Search Results (227)

Background: Despite advances in prostate cancer (PC) radiotherapy, including intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic body radiotherapy (SBRT), genitourinary (GU) and gastrointestinal (GI) toxicities remain important complications. Identifying reliable predictors is essential for personalized treatment. Objective: The aim of this study was to summarize current evidence on clinical, dosimetric, immunological, and genetic predictors of acute and late GU and GI toxicities after PC radiotherapy. Materials and Methods: A structured literature review of studies published between 2000 and 2026 was conducted using PubMed, Scopus, and Europe PMC. Eligible studies included clinical investigations, randomized controlled trials, meta-analyses, and reviews assessing toxicity according to RTOG and/or CTCAE criteria. Results: GU toxicity was associated with pretreatment International Prostate Symptom Score (IPSS), large prostate volume, prior TURP, smoking, alpha-blocker use, and bladder/urethral dose. GI toxicity correlated with rectal dose–volume parameters, anorectal irradiation, anticoagulant therapy, and cardiovascular comorbidities. Acute grade ≥ 2 toxicity predicts late toxicity. Preliminary data from small single-center cohorts associate elevated IL-6, TGF-β1, TNF-α, and systemic immune-inflammation index with higher toxicity risk, and higher lymphocyte counts with lower risk; these findings require prospective validation. The PROSTOX radiogenomic signature is promising for the prediction of late GU toxicity but still requires independent external validation in larger, ethnically diverse cohorts with longer follow-up, and is not currently suitable for routine clinical decision-making. Conclusions: GU and GI toxicities have distinct predictive profiles. Integrating clinical, dosimetric, immunological, and genetic factors may improve personalized radiotherapy, although prospective multicenter validation remains necessary. Full article

Pancreatic ductal adenocarcinoma is one of the most aggressive tumours, with an estimated 5-year overall survival rate of 5% and median survival of 5–11 months. Approximately one third of patients die of complications due to local disease progression, especially among patients with borderline resectable or locally advanced disease; hence achieving local control is significant for improved survival outcomes. Stereotactic body radiotherapy (SBRT) allows safe and effective delivery of ablative doses of radiation and is associated with improved locoregional tumour control and progression free survival. Our article describes the rationale and the safe and effective delivery of Linac-based SBRT treatment for pancreatic cancer. Full article

Purpose: While magnetic resonance-guided radiation therapy (MRgRT) may provide significant clinical advantages, delivery times tend to be longer than other radiation therapy (RT) modalities and published data on these times are limited. We evaluated longitudinal treatment times across our 8-year institutional MRgRT experience. Methods/Materials: A retrospective analysis of patients treated at our institution on a 0.35-Tesla MR-Linac between April 2018 and April 2026 was performed. All fractions were delivered with continuous intrafraction cine-MRI, soft tissue tracking, automatic beam gating, and online adaptive radiation therapy (oART) when indicated. The primary objective was to characterize changes in total in-room time (TIRT), treatment delivery time (TDT), and total adaptive time (TAT). For analysis of efficiency gains, our overall experience was separated into early (2018–2022) and late (2022–2026) periods. Results: A total of 1026 patients, 1203 treatment courses, and 7665 fractions were included. The median age was 69 years (range: 19–94) and the most commonly treated sites by treatment course were pancreas (n = 430; 35.7%), thorax (n = 203; 16.9%), abdominopelvic lymph nodes (n = 181; 15.0%), liver (n = 138; 11.5%), and adrenal gland (n = 83; 6.9%). The median prescription dose was 50 Gy (range: 16.0–76.0) in a median of five fractions (range: 1–36). Breath-hold and stereotactic body radiation therapy (SBRT) were used in 87.9% and 88.5% of treatment courses, respectively. From the early (2018–2022) to late (2022–2026) study period, the proportion of fractions utilizing SBRT (49.9% vs. 81.1%; p < 0.001), oART (32.9% vs. 80.2%; p < 0.001), respiratory gating (75.9% vs. 88.8%; p < 0.001), and elective nodal coverage (61.8% vs. 78.2%; p < 0.001) increased, as did the proportion of pancreatic treatments (20.4% vs. 38.4%; p < 0.001) and the utilization of single-fraction courses (3.4% vs. 10.3%; p < 0.001). Despite this increasing complexity between study periods, median oART TIRT decreased from 67.0 to 48.0 min (28.4% reduction; p < 0.001), driven primarily by a reduction in TAT from 20.0 to 7.0 min, p < 0.001. Pancreatic oART fractions showed the greatest improvement (median TIRT, 70.0 to 47.0 min; p < 0.001). In 2022–2026, 78.1% of oART fractions were completed within 60 min vs. 35.5% in 2018–2022 (p < 0.001). Conclusions: Ablative MRgRT, with or without oART, can often be delivered in 60 min or less, including for mobile and anatomically unfavorable tumors. Future software and hardware advances are expected to further improve MRgRT treatment efficiency. Full article

