Assessment of tumor control probability for high-dose-rate interstitial brachytherapy implants

Abstract

Aim

The study was designed to propose a novel concept of biologically effective equivalent uniform dose to calculate tumor control probability for HDR implants.

Materials and Methods

The expression of biologically effective equivalent uniform dose was derived for non-uniform dose distribution in HDR implants using quality indices and voxel-based tumor control probability.

Results

The results of this study show that high dose regions of the implant have higher tumor control probability. But these regions may also have a large number of normal cells and consequently may lead to severe normal tissue complications. If tumor coverage was not proper then the overall tumor control probability would be low and might result in tumor recurrence. Higher values of external volume index, dose non-uniformity ratio and overdose volume index were related to higher normal tissue complication rates outside and inside the implants.

Conclusion

The present concept may provide an alternative approach to calculate tumor control probability for HDR implants.