Combined neutron-photon-therapy of locally recurrent rectosigmoidal tumors

21 patients with unresectable recurrent adenocarcinoma of the rectum were treated with combined photon-neutron radiation therapy. 40 Gy photon were given to the whole pelvis followed by a boost field of 6.6 or 10 Gy utilizing 14 MeV monoenergetic neutrons. The latter was given with an arc therapy technique whereby the dose output fluctuations normally encountered during gantry rotation were compensated for by a computer guided system. All patients had severe pain symptoms before therapy. Twelve patients had a full remission of the symptoms and nine reported considerable relief of pain during follow-up examination. In three patients, further pain symptoms developed after six, seven, and nine months due to renewed tumor progression. In spite of the relative high neutron doses applied, side effects with the arc-technique remained minimal and did not exceed those encountered with photon therapy alone. Although the total follow-up time is relatively short at a maximum of 20 months, with a mean time of 8.5 months, the preliminary results so far are extremely optimistic leading us to further pursue the study.

Pleural metastasis of malignant thymoma. A pitfall in the CT-diagnosis of pleural mesothelioma

We report two cases with metastatic thymomas mimicking the CT feature of pleural mesothelioma.

[Sonographic diagnosis of head and neck tumors in association with therapy]

Basing on the experience with 558 patients suffering from tumours or suspicious lesions in the head and neck region, sonographic pointers that have been inadequately noted so far, are pointed out to improve diagnosis, follow-up, and post-therapeutic care. Among the possibilities offered by sonography are: to confirm or exclude bony involvement of the mandible in tumours of the oral cavity and the oropharynx, to objectify the results of antineoplastic chemotherapy, to offer possibilities to optimize radiotherapy, as well as to show criteria for the early detection of a relapse under consideration of the primary therapy.

[Radiotherapy using photons and neutrons in recurrences of colorectal tumors]

74 patients with locoregional recurrences of colorectal carcinomas were subjected to radiotherapy with photons. In 72% of the patients a palliative effect was seen with considerable or complete pain relief. The median survival times of the patients with and without remote metastases were 7 and 15 months, respectively. Radiobiological experience leads us to expect a higher degree of efficacy when using highly ionising radiation such as neutrons. The relatively poor physical parameters of conventional neutron generators were optimised by means of a novel irradiation technique developed at the German Research Centre in Heidelberg. Using this technique, a study was started for the combined photon/neutron irradiation in recurrent sacral tumours. 14 MeV neutrons of a DT (deuterium-tritium) generator ("KARIN" supplied by Haefely) were applied as boost. 26 patients have so far been treated by this method. Palliative results are excellent and the results obtained so far have been so encouraging that an extension of the study is under consideration.

[The results of radiotherapy in advanced oral carcinomas. The effect of altered therapeutic strategies]

During the period from 1968 through 1984, 197 patients with advanced carcinomas of the oral cavity have been irradiated. The authors investigate the influence of a standardized chemotherapy as initial therapy measure on the subsequent radiotherapy and the therapy results. Whereas 4.2% of patients were submitted to this treatment between 1968 and 1975, 64.5% of patients received a chemotherapy during 1976 and 1984. The remission rate following to cytostatic therapy was 71%; most of them were partial remissions. The influence of chemotherapy manifested itself by an increase of macroscopically radical tumor resections, especially in stage IV, but also by an increased number of radiotherapy interruptions in case of strong mucosal reactions. An increase of the median survival time from 20 to 30.5 months was connected with the intensified therapy. Further on, this difference vanished, and the five-year survival rates were identical.

[Computed tomographic diagnosis of diseases of the pituitary region]

Because of the high density and spatial resolution it allows, CT scanning has come to play a key role in the diagnosis of diseases of the pituitary region. While the extension of macroadenomas is regularly detected, only meticulous techniques using coronary scanning following intravenous bolus injection of contrast agent coupled with knowledge of artefacts and normal variations can allow sufficient certainty in the diagnosis of intrasellar lesions. In this respect, the finding of a localized, round hypodense region within the pituitary is of major importance. The so-called indirect signs of a pituitary mass are of minor significance. Demonstrations of typical changes in the CAT scan in combination with the clinical and hormonal findings can contribute to the differential diagnosis of diseases of the pituitary region.

