Cancer Cell Radiobiological Studies Using In-House-Developed α-Particle Irradiator

• Published in: Cancer biotherapy & radiopharmaceuticals Vol. 30; no. 9; pp. 386 - 394
• Main Authors: Nilsson, Jenny, Bauden, Monika Posaric, Nilsson, Jonas M, Strand, Sven-Erik, Elgqvist, Jörgen
• Format: Journal Article
• Language: English
• Published: United States 01.11.2015
• Subjects: Alpha Particles - therapeutic use; Americium - chemistry; Cancer and Oncology; Cancer och onkologi; Cell Survival - radiation effects; Cesium Radioisotopes - pharmacokinetics; Clinical Medicine; Dose-Response Relationship, Radiation; Humans; Klinisk medicin; Male; Medical and Health Sciences; Medicin och hälsovetenskap; Pancreatic Neoplasms - pathology; Pancreatic Neoplasms - radiotherapy; Prostatic Neoplasms - pathology; Prostatic Neoplasms - radiotherapy; Radiation Tolerance - radiation effects; Radiobiology; Radiologi och bildbehandling; Radiology, Nuclear Medicine and Medical Imaging; Relative Biological Effectiveness; Tumor Cells, Cultured; pancreatic cancer; prostate cancer; radioimmunotherapy; dosimetry; high-LET radiation
• ISSN: 1084-9785; 1557-8852; 1557-8852
• DOI: 10.1089/cbr.2015.1895

An α-particle irradiator, enabling high-precision irradiation of cells for in vitro studies, has been constructed. The irradiation source was a (241)Am source, on which well inserts containing cancer cells growing in monolayer were placed. The total radioactivity, uniformity, and α-particle spectrum were determined by use of HPGe detector, Gafchromic dosimetry film, and PIPS detector measurements, respectively. Monte Carlo simulations were used for dosimetry. Three prostate cancer (LNCaP, DU145, PC3) and three pancreatic cancer (Capan-1, Panc-1, BxPC-3) cell lines were irradiated by α-particles to the absorbed doses 0, 0.5, 1, and 2 Gy. For reference, cells were irradiated using (137)Cs to the absorbed doses 0, 1, 2, 4, 6, 8, and 10 Gy. Radiation sensitivity was estimated using a tetrazolium salt-based colorimetric assay with absorbance measurements at 450 nm. The relative biological effectiveness for α-particles relative to γ-irradiation at 37% cell survival for the LNCaP, DU145, PC3, Capan-1, Panc-1, and BxPC-3 cells was 7.9 ± 1.7, 8.0 ± 0.8, 7.0 ± 1.1, 12.5 ± 1.6, 9.4 ± 0.9, and 6.2 ± 0.7, respectively. The results show the feasibility of constructing a desktop α-particle irradiator as well as indicate that both prostate and pancreatic cancers are good candidates for further studies of α-particle radioimmunotherapy.