Reports of Practical Oncology and Radiotherapy最新文献

Background: This study evaluates the quality of synthetic computed tomography (sCT) images for MR-only radiotherapy in prostate cancer using gamma analysis. A software tool, MRGamma, was developed to address challenges like the absence of electron density maps and registration uncertainties between magnetic resonance imaging (MRI) and planning CT (pCT).

Materials and methods: Aplication developed in MATLAB assesses Hounsfield units (HU) discrepancies between CT and sCT images via 2D and 3D gamma analysis (GA). GA computes a gamma index (γ) for each voxel based on HU differences and distance to agreement (DTA). The study analyzed prostate cancer patients using the MRCAT algorithm to generate sCT images. Preprocessing included registration, resampling, and cropping to standardize image dimensions. GA was performed with thresholds of 100 HU and 70 HU for HU differences and 3 mm for DTA to evaluate image quality.

Results: Aplication demonstrated high agreement between sCT and CT images. For 3D GA (100 HU, 3 mm), 95.5 ± 1.8% of voxels passed the threshold, with slightly lower rates for 70 HU. Discrepancies were most pronounced at tissue interfaces and air cavities, where HU variations were more significant. Mean γ values for 3D GA were 0.19 ± 0.04 (milder parameters) and 0.23 ± 0.05 (stricter parameters), showing consistent trends in 2D GA. Maximum γ values confirmed good overall agreement.

Conclusions: Aplication effectively evaluates sCT quality, supporting the feasibility of MR-only radiotherapy. By providing detailed HU comparisons, the tool enhances MR-based treatment planning, reducing costs and ionizing radiation exposure. Its implementation may improve workflow efficiency and patient safety in clinical practice.

Background: Triple-negative breast cancer (TNBC) shows a high aggressiveness and chemoresistance. It is important to understand the biology of TNBC, including the influence of immune cells, such as macrophages, on cancer cells (CCs) and their response to chemotherapeutics. The research aimed to determine the effect of cisplatin (CisPt) and paclitaxel (PTX) on the viability, migratory ability and expression of selected genes of TNBC cells co-cultured with macrophages. The influence of macrophages alone on CCs was also studied.

Materials and methods: The experiments were conducted with TNBC cell line (MDA-MB 231) and macrophages (THP1) in four experimental setups: MDA-MB231; MDA-MB231 + THP1; MDA-MB231 + CisPt or PTX; MDA-MB231 + THP1 + CisPt or PTX, using cytotoxicity and wound healing (WH) assays, flow cytometry and quantitative polymerase chain reaction (qPCR).

Results: Under PTX action, but not CisPt, a significant decrease in the number of MDA-MB 231 cells and their migration ability was observed. The presence of THP1 cells increases the survival of MDA-MB231 cells treated with CisPt, not PTX. A heat-map with the gene expression level has revealed that under THP1 CCs treated with PTX increase CDH2, GLUT-1 and LDHA expression.

Conclusion: PTX is more toxic against MDA-MB231 cells than CisPt. M2 macrophages play an important role in MDA-MB231 cells gene expression, inducing changes in their metabolism and phenotype.

Background: This study investigates the impact of voxel size on dose calculations for the FlexiSource iridium-192 (¹⁹²Ir) high-dose-rate brachytherapy source using the TOol for PArticle Simulation (TOPAS) Monte Carlo code. It aims to establish a new dataset for future research by determining TG-43 parameters.

Materials and methods: TG-43 parameters (radial function and anisotropy function) were calculated using 0.5 mm³ and 1 mm³ voxel sizes. Mean dose calculations were performed at various distances from the source. The ¹⁹²Ir spectrum from the National Nuclear Data Center (NNDC) was utilized.

Results: The measured air-kerma strength per unit source activity differed by 2.34% from consensus data. Radial function analysis showed consistent results, with 0.5 mm³ voxels deviating up to 1.78% near the source and 7% at greater distances. The 1 mm³ voxels showed similarities at greater distances (up to 1.52% deviation) but significant differences near the source (up to 20% deviation). Anisotropy function analysis revealed variations of 3-4% for angles < 7° and > 175° with 1 mm³ voxels, and 10-20% for angles < 12° and > 177° with 0.5 mm³ voxels compared to Carleton Laboratory for Radiotherapy Physics (CLRP) reference values.

Conclusions: These findings validate the TOPAS Monte Carlo code's accuracy for dose calculation and emphasize the importance of voxel size selection. The generated dataset shows promise for future research efforts in brachytherapy dose calculations.

Cervical cancer continues to pose a significant global health challenge, highlighting the urgent need for accurate and efficient diagnostic techniques. Recent progress in deep learning has demonstrated considerable potential in improving the detection and classification of cervical cancer. This review presents a thorough analysis of deep learning methods utilized for cervical cancer diagnosis, with an emphasis on critical approaches, evaluation metrics, and the ongoing challenges faced in the field. We explore various deep learning architectures, particularly convolutional neural networks (CNNs), and their applications in the segmentation and classification of cervical cytology images. Key performance indicators, such as accuracy, sensitivity, specificity, and the area under the curve (AUC), are reviewed to assess the effectiveness of these models. Despite advancements, challenges like limited annotated datasets, inconsistencies in medical imaging, and the demand for more resilient models remain. Strategies like data augmentation, transfer learning, and semi-supervised learning are examined as potential solutions. This review synthesizes current research to guide future studies and clinical implementations, ultimately advancing early detection and treatment of cervical cancer through cutting-edge deep learning technologies.

