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Copyright of Der Onkologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Modern Treatment Concepts in Radiation Oncology Abstract. Radiotherapy is a widely used form of therapy that is used in half of all cancer patients. Advances in understanding the fundamentals of tumor and radiation biology, in medical physics and computer science as well as technical developments have continuously improved the effectiveness and healing success of radiotherapy. Patients benefit from new treatment concepts such as hypofractionated radiotherapy for breast and prostate cancer, leading to a reduction in the duration of treatment by several weeks. Selected patients with early stages of breast cancer can be treated with partial breast irradiation with focus on the tumor bed after breast conserving surgery increasing tolerability and comfort. High dose stereotactic radiotherapy over five to six sessions of radiation or only one fraction (radiosurgery) have expanded treatment options for common tumor entities leading to long-lasting tumor control resulting in improved survival and quality of life for those affected. In early lung cancer stereotactic radiotherapy is an alternative to primary tumor surgery. For patients with oligometastatic tumor disease stereotactic radiotherapy allows a curative approach by effectively treating metastases. In patients with brain metastases whole-brain irradiation is replaced by stereotactic irradiation of the individual metastases with fewer side effects. Recently, promising results for improved tumor control with the combination of radiotherapy and immunotherapy have been presented. Radioimmunotherapy represents a new therapy combination. However, final assessment of its efficacy and side effects profile is still missing. In order to gain therapeutic certainty, further prospective study data are necessary.

Background: Conformal radiotherapy techniques as used in prostate treatment allow to spare normal tissue by conforming the radiation fields to the shape of the planning target volume (PTV). To be able to fully utilize the advantages of these techniques correct patient positioning is an important prerequisite. This study employing an electronic portal imaging device (EPID) investigated the positioning uncertainties that occur in the pelvic region for different patient positioning devices., Patients and Methods: 15 patients with prostate cancer were irradiated with or without rectal balloon/pelvic mask at a linear accelerator with multileaf collimator (MLC). For each patient multiple portal images were taken from different directions and compared to the digitally reconstructed radiographs (DRRs) of the treatment planning system and to simulation films (Table 1, Figure 1)., Results: In spite of different positioning devices, all patients showed comparable total positioning uncertainties of 4.0 mm (lateral), 4.5 mm (cranio-caudal) and 1.7 mm (dorso-ventral). The lateral positioning error was reduced for the pelvic mask patients while the cranio-caudal error increased (Table 2, Figure 2). A systematic and a random component sum up to the total positioning error, and a good estimate of the magnitudes of the two is possible from six to eight portal images (Figure 3)., Conclusions: With a small number of portal images it is possible to find out the systematic and random positioning error of a patient. Knowledge of the random error can be used to resize the treatment margin which is clinically relevant since this error differs greatly for different patients (Figure 4). Image analysis with EPID is convenient, yet has some problems. For example, one only gets indirect information on the movement of the ventral rectum wall (Figure 5). The successful operation of positioning devices, although, needs further improvement--especially if one focuses on IMRT.

Purpose: The aim of this study was to investigate whether the yolk sac blood vessel system of chick embryos represents a useful model of in-vivo measurements of angiogenesis in radiobiology., Material and Methods: The fertilized eggs of the crossbreeding White Plymouth Rox X Sussex were used for the study of the extraembryonic vascularisation after irradiation with different fractionation and dosage. On day 3 of incubation an oval window was cut into the shell and then the area vasculosa was irradiated with 1.0 cm in diameter. Forty-eight hours after irradiation in-vivo photographs were taken for quantitative evaluation of blood vessel density., Results: Irradiation from 2.0 to 8.0 Gy in a single fraction leads to a slight decrease in vascular density. After a single fraction of 10.0 Gy a distinct increase in vascular density occurs. Fractionated irradiation leads to a considerable clear increasing of vascular density in comparison with the single fraction and same total dose., Conclusion: Our model of the fertilized egg enables in-vivo measurements of angiogenesis in radiobiology.

Background: To improve the quality of life for patients with recurrent and metastatic breast cancer, palliation of pain, skin and soft tissue metastases and complicating lymph node relapses are mandatory. Toxicity and efficacy of 2 simultaneous radiochemotherapy regimens was tested in this study., Patients and Methods: From October 1989 to March 1993, 48 patients with locoregional relapse of breast carcinoma after primary mastectomy and no option for curative resection were entered in the study. Seventeen patients had additional distant metastases. Two different radiochemotherapy regimens were applied: Group A (28 patients) received a "split course" radiotherapy within 10 weeks (1.8 to 2 Gy single dose) on day 1 to 12, 29 to 40 and 57 to 68 up to a total dose of 54 Gy. Chemotherapy with 5-FU, methotrexate and cyclophosphamide was applied simultaneously with radiation. After the second and fourth week the treatment was interrupted for 2 weeks. Group B (20 patients) received "conventional" radiotherapy over 6 weeks with 1.8 to 2 Gy single and 54 Gy total dose. 5-FU and mitomycin C was applied in the first and fifth week of radiotherapy. Treatment toxicity was analyzed in 48 patients, while treatment efficacy was assessed in 44 patients with a minimum follow-up of at least 1 year., Results: Overall treatment response (CR+PR) was 82% in group A (CR 21%). Five of 28 patients developed toxicities of grade 3 to 4 (EORTC/RTOG/WHO). The overall response rate in group B was 87% (CR 19%). In this group 6 of 20 patients experienced toxicities of grade 3 to 4. In both groups, the local response rate was remarkably reduced in patients with additional visceral metastases., Conclusions: Both treatment concepts achieved similar response rates. Group B patients experienced a higher toxicity rate, but treatment duration was considerably shorter. The local response rate correlated well with the extent of systemic metastatic disease.

Background: In current radiooncology the consistent use of best supportive care during aggressive combined treatment protocols is indispensible. Presently the optimal management of fever in granulocytopenic patients is controversially discussed., Material and Methods: Based on own clinical experiences and a literature review we report about empiric antibiotic and antifungal therapy in febrile patients with granulocytopenia. Particular consideration is given to the new antifungal agent fluconazole (compared to amphotericin B) and the beta-lactamase inhibitor sulbactam. We also discuss the use of hematopoietic growth factors and selective gastrointestinal decontamination., Results: In fever of unknown origin the use of a two drug antibiotic combination containing an ureidopenicillin (acyl-penicillin) and an aminoglycoside is recommended. After five days of persisting fever additional antimycotic therapy is initiated. Fluconazole shows a high response rate with only few side effects in the treatment of infections with candida albicans and cryptococcus neoformans. In the early empiric antifungal therapy it is more and more replacing amphotericin B. With encouraging results sulbactam can be combined with piperacillin or mezlocillin during radiochemotherapy. Concerning G-CSF there are no general recommendations allowed. We prefer a calculated prophylaxis for patients who receive a myelotoxic chemotherapy and have a high individual risk for severe neutropenia. During the second day of reverse isolation we start a selective decontamination of the digestive tract until white-blood-cell-count increases to more than 1000 to 1500 granulocytes/mm3., Conclusion: The radiooncologist should be able to completely manage prevention and treatment of infectious diseases to provide an optimal use of all new options in combined modality treatment in radiooncology.