2Department of Radiation Oncology and Medical Physics, Jawaharlal Nehru Cancer Hospital and Research Centre, Bhopal-India DOI : 10.5505/tjo.2022.3657 OBJECTIVE
In this study, we analyzed dose to organ at risk in the left breast cancer patients, in terms of dose volume histogram (DVH), with the quantitative analysis of normal tissue effects in the clinic dose constraints and calculate potential toxicity in terms of normal tissue complication probability (NTCP).
METHODS
This study included 60 post-operated left breast cancer patients who received chest wall/breast irradiation
by three-dimensional conformal radiotherapy (RT). The patients had received a total dose of 40Gy
in 15 fractions to whole breast/chest wall (two fields) and dose to supraclavicular fossa (three fields). We
compared the DVH for heart, lung, and spinal cord in both fields.
RESULTS
Mean dose for lung was 17.49Gy and for heart 12.31Gy, and spinal cord maximum dose was 0.78Gy.
The average lung NTCP for RP was 3.11%. The risk of RP was significantly greater in three-field radiation
as compared to two field for lung (p<0.05). We observed the statistically significant correlation
of MHD and NTCP (p<0.00001 and p=0.000402). The correlation of central lung distance (CLD) was
observed to be significant with three fields, that is, as the CLD increased risk of organ damage to lungs
increased (p=0.00022). The correlation of CLD and MHD with DVH was observed to be statistically
significant (p<0.001).
CONCLUSION
This study results are useful to reanalyze the previous 2D-based clinical reports about breast RT complications
as a view point of the NTCP. Further studies are needed for the actual clinical data of complications
with this DVH analysis.