OBJECTIVE: To identify swallowing-related structures (SRSs) predicting post-radiotherapy dysphagia in oropharyngeal carcinoma patients.
METHODS: Between September 2020 and October 2022, oropharyngeal cancer patients who had completed radiotherapy at least one year before without recurrence or residuals were selected. They underwent flexible endoscopic evaluation of swallowing (FEES) assessments and dysphagia grading. The mean radiation doses delivered to their SRSs were recalculated. The correlation between radiation doses to each SRS and FEES scores was analysed.
RESULTS: Twenty-nine participants, aged 51-73 years, were enrolled. Six patients had received two-dimensional radiotherapy, eight had undergone three-dimensional conformal radiotherapy, and fifteen had received intensity-modulated radiation therapy. Radiation doses to the inferior pharyngeal constrictor, cricopharyngeus and glottic larynx significantly predicted dysphagia for both semisolids (p = 0.023, 0.030 and 0.001) and liquid diets (p = 0.021, 0.013 and 0.002). The esophageal inlet significantly predicted swallowing outcomes for only the liquid diet (p = 0.007).
CONCLUSIONS: This study supports that SRS-sparing during radiotherapy for oropharyngeal cancers improves swallowing outcomes.

Deep-inspiration breath-hold (DIBH) reduces the radiation dose to the heart and lungs during breast radiotherapy in cancer. However, there is not enough discussion about suitable breathing methods for DIBH. Therefore, we investigated the radiation doses and organ and body surface displacement in abdominal DIBH (A-DIBH) and thoracic DIBH (T-DIBH). Free-breathing, A-DIBH, and T-DIBH computed tomography images of 100 patients were used. After contouring the targets, heart, and lungs, radiotherapy plans were created. We investigated the heart and lung doses, the associations between the heart and left lung displacements, and the thorax and abdominal surface displacements. No significant differences were observed in the target dose indices. However, the heart and lung doses were significantly lower in A-DIBH than in T-DIBH for all the indices; the mean heart and lung doses were 1.69 and 3.48 Gy, and 1.91 and 3.55 Gy in A-DIBH and T-DIBH, respectively. The inferior displacement of the heart and the left lung was more significant in A-DIBH. Therefore, inferior expansion of the heart and lungs may be responsible for the respective dose reductions. The abdominal surface displaced more than the thoracic surface in both A-DIBH and T-DIBH, and thoracic surface displacement was greater in T-DIBH than in A-DIBH. Moreover, A-DIBH can be identified because abdominal surface displacement was greater in A-DIBH than in T-DIBH. In conclusion, A-DIBH and T-DIBH could be distinguished by comparing the abdominal and thoracic surfaces of A-DIBH and T-DIBH, thereby ensuring the implementation of A-DIBH and reducing the heart and lung doses.

UNASSIGNED: The embryo/fetus may be accidentally exposed to ionizing radiation. The aim of this study is to calculate embryo/fetus doses in pregnant women who underwent F-18 fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan.
UNASSIGNED: Between June 2015 and June 2021, 15 pregnant women underwent F-18 FDG PET/CT applied to the Genetic Research Center (GETAM). The OLINDA/EXM package program was used for internal radiation dosimetry according to the Medical Internal Radiation Dose scheme. FetDose V4 computer software was used to compute the embryo/fetus absorbed dose from CT scan.
UNASSIGNED: The amount of the injected F-18 FDG activity to patients varied between 333 and 555 MBq. The mean embryo/fetal dose from F-18 FDG was 7.2 ± 2.8 mGy. In addition, the CT component dose to the embryo/fetus dose ranged from 8.5 to 16 mGy with a mean of 12.14 ± 2.05.
UNASSIGNED: The embryo/fetus dose from F-18 FDG PET/CT was <15 mGy, however, questioning the women\'s childbearing prior to scintigraphy is the first-line strategy to avoid accidental radiation exposure and stochastic risks.

