title: Partial breast radiotherapy with simple teletherapy techniques.
abstract: A prospective pilot study of partial breast irradiation (PBI) with conventional vs hypofractionated schedules was set out. The study aimed to determine efficacy, acute and late side effects, and the preference of photon vs electron irradiation based on individual features. Patients were enrolled according to internationally accepted guidelines on PBI. Conformal radiotherapy plans were generated with both photon and electron beams, and the preferred technique based on dose homogeneity and the radiation exposure of healthy tissues was applied. For electron dose verification, a special phantom was constructed. Patients were randomized for fractionation schedules of 25 × 2 vs 13 × 3Gy. Skin and breast changes were registered at the time of and ≥1 year after the completion of radiotherapy. Dose homogeneity was better with photons. If the tumor bed was located in the inner quadrants, electron beam gave superior results regarding conformity and sparing of organ at risk (OAR). If the tumor was situated in the lateral quadrants, conformity was better with photons. A depth of the tumor bed ≥3.0cm predicted the superiority of photon irradiation (odds ratio [OR] = 23.6, 95% CI: 5.2 to 107.5, p < 0.001) with >90% sensitivity and specificity. After a median follow-up of 39 months, among 72 irradiated cases, 1 local relapse out of the tumor bed was detected. Acute radiodermatitis of grade I to II, hyperpigmentation, and telangiectasia developed ≥1 year after radiotherapy, exclusively after electron beam radiotherapy. The choice of electrons or photons for PBI should be based on tumor bed location; the used methods are efficient and feasible.
authors.affiliation: Department of Oncotherapy, University of Szeged, Szeged, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Fekete
authors.affiliation: Department of Oncotherapy, University of Szeged, Szeged, Hungary.
authors.forename: Dóra
authors.initials: D
authors.lastname: Újhidy
authors.affiliation: Department of Oncotherapy, University of Szeged, Szeged, Hungary.
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Együd
authors.affiliation: Department of Oncotherapy, University of Szeged, Szeged, Hungary.
authors.forename: Laura
authors.initials: L
authors.lastname: Kiscsatári
authors.affiliation: Department of Oncotherapy, University of Szeged, Szeged, Hungary.
authors.forename: Gusztáv
authors.initials: G
authors.lastname: Marosi
authors.affiliation: Department of Oncotherapy, University of Szeged, Szeged, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kahán
authors.affiliation: Department of Oncotherapy, University of Szeged, Szeged, Hungary. Electronic address: varga.zoltan@med.u-szeged.hu.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Varga
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy*; D002277:Carcinoma / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D020266:Radiotherapy, Conformal / Q000379:methods*; D016896:Treatment Outcome
keywords: Acute skin toxicity; Electron beam; Fractionation; Late skin toxicity; Partial breast radiotherapy; Photon beam