Radiation Oncology Journal最新文献

Purpose: To analyze the gene mutation, immune infiltration and tumor growth of primary tumor and distant tumor under different treatment modes.

Materials and methods: Twenty B16 murine melanoma cells were injected subcutaneously into the of both sides of the thigh, simulating a primary tumor and a secondary tumor impacted by the abscopal effect, respectively. They were divided into blank control group, immunotherapy group, radiotherapy group, and radiotherapy combined immunotherapy group. During this period, tumor volume was measured, and RNA sequencing was performed on tumor samples after the test. R software was used to analyze differentially expressed genes, functional enrichment, and immune infiltration.

Results: We found that any treatment mode could cause changes in differentially expressed genes, especially the combination treatment. The different therapeutic effects might be caused by gene expression. In addition, the proportions of infiltrating immune cells in the irradiated and abscopal tumors were different. In the combination treatment group, T-cell infiltration in the irradiated site was the most obvious. In the immunotherapy group, CD8+ T-cell infiltration in the abscopal tumor site was obvious, but immunotherapy alone might have a poor prognosis. Whether the irradiated or abscopal tumor was evaluated, radiotherapy combined with anti-programmed cell death protein 1 (anti-PD-1) therapy produced the most obvious tumor control and might have a positive impact on prognosis.

Conclusion: Combination therapy not only improves the immune microenvironment but may also have a positive impact on prognosis.

Purpose: To report the trends of radiotherapy in the management of elderly patients with hepatocellular carcinoma (HCC).

Materials and methods: We retrospectively reviewed patients who entered HCC registry of Samsung Medical Center between 2005 and 2017. Patients who were 75 years or older at the time of registration were defined as elderly. They were categorized into three groups based on the year of registration. Radiotherapy characteristics were compared between the groups to observe differences by age groups and period of registration.

Results: Out of 9,132 HCC registry patients, elderly comprised 6.2% (566 patients) of the registry, and the proportion increased throughout the study period (from 3.1% to 11.4%). Radiotherapy was administered to 107 patients (18.9%) in elderly group. Radiotherapy utilization in the early treatment process (within 1 year after registration) has rapidly increased from 6.1% to 15.3%. All treatments before 2008 were delivered with two-dimensional or three-dimensional conformal radiotherapy, while more than two-thirds of treatments after 2017 were delivered with advanced techniques such as intensity-modulated radiotherapy, stereotactic body radiotherapy, or proton beam therapy. Overall survival (OS) of elderly was significantly worse than younger patients. However, for patients who received radiotherapy during the initial management (within one month after registration), there was no statistically significant difference in OS between age groups.

Conclusion: The proportion of elderly HCC is increasing. Radiotherapy utilization and adoption of advanced radiotherapy technique showed a consistently increasing trend for the group of patients, indicating that the role of radiotherapy in the management of elderly HCC is expanding.

Purpose: Indians have a higher incidence of cardiovascular diseases, often at a younger age, than other ethnic groups. This higher baseline risk requires consideration when assessing additional cardiac morbidity of breast cancer treatment. Superior cardiac sparing is a critical dosimetric advantage of proton therapy in breast cancer radiotherapy. We report here the heart and cardiac-substructure doses and early toxicities in breast cancer patients treated post-operatively with proton therapy in India's first proton therapy center.

Materials and methods: We treated twenty breast cancer patients with intensity-modulated proton therapy (IMPT) from October 2019 to September 2022, eleven after breast conservation, nine following mastectomy, and appropriate systemic therapy, when indicated. The most prescribed dose was 40 GyE to the whole breast/chest wall and 48 GyE by simultaneous integrated boost to the tumor bed and 37.5 GyE to appropriate nodal volumes, delivered in 15 fractions.