Background/Objectives: Stereotactic body radiotherapy (SBRT) is increasingly used for hepatocellular carcinoma (HCC) that is unsuitable for surgery, radiofrequency ablation (RFA), or transplantation. Although current evidence for imaging assessment after SBRT is largely based on contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), repeated contrast-enhanced imaging may be difficult to perform at every routine follow-up visit. Thus, we evaluated whether conventional abdominal ultrasound (US) can monitor tumor size after SBRT for HCC. Methods: We retrospectively reviewed 67 consecutive patients who underwent SBRT for HCC at our institution between January 2015 and October 2020. After excluding patients treated for local recurrence after RFA or transarterial chemoembolization, those whose lesions were not visible on pretreatment US, and those without follow-up US within one year, 32 patients with 32 nodules were analyzed. Tumor visibility and size changes on US were assessed before treatment and at <6, 6–12, and 12–18 months after SBRT. Results: The treated lesion was identified as a discrete nodule on US in 100% (15/15; 95% CI, 78.2–100%), 75.0% (18/24; 95% CI, 53.3–90.2%), and 50.0% (8/16; 95% CI, 24.7–75.3%) of examinations at <6, 6–12, and 12–18 months, respectively. In all cases in which the lesion was no longer measurable on US, contrast-enhanced CT/MRI showed complete or partial response. Local tumor progression occurred in one patient (3.1%) during a median follow-up of 24.1 months; in this patient, interval enlargement was first detected by US 3.7 months after SBRT and was subsequently confirmed by dynamic CT/MRI. Conclusions: These descriptive findings suggest that in selected patients with lesions clearly visible on pretreatment US, conventional abdominal US may provide complementary morphologic information during the first year after SBRT when used alongside periodic dynamic CT/MRI. Prospective validation is required before routine implementation. Full article

Stereotactic body radiotherapy (SBRT) is an effective and increasingly utilized treatment modality for abdominal tumors, offering high rates of local control with generally acceptable toxicity profiles. Nevertheless, rare but severe late gastrointestinal complications, including radiation-induced ulceration, may occur and significantly impair patients’ quality of life, as well as continuation of oncologic treatment. Hyperbaric oxygen therapy (HBOT) has shown potential benefit in the management of chronic radiation-induced tissue injury, although evidence regarding its role following SBRT remains limited. We report the case of a 75-year-old woman with cholangiocellular carcinoma who developed severe radiation-induced duodenal ulceration following liver SBRT, presenting with persistent postprandial pain, nausea, vomiting, and substantial weight loss despite standard supportive treatment. Helicobacter pylori testing was negative, non-steroidal anti-inflammatory drug use was excluded, and histopathology showed chronic inflammatory and fibrotic mucosal injury with reactive epithelial changes. Despite high-dose proton pump inhibition, bismuth subcitrate, and nutritional support, symptoms and endoscopic ulceration persisted. HBOT was administered at 2.4 atmospheres absolute for 60 min over 30 sessions. Clinical improvement was noted after three sessions, and treatment was completed without adverse effects. Follow-up endoscopy demonstrated almost complete ulcer regression, with complete symptom resolution, improved oral intake, and a 10 kg weight gain. To the best of our knowledge, this represents the first reported case describing the successful use of HBOT as a potentially effective adjunctive treatment for severe radiation-induced duodenal ulceration following liver SBRT in a patient with cholangiocarcinoma. Although encouraging, this observation should be interpreted cautiously, and prospective clinical studies are needed to further evaluate the efficacy, safety, and optimal timing of HBOT in this setting. Full article