Intensity-modulated radiotherapy (IMRT) is a treatment method that is used in the treatment of head and neck cancers. Impairment of chewing and swallowing functions in the early and late periods of radiotherapy is frequent. Therefore, revealing the dose-effect relationship is important. The main purpose of this study is to investigate the dose-effect relationship between chewing and swallowing structures objectively via a standardized videofluoroscopy protocol. The study included 35 participants treated with chemo-IMRT. A videofluoroscopic swallowing study (VFSS) was performed before IMRT, and 3 and 6 months after IMRT. VFSS results were scored according to the Modified Barium Swallow Impairment Profile (MBSImP) and the Penetration-Aspiration Scale (PAS). Maximum interincisor mouth opening, body mass index (BMI), and Functional Oral Intake Scale levels were determined in these cases. The quality of life of participants was evaluated. There was a significant increase in PAS and MBSImP scores and a significant decrease in BMI scores of the patients after treatment. Xerotomy and sticky saliva complaints increased after treatment. The dose to the mastication muscles (> 40 Gy) and the temporomandibular joint (> 46 Gy) were found to be associated with a decrease in BMI; the dose to the superior pharyngeal constructor muscle (> 58 Gy) was found to be associated with pharyngeal stripping wave. The presence of aspiration was associated with the inferior pharyngeal constructor muscle, glottic larynx, supraglottic larynx, and upper esophageal sphincter. Important findings to emerge from this study include detected toxic dose limits. These findings may guide physicians to minimize the side effects of IMRT.

BACKGROUND: Immunotherapy (IO) provides a significant benefit for a subgroup of non-small cell lung cancer (NSCLC) patients. Radiotherapy (XRT) might enhance the efficacy of IO. We evaluated the impact of the specifics of XRT treatments on the OS of IO-treated NSCLC patients.
METHODS: Metastatic NSCLC patients treated with IO were retrospectively identified. Parameters included demographics, tumor characteristics, IO and XRT details. Correlation between the parameters and OS was tested with Cox regression.
RESULTS: 453 patients were included. No XRT was given to 167 (36.9%) patients, whereas XRT prior and after IO had 182 (40.2%) and 104 (22.9%) patients, respectively. XRT total doses between 30 and 40 Gy had better overall survival (OS) compared to non-irradiated patients (hazard ratio (HR) 0.5, 95% CI 0.25-1.0, p = 0.049). Worse outcome was seen with total doses ≤ 10 Gy (HR 1.67, 95% 1.13-2.5, p = 0.01), XRT fractions of 4.1-8 Gy (HR 1.48, 95% CI 1.05-2.1, p = 0.027) and XRT to the bone (HR 1.36, 95% CI 1.01-1.8, p = 0.04). Several clinical parameters correlated with OS in the univariate analysis of the IO-treated patients. While, in the multivariate analysis, only ECOG-PS, treatment line, type of IO, albumin and NLR remained statistically significant.
CONCLUSIONS: Specific doses, fractions and sites of XRT correlated with the OS of IO-treated NSCLC patients in the univariate analysis, although not in the multivariate analysis.

While ionizing radiation (IR) is a powerful tool in medical diagnostics, nuclear medicine, and radiology, it also is a serious threat to the integrity of genetic material. Mutagenic effects of IR to the human genome have long been the subject of research, yet still comparatively little is known about the genome-wide effects of IR exposure on the DNA-sequence level. In this study, we employed high throughput sequencing technologies to investigate IR-induced DNA alterations in human gingiva fibroblasts (HGF) that were acutely exposed to 0.5, 2, and 10 Gy of 240 kV X-radiation followed by repair times of 16 h or 7 days before whole-genome sequencing (WGS). Our analysis of the obtained WGS datasets revealed patterns of IR-induced variant (SNV and InDel) accumulation across the genome, within chromosomes as well as around the borders of topologically associating domains (TADs). Chromosome 19 consistently accumulated the highest SNVs and InDels events. Translocations showed variable patterns but with recurrent chromosomes of origin (e.g., Chr7 and Chr16). IR-induced InDels showed a relative increase in number relative to SNVs and a characteristic signature with respect to the frequency of triplet deletions in areas without repetitive or microhomology features. Overall experimental conditions and datasets the majority of SNVs per genome had no or little predicted functional impact with a maximum of 62, showing damaging potential. A dose-dependent effect of IR was surprisingly not apparent. We also observed a significant reduction in transition/transversion (Ti/Tv) ratios for IR-dependent SNVs, which could point to a contribution of the mismatch repair (MMR) system that strongly favors the repair of transitions over transversions, to the IR-induced DNA-damage response in human cells. Taken together, our results show the presence of distinguishable characteristic patterns of IR-induced DNA-alterations on a genome-wide level and implicate DNA-repair mechanisms in the formation of these signatures.