[Radiotherapy of locally recurring colorectal tumors. Prognostic factors, follow-up diagnosis and results]

From 1979 through April, 1985, 74 patients were treated by percutaneous irradiation for local recurrences of colorectal carcinomas. The treatment consisted of a contralateral irradiation up to a dose of 40 Gy and a small-volume boost up to 60 to 66 Gy. In case of progressive remote metastases, the treatment was finished at 50 Gy. 53 patients received a dose of 50 Gy or more and were followed for at least six months. The decisive prognostic parameter was the presence of remote metastases when the recurrence appeared (n = 32). The median survival was six months, in patients without remote metastases at this moment it was 15 months. A complete or considerable relief of pain was obtained in 78%; it continued for a median period of 8.5 months, although most of the patients showed a new local tumor progression after an interval of three to 26 months. Computed tomography showed only small regressions or, in most cases, unchanged volumes of the tumors.

[Indications for and value of computed tomography and conventional skeletal diagnosis in suspected bone metastases]

In 1003 patients with a total of 2467 clinically or scintigraphically suspect skeletal parts, conventional x-ray examination at the time of first study resulted in 95% of cases (2331 skeletal parts) in a correct diagnosis. Computed tomography permitted an exact diagnosis in 52% of roentgenologically equivocal findings (136 skeletal parts). In 40% of these patients even by computed tomography metastasis was only suspected, in 8% there were unspecific findings, while by follow-up bone metastasis was proven. In 64.8% of the whole patient collective there were metastatic destructions and in 32.6% of patients benign lesions were found. Superiority of CT compared to conventional x-ray diagnosis resulted from exact demonstration of the intra- and extraosseous extent of lesions and the possibility of density measurements. It depended mainly upon the localisation of the pathologic process.

[Computed tomographic imaging of collateral pathways in stenoses of the large mediastinal veins]

Scans of angio-computed tomography (CT) of 53 patients suffering from mediastinal space-occupying growths were reviewed: 16 patients showed stenosis of mediastinal veins with demonstration of subcutaneous venous channels, 17 showed an obstruction without collateral pathways and 20 patients had normal mediastinal vessels. Two-thirds of the cases with external vein compression were caused by bronchogenic carcinoma. The degree of obstruction in patients showing collateral circulation was between 70 and 100 percent and significantly greater than in patients without collaterals (40%). The most important collaterals bypassing the upper mediastinal veins are discussed.

[Electron therapy of malignant parotid tumors]

Between 1968 and 1984, 61 patients with malignant parotid tumors were irradiated with fast electrons. The irradiation was performed after surgery in 58 patients, 37 out of them had tumor reresidues at the beginning of radiotherapy. The local recurrence rate was 16%, and there were no differences between patients operated in sano and patients operated non in sano. The survival at five years, however, was only 43%. This is explained by the preponderance of tumor histologies with unfavorable prognoses. Distant metastases were observed in 38% of patients. 8/10 patients with local recurrences developed distant metastases. It is noticeable that polymorphous adenomas were found in the anamneses of ten patients and histologically different secondary carcinomas in 9/61 cases.

[Results of radiotherapy in advanced oropharyngeal carcinomas. Primary and postoperative radiotherapy versus radiotherapy following polychemotherapy]

Within the period from 1971 through 1984, 185 patients with advanced oropharynx carcinomas were irradiated during primary therapy. The influence of a standardized chemotherapy (Heidelberg scheme) as initial therapeutic measure is investigated. Whereas 10% of the patients were treated in this way from 1971 through 1977, this part was 78% from 1978 through 1984. The remission rate after chemotherapy was 62%; the greater part of these remissions were partial remissions. The influence of chemotherapy was seen in increased radical macroscopic tumor resections, but also in an increased frequency of radiotherapy interruptions in case of severe mucous reactions. An increased rate of complete tumor remissions after irradiation was not observed. Nonresponders to chemotherapy showed a significantly poorer response to subsequent radiotherapy. There were no differences in survival times between the two periods in spite of the considerably modified therapy methods.