Background: A combination of cyclin-dependent kinase 4/6 inhibitors (CDKi) and radiotherapy (RT) may enhance antitumoral immunity, yet clinical evidence of this interaction in HR+/HER2− metastatic breast cancer (MBC) remains limited. This study evaluates the impact of combined CDKi and stereotactic body radiotherapy (SBRT) on immune biomarkers and treatment response. Methods: We report a case of a 51-year-old woman with oligometastatic HR+/HER2− MBC involving the sacrum. Clinical management included letrozole plus palbociclib and SBRT (30 Gy in 3 fractions). Serial Neutrophil-to-lymphocyte ratio (NLR) measurements, MRI, and PET-CT scans were used to monitor systemic immune modulation and treatment efficacy over a five-year period. Results: Baseline NLR was 1.068. Following four weeks of CDKi, NLR decreased by 44.7% (0.591). Post-SBRT, a further 17.8% reduction was observed (nadir 0.486). Five months post-RT, MRI showed a volumetric increase in sacral lesions despite clinical improvement. Subsequent PET-CT demonstrated a complete metabolic response, confirming the MRI findings as pseudoprogression. As of January 2026, the patient remains in sustained complete metabolic remission. Conclusion: The integration of CDKi and SBRT might induce an immune-mediated antitumoral response, evidenced by dynamic NLR reductions and radiologic pseudoprogression. Multimodal imaging is essential to differentiate immune-mediated swelling from true progression in this setting. Full article

Background: Osteosarcoma remains a biologically complex and clinically challenging malignancy, with survival gains plateauing despite decades of multimodal therapy incorporating surgery and cytotoxic chemotherapy. Unlike cancers in which mutation-centric precision oncology has yielded transformative advances, osteosarcoma is characterized by profound structural variation, copy number alteration dominance, and dynamic clonal evolution, limiting the effectiveness of single-target approaches. These realities motivate alternative strategy-level frameworks that better align treatment selection with evolving disease behavior. Methods: This narrative educational review synthesizes contemporary evidence from osteosarcoma biology, radiobiology, and translational oncology to propose a state-based framework for integrating radiotherapy—particularly stereotactic body radiotherapy (SBRT/SABR) and spatially fractionated radiotherapy (SFRT)—into osteosarcoma management and clinical trial design. Rather than relying solely on static anatomic stage, this framework emphasizes clinically actionable, time-varying state variables, including disease burden patterns (localized, oligometastatic, polymetastatic), tempo of progression, prior systemic response, and feasibility of complete local control. Results: Within this context, radiotherapy is presented not only as a local control modality but also as a hypothesis-generating biologic intervention, capable of perturbing tumor vasculature, inflammatory signaling, innate DNA-sensing pathways, and immune/myeloid programs in a dose-, fractionation-, and spatial-distribution-dependent manner. The review critically examines both the potential opportunities (e.g., local eradication, immune modulation) and limitations (e.g., rarity of abscopal responses, risk of unintended systemic signaling) of radiobiotherapy combinations, emphasizing the need for cautious interpretation and prospective validation. Conclusions: Finally, the article outlines practical implications for state-stratified, biomarker-embedded clinical trials, highlighting endpoints beyond conventional response criteria, including circulating tumor DNA dynamics, immune and myeloid signatures, and long-term patterns of disease progression. Overall, this review frames radiobiotherapy as an educational and investigational paradigm intended to support rational hypothesis generation, multidisciplinary decision-making, and learning-oriented trial designs in osteosarcoma, rather than as definitive clinical guidance. Full article

Background: Neoadjuvant partial breast irradiation using stereotactic body radiotherapy (SBRT) has emerged as a strategy to induce tumor and immune responses in early-stage, low-risk breast cancer. While prior studies have demonstrated encouraging response rates and evidence of immune modulation, the optimal radiotherapy regimen for immune priming remains unclear. SIGNAL 2.0 is a randomized phase II trial designed to compare the biological and immunological impact of a single-fraction versus three-fraction neoadjuvant SBRT. Materials and Methods: Sixty-one postmenopausal patients ≥ 50 years with unifocal, hormone positive, node-negative invasive ductal carcinoma < 3 cm were randomized 1:1 to receive either 21 Gy in one fraction or 30 Gy in three fractions, delivered to the tumor in the prone position. Core biopsies were collected pre-SBRT and 14–20 days post-SBRT at the time of surgery. Immune markers were assessed using tumor-infiltrating lymphocyte (TIL) scoring, NanoString nCounter PanCancer Immune Profiling, and NanoString GeoMx Digital Spatial Profiling (DSP). Results: Available tumor samples from 47 patients underwent paired tissue analysis. Three-fraction SBRT induced 200 differentially expressed genes, including enrichment of pathways related to adaptive immune activation, with significant increases in expression levels of macrophages, dendritic cells, neutrophils and CD8 T-cells. Proteomic profiling also identified a significant increase in the expression levels of neutrophils, Treg cells, macrophages, and NK cells in the tumor microenvironment of the samples from patients receiving the three-fraction regimen. Conclusions: Neoadjuvant SBRT induces measurable immune activation, with three-fraction regimens generating more extensive transcriptional, proteomic, and cellular immune changes than a single fraction. Three-fraction neoadjuvant SBRT may provide superior immune priming, providing a foundation for future trials integrating neoadjuvant radiotherapy with immunomodulatory therapies. Full article