Results: Adequate coverage was achieved for clinical target volume (breast/chest wall), i.e., CTV40, and regional nodes, with 99% of the targets receiving 95% of the prescribed dose (V95% > 99%). The mean heart dose was 0.78 GyE and 0.87 GyE for all and left breast cancer patients, respectively. The mean left anterior descending artery (LAD) dose, LAD D0.02cc, and left ventricle dose were 2.76, 6.46, and 0.2 GyE, respectively. Mean ipsilateral lung dose, V20Gy, V5Gy, and contralateral breast dose (Dmean) were 6.87 GyE, 14.6%, 36.4%, and 0.38 GyE, respectively.

Conclusion: The dose to heart and cardiac substructures is lower with IMPT than published photon therapy data. Despite the limited access to proton therapy at present, given the higher cardiovascular risk and coronary artery disease prevalence in India, the cardiac sparing achieved using this technique merits consideration for wider adoption in breast cancer treatment.

Radiation enteritis is a kind of intestinal radiation injury in patients with pelvic and retroperitoneal malignancies after radiotherapy, and its occurrence and development process are very complicated. At present, studies have confirmed that intestinal microecological imbalance is an important factor in the formation of this disease. Abdominal radiation causes changes in the composition of the flora and a decrease in its diversity, which is mainly manifested by a decrease in beneficial bacterial species such as Lactobacilli and Bifidobacteria. Intestinal dysbacteriosis aggravates radiation enteritis, weakens the function of the intestinal epithelial barrier, and promotes the expression of inflammatory factors, thereby aggravating the occurrence of enteritis. Given the role of the microbiome in radiation enteritis, we suggest that the gut microbiota may be a potential biomarker for the disease. Treatment methods such as probiotics, antibiotics, and fecal microbiota transplantation are ways to correct the microbiota and may be an effective way to prevent and treat radiation enteritis. Based on a review of the relevant literature, this paper reviews the mechanism and treatment of intestinal microbes in radiation enteritis.

Purpose: We aimed to determine whether low-dose radiotherapy (LDRT) is effective in patients with Alzheimer disease (AD).

Materials and methods: We included patients according to the following criteria: probable Alzheimer's dementia according to the New Diagnostic Criteria for Alzheimer's Disease; confirmation of amyloid plaque deposits on baseline amyloid positron emission tomography (PET); a Korean Mini-Mental State Examination 2nd edition (K-MMSE-2) score of 13-26; and a Global Clinical Dementia Rating (CDR) score of 0.5-2 points. LDRT was performed six times at 0.5 Gy each. Post-treatment cognitive function tests and PET-CT examinations were performed to evaluate efficacy. The medication for AD treatment was maintained throughout the study period.

Results: At 6 months after LDRT, neurological improvement was seen in 20% of patients. Patient #2 showed improvement in all domains of the Seoul Neuropsychological Screening Battery II (SNSB-II). Moreover, the K-MMSE-2 and Geriatric Depression Score-Short Form scores improved from 20 to 23 and from 8 to 2, respectively. For patient #3, the CDR score (sum of box score) improved from 1 (4.0) to 1 (3.5) at 3 months follow-up. Moreover, the Z scores for language and related functions, memory, and frontal executive function improved to -2.56, -1.86, and -1.32, respectively at the 6-month follow-up. Two patients complained of mild nausea and mild hair loss during LDRT, which improved after treatment.

Conclusion: One of the five patients with AD treated with LDRT experienced a temporary improvement in SNSB-II. LDRT is tolerable in patients with AD. We are currently under follow-up and will conduct cognitive function tests after 12 months after LDRT. A large-scale randomized controlled trial with a longer follow-up period is warranted to determine the effect of LDRT on patients with AD.

Purpose: Patients with cancer are particularly vulnerable to coronavirus disease (COVID). Transportation barriers made travel to obtain medical care more difficult during the pandemic. Whether these factors led to changes in the distance traveled for radiotherapy and the coordinated location of radiation treatment is unknown.

Materials and methods: We analyzed patients across 60 cancer sites in the National Cancer Database from 2018 to 2020. Demographic and clinical variables were analyzed for changes in distance traveled for radiotherapy. We designated the facilities in the 99th percentile or above in terms of the proportion of patients who traveled more than 200 miles as "destination facilities." We defined "coordinated care" as undergoing radiotherapy at the same facility where the cancer was diagnosed.

