Comparison of Clonogenic Survival Data Obtained by Pre- and Post-Irradiation Methods

Takahiro Oike; Yuka Hirota; Narisa Dewi Maulany Darwis; Atsushi Shibata; Tatsuya Ohno

doi:10.3390/jpm10040171

Comparison of Clonogenic Survival Data Obtained by Pre- and Post-Irradiation Methods

J Pers Med. 2020 Oct 15;10(4):171. doi: 10.3390/jpm10040171.

Authors

Takahiro Oike^{1

2}, Yuka Hirota¹, Narisa Dewi Maulany Darwis^{1

3}, Atsushi Shibata⁴, Tatsuya Ohno^{1

2}

Affiliations

¹ Department of Radiation Oncology, Gunma University Graduate School of Medicine, 3-39-22, Showa-machi, Maebashi 371-8511, Japan.
² Heavy Ion Medical Center, Gunma University, 3-39-22, Showa-machi, Maebashi 371-8511, Japan.
³ Department of Radiation Oncology, Faculty of Medicine Universitas Indonesia-Dr. Cipto Mangunkusumo Hospital, Jl. P. Diponegoro no. 71, Jakarta 10430, Indonesia.
⁴ Initiative for Advanced Research (GIAR), Gunma University, 3-39-22, Showa-machi, Maebashi 371-8511, Japan.

Abstract

Clonogenic assays are the gold standard to measure in vitro radiosensitivity, which use two cell plating methods, before or after irradiation (IR). However, the effect of the plating method on the experimental outcome remains unelucidated. By using common cancer cell lines, here we demonstrate that pre-IR and post-IR plating methods have a negligible effect on the clonogenic assay-derived photon sensitivity as assessed by SF₂, SF₄, SF₆, SF₈, D₁₀, or D₅₀ (N.B. SFx indicates the survival at X Gy; Dx indicates the dose providing X% survival). These data provide important biological insight that supports inter-study comparison and integrated analysis of published clonogenic assay data regardless of the plating method used.

Keywords: cancer; clonogenic assays; methods; plating; radiation; radiosensitivity.