Should breathing adapted radiotherapy also be applied for right-sided breast irradiation?
BACKGROUND
Voluntary moderate deep inspiration breath-hold (vmDIBH) is widely used for left sided breast cancer patients. The purpose of this study was to investigate the usefulness of vmDIBH in local and locoregional radiation therapy (RT) of right-sided breast cancer.


METHODS
For fourteen right-sided breast cancer patients, 3D-conformal (3D-CRT) RT plans (i.e., forward IMRT) were calculated on free-breathing (FB) 3D-CRT(FB) and vmDIBHCT-scans, for local- as well as locoregional breast treatment, with and without internal mammary nodes (IMN). Dose volume parameters were compared.


RESULTS
For local breast treatment, no relevant reduction in mean lung dose (MLD) was found. For locoregional breast treatment without IMN, the average MLD reduced from 6.5 to 5.4 Gy (p < 0.005) for the total lung and from 11.2 to 9.7 Gy (p < 0.005) for the ipsilateral lung. For locoregional breast treatment with IMN, the average MLD reduced from 10.8 to 9.1 Gy (p < 0.005) for the total lung and from 18.7 to 16.2 Gy (p < 0.005) for the ipsilateral lung, whilea small reduction in mean heart dose of 0.4 Gy (p = 0.07) was also found.


CONCLUSIONS
Breathing adapted radiation therapy in left-sided breast cancer patients is becoming widely introduced. As a result of the slight reduction in lung dose found for locoregional right-sided breast cancer treatment in this study, a slightly lower risk of pneumonitis and secondary lung cancer (in ever smoking patients) can be expected.In addition, for some patients the heart dose will also be reduced by more than 0.5 up to 2.6 Gy. We therefore suggest to also apply breath-hold for locoregional irradiation of right-sided breast cancer patients.
a Department of Medical Physics , Instute Verbeeten , Tilburg , The Netherlands ;
Marion
M
Essers
b Department of Radiation Oncology , Radboud university medical centre , Nijmegen , The Netherlands ;
Philip M
PM
Poortmans
c Department of Radiation Oncology , Institute Verbeeten , Tilburg , The Netherlands.
Karijn
K
Verschueren
c Department of Radiation Oncology , Institute Verbeeten , Tilburg , The Netherlands.
Sandra
S
Hol
c Department of Radiation Oncology , Institute Verbeeten , Tilburg , The Netherlands.
David C P
DC
Cobben
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000532:radiotherapy*; D062485:Breath Holding; D005260:Female; D006321:Heart / Q000528:radiation effects; D006801:Humans; D008168:Lung / Q000528:radiation effects; D008875:Middle Aged; D058958:Organs at Risk / Q000528:radiation effects; D011832:Radiation Injuries / Q000209:etiology; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods*; D012119:Respiration