2Department of Nuclear Medicine, Medipol University, İstanbul, Turkey DOI : 10.5505/tjo.2017.1674 OBJECTIVE
The tumor bed within the breast shifts during oncoplastic surgery (OPS) for breast cancer (BC). Preoperative imagery is used to determine the boost volume (BV) for patients not implanted with surgical clips. This prospective study was conducted to geometrically compare BVs determined using preoperative imagery and BVs determined utilizing surgical clips.
METHODS
Patients diagnosed with BC were scanned using PET-CT during 2013?2015. Twenty patients who had
undergone OPS but who did not have metastasis underwent CT prior to radiotherapy. Their preoperative
images were fused with planning CT images. The tumor volume (CTVboost-pet), as determined
from the preoperative PET-CT images, was contoured. Next, CTVboost-clips was determined using
surgical clips. Geometric relationships between these two volumes were statistically compared.
RESULTS
Planar projections of CTVboost-pet and CTVboost-clips were evaluated. Displacements between CTVboost-
pet and CTVboost-clips in the axial (XZ) and coronal (XY) planes were 1.17 cm (min?max: 0.03?
3.64 cm) and 1.67 cm (min?max: 0.38?4.14 cm), respectively, and were statistically significant (p<0.001),
whereas the displacement in the sagittal (YZ) plane was 1.07 cm (min?max: 0.04?4.45 cm) and was not
significant (p>0.7).
CONCLUSION
Preoperative imaging alone was not reliable when determining the BV in patients who had undergone OPS and had
no clips. Large PTV margins can be an option to overcome this issue. Surgical clips need to be inserted during OPS.