Relationships between acute reactions to radiotherapy in head and neck cancer patients and parameters of radiation-induced DNA damage and repair in their lymphocytes

Assessment of Individual Radiosensitivity in Breast Cancer Patients Using a Combination of Biomolecular Markers

About 5% of patients undergoing radiotherapy (RT) develop RT-related side effects. To assess individual radiosensitivity, we collected peripheral blood from breast cancer patients before, during and after the RT, and γH2AX/53BP1 foci, apoptosis, chromosomal aberrations (CAs) and micronuclei (MN) were analyzed and correlated with the healthy tissue side effects assessed by the RTOG/EORTC criteria. The results showed a significantly higher level of γH2AX/53BP1 foci before the RT in radiosensitive (RS) patients in comparison to normal responding patients (NOR). Analysis of apoptosis did not reveal any correlation with side effects. CA and MN assays displayed an increase in genomic instability during and after RT and a higher frequency of MN in the lymphocytes of RS patients. We also studied time kinetics of γH2AX/53BP1 foci and apoptosis after in vitro irradiation of lymphocytes. Higher levels of primary 53BP1 and co-localizing γH2AX/53BP1 foci were detected in cells from RS patients as compared to NOR patients, while no difference in the residual foci or apoptotic response was found. The data suggested impaired DNA damage response in cells from RS patients. We suggest γH2AX/53BP1 foci and MN as potential biomarkers of individual radiosensitivity, but they need to be evaluated with a larger cohort of patients for clinics.

Effect of "timing it right" on comprehensive unmet needs and psychological pain in patients with head and neck cancer undergoing radiotherapy: a randomized controlled trial

PURPOSE

We assessed the effectiveness of "timing it right" (TIR) applications in patients undergoing radiotherapy for head and neck cancer through a carefully designed TIR intervention program. The assessment in this study emphasized the impact of the TIR intervention on the unmet needs and psychological pain of patients with head and neck cancer at different stages of radiotherapy.

METHODS

In total, 140 radiotherapy patients were randomly recruited into two study groups: (1) the TIR intervention group received routine nursing follow-up and comprehensive nursing intervention based on TIR, and (2) the control group received routine nursing care. Assessments were conducted at baseline, before discharge, and 3 months and 6 months after discharge. The comprehensive needs and psychological pain of patients with radiotherapy were measured using the Comprehensive Needs Assessment Tool in Cancer for Patients (CNAT) and the Distress Thermometer (DT), respectively. A linear mixed model was applied to analyze the effects.

RESULTS

A total of 137 patients completed the study. Compared to the control group, the TIR group showed significant improvements in information needs, health and psychological problems, healthcare staff, physical symptoms, health facilities and services, religious/spiritual support, and psychological pain (F=8.503, p=0.004; F=1.896, p=0.003; F=12.422, p<0.001; F=9.634, p=0.001; F=7.310, p=0.006; F=1.684, p=0.009; F=1.692, p=0.041). In addition to practical support, the remaining indicators differed significantly by time point, group, and group-time interaction.

CONCLUSIONS

The patient support application based on TIR can effectively address unmet needs and improve psychological pain, supporting TIR as an effective psychological management and intervention strategy for radiotherapy patients in the early stage of long-term rehabilitation.

TRIAL REGISTRATION

Chictr.org.cn Chi CTR2100047960.

Prediction of the Acute or Late Radiation Toxicity Effects in Radiotherapy Patients Using Ex Vivo Induced Biodosimetric Markers: A Review

A search for effective methods for the assessment of patients' individual response to radiation is one of the important tasks of clinical radiobiology. This review summarizes available data on the use of ex vivo cytogenetic markers, typically used for biodosimetry, for the prediction of individual clinical radiosensitivity (normal tissue toxicity, NTT) in cells of cancer patients undergoing therapeutic irradiation. In approximately 50% of the relevant reports, selected for the analysis in peer-reviewed international journals, the average ex vivo induced yield of these biodosimetric markers was higher in patients with severe reactions than in patients with a lower grade of NTT. Also, a significant correlation was sometimes found between the biodosimetric marker yield and the severity of acute or late NTT reactions at an individual level, but this observation was not unequivocally proven. A similar controversy of published results was found regarding the attempts to apply G2- and γH2AX foci assays for NTT prediction. A correlation between ex vivo cytogenetic biomarker yields and NTT occurred most frequently when chromosome aberrations (not micronuclei) were measured in lymphocytes (not fibroblasts) irradiated to relatively high doses (4-6 Gy, not 2 Gy) in patients with various grades of late (not early) radiotherapy (RT) morbidity. The limitations of existing approaches are discussed, and recommendations on the improvement of the ex vivo cytogenetic testing for NTT prediction are provided. However, the efficiency of these methods still needs to be validated in properly organized clinical trials involving large and verified patient cohorts.

FDG uptake in normal tissues assessed by PET during treatment has prognostic value for treatment results in head and neck squamous cell carcinomas undergoing radiochemotherapy

BACKGROUND AND PURPOSE

Pronounced early side effects have been suggested to be a positive prognostic factor in patients undergoing chemo-radio-therapy (CRT) for head and neck squamous cell carcinomas (HNSCC). We assessed the utility of positron emission tomography (PET) during treatment to analyze the correlation of 18F-fluorodeoxyglucose (FDG) uptake in off target structures within the irradiated volume with outcome.

