Quality assurance in radiotherapy--a clinical view-point.

Despite the advanced treatment methods now available, the total result in 5-year survival is 40-50% of all patients with malignancies and 20% of these patients will have the chance of a 10-year survival. In the course of their disease a radiotherapy is indicated in about 2/3 of all cancer patients. Thus, radiotherapy makes quite a considerable contribution to the qualitative improvement of the treatment of patients with malignancies. Eradication of the tumor and protection of normal tissue can be only a compromise between tumor control and the production of complications. For the risk assessment of radiotherapy, the steepness of dose-response curves is of paramount importance. That means, small errors in defining and delivering dose can have catastrophic results in terms of failure to control the patient's disease and, on the other side, in terms of complications, that means in quality of life. Although the costs of therapy, in absolute values, vary from one country to the other, it can be stated in rough approximation that a failed radiotherapy will make rise the costs by a factor of 3. Proceeding on the fact that in 30-40% of patients, who received radiotherapy, the initial treatment failed to control the primary disease, the enormous additional costs involved become obvious, not to speak of the main argument--the regrowth of the patient's tumor. For the improvement of this situation quality assurance (QA) is an essential prerequisite, which should be guaranteed in all successive steps of radiotherapy. In the paper an analysis is given for all individual steps in the chain of radiotherapeutic measures.(ABSTRACT TRUNCATED AT 250 WORDS)

[A comparison of systemic radiotherapy, chemotherapy or local radiotherapy in the treatment of extensive small-cell bronchial carcinoma. Results of a randomized series]. / Vergleich zwischen systemischer Strahlentherapie, Chemotherapie oder lokaler Strahlentherapie bei der Behandlung des ausgedehnten kleinzelligen Bronchialkarzinoms. Ergebnisse einer randomisierten Serie.

Between 1982 and 1987 we carried out a prospective randomized study to compare the effectiveness of high-dose half-body irradiation (HBI) (A), intensive combined chemotherapy (B), and local or locoregional radiotherapy (C) in the therapy of extended small cell lung carcinoma (SCLC). 99 patients with a histologically proved SCLC were assigned to the three therapeutic groups of series: A = 31 patients, B = 37 patients, C = 31 patients. The median survival period showed a statistically significant advantage (p less than 0.01) for the chemotherapy group (B = 46 weeks) versus the two radiotherapy groups (A = 19 weeks, C = 23 weeks). The survival after half a year, one year, and two years also gave a clear advantage for the chemotherapy group. No difference was found between the radiotherapy groups A and C. The high-dose HBI gave no improvement of the sad therapeutic situation for the extended SCLC.

A randomized clinical trial comparing systemic radiotherapy versus chemotherapy versus local radiotherapy in small cell lung cancer.

Between 1982 and 1987 a prospectively randomized trial of sequential hemibody irradiation (SHBI) (A), a non-cross-resistant chemotherapy drug combination (B) and local and/or locoregional radiotherapy (C) in small cell lung cancer (SCLC) was conducted. Previously untreated patients with extensive SCLC were randomized into three arms: A = 31 patients, B = 37, C = 31. In the chemotherapy combination, the following were used: etoposide, doxorubicin, methotrexate (VAM) and procarbacine, vincristine, cyclophosphamide, lomustine (POCC) and prophylactic cranial irradiation (30 Gy). The results show that the median survival was significantly (P less than 0.01) better in chemotherapy (44 weeks) compared with 17 and 20 weeks in arms A and C, respectively. One year and 2 year survival rates were better for the chemotherapy arm. No differences were found between groups A and C. In comparing the total hospitalization time expressed as a percentage of overall survival, an advantage for group B was shown. In conclusion, high dose SHBI cannot be recommended as a standard therapy for extensive SCLC.

[Computed tomography in the diagnosis of isolated bone metastases and its influence in therapy planning]. / Computertomographie in der Diagnostik isolierter Knochenmetastasen und ihr Einfluss auf die Therapie-Planung.

In a collective of 70 patients with bone metastases the importance of CT for detection and extension diagnosis is shown. In 53% CT proved the scintigraphic and/or roentgenologic suspicion. In 30% CT gave more information than scintigraphy and plain radiography, but without any influence in the treatment. In 17% only CT gave such important information, that the planned treatment must be changed. The results led to the conclusion, that CT can be important for the optimization of radiological treatment.

[Dermatofibrosarcoma protuberans. Results of radiosurgical therapy by photon and electron rays or fast neutrons]. / Dermatofibrosarcoma protuberans. Ergebnisse der radiochirurgischen Therapie mit Photonen- und Elektronenstrahlung bzw. schnellen Neutronen.

