title: Radiobiological characterization of post-lumpectomy focal brachytherapy with lipid nanoparticle-carried radionuclides.
abstract: Post-operative radiotherapy has commonly been used for early stage breast cancer to treat residual disease. The primary objective of this work was to characterize, through dosimetric and radiobiological modeling, a novel focal brachytherapy technique which uses direct intracavitary infusion of β-emitting radionuclides (186Re/188Re) carried by lipid nanoparticles (liposomes). Absorbed dose calculations were performed for a spherical lumpectomy cavity with a uniformly injected activity distribution using a dose point kernel convolution technique. Radiobiological indices were used to relate predicted therapy outcome and normal tissue complication of this technique with equivalent external beam radiotherapy treatment regimens. Modeled stromal damage was used as a measure of the inhibition of the stimulatory effect on tumor growth driven by the wound healing response. A sample treatment plan delivering 50 Gy at a therapeutic range of 2.0 mm for 186Re-liposomes and 5.0 mm for 188Re-liposomes takes advantage of the dose delivery characteristics of the β-emissions, providing significant EUD (58.2 Gy and 72.5 Gy for 186Re and 188Re, respectively) with a minimal NTCP (0.046%) of the healthy ipsilateral breast. Modeling of kidney BED and ipsilateral breast NTCP showed that large injected activity concentrations of both radionuclides could be safely administered without significant complications.
authors.affiliation: Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Hrycushko
authors.forename: Alonso N
authors.initials: AN
authors.lastname: Gutierrez
authors.forename: Beth
authors.initials: B
authors.lastname: Goins
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Yan
authors.forename: William T
authors.initials: WT
authors.lastname: Phillips
authors.forename: Pamela M
authors.initials: PM
authors.lastname: Otto
authors.forename: Ande
authors.initials: A
authors.lastname: Bao
mesh_terms: D000818:Animals; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D001940:Breast / Q000528:radiation effects; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D007668:Kidney / Q000528:radiation effects; D008081:Liposomes / Q000737:chemistry*; D015412:Mastectomy, Segmental; D058958:Organs at Risk / Q000528:radiation effects; D011336:Probability; D011853:Radiobiology / Q000379:methods*; D011868:Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D011874:Radiometry; D051381:Rats; D012211:Rhenium / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D008081:Liposomes; D011868:Radioisotopes; D012211:Rhenium