Computed tomography (CT) is a widely used medical imaging modality for diagnosing various diseases. Among CT techniques, 4-dimensional CT perfusion (4D-CTP) of the brain is established in most centers for diagnosing strokes and is considered the gold standard for hyperacute stroke diagnosis. However, because the detrimental effects of high radiation doses from 4D-CTP may cause serious health risks in stroke survivors, our research team aimed to introduce a novel image-processing technique. Our singular value decomposition (SVD)-based image-processing technique can improve image quality, first, by separating several image components using SVD and, second, by reconstructing signal component images to remove noise, thereby improving image quality. For the demonstration in this study, 20 4D-CTP dynamic images of suspected acute stroke patients were collected. Both the images that were and were not processed via the proposed method were compared. Each acquired image was objectively evaluated using contrast-to-noise and signal-to-noise ratios. The scores of the parameters assessed for the qualitative evaluation of image quality improved to an excellent rating (p < 0.05). Therefore, our SVD-based image-denoising technique improved the diagnostic value of images by improving their quality. The denoising technique and statistical evaluation can be utilized in various clinical applications to provide advanced medical services.

BACKGROUND: To assess the relationship between radiation doses to the coronary arteries (CAs) and location of a coronary stenosis that required intervention after three-dimensional conformal radiotherapy (3DCRT) for breast cancer (BC).
METHODS: The study population consisted of 182 women treated for BC in Sweden between 1992 and 2012. All women received 3DCRT and subsequently underwent coronary angiography due to a suspected coronary event. CA segments were delineated in the patient\'s original planning-CT and radiation doses were recalculated based on the dose distribution of the original radiotherapy (RT) plan. The location of the CA stenosis that required intervention was identified from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). Logistic regression analysis was used to assess the relationship between CA radiation doses and risk of a later coronary intervention at this specific location.
RESULTS: The odds ratio (OR) varied by radiation dose to the mid left anterior descending artery (LAD) (p = 0.005). Women receiving mean doses of 1-5 Gray (Gy) to the mid LAD had an adjusted OR of 0.90 (95% CI 0.47-1.74) for a later coronary intervention compared to women receiving mean doses of 0-1 Gy to the mid LAD. In women receiving mean doses of 5-20 Gy to the mid LAD, an adjusted OR of 1.24 (95% CI 0.52-2.95) was observed, which increased to an OR of 5.23 (95% CI 2.01-13.6) for mean doses over 20 Gy, when compared to women receiving mean doses of 0-1 Gy to the mid LAD.
CONCLUSIONS: In women receiving conventional 3DCRT for BC between 1992 and 2012, radiation doses to the LAD remained high and were associated with an increased requirement of coronary intervention in mid LAD. The results support that the LAD radiation dose should be considered in RT treatment planning and that the dose should be kept as low as possible. Minimising the dose to LAD is expected to diminish the risk of later radiation-induced stenosis.

Radiological imaging is an important modality of today\'s overall practicum. Imaging can begin as early as the 1st day of life. Neonates are 3-4 times more sensitive to radiation than adults. The purpose of the work was to assess the diagnostic reference level (DRL), the radiation organ dose, and effective organ dose for both sexes from chest anteroposterior radiograph, which is the most common radiographic examination performed at the Neonatal Intensive Care Unit (NICU). The entrance air kerma was measured using a solid-state PIN type detector, and the value was used as the input factor to PCXMC-2.0 software to calculate the entrance surface air kerma (ESAK), patient-specific organ dose, and effective dose originated from chest anteroposterior examinations of neonates at NICU. The mean value of ESAK is taken as a diagnostic reference level (DRL) for neonates (both male and female). The mean ESAK value of male neonates is (79.6 ± 1.4) μGy and for female is (79.9 ± 1.9) μGy, and the institutional diagnostic reference level (DRL) is 80.35 μGy for male and 81.2 μGy for female (i.e., third quartile value). A statistical dependency (correlation) between neonates body mass index (BMI) and ESAK was defined for both the sexes. Significant positive correlation was found between ESAK per patient with respect to BMI of both male (R = 0.83, P = 0.00001) and female (R = 0.72, P = 0.00055) neonates. The results for neonatal dose in NICU were compatible with the literature. The result presented will serve as baseline data for the selection of technical parameters in neonatal chest anteroposterior X-ray examination.

暂无摘要。