[Linitis plastica of the stomach in breast cancer]

Metastasis of the stomach wall in mammary cancer as first sign of disease spread 9 years after removal of the primary carcinoma is reported. The diagnosis was proven by surgical biopsy with demonstration of positive hormone receptors. The radiological and CT signs of infiltration of the stomach wall without mucosal destruction is a rare but typical finding in tubular invasive breast cancer.

[Results of radiation therapy in brain metastases with reference to computerized tomography]

Between 1979 and 1985, 193 patients were submitted to radiotherapy of the brain for formation of metastases. A primary irradiation was performed in 159 patients, 34 patients had been treated by surgery. The median survival time after diagnosis of all irradiated patients (40 to 60 Gy within four to six weeks) was 4.9 months, 22% of the patients survived one year. Patients with mammary carcinomas and patients with bronchial carcinomas showed marked differences in median survival times (4.2 and 6.9 months, respectively) and one-year survival rate (11% and 32%, respectively). In histologic examination, the extent of extracerebral formation of metastases was the decisive parameter for survival. At the end of radiotherapy, 47% of patients showed an amelioration in neurologic deficiency, 16% deteriorated. A follow-up by computed tomography with observation periods between four and 34 months was possible in 84 patients. Most of these patients showed improvement in computed tomography during a period of four to twenty weeks after the beginning of radiotherapy. Later on, about two thirds of the controlled patients had again deterioration with local progression or new formation of metastases in spite of total brain irradiation. A long-term normalization (greater than one year) was observed only in patients with mammary carcinomas.

Does in vitro colony formation and chemosensitivity relate to DNA ploidy and S-phase fractions?

In vitro colony formation and chemosensitivity were analyzed in 65 human solid tumors and compared to proliferation parameters simultaneously obtained by DNA flow cytometry of the same tumor specimens. Colony growth in the human tumor colony assay was enhanced in aneuploid tumors (39/65) in comparison to diploid tumors (26/65, P less than 0.05). In addition, there was a relationship between % S-phase and colony growth. The existence of polyploid sublines (23/65) improved in vitro growth even in tumors with a diploid main G0/1-peak or with a low % S-phase. Metastases exhibited a higher proportion of aneuploidy and showed slightly better growth in vitro than primary tumors. Sensitivity testing in 34 of the 65 tumors showed no convincing relation between DNA parameters and the inhibition of colony formation by five standard anticancer agents with different mechanisms of action. This indicates additional factors other than the proliferative activity of the tumor to be responsible for drug sensitivity or resistance.

Comparison of 5-FU versus FUDR activity in human colorectal cancer using an in vitro clonogenic assay (HTCA)

Comparative in vitro drug testing was performed in 72 of 183 surgically removed human colorectal cancer specimens (34 primary lesions, 38 metastases). In 10 of these tumors, comparative dose-response curves were obtained. Given a greater than or equal to 70% ICF (inhibition of colony formation) as threshold for in vitro sensitivity, 5-FU was active in 16/62 specimens, and FUDR in 14/62. Significantly discordant sensitivity results were observed in 8/62 tests, 5-FU being the more active agent in 5 of these cases. These data are supported by the finding of 3 considerably differing dose-response curves in 10 additional comparative studies of human primary tumors.

[Intra-arterial dynamic computed tomography in characterizing liver metastases of colorectal cancer]

Locoregional chemotherapy of liver metastases from colorectal tumours is a promising new approach. The results of CT in fifteen patients after intravenous and intra-arterial contrast injection are compared. The liver metastases are supplied mainly by the arterial route and this permits a means of assessing therapy. Contrast injections through a hepatic catheter may result in flow phenomena which limits the value of this investigation. It is unknown whether such flow phenomena may influence the result of intra-arterial chemotherapy. Although the margins of the metastases were more clearly defined, diagnostic accuracy was not increased, as compared with intravenous CT enhancement.

