The purple line indicates the border of the V10Gy ISV, the red delineation represents the prostate PTV and the green delineation shows the PTV_PVS (prostate and vesicular seminalis). The rectum and bladder was indicated with blue and yellow color, respectively.
Lymphocytes, which can be regarded as a beneficial surrogate typical cells into the biodosimetry, flow through the irradiated volumes as they are continuously replaced because of the new of these. This is why, just due to the irradiated frequency may lead to erroneous dose estimate as a very high irradiated frequency does not necessarily mean a beneficial higher physical effect. Because of your own above, there is an importance of a study one to examines the outcome from irradiated amounts to your physiological serving when you look at the radiation therapy.
There is a large number of courses on dosimetric calculation or even in vivo dosimetry for the radiotherapy, however, according to our very own education courses writing about the latest determine away from isodose skin quantities to your physical dosimetric opinions will always be lost. Additionally, all analyses out-of volumetric investigation explore organ associated amounts, for this reason they are not applicable for chromosome aberrations.
Efficiency
The following isodose surface volumes (ISVs) of absolute and relative doses were recorded: V1%, V1Gy, V10%, V10Gy, V100%, V150% (Table 1) (except V1% in the case of HDR therapy, discussed below). These volumes cover all the irradiated volumes getting at least a minimum of these doses, regardless of the affected organs. The variability in ISVs was high among patients. For the sake of example, the highest ratio of maximum to minimum was 3.9 for V150% in HDR therapy. The higher ratios can be seen at higher doses in all therapies, but the highest differences were found mostly in HDR therapy (Table 1).
Testing away from amounts between therapy
The prescribed doses were different for the three modalities, consequently the absolute and relative doses also vary. Patients with bigger prostate (more than 60 cm 3 ) are not eligible for brachytherapy, furthermore in EBRT extra margin was added around the prostate to get PTV, therefore all average ISVs of the EBRT patients were considerably larger than those of the BT patients. For example, the mean V100% of LDR patients was 2.4 times smaller than that of the EBRT patients, and the ratio was 3.6 for V1Gy (Table 1). Although the V100% values of HDR and LDR therapy did not differ significantly, the average V10% in HDR is 2.0 times larger than that in LDR therapy (Table 1).
Evaluation regarding chromosome aberrations
Baseline values of total aberrations obtained fling prior to the treatment (2.2; 4.0; 2.9 for HDR, EBRT and LDR therapy, respectively) were less than the cutoff limit used in our laboratory for healthy people (5 aberrations/100 cells) in every modality (Fig. 2a). Total aberrations were increased to 4.3; 12.1 and 2.9 total aberrations/100 cells for HDR, EBRT and LDR therapy, respectively (significantly different between HDR and EBRT baseline and post radiotherapy) right after radiotherapy. However, after seed therapy the highest growth was seen in the first 3 months interval (from 2.9 to 6.5 total aberrations/100 cells, p < 0.0001). This is due to the long dose delivery of the low dose rate therapy. The chromosome aberration values are the highest after EBRT therapy in every time point. After 3 months stagnation was observed, except in the EBRT group, where a slow non-significant decrease could be seen (Fig. 2a). Only the total aberration value of the HDR group decreased to baseline levels (5 aberrations/100 cells) during the 1 year follow-up. The dicentrics and ring data showed a similar pattern with lower values (1.2; 5.4 and 0.4 dicentrics + rings/100 cells directly after the therapy for HDR, EBRT and LDR therapy, respectively and 2.1 dicentrics + rings/100 cells for LDR therapy at the third month after the therapy) (Fig. 2b).