MATERIAL AND METHODS

Two independent cohorts of patients with locally advanced HNSCC, both treated within prospective clinical imaging trials with curatively intended CRT were retrospectively analyzed. The exploratory cohort included 50, the independent validation cohort 26 patients. Uptake of FDG in mucosa and submucosal soft tissues (MST) as well as in other structures was assessed at week 4 during treatment. Considered endpoints were local tumor control (LC) and overall survival (OS). The prognostic value of FDG uptake on the endpoints was measured by the concordance index (ci) using univariate and multivariate Cox regression analyses based on the continuous variables of the exploratory cohort.

RESULTS

In the exploratory cohort FDG uptake in MST was prognostic for LC (hazard ratio HR=0.23, p=0.025) and OS (HR=0.30, p=0.003) in univariate analyses. These findings remained significant upon multivariate testing (LC HR=0.14, p=0.011; OS HR=0.20, p=0.001) and were confirmed in the validation cohort for LC (HR=0.15, p=0.034) and OS (HR=0.17, p=0.003). Also the SUV_mean threshold of MST that was generated within the exploratory cohort (2.375) yielded significant differences in OS (p=0.006) and a statistical trend for LC (p=0.078) when applied to the validation cohort.

CONCLUSIONS

FDG uptake in normal tissues within the irradiated volume measured by PET during treatment has significant prognostic value in HNSCC. This effect may potentially be of use for personalized treatment adaptation.

Predicting radiotherapy-related clinical toxicities in cancer: a literature review

Assessment of patients receiving radiotherapy for cancer is essential, with the ability to identify those who may be more likely to experience radiotherapy-related side effects noted as an important issue for nurses. Body mass, age, and radiation dose may be predictive factors for the development of such side effects. This review considers these factors and how nurses can use this evidence to inform their care, with results indicating that the dose of radiation, the site treated, and body mass index are predictive of toxicities that may develop. Increased awareness of these predictive factors will aid nurses in identifying patients at greater risk of developing radiation-related side effects. This will assist in guiding nursing interventions, as well as enabling the individualization of patient education, by placing greater emphasis on preventive measures for patients who are more vulnerable to the development of radiation-related toxicities.

Evaluation of different biomarkers to predict individual radiosensitivity in an inter-laboratory comparison--lessons for future studies

Radiotherapy is a powerful cure for several types of solid tumours, but its application is often limited because of severe side effects in individual patients. With the aim to find biomarkers capable of predicting normal tissue side reactions we analysed the radiation responses of cells from individual head and neck tumour and breast cancer patients of different clinical radiosensitivity in a multicentric study. Multiple parameters of cellular radiosensitivity were analysed in coded samples of peripheral blood lymphocytes (PBLs) and derived lymphoblastoid cell lines (LCLs) from 15 clinical radio-hypersensitive tumour patients and compared to age- and sex-matched non-radiosensitive patient controls and 15 lymphoblastoid cell lines from age- and sex- matched healthy controls of the KORA study. Experimental parameters included ionizing radiation (IR)-induced cell death (AnnexinV), induction and repair of DNA strand breaks (Comet assay), induction of yH2AX foci (as a result of DNA double strand breaks), and whole genome expression analyses. Considerable inter-individual differences in IR-induced DNA strand breaks and their repair and/or cell death could be detected in primary and immortalised cells with the applied assays. The group of clinically radiosensitive patients was not unequivocally distinguishable from normal responding patients nor were individual overreacting patients in the test system unambiguously identified by two different laboratories. Thus, the in vitro test systems investigated here seem not to be appropriate for a general prediction of clinical reactions during or after radiotherapy due to the experimental variability compared to the small effect of radiation sensitivity. Genome-wide expression analysis however revealed a set of 67 marker genes which were differentially induced 6 h after in vitro-irradiation in lymphocytes from radio-hypersensitive and non-radiosensitive patients. These results warrant future validation in larger cohorts in order to determine parameters potentially predictive for clinical radiosensitivity.

Factors influencing heterogeneity of radiation-induced DNA-damage measured by the alkaline comet assay

Background

To investigate whether different conditions of DNA structure and radiation treatment could modify heterogeneity of response. Additionally to study variance as a potential parameter of heterogeneity for radiosensitivity testing.

Methods

Two-hundred leukocytes per sample of healthy donors were split into four groups. I: Intact chromatin structure; II: Nucleoids of histone-depleted DNA; III: Nucleoids of histone-depleted DNA with 90 mM DMSO as antioxidant. Response to single (I-III) and twice (IV) irradiation with 4 Gy and repair kinetics were evaluated using %Tail-DNA. Heterogeneity of DNA damage was determined by calculation of variance of DNA-damage (V) and mean variance (Mvar), mutual comparisons were done by one-way analysis of variance (ANOVA).

Results

Heterogeneity of initial DNA-damage (I, 0 min repair) increased without histones (II). Absence of histones was balanced by addition of antioxidants (III). Repair reduced heterogeneity of all samples (with and without irradiation). However double irradiation plus repair led to a higher level of heterogeneity distinguishable from single irradiation and repair in intact cells. Increase of mean DNA damage was associated with a similarly elevated variance of DNA damage (r = +0.88).

Conclusions

Heterogeneity of DNA-damage can be modified by histone level, antioxidant concentration, repair and radiation dose and was positively correlated with DNA damage. Experimental conditions might be optimized by reducing scatter of comet assay data by repair and antioxidants, potentially allowing better discrimination of small differences. Amount of heterogeneity measured by variance might be an additional useful parameter to characterize radiosensitivity.