DISCUSSION 



significantly the survival results of treatment. Laboratory tests with tissue cultures 

 and animal experiments with a large series of chemical compounds (Mitchell and 

 Simon-Reuss*, 1952), have shown the superiority of this temporarily solubilized 



quinol. 



The work here described is concerned with the animal experiments only as the 

 clinical material available would not allow as yet any data regarding the effectiveness 

 of Synkavit as a coadjuvant of radiotherapy to be presented. 



Thirty-five rabbits and 37 rats were given subcutaneous injections of Synkavit, the 

 amounts given to rabbits ranging from 10-50mg daily, but constantly lOmg in 

 the case of rats. The drug was given in some cases for a few days before the delivery 

 of the X-ray dose and continued for a time varying from 10-17 days. The dose of 

 X-rays given in the case of rabbits ranged from 600-1,500 r. There were three 

 groups of rats which received respectively 480 r, 585 r and 650 r ; the first two 

 groups contained 25 rats and the last 26. 



All the rabbits and all the rats were exposed to a beam of radiation covering the 

 whole body. The physical factors were 180 kV, 10 mA, 50 cm F.S.D. with a 

 H.V.L. varying according to the filtration, which was either the inherent tube shield 

 filtration alone or 0-5mm Cu (H.V.L. 0-85 mm Cu). The irradiation was carried 

 out with the tube head and the applicator inverted, with the box containing the 

 animals standing on top of the applicator end. 



RESULTS 



Rabbits 



The difference in survi\al rates between the Synkavit plus X-rays series of rabbits 



with the series of rabbits which received X-rays alone was not significant when 



the assessment was made on the whole series of 35 rabbits which received Synkavit 



injections. 



In the Synkavit group the majority maintained their weight fairly well throughout 

 the observation period or gained ground slightly. This was particularly so in the 

 case of the rabbits which received Synkavit injections for a few days prior to exposure 

 to X-rays. In the series of rabbits exposed to X-rays without Synkavit there was a 

 consistent drop in the weight curve, with the exception of one surviving rabbit 

 which gained some 10 per cent in weight over a period of 30 days. The Synkavit 

 rabbits were on the whole more lively and taking food more liberally than the 

 animals without Synkavit. 



Rats 



The 76 rats used in these experiments were dealt with in three separate series. 



Group 7—13 rats received lOmg of Synkavit injections daily (7 rats for four days 

 and 6 rats for five days) prior to exposure to a dose of 580 r and subsequently daily 

 until their death, and a group of 13 rats received a similar dose of X-rays to the 

 whole body without any injections. In the Synkavit group there was 1 survivor 

 and in the non-Synkavit series there were no survivors at 30 days. 



Group //—Of 25 rats in this group 24 were exposed to a dose of 650 r to the 

 whole body. Of these, 11 were given injections of lOmg of Synkavit daily, and 13 

 were given daily injections of 1 c.c. of sterile normal solution of saline. With the 

 exception of the control rat which survived the 30 days' period there were no 30-day 

 survivals in the whole series. 



Group III^A group of 25 rats were exposed to a dose of 480 r to the whole body. 

 Of these 9 received seven and 4 received five injections, 10 mg daily, of Synkavit 

 prior to exposure to X-rays and eight to eleven daily injections after exposure. 

 8 rats received six pre-X-ray treatment and 10 post-treatment injections of 1 c.c. of 



* Mitchell, J. S. and Simon-Reuss, I. Brit. J. Cancer, 1952. 6 305, 317. 



191 



