TITLE:
Clinical Experience and Dosimetry Outcome in Treating Breast Cancer with Field-in-Field Technique
AUTHORS:
Bidyapati Jha, Hari Prasad Lamichhane, GisupNikha Prasiko, Raju Prasad Srivastava
KEYWORDS:
Field in Field (FiF), Planning Target Volume (PTV), Treatment Planning Sys-tem (TPS), Homogeneity Index (HI), Conformity Index (CI)
JOURNAL NAME:
Advances in Breast Cancer Research,
Vol.10 No.3,
June
9,
2021
ABSTRACT: Purpose: The study is aimed to establish the dosimetric characteristics of
field-in-field (FiF) technique for carcinoma of breast treatment in Nepal. We
assumed that FIF technique may result in improved dose distribution and reduced
acute toxicity in these patients. Methods: Forty breast cancer patients participated in this study.
A total dose of 50 Gy in 25 fractions was prescribed to the planning target
volume. FiF plan was generated in treatment planning system. Dose volume
histograms were evaluated for PTV and organs at risks. Several parameters were analyzed
for the PTVs and organ at risks (OARs) together with the Conformity index (CI),
and the Homogeneity index (HI). Results: The dose coverage of breast
volume was achieved. The V95% (volume of 95%) of PTV covered D95% (Dose of 95%). The PTV dose was covered to 49.98 ± 0.9 Gy and 49.81 ± 1.1 Gy
for the left and right breast, respectively. The mean lung dose was 14.87 ± 0.91
Gy. The homogeneity index (0.26 ± 0.17 and 0.22 ± 0.13) and conformity index
(1.59 ± 0.75 and 1.36 ± 0.45) were analyzed for left and right breast,
respectively. Conclusion: The study supports the viability of FiF
technique in the treatment of breast cancer in Nepal. The FIF technique enables
better dose distribution in the PTV and reduces dose to OARs. The FiF technique
provides dosimetric advantages and requires less planning time.