Delivering focused radiation doses via linear accelerators is a crucial component of stereotactic radiosurgery (SRS) for brain metastases. The Varian Edge linear accelerator provides highly conformal radiation therapy through a high-definition multi-leaf collimator (HD120 MLC) and conical collimator (CC). HD120 MLC adapts to the shape of the target volume using movable tungsten leaves, while CC has a block of conical shape (cones). CC in SRS treatments of small brain metastases is preferred due to its mechanical stability and steeper dose fall-off, potentially sparing organs at risk (OARs) and the brain better than HD120 MLC. This study aims to determine if CC offers significant advantages over HD120 MLC for SRS treatments. For 116 metastatic lesions, CC and HD120 MLC treatment plans were created in Varian Eclipse TPS and compared based on various dose parameters, robustness tests, and QA measurements. The results indicate that CC provides no significant advantages over HD120 MLC, except for slight, clinically insignificant benefits in brain sparing and dose fall-off for the smallest lesions. HD120 MLC outperforms CC in almost every aspect, making it a better choice for irradiating brain metastases with 0.1 cm³ or higher volumes.

Background: The aim of this retrospective, single-arm study was to present the technique and preliminary efficacy and safety results of a single-fraction SBRT for LAPC using total intravenous anaesthesia and optical surface guidance as motion management. Methods: Fifty-five patients with locally advanced pancreatic cancer were treated with SBRT with a single-fraction receiving a median BED₁₀ = 128.9 Gy. Forty-two patients received systemic treatment. End points were OS, FFLP, PFS, and toxicity. Actuarial survival analysis and univariate analysis were investigated. Results: The median follow-up was 15 months, mean OS was 18 months (95% CI: 16.7 to 19.3), and the one-year FFLP and 1-year OS were 100% and 90.9% (95% CI: ± 1.5%), respectively. Median PFS was 12 months (95% CI: 9.5 to 14.4), and 1-year PFS was 85.5% (95% CI: ± 1.4%). Thirty-five patients (63.6%) were alive at the time of analysis. No acute/late toxicity > G2/G1 was reported. Conclusions: SBRT for LAPC using total intravenous anaesthesia and optical surface guidance presented as an effective and safe treatment with very low toxicity.

Background: The aim of this study was to present the technique and preliminary results of efficacy and safety for single-fraction SBRT for LAPC using Total Intravenous Anaesthesia and Optical Surface Guidance as motion management. Methods: Fifty-five patients were treated with SBRT in a single-fraction receiving median BED₁₀ = 128.9 Gy. Forty-two patients received systemic treatment. End points were OS, FFLP, PFS, and toxicity. Actuarial survival analysis and univariate analysis were investigated. Results: Median follow-up was 15 months. Mean OS was 26.7 months. One-year FFLP and 1-year OS were 100% and 90.9%, respectively. Median PFS was 18 months, and 1-year PFS was 85.5%. Thirty-five patients (63.6%) were alive at the time of analysis. No acute/late toxicity > G2/G1 was reported. Conclusions: SBRT for LAPC using Total Intravenous Anaesthesia and Optical Surface Guidance presented as an effective and safe treatment with very low toxicity.

Background/Objectives: Metastatic melanoma increasingly includes clinical scenarios in which metastasis-directed treatment may complement systemic immunotherapy, particularly in oligometastatic disease. We evaluated outcomes of stereotactic body radiotherapy (SBRT) combined with immunotherapy in patients with metastatic melanoma, focusing on local control, survival, treatment sequencing, and safety. Methods: In this retrospective single-center study, 63 patients underwent SBRT for 97 extracranial metastatic lesions while receiving immune checkpoint inhibitors. The primary endpoint was local control (LC), while secondary endpoints included progression-free survival (PFS), overall survival (OS), and treatment-related toxicity. Results: LC rates at 12, 24, and 36 months were 95.9%, 89.7%, and 89.7%, respectively, demonstrating durable long-term control of treated lesions. Median OS was 47 months, while median PFS was not reached. A numerical trend toward longer PFS was observed among patients receiving SBRT during immunotherapy, although the differences were not statistically significant. No significant differences in LC were identified across oligometastatic disease subcategories. Combined treatment was well tolerated, with predominantly low-grade toxicity and no signal of increased immune-related adverse events. Conclusions: SBRT combined with immunotherapy appears to be a feasible and effective metastasis-directed treatment strategy in selected patients with metastatic melanoma. Durable local control, encouraging survival outcomes, and favorable tolerability support further prospective studies to optimize treatment sequencing and the integration of local and systemic therapies.

