[Dose-volume histograms and 3-D planning in breast-saving therapy of breast carcinoma].
OBJECTIVE
Improvement of the dose homogeneity in radiation treatment of the intact breast using 3D-planning and dose volume histograms.


METHODS
3D-planning, including the calculation of dose volume histograms of the planning target volume, was performed on 15 patients, who underwent radiation therapy with tangential photon beams. A standard plan and 2 modified or optimized plans were evaluated. Different dosimetric parameters like maximum dose, mean dose, standard deviation and the fractional volume which receives doses from 95 to 105% of the reference dose were compared and correlated with breast size.


RESULTS
With increasing breast size standard planning leads to increased overdosage, both in magnitude and volume. Individual optimization by modifying weights and wedges gives no improvement in dose homogeneity, whereas a photon energy of 10 MV results in a more homogeneous dose distribution. The drawback of the higher energy is the increased underdosage of the skin.


CONCLUSIONS
Using the standard geometry of tangential fields the dose homogeneity cannot be improved significantly by 3D-planning, compared to our standard technique.
Schiessl
W
W
Klinik und Poliklinik für Strahlentherapie, TU München.
Borojevic
N
N
Pietzsch
C
C
Bayerl
A
A
Molls
M
M
Kneschaurek
P
P
D001943:Breast Neoplasms / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*
Dosis-Volumen-Histogramme und 3D-Planung bei der brusterhaltenden Therapie des Mammakarzinoms.