease, chemotherapy administered outside the CNS is the treatment of choice.

At the University of Tübingen a Linac based stereotactic system for radiosurgery has been used since 1991. The floorstand system (SRS 200, Phillips) developed at Gainsville is used in combination with a Cosman Roberts Weels system by Radionics. The floorstand enables the gantry to be rotated vertically and the table to be rotated in the horizontal plane. Additionally, patient's movements are reduced by the fixation of the stereotactic ring to the stereotactic floorstand. We report our experience with the first 50 patients treated between December 1991 and June 1995. The patients were treated with an interdisciplinary approach. This cooperation eases the transition from radiosurgery to other methods such as embolization, operation, and other radiooncologic treatment options.

Introduction: The principles of radiosurgery were developed in 1951 by Leksell. Their technical realization led to the development of the gamma knife and stereotactically modified linear accelerator.

INTRODUCTION:The principles of radiosurgery were developed in 1951 by Leksell. Their technical realization led to the development of the gamma knife and stereotactically modified linear accelerator. METHODS:In addition to the gamma knife, we present the different principles of convergent beam irradiation (radiosurgery with linear accelerator), the further development to fractionated stereotactic conformal radiotherapy, and the necessary quality-assurance steps. RESULTS:The greatest uncertainties in the precision of radiosurgery result from medical imaging (CT 0.7 x 0.7 x 1 mm; DSA 1-5 mm; MR angiography < 2 mm). The focusing accuracy of the gamma knife (+/- 0.3 mm) can also be achieved today by linear accelerators using a stereotactic floorstand. For the same indication and the same dosage for the target volume, there are no clinical differences between the gamma knife and the linear accelerator (AVM: 80% complete obliteration; metastases: 85% local tumor control; AN: 90% tumor control). However, there are greater differences in costs. There is no constellation where the gamma knife is just as expensive or more cost-effective than the linear accelerator treatment. The most cost-effective solution is modification of an available linear accelerator, resulting in treatment costs per patient of 9,201.25 DM (50 patients/year). CONCLUSION:There seem to be no methodological, physical, clinical or cost reasons for using a gamma knife, especially because the trend is going towards fractionated conformation radiotherapy instead of the application of high single doses.

Percutaneous endoscopic gastrostomy (PEG) has become a widely used method for nutritional support, particularly in patients with advanced head and neck carcinomas. Since the method is easy and widely established it is necessary to assess possible complications, even rare ones. In this paper we report on two patients with vaccination metastasis following PEG insertion. Both patients had advanced squamous cell carcinoma of the head and neck or the upper esophagus. In three patients previous bougienage was performed, because of considerable stenosis of the pharynx and/or esophagus. Fast-growing metastases were found at the site of PEG insertion, with and without involvement of the gastric wall. In neither case was abdominal wall metastasis the cause of death. There is a small but definite risk of tumor seeding into the abdominal wall after PEG insertion for obstructive malignant tumors. The clinical impact of this finding, however, is still undefined and needs further investigation.

By means of preliminary results in the treatment of patients with acoustic neurinoma the achievable accuracies, dose distributions and time consumption of stereotactic LINAC-based convergent beam radiosurgery are compared to those achieved with fractionated stereotactic conformation beam radiotherapy. Characteristics of both techniques are described. With the Tübingen radiosurgery system a good adaptation of the dose distribution to spherical or oval target volumes with a steep dose gradient was achieved, whereas homogeneity and adaptation of the dose distribution to irregularly shaped targets were better with the Heidelberg conformation technique. The mechanical accuracy of the Tübingen floorstand system was 0.3 mm +/−0.2 mm, and that of the Heidelberg mask fixation system < 1 mm. Both methods require similar total treatment times. Nine patients were treated by the Tübingen radiosurgery system. The results are compared with 12 patients treated by conformation radiotherapy in Heidelberg. In both patient groups no further tumour growth occurred. Four of 9 single dose treated patients developed side-effects, such as temporary trigeminal and facial paraesthesia hearing deterioration and oedema. In contrast, patients treated by fractionated radiotherapy showed no side-effects.