[Functional heterogeneity of liver metastases in 3-phase computerized tomograms]

Ninety patients with liver metastases (68 colorectal carcinomas, 22 breast carcinomas) were examined by triphasic angio-CT. This included demonstration of the entire liver after a bolus-like injection of contrast. Originally, the metastases were hypodense, but showed four patterns of contrast enhancement. Quantitative evaluation of the mammary carcinomas showed a marked increase in density during the bolus phase, with similar contrast values in the liver and at the centre and edge of the metastasis at ten minutes after the injection. Colorectal carcinomas showed only slight increase in density after contrast injection. The difference in density between the centre and the periphery of the metastasis was still present on later images. This finding indicates that there are differences in the vascularisation of these metastases.

[Diagnosis of lesions in the area of the facial skull--indications and effectiveness of the conventional roentgen technic in comparison with computer tomography]

The substantial information conveyed by conventional radiodiagnostics of pathological alterations of the facial skull is shown in 243 patients examined by conventional radiodiagnostic means and by computerised tomography. Except in case of special demands, conventional tomography has to be preferred in routine diagnostics of the facial skull as a primary method supplying an answer to the most important questions at a lower cost and in a shorter time.

Potentiation by amphotericin B of the cytotoxicity of anticancer agents against MOPC-315 plasmacytoma and Lewis lung carcinoma

The ability of amphotericin B (AmB) to potentiate the cytotoxicity of several different anticancer agents against two murine tumor models was examined. A spleen colony assay was used to quantitate the cytotoxicity of BCNU, CCNU, and L-PAM, either alone or in combination with AmB against the MOPC-315 plasmacytoma. A high level of potentiation of the effects of CCNU and L-PAM by AmB occurred, but AmB did not increase the cytotoxicity of BCNU. Tumor growth curves and calculation of cell survival demonstrated significant potentiation of the cytotoxicity of CCNU by AmB against SC Lewis lung carcinoma.

Differential effect of hyperthermia on murine bone marrow normal colony-forming units and AKR and L1210 leukemia stem cells

Thermal dose-survival curves for normal hematopoietic and leukemia cells were assessed by spleen colony assays after in vitro heat exposure ranging from 41 degrees to 45 degrees. No effect of 43 degrees heat treatment on the fraction of cells lodging in the spleen was observed. Marked differences in heat sensitivity were observed between normal, L1210, and AKR leukemia cells, the first being les sensitive than were the malignant cells. Furthermore, a greater relative difference between normal stem cells and leukemia cells was observed at lower temperatures. Normal bone marrow cells forced into regenerative activity prior to heat treatment were more heat sensitive than was their undisturbed counterpart, suggesting that noncycling hematopoietic cells are less heat sensitive than are proliferating cells.

Analysis of MOPC-315 plasmacytoma by elutriation and flow cytometry

Intravenously transplanted murine plasmacytoma MOPC-315 cells were separated from normal spleen cells from a tumour-bearing mouse by elutriation and characterized according to morphology, immunologic properties and clonogenicity. Morphologically, both lymphocytoid and plasmacytoid cells were separable by elutriation. Flow cytometry correlated DNA content and intracytoplasmic IgA content and demonstrated two distinct populations, both in cell cycle, but with markedly different cellular IgA levels. Density gradient separation characterized the lower-density cells with lower IgA content and higher clonogenicity. From these studies a model of cellular differentiation is proposed.

The effect of hyperthermia on hemopoietic progenitor cells of the mouse

We have studied the effect of heat on four lineage-specific clonogenic cells from mouse bone marrow. The thermal sensitivities of two red cell precursors, one primitive (BFU-E) and one more differentiated (CFU-E), a granulocyte-macrophage precursor (CFU-GM), and a megakaryocyte precursor (CFU-M) were determined after exposure to 42, 43, and 44 degrees C. We found that the erythroid precursors were much more heat sensitive than either the CFU-GM or CFU-M. At 42 degrees C the CFU-E and BFU-E had a D0 of about 30 min, while the CFU-GM and CFU-M had D0 values of about 60 min. Thus the four progenitors could be divided into two distinct classes with respect to their sensitivity to hyperthermia. These results suggest that erythropoiesis is more likely to be suppressed than either thrombopoiesis or leukocyte production when hyperthermia is applied in a clinical setting.