Results: We evaluated 1,151,954 patients. There was a greater than 1% decrease in the proportion of patients treated in the Mid-Atlantic States. Mean distance traveled from place of residence to radiation treatment decreased from 28.6 to 25.9 miles, and the proportion traveling greater than 50 miles decreased from 7.7% to 7.1%. At "destination facilities," the proportion traveling more than 200 miles decreased from 29.3% in 2018 to 24% in 2020. In comparison, at the other hospitals, the proportion traveling more than 200 miles decreased from 1.07% to 0.97%. In 2020, residing in a rural area resulted in a lower odds of having coordinated care (multivariable odds ratio = 0.89; 95% confidence interval, 0.83-0.95).

Conclusion: The first year of the COVID pandemic measurably impacted the location of U.S. radiation therapy treatment.

Purpose: This study aimed to evaluate the role of inflammatory blood markers in predicting the pathological response rate after neoadjuvant chemoradiation (neo-CRT) in patients with locally advanced rectal cancer (LARC).

Materials and methods: In this prospective cohort study, we analyzed the data of patients with LARC who underwent neo-CRT and surgical removal of the rectal mass between 2020 and 2022 in a tertiary medical center. Patients were examined weekly during chemoradiation and neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and systemic immune inflammation index (SII) were calculated from weekly laboratory data. Wilcoxon signed-ranks and logistic regression analysis were utilized to determine whether any laboratory parameters during different time point assessments or their relative changes could predict the tumor response based on a permanent pathology review.

Results: Thirty-four patients were recruited for the study. Eighteen patients (53%) achieved good pathologic response. Statistical analysis by Wilcoxon signed-ranks method indicated significant rises in NLR, PLR, MLR, and SII on weekly assessments during chemoradiation. Having an NLR over 3.21 during chemoradiation was correlated with the response on a Pearson chi-squared test (p = 0.04). Also, a significant correlation was found between the PLR ratio over 1.8 and the response (p = 0.02). NLR ratio over 1.82 marginally missed a significant correlation with the response (p = 0.13). On multivariate analysis, a PLR ratio over 1.8 showed a trend for response (odds ratio = 10.4; 95% confidence interval, 0.9-123; p = 0.06).

Conclusion: In this study, PLR ratio as an inflammatory marker showed a trend in the prediction of response in permanent pathology to neo-CRT.

Purpose: Studies about the effect of radiation therapy (RT) on immune cells are usually limited to a high-grade glioma mostly exposed to chemotherapy and a high dose of steroid which also could affect immune cells. The purpose of this retrospective analysis of low-grade brain tumor patients treated by RT alone is to determine significant factors influencing neutrophil-to-lymphocyte ratio (NLR), absolute neutrophil counts (ANC), and absolute lymphocyte counts (ALC).

Materials and methods: A total of 41 patients who received RT between 2007 and 2020 were analyzed. Patients who received chemotherapy and high-dose of steroid were excluded. ANC and ALC were collected before starting RT (baseline) and within one-week before ending RT (post-treatment). Changes of ANC, ALC, and NLR between baseline and post-treatment were calculated.

Results: ALC decreased in 32 patients (78.1%). NLR increased in 31 patients (75.6%). No patients developed grade 2 or higher hematologic toxicities. The decrease of ALC was significantly correlated with the dose to brain V15 in a simple and multiple linear regression (p = 0.043). Brain V10 and V20 adjacent to V15 were also marginally significant factors determining the reduction of lymphocytes (p = 0.050 and p = 0.059, respectively). However, it was difficult to find predictive factors affecting changes of ANC and NLR.

Conclusion: In low-grade brain tumor patients who are treated by RT alone, ALC decreased and NLR increased in three-fourth of patients, although the magnitude was minimal. The decrease of ALC was mainly affected by low dose to the brain. However, RT dose was not correlated with changes of ANC or NLR.