Individual Radiosensitivity in Lung Cancer Patients Assessed by G0 and Three Color Fluorescence in Situ Hybridization

Abstract

Background: It is well known that radiosensitivity varies substantially from individual to individual. This may influence the tumor response and also cause side effects in normal tissues following the radiotherapy treatment for cancers. Therefore, we aimed to analyze the sensitivity of a lung cancer cohort to see whether patients display similar radiosensitivity distribution as compared to healthy individuals. Methods: Blood samples of healthy individuals (n = 244) and a small group of lung cancer patients (n= 38) were irradiated ex vivo and chromosomes # 1, 2 and 4 were analyzed by the 3-color fluorescence in situ hybridization (FISH) technique. Additionally, the data from 400 individuals from previously published studies were also analyzed, which included a healthy cohort as well as rectal cancer patients. Chromosomal aberrations were counted and expressed as breaks per metaphase (B/M). The chromosomal aberrations in the control sample (background) were subtracted to obtain only the radiation-induced aberrations. Results: The lung cancer cohort had significantly increased background B/M values (p<0.001). Increased radiosensitivity was stated if the B/M value exceeded 0.55. The percentage of individuals with increased radiosensitivity was slightly higher in the patient groups compared to that in healthy individuals. Conclusions: Individualizing treatment by adjusting the radiation dose can help in reducing side effects, as cancer patients have a broader range of individual radiosensitivity.

Influence of Gender on Radiosensitivity during Radiochemotherapy of Advanced Rectal Cancer

“…The 95%, 90%, 80%, 60%, 40%, 30% and 20% isodose volumes were derived from the treatment planning software (TPS) Pinnacle (Philips Radiation Oncology Systems, Fitchburg, WI, USA). Deposited energy values were calculated according to the equation described previously (Figure 3B) [ 8 ].…”