title: Forward planned intensity modulated radiotherapy (IMRT) for whole breast postoperative radiotherapy. Is it useful? When?
abstract: The purpose was to compare the dosimetric results observed in 201 breast cancer patients submitted to tangential forward intensity-modulated radiation therapy (IMRT) with those observed in 131 patients treated with a standard wedged 3D technique for postoperative treatment of whole breast, according to breast size and supraclavicular node irradiation. Following dosimetric parameters were used for the comparison: D(max), D(min), D(mean), V(95%) and V(107%) for the irradiated volume; D(max), D(mean), V(80%) and V(95%) for the ipsilateral lung; D(max), D(mean), V(80%) and V(95%) for the heart. Stratification was made according to breast size and supraclavicular (SCV) nodal irradiation. As respect to irradiated volume, a significant reduction of V(107%) (mean values: 7.0 ± 6.6 versus 2.4 ± 3.7, p < 0.001) and D(max) (mean % values: 111.2 ± 2.7 versus 107.7 ± 6.3, p < 0.001), and an increase of D(min) (mean % values: 65.0 ± 17.4 versus 74.9 ± 12.9, p < 0.001) were observed with forward IMRT. The homogeneity of dose distribution to target volume significantly improved with forward IMRT in all patient groups, irrespective of breast size or supraclavicular nodal irradiation. When patients treated with supraclavicular nodal irradiation were excluded from the analysis, forward IMRT slightly reduced V(80%) (mean values: 3.7 ± 2.6 versus 3.0 ± 2.4, p = 0.03) and V(95%) (mean values 1.9 ± 1.8 versus 1.2%± 1.5; p = 0.001) of the ipsilateral lung. The dose to the heart tended to be lower with IMRT but this difference was not statistically significant. Tangential forward IMRT in postoperative treatment of whole breast improved dosimetric parameters in terms of homogeneity of dose distribution to the target in a large sample of patients, independent of breast size or supraclavicular nodal irradiation. Lung irradiation was slightly reduced in patients not undergoing to supraclavicular irradiation.
authors.affiliation: Radiotherapy Unit, Department of Oncology, John Paul II Center for High Technology Research and Education in Biomedical Sciences, Campobasso, Italy.
authors.forename: Alessio G
authors.initials: AG
authors.lastname: Morganti
authors.forename: Savino
authors.initials: S
authors.lastname: Cilla
authors.forename: Andrea
authors.initials: A
authors.lastname: de Gaetano
authors.forename: Simona
authors.initials: S
authors.lastname: Panunzi
authors.forename: Cinzia
authors.initials: C
authors.lastname: Digesù
authors.forename: Gabriella
authors.initials: G
authors.lastname: Macchia
authors.forename: Mariangela
authors.initials: M
authors.lastname: Massaccesi
authors.forename: Francesco
authors.initials: F
authors.lastname: Deodato
authors.forename: Gabriella
authors.initials: G
authors.lastname: Ferrandina
authors.forename: Numa
authors.initials: N
authors.lastname: Cellini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Scambia
authors.forename: Angelo
authors.initials: A
authors.lastname: Piermattei
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Valentini
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D011184:Postoperative Period; D011874:Radiometry / Q000379:methods; D011878:Radiotherapy / Q000379:methods; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*