The dermatofibrosarcoma protuberans, a rare entity of soft tissue sarcomas, is specified as a tumor of intermediate malignancy because of its marked tendency to form local recurrences. Regarding the prevention of local recurrences, the results of combined radiosurgical therapy (n = 13) could be improved in our patients by the application of fast neutrons (n = 6). Despite multiple previous operations for recurrences, a reliable prevention of local recurrences (average follow-up period 5.5 years) was achieved in all patients by neutron irradiation with focal doses of approximately 9 Gy. One patient with multiple macroscopic recurrences received two neutron series with 17 Gy. At seven years, she is still recurrence-free. We consider the postoperative irradiation of the dermatofibrosarcoma protuberans with fast neutrons following to primary tumor excision as method of choice for a reliable prophylaxis of local recurrences, because this method allows to dispense with major radical surgery.

[Results of high-voltage and neutron therapy in the treatment of the postoperative anastomotic recurrence of stomach cancer]. / Ergebnisse der Hochvolt- und Neutronentherapie in der Behandlung des Anastomosenrezidivs beim operierten Magenkarzinom.

Local recurrence in anastomotic region after resection of stomach cancer is not a rare event. The role of radiotherapy in palliative treatment is commonly underestimated. Our experiences were demonstrated in 2 treatment groups (megavoltage therapy alone, 23 cases; in combination with neutrons, 13 patients). Decrease in dysphagia in 75% of patients was comparable with roentgenologic findings, where reduced tumor in 63% was established. These encourageable findings were confirmed in examination of anastomotic region in autopsy (megavoltage therapy 14 cases, combined neutron therapy 12 cases). Smaller tumors could be totally destroyed by megavoltage therapy. The local tumor destroying rate increased by combination with neutrons (6/12 cases). No advantage in life prolongation could be stated, because local recurrence was quickly followed by widespread disease (77%). Finally we demonstrate a treatment plan, which bases on our clinical experience. With 3-4 fractions of 5-7 Gy a real clinical and radiological demonstrable palliation effect is to be reached.

[Treatment of inoperable small-cell bronchial carcinoma with local radiotherapy and supplementary high-dosage one-time upper and lower half-body irradiation]. / Zur Behandlung inoperabler kleinzelliger Bronchialkarzinome mit lokaler Strahlentherapie und zusätzlicher hochdosierter einzeitiger oberer und unterer Halbkörperbestrahlung.

37 patients with histologically verified inoperable small-cell bronchial carcinomas were treated with local tumor irradiation (40 Gy), combined with upper and lower half-body irradiation. Continuous analysis of the treatment results led to modification of therapy, from which two groups of patients resulted. In group I the whole-body treatment consisted of an irradiation of the upper, and six weeks later, of the lower half of the body with a dose of 8.8 Gy. In group 2 the half-body dose of 8.8 Gy was applied in 2 fractions on the same day (6.0 Gy, break of 5 hours, 2.0 Gy). The critical organ was the lung: the pneumonitis rate and the effect on tumor and metastases and survival times are reported.

Preliminary report on "one-time" and high dose irradiation of the upper and lower half-body in patients with small cell lung cancer.

Forty-two patients with histologically confirmed inoperable small (oat) cell lung cancer were treated with local tumor irradiation (approximately 4,000 cGy) combined with "one-time" irradiation of the upper and lower half of the body. Twenty-five patients (Group I) received the irradiation in lateral position first to the upper half-body, and six weeks later to the lower half-body, the midplane dose averaging 880 cGy (not corrected for lung tissue). In 17 patients, lethal pneumonitis occurred. The mean time of survival was 8.2 months for 22 patients having the disease limited to one thorax-side and 4.0 months for three patients having distant metastases, stated by conventional clinical and X ray investigations. Seventeen patients (Group II) received the two half-body irradiation treatments through anterior-posterior fields. The average dose had been reduced to 800 cGy (uncorrected) and was given on one day in two fractions (600 and 200 cGy, separated by an interval of 5 hours). Furthermore, the forearms and the lower legs had been left outside the fields. Only one patient showed pneumonitis. The mean time of survival was 14.3 months for 12 patients having the disease limited to one thorax-side and 6.6 months for five patients having distant metastases. In both groups, serious reactions of the bone marrow were not observed. In Group II, leucocytes and lymphocytes had reached their original values three months after the end of irradiation. For all 42 patients, X ray films showed complete regression of the primary tumor. In 12 out of 35 autopsy specimens, the primary tumor could not be detected histologically, but only five of these were free of metastases. Presently, additional irradiation of the two halves of the body with lower and fractionated doses are being tested in order to achieve the further reduction of tumor cell numbers.