Background: As part of different navigational bronchoscopy (NVB) modalities, radial-probe endobronchial ultrasound (rEBUS) is used to confirm the peribronchial localization of peripheral pulmonary nodules (PPNs) immediately before collecting samples for histopathological analysis. Methods: This retrospective case series study presents the results of en bloc cryobiopsy of PPNs using a flexible 1.1-mm cryoprobe with different NVB modalities. For PPNs classified as adjacent or eccentric lesions by rEBUS (ES-rEBUS), the cryoprobe’s position was adjusted by 90–180° in relation to the ultrasound image of the lesion during the first and second biopsies. Results: All patients with a final histopathologically confirmed diagnosis of PPNs had positive rEBUS findings, regardless of the navigation modality, eccentric (18/42 patients, 43%) and concentric (24/42 patients, 57%) rEBUS view. In 5 out of 6 patients without a histopathological diagnosis, PPNs were not visualized by radial ultrasound. In the (ES-rEBUS) group of patients, 4 out of 18 had fewer than three biopsy samples collected per procedure, which means only an adjusted probe position has been applied, although diagnostic outcomes were achieved. Common Terminology Criteria for Adverse Events (CTCAE) grade 2 complications were reported in 10.4% of the patients, and grade 3 complications in 2% of the patients. Conclusions: Confirming the localization of nodules by rEBUS and properly adjusting the cryoprobe immediately before cryobiopsy of PPNs resulted in a diagnostic yield meeting the literature standards.

PET/CT is the most sensitive and highly specific imaging technique for determining the location of tumors, primary tumors of unknown location, determining the extent and activity of malignant disease, monitoring treatment effects, detecting local recurrence and distant malignancy, precise planning of various treatment modalities and planning/determining the radiation field. PET uses biologically active molecules labeled with short-lived radionuclides that emit positrons and are the product of nuclear reactions in a cyclotron. Fluorine-18 (18F) is the most commonly used radionuclide in nuclear medicine, and its relatively long half-life of 110 minutes allows adequate synthesis of radiopharmaceuticals and monitoring of biological processes, as well as delivery to PET machines in remote facilities. The most commonly used radiopharmaceutical, which is now used in clinical practice in more than 90% of PET/CT examinations, is 2-(18F)-fluoro-2-deoxy-D-glucose (18F FDG), a glucose derivative that reflects the accumulation and consumption of glucose in cells, i.e. glucose metabolism. PET/CT has an advantage over other diagnostic imaging techniques because by combining PET, which is the evaluation of the intensity of the metabolic activity of a specific radiopharmaceutical in the cells, and CT, which shows the anatomy and morphology of the organs, we simultaneously obtain information about pathological abnormalities in both the function and morphology of the lesions or organ and the presence of viable tumor or inflammatory tissue. It is important to mention that with the latest PET/CT equipment we have the possibility to visualize metabolic activity even in very small lesions (2 mm). The advantage of this diagnostic method is that the findings are not only analyzed visually, but also quantitatively by measuring the intensity of radiopharmaceutical accumulation in the lesions, thus achieving objectification of the findings and the possibility of adequately monitoring the effect of different forms of treatment in control imaging. PET/CT allows us to identify prognostically risky patients and to select the most appropriate forms of treatment for each individual patient. PET/CT is the most sensitive method for distinguishing treatment-related changes from residual or recurrent disease. A continuous decrease in metabolic activity in the tumor area indicates a positive effect of the treatment. PET/CT enables precise monitoring of the effect of all forms of treatment (surgical, chemotherapeutic, radiotherapeutic and radiosurgical procedures) and has the advantage that the entire body is captured and analyzed with one image in the field of view and not just a single segment. The radiation exposure in PET/CT results from the use of radiopharmaceuticals and CT imaging, and the ALARA principle (as low as reasonably achievable) is followed, whereby the dose is adjusted taking into account the weight and age of the child and the type of device, taking into account the longer life and radiation sensitivity of the child's organism.To assess the treatment effect, the RECIST criteria (Response Evaluation Criteria in Solid Tumors) are used to evaluate the size of the lesions and the PERCIST criteria (PET Response Criteria in Solid Tumors) to evaluate the metabolic activity of the lesions. Inclusion should also take into account the characteristics of the pediatric population, such as the need for parental or guardian consent for the examination, the period of starvation before the examination, etc., difficulties in establishing venous access, sedation/anesthesia of young children due to the need for rest during imaging, and marked physiological accumulation of radiopharmaceuticals in different parts of the body.Compared to adults, there is a slightly higher percentage of total accumulation of radiopharmaceuticals in the brain, lower excretion of activity in the urine, greater accumulation in the bone marrow due to more pronounced hematopoiesis, greater accumulation in regions with lymphatic tissue, pronounced physiological accumulation in growth zones, greater accumulation in brown adipose tissue, greater accumulation in the thymus (physiological, after chemotherapy), while the use of hematopoietic growth-promoting factors can lead to a pronounced diffuse accumulation of activity in the spleen and bone marrow. PET/MR offers a safer, more specific and more efficient assessment of the extent of disease in children than any other diagnostic imaging technique. The advantage over other hybrid diagnostic procedures is that a high resolution and a high contrast between diseased and healthy tissue is achieved with significantly less exposure to ionizing radiation. Artificial intelligence tools are now used to process the image data and analyze the findings, which improve image quality and perform the most accurate data reconstruction and support the physician in the search for suspicious lesions, measuring and determining the etiology of pathological processes in comparison with earlier diagnostic methods, and reducing the possibility of overlooking suspicious lesion.