Initially, pseudogenes were considered to be "junk DNA", and their biological role was unclear. However, some of the pseudogenes are engaged in the process of cancerogenesis and perform essential functions in competing for endogenous ribonucleic acid (ceRNA) networks and competing for RNA binding proteins (RBPs). They either positively or negatively regulate gene expression and act as suppressive and oncogenic transcripts. In this review, we look at some of the pseudogenes that play a role in the epithelial-to-mesenchymal transition (EMT) process and the maintenance of cancer-initiating cells (CIC), which are essential in understanding cancer development and progression metastasis and resistance to commonly used therapies. The group of discussed pseudogenes consists of CHIAP2, PTENP1, SUMO1P3, NANOGP8, OCT4-PG1/4, or HMGA1-P6, which are connected with different molecular pathways. Moreover, we discussed pseudogenes as potential diagnostic molecules that can be used as a new class of biomarkers. This potential usage may be valuable for oncology and personalized medicine in the future.

Background: This study aimed to compare the treatment plan between free breathing (FB) and deep inspiration breath-hold (DIBH) in patients with left-sided breast cancer. We aimed to investigate the dose to the heart and left lung.

Materials and methods: Fifty-five patients with left-sided breast cancer treated with three-dimensional conformal radiotherapy were retrospectively compared with those planned with FB and DIBH in terms of doses to the heart and left lung. The prescribed dose was 42.56 Gy which was delivered in 16 fractions.

Results: Compared with FB, DIBH effectively reduced the mean dose to the heart by an average of 55% (2.0 Gy vs. 0.9 Gy, p < 0.001). DIBH resulted in significantly greater left lung volumes, with an average of 74.7% (980.5 cc vs. 1713.0 cc, p < 0.001). The DIBH plan delivered a significantly lower relative volume to the left lung, with an average of 1.6% at V_20Gy (11.7% vs. 10.1%, p < 0.001) but delivered a significantly higher absolute irradiated volume to the left lung at V_20Gy, with an average of 45.9% (118.2 cc vs. 172.5 cc, p < 0.001).

Conclusion: DIBH is an effective treatment technique for reducing the dose to the heart and the relative irradiated left lung volume for left-sided breast cancer, although the absolute irradiated left lung volume is increased.

In the recent years, the clinical stage where the cancer has spread beyond the primary site, but has not yet metastasised extensively, and which is known as oligometastatic disease (OMD), has become an object of interest to radiation oncologists. OMD is a kind of an "umbrella term" for a variety of clinical situations. This review focuses on the role of radiotherapy (RT) in the treatment of oligometastatic non-small cell lung cancer (OM-NSCLC). Currently, a wide range of techniques and fractionation regimens are used to treat OM-NSCLC and, unfortunately, it is not yet possible to determine which approach is the most effective. Therefore, more than ever, we should use the concept of risk-adapted RT and consider many factors when choosing the fractionation regimen and total dose applied. For different clinical scenarios, we set different treatment goals and derive different RT techniques and fractionations. Oligoprogression (OP) is a specific type of OMD that is increasingly encountered in clinical situations, probably due to the increased use of targeted therapy and the subsequent acquired resistance of a certain subpopulation of tumour cells. OP is the progression of a limited number of metastases after an initial response to systemic therapy. The rationale for using RT in areas of progression is to overcome tumour resistance in these progressive lesions. A number of trials are currently underway to find the optimal RT techniques for the most appropriate patients at a precise clinical stage.

Background: Paragangliomas are highly vascularized tumours that have benign histology, with malignant dissemination being infrequent (< 5%). Surgery is the only option offering complete resection; however, there is significant morbidity. Treatment with radiotherapy (RT) offers good results in controlling the disease.

Materials and methods: Retrospective, observational and descriptive study from the RT Service of the General Hospital of Mexico conducted from January 1, 2016 to January 1, 2021 that included patients with carotid paraganglioma in whom RT response was evaluated by determining clinical and image size at the beginning of the study and end of follow-up. Correlation of response to treatment, and toxicity related to RT, were analysed.

Results: 55 patients were included, 92.7% were female, the mean age was 58.7 years, and the mean follow-up time was 28.87 months. The mean initial clinical size was 4.75 cm. Initial imaging study mean size was 4.76 cm. A total of 92.7% received intensity-modulated radiotherapy (IMRT) and conformal RT (7.3%), mean prescribed dose was 51.90 Gy (50-54), with a median of 50.4 Gy/25 fractions. The mean final clinical size was 3 cm. The final imaging study mean size was 3.48 cm. At the end of the study, 96.4% showed a response to treatment and 3.6% progressed. Analysis showed no significance between treatment response and RT dose (p < 0.5) or between RT response and the % dose to the planned treatment volume (PTV) (p = 0.91). Acute toxicity was found in 55 patients, with grade 1 radiodermatitis, and chronic toxicity in 44 patients, with atrophy grade 1.

Conclusion: RT represents a therapeutic option in the management of patients with carotid paraganglioma because it offers a high probability of local control, without toxicity.

Currently, photodynamic therapy (PDT) is widely used, mainly in treatment of actinic keratosis (AK), especially grades I and II following the Olsen classification. The main side effects include burning, stinging, and pain during irradiation. Alternative protocols include daylight PDT (dPDT), which uses sunlight instead of artificial light after applying a photosensitizer. Unlike conventional PDT, daylight therapy is less painful and more comfortable for patients. This article presents the mechanism of dPDT, indications for this method as well as its efficiency, side effects, advantages and disadvantages. In the end, current treatment protocols of dPDT are presented.