The Relative Biological Effectiveness for Carbon and Oxygen Ion Beams Using the Raster-Scanning Technique in Hepatocellular Carcinoma Cell Lines

Abstract

BackgroundAim of this study was to evaluate the relative biological effectiveness (RBE) of carbon (12C) and oxygen ion (16O)-irradiation applied in the raster-scanning technique at the Heidelberg Ion beam Therapy center (HIT) based on clonogenic survival in hepatocellular carcinoma cell lines compared to photon irradiation.MethodsFour human HCC lines Hep3B, PLC, HepG2 and HUH7 were irradiated with photons, 12C and 16O using a customized experimental setting at HIT for in-vitro trials. Cells were irradiated with increasing physical photon single doses of 0, 2, 4 and 6 Gy and heavy ionsingle doses of 0, 0.125, 0.5, 1, 2, 3 Gy (12C and 16O). SOBP-penetration depth and extension was 35 mm +/−4 mm and 36 mm +/−5 mm for carbon ions and oxygen ions respectively. Mean energy level and mean linear energy transfer (LET) were 130 MeV/u and 112 keV/um for 12C, and 154 MeV/u and 146 keV/um for 16O. Clonogenic survival was computated and realtive biological effectiveness (RBE) values were defined.ResultsFor all cell lines and both particle modalities α- and β-values were determined. As expected, α-values were significantly higher for 12C and 16O than for photons, reflecting a steeper decline of the initial slope of the survival curves for high-LET beams. RBE-values were in the range of 2.1–3.3 and 1.9–3.1 for 12C and 16O, respectively.ConclusionBoth irradiation with 12C and 16O using the rasterscanning technique leads to an enhanced RBE in HCC cell lines. No relevant differences between achieved RBE-values for 12C and 16O were found. Results of this work will further influence biological-adapted treatment planning for HCC patients that will undergo particle therapy with 12C or 16O.

Effects of Ion Irradiation on Seedlings Growth Monitored by Ultraweak Delayed Luminescence

“…The best fit (reduced χ 2 < 1, R 2 = 0.990) is obtained when α = (11.4 ± 0.6)×10 −4 . Eq (1) describes the linear dose-response relationship that characterises the effect of densely ionizing radiation on cell survival [10]. Actually in our case, as above said, seeds germination capability remain enough high, while ion irradiation significantly affects seed growth.…”

The Study of Biological Effectiveness of U-70 Accelerator Carbon Ions Using Melanoma B-16 Clonogenic Assay

“…The linear-quadratic model was applied to receive dose-survival dependencies (1). The agreement between the experimental data and the model was estimated using the χ 2 criterion.…”

“…Its advantage over the conventional radiotherapy is proved for tumors of different etiology. According to some studies [1,2], carbon ions are more appropriate for head and neck tumors, lung cancer, prostate and hepatocellular carcinomas. It is shown in simulation study [3] that carbon ions are more effective comparing to protons in case of deep-seated tumors with a diameter of up to 4 cm.…”

“…Available data on biological effectiveness of carbon ions are mainly related to ranges A and B [1,[4][5][6][7]. Range C, the area that follows the peak, has not been studied enough.…”

Clinical Limitations of Photon, Proton and Carbon Ion Therapy for Pancreatic Cancer

“…As a result, investigations into heavier particles which induce more severe DNA damage continue (compared to both PT and XRT). Carbon-ion therapy (Cion) utilises charge carbon-12 ions of larger mass to increase direct DNA damage effectiveness by a factor of approximately two to four [13][14][15][16]. Recently established at a handful of institutions, the improved dose conformation and potential for overcoming effects of hypoxia is currently being investigated as a potential solution for LAPC [11,17].…”