Measurement of ipsilateral lung and heart dose in radiotherapy of left sided mastectomy patients in common different clinical techniques: A phantom study

Background: the aim of this study was to compare the radiaon dose to ipsilaterallung and heart for different radiotherapy (rt) techniques including; two tangenalphoton beams, electron therapy and combined photon-electron. materials andmethods: treatment planning of the menoned techniques on the ct images of achest phantom was done using treatment planning system (tigrt, lina tech,china). according to the plans, the phantom was irradiated with 6 mv photon and10 mev electron beams of siemens primus linac. radiaon dose was also measuredusing lif thermo luminescence dosimeter (tld) which was placed inside 3 mmdepth holes of ipsilateral lung and heart on the phantom. results: the mean(± sd) radiaon dose to the ipsilateral lung of the combined photon-electronwas 66.12 ± 5.16% of prescribed dose. whereas for the heart, it was 64.05 ±2.62%. mean (± sd) dose of ipsilateral lung and heart for electron irradiaonwas 54.51 ± 3.88 % and 34.21 ± 3.41%, respecvely. the mean (± sd)radiaon dose to ipsilateral lung and heart of the tangenal was 50.73 ± 3.01% and 31.36 ± 3.13%, respecvely. the mean (± sd) radiaon dose to thechest wall-lung interface for electron therapy (72.44 ± 2.01 %) wassignificantly different in comparison with tangenal (65.23± 4.20%; p = 0.045)and combined photon-electron (68.14± 3.53 %; p = 0.032). conclusion:tangenal beams is more suitable for treang mastectomy paents compared tothe other techniques such as electron therapy and combined photon-electron, dueto lower radiaon dose to paent's ipsilateral lung and heart.