Open AccessComparison of Oncentra ® Brachy IPSA and graphical optimisation techniques: a case study of HDR brachytherapy head and neck and prostate plans
Author(s) -
Jameson Michael G.,
Ohanessian Lucy,
Batumalai Vikneswary,
Patel Virendra,
Holloway Lois C.
Publication year - 2015
Publication title -
journal of medical radiation sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 18
eISSN - 2051-3909
pISSN - 2051-3895
DOI - 10.1002/jmrs.107
Subject(s) - brachytherapy , radiation treatment planning , nuclear medicine , dosimetry , prostate brachytherapy , computer science , medicine , radiation therapy , surgery
There are a number of different dwell positions and time optimisation options available in the Oncentra ® Brachy (Elekta Brachytherapy Solutions, Veenendaal, The Netherlands) brachytherapy treatment planning system. The purpose of this case study was to compare graphical ( GRO ) and inverse planning by simulated annealing ( IPSA ) optimisation techniques for interstitial head and neck ( HN ) and prostate plans considering dosimetry, modelled radiobiology outcome and planning time. Four retrospective brachytherapy patients were chosen for this study, two recurrent HN and two prostatic boosts. Manual GRO and IPSA plans were generated for each patient. Plans were compared using dose–volume histograms ( DVH ) and dose coverage metrics including; conformity index ( CI ), homogeneity index ( HI ) and conformity number ( CN ). Logit and relative seriality models were used to calculate tumour control probability ( TCP ) and normal tissue complication probability ( NTCP ). Approximate planning time was also recorded. There was no significant difference between GRO and IPSA in terms of dose metrics with mean CI of 1.30 and 1.57 ( P > 0.05) respectively. IPSA achieved an average HN TCP of 0.32 versus 0.12 for GRO while for prostate there was no significant difference. Mean GRO planning times were greater than 75 min while average IPSA planning times were less than 10 min. Planning times for IPSA were greatly reduced compared to GRO and plans were dosimetrically similar. For this reason, IPSA makes for a useful planning tool in HN and prostate brachytherapy.