The importance of the implant quality in APBI – Gliwice experience. Dosimetric evaluation

Abstract

This study includes four years of our clinical trials to improve implant quality in multicatheter accelerated partial breast irradiation (APBI). The progress in dosimetric and volumetric parameters of the treatment plans was evaluated. One hundred and ninety-one women, for whom treatment plans were made based on three dimensional imaging, were selected for the study. To evaluate progress made in our APBI procedure, following parameters and indices were taken into account: percentage of the target volume receiving the reference dose (PTVref), minimum dose in the target volume expressed as a percentage of reference dose (PTVmin), dose homogeneity index (DHI), and conformity index (COIN). Additionally, the plan quality index was calculated for every group as the sum of mean values of four evaluated parameters. PTVref have increased from the mean value of 83.4% at the beginning to recent 94.8%. The maximum value equals to 95.4%. The same trend can be observed with PTVmin value, which has been improved from 51.7% to 70.1%, maximally. DHI and COIN mean values present similar progress. DHI value increased from 0.53 level to 0.68, and COIN from 0.58 in 2009 to 0.74. Plan quality index has increased from 2.46 in 2009 to 3.06, recently. The implant quality is crucial for the accurate dose distribution. This paper shows the progress that was made in APBI procedure to improve implant quality. Nowadays, our implant technique is based on three-dimensional CT imaging results in acceptable dose distributions.

Multi-catheter interstitial brachytherapy for partial breast irradiation: an audit of implant quality based on dosimetric evaluation comparing intra-operative versus post-operative placement

“…In the updated report of their experience, Cholewka et al . reported 95% coverage of CTV, DHI of 0.68, and COIN of 0.75 [ 16 ]. We adopted the evaluation of PQI of implants similar to the above authors to qualitatively estimate our procedure [ 16 ].…”

“…reported 95% coverage of CTV, DHI of 0.68, and COIN of 0.75 [ 16 ]. We adopted the evaluation of PQI of implants similar to the above authors to qualitatively estimate our procedure [ 16 ]. On the contrary, when we analyzed our results over the years, it was seen that all the dosimetric indices except tumor bed coverage improved in the later couple of years.…”

Treatment planning for multicatheter interstitial brachytherapy of breast cancer – from Paris system to anatomy-based inverse planning

“…Furthermore, a learning curve can be observed during this process as it was well demonstrated by Cholewka et al . [ 36 ] and reported by Wiercinska et al . [ 18 ].…”

Transition from Paris dosimetry system to 3D image-guided planning in interstitial breast brachytherapy

“…Cholewka et al . analyzed their learning curve in first experiences with 3D image-based partially breast brachytherapy [ 24 ]. They've noticed a gentle progress every 6 months during the whole 4 years of observation.…”