Sajeev George Pulickal1, Reshma Bhaskaran2, Aparna Perumangat3, Harikrishnan Reghu4, Girish Babu Moolath5
BACKGROUND
Acute esophagitis (AE) is a common toxicity seen in patients undergoing
radiotherapy (RT) for breast cancer, which can affect their quality of life. Thus,
majority of our patients receiving hypo fractionated dose of 40 Gy in 15 fractions
were having AE. We conducted this study to evaluate the dosimetric parameters
of oesophagus and correlate with published literature.
METHODS
Treatment plans of 80 post mastectomy patients who underwent radiotherapy for
carcinoma of breast (Ca breast) with a dose of 40 Gy in 15 fractions to the chest
wall along with supra clavicular fossa (SCF) were selected. Out of these, 44
patients (22 each in right and left side) were simulated in neck straight position
and 36 in neck tilted position (18 each in right and left side). The oesophageal
volume was contoured in already executed plans from the inferior border of cricoid
cartilage to the inferior border of the SCF planning target volume (PTV). No plan
modification was done after contouring the oesophagus. Dosimetric parameters
like the maximum dose (Dmax) and mean dose (Dmean) to oesophagus, volume of
oesophagus receiving ≥ 5 Gy (V5), ≥ 10 Gy (V10), ≥ 15 Gy (V15), ≥ 20 Gy (V20),
≥ 25 Gy (V25), ≥ 30 Gy (V30) were derived from dose volume histogram (DVH)
data and analysed.
RESULTS
Dmean in straight neck group irrespective of side was 18.57 (± 7.30) Gy and in
tilted neck 22.94 (± 9.53,) Gy, P = 0.023. Subgroup analysis shows Dmean was
significantly high in patients with left sided disease than those with right sided
disease (24.10 vs. 13.03, P = 0.00) in the straight neck cases. In the neck tilted
group there was a nonsignificant increase in Dmean in left sided cases (25.36 vs.
20.53, P = 0.13).
CONCLUSIONS
Evaluation of oesophageal dosimetric parameters in hypofractionated dose
showed that DmeanEQD2 was within the values of published studies in conventional
fractionation.
