[Optimizing radiotherapy for carcinomas of the tongue and floor of the mouth. Measurement of oncoradiogenic enzyme peaks of GPI]. / Optimierung der Strahlentherapie von Zungen- und Mundbodenkarzinomen. Messung des onkoradiogenen Enzympeaks der GPI.

After a first irradiation with 2 and 5 Gy blood samples were collected at 30 minutes' intervals for 24 hours in 19 tongue cancer patients to assess the activity of the glycosis enzyme glucose-6-phosphate isomerase (GPI) and the creatine kinase (CK). In all patients the GPI activity exhibited peaks at reproducible points in time. Observed for the very first time, this GPI peak had a height at 15 to 18 hours following radiation that correlated with the tumor volume and the irradiation dose. We refer to it as the oncoradiogenic enzyme peak. The frequency of the appearance of a late enzyme peak is significantly related to the presence of regional lymph node metastases. The radiobiological considerations regarding the potential causes for such post-irradiation increases in enzyme activity are discussed. The impact of demonstrating oncoradiogenic GPI peaks for optimizing radiotherapy is outlined.

[Detection of early tumor reactions in irradiation of tumors of the gastrointestinal tract by measuring the onco-radiogenic enzyme peak of glucosephosphate isomerase]. / Nachweis früher Tumorreaktionen bei Bestrahlung von Tumoren des Magen-Darm-Traktes durch Messung des onkoradiogenen Enzympeaks der GPI.

In 43 patients with oesophageal, pancreatic and rectal carcinoma blood samples were taken after the first irradiation and the activity of the glycolytic enzyme glucose-6-phosphate isomerase was measured. In all patients GPI peaks occurred at reproducible time intervals. The height of the enzyme peak occurring 15.5 to 19.5 hours p.irr. was significantly dependent on tumour size and irradiation dose. The frequency of a late occurring enzyme peak was dependent on the presence of regional lymph node metastases. Possible sources of the enzyme peaks are discussed from a radiobiological point of view and the meaning of such enzyme peaks for the optimization of radiation therapy is pointed out.

[Possibilities for optimizing radiotherapy of cervix cancers by measuring the enzyme peak of GPI after initial irradiation]. / Möglichkeiten der Optimierung der Strahlentherapie von Zervixkarzinomen durch Messung des Enzympeaks der GPI nach der ersten Bestrahlung.

Following the first irradiation with a dose of 1.6 respectively 2 Gy we determined the activity of glucose-6-phosphate isomerase (GPI) and of creatine kinase in intervals of 30 minutes for 24 hours. In all patients we could observe peaks of GPI-activity 15.5 to 19.5 hours after irradiation corresponding to tumour volume and grading. Frequency depends on present lymph node metastases detected by lymphography and/or computed tomography. Possible reasons have been discussed by the viewpoint of radiation biology and the meaning with respect to an optimal radiation treatment.

[Possibilities for optimization of radiotherapy of esophageal carcinoma through measurement of the oncoradiogenic enzyme peak of glucosephosphate isomerase]. / Möglichkeiten der Optimierung der Strahlentherapie von Oesophaguskarzinomen durch die Messung des onkoradiogenen Enzympeaks der GPI.

In 20 patients with oesophageal carcinoma blood samples were taken after the first irradiation and the activity of the glycolytic enzyme glucose-6-phosphate isomerase was measured. In all patients there occur GPI peaks at reproducible times. The height of the enzyme peak occurring 15.5 to 19.5 hours p.irr. expresses a significant dependence on tumour size and irradiation dose. The frequency of a late occurring enzyme peak depends on the appearance of regional lymph node metastases. Possible sources of the enzyme peaks are discussed from a radiobiological point of view and the meaning of such enzyme peaks for the optimization of radiation therapy is pointed out.