Abstract:
The prone position can be used for the planning of adjuvant radiotherapy after conservative
breast surgery in order to deliver less irradiation to lung and cardiac tissue. In the present
study, we compared the results of three-dimensional conformal radiotherapy planning for
15patients irradiated in the supine and prone position used compared. Tumor stage was
T2N0M0 in group of patients and T2N1M0 in other .All patients had been previously
submitted to conservative breast surgery. Breast size was large in 15patients and moderate
in 10and small in 5. Planning in the prone position was performed using an immobilization
foam pad with a hole cut into it to accommodate the breast so that it would hang down away
from the chest wall. Dose-volume histograms showed that mean irradiation doses reaching
the ipsilateral lung were (8.3 ± 3.6) Gy with the patient in the supine position and (1.4 ± 1.0)
Gy with the patient in the prone position .The values for the contra lateral lung were (1.3 ±
0.7) Gy in supine and (0.3 ± 0.1) Gy in prone and the values for cardiac tissue were (4.6 ±
1.6)in supine and (3.0 ± 1.7)Gy in prone, respectively. Thus, the dose-volume histograms
demonstrated that lung tissue irradiation was lower with the patient in the prone position
than in the supine position. Large-breasted women appeared to benefit most from irradiation
in the prone position. Prone position breast irradiation appears to be a simple and effective
alternative to the conventional supine position for patients with large breasts, since they are
subjected to lower pulmonary doses which may cause less pulmonary side effects in the
future.