[High-dose brachytherapy for prostate cancer in real time using 192-IR (specifics of dosimetric planning)]

There were analyzed dosimetric plans obtained during the first session of HDR brachytherapy in 70 primary prostate cancer patients. Assessments were subjected to dosimetric parameters (V100, D90, D2cc, D10) obtained after implantation in the prostate needle-intrastats estimated before and after adjustment of contours of the prostate and surrounding organs at risk. It was showed that in most cases they were matched to the intended dosimetric parameters: V100 average--94,1% (V100 more than 90% in 97.2% of cases), D90 average--104,3% (D90 100% achieved in 95.7% of cases). In contrast, when using primary plan dosimetry without estimation of changing the geometry of the prostate and organs at risk in 38.6% patients V100 value was below 80%, in 41.4% patients--was in the range from 80% to 90%. In 24.3% patients index D90 did not exceed 80%, in 31.4% patients determined in the range from 80% to 90% and in 24.3% patients was close to 100%. In the absence of correction of contours of the urethra and the prostate in 18% patients the value of D10 for the urethra was higher border 115% and could increase to critical 189%.