TITLE:
A Dosimetric Comparison of Radiotherapy Techniques in the Treatment of Carcinoma of Breast
AUTHORS:
Zakiya Salem Al-Rahbi, Ramamoorthy Ravichandran, Johnson Pichy Binukumar, Cheriyithmanjiyil Antony Davis, Namrata Satyapal, Zahid Al-Mandhari
KEYWORDS:
Breast Radiotherapy; TL Detectors; Electronic Compensators; Second Malignancy
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.4 No.11A,
December
2,
2013
ABSTRACT:
Objectives of present study are a) to
compare the planning and delivery aspects of five different techniques, planned
by a) forward, inverse planning and electronic tissue compensation methods; and
b) to evaluate and verify the accuracy of the planning system using phantom to
estimate the skin dose for target and contraletral breast from five techniques. In-vivo skin dosimetry is planned
with TL detectors. Five different radiotherapy techniques for treatment of
carcinoma breast were studied using archived computed tomography (CT) scans of
25 breast conserving surgery patients (leftsided whole breast), planned for 50
Gy in 25 fractions. Linear accelerator (Clinac 2300 CD) photon beams were used
and thermoluminescent detectors (TLD) [LiF:Mg, Ti] estimated dose on humanoid
phantom. Dose coverage (95%) (to PTV) and hot spot (105%) covering volumes did
not show differences (p > 0.05) in all 5 plans; Electronic compensator plans are better than others. IP-IMRT plan
showed the worst
Homogeneity Index (HI) (p , contra-lateral breast (CB) and heart OARs (V20 ipsi.lung,
CB, V30 Heart,)
are the least with
IP-IMRT. IP-IMRT and E-COMP plans resulted in significantly lower mean dose to the
superficial skin (Dmean, V40skin, 45skin, 50skin) (p the least doses to the skin of PTV and contra-lateral
breast and less hot spots; E-COMP showed better homogeneity, fewer MUs, and the least dose in non-target zones.