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. Full article

Prostate cancer (PCa) is one of the most common malignancies in men and remains a major cause of cancer-related death worldwide. Radiotherapy is a well-established treatment modality for PCa, offering clinical outcomes comparable to surgical approaches. In recent years, stereotactic body radiotherapy (SBRT), characterized by the delivery of high radiation doses in a limited number of fractions, has been increasingly adopted as a standard approach in the treatment of prostate cancer, due to its favorable efficacy and toxicity profile. CyberKnife (CK) is one of the most commonly used hypofractionated radiotherapy techniques. This preliminary study aimed to evaluate and compare the radiation dose delivery and treatment time of CK-based SBRT using two different collimation systems: the multileaf collimator (MLC) and the IRIS variable aperture collimator, a dynamic device that adjusts its opening to simulate different circular field sizes. A total of 19 patients with low-to-intermediate-risk PCa were selected and treated at the Radiation Oncology Department of the National Cancer Institute IRCCS Fondazione G. Pascale in Naples between January 2024 and January 2025. For each patient, two treatment plans were generated—one with the IRIS collimator and one with the MLC. The results demonstrated that the use of the MLC significantly reduced treatment time while maintaining dosimetric quality comparable to IRIS-based plans. These findings support the clinical benefit of MLC implementation in prostate SBRT with the CK system. Full article

Background/Objectives: Stereotactic body radiation therapy (SBRT) provides improved pain response and local control for spinal metastases. However, management of local failure after initial SBRT is challenging. We report institutional outcomes, dosimetry, and toxicity for reSBRT following SBRT. Methods: We retrospectively reviewed 61 lesions (55 patients) treated with reSBRT after prior SBRT. Both SBRT courses delivered a median dose of 27 Gy. Patients underwent clinical and radiological evaluation every three months. Toxicity was graded using CTCAE v5.0. Dosimetric parameters for the spinal cord (SC), cauda equina (CE), planning organ-at-risk volumes (PRV), and thecal sac were converted to equivalent dose in 2 Gy fractions (EQD₂) using the linear–quadratic model (α/β = 2). Results: Median follow-up was 10.3 months. Forty lesions (65%) were cervicothoracic and 21 (35%) were lumbosacral. One- and two-year overall survival (OS) were 45% and 29%, respectively, and one- and two-year local control (LC) were 89% and 88%, respectively. Gastrointestinal primary tumors were associated with inferior LC (HR 2.41, 95% CI 1.11–5.23, p = 0.026). Fifteen patients (27%) reported myelitis/neuropathic symptoms during follow-up; four (7%) developed new post-radiation myelitis or neuropathy (RMN) without radiologic progression. Five patients (9%) developed vertebral compression fractures (VCF). Cumulative EQD₂ was not significantly associated with RMN (p = 0.344); all affected patients had thecal sac EQD₂ > 95.5 Gy and relevant nerve roots EQD₂ > 108 Gy. Conclusions: ReSBRT provided a favorable LC with acceptable toxicity. High cumulative dose to the thecal sac and nerve roots may contribute to neurologic toxicity as peripheral nerve injury. Full article

Purpose: Surgical resection of liver or pulmonary oligometastases (LP-OMD) in colorectal cancer (CRC) has been shown to improve survival. Stereotactic body radiotherapy (SBRT) is a promising alternative for patients with primary lung cancer. However, the efficacy of SBRT for LP-OMD in CRC remains inconclusive, and local control (LC) rates are often unsatisfactory. This prospective study aimed to evaluate the treatment outcomes of dose-escalated and convergent SBRT for patients with LP-OMD from CRC, with the goal of demonstrating its effectiveness as a treatment option for these patients. Methods and materials: This study included 23 CRC patients with LP-OMD who received SBRT between 2017 and 2022. The inclusion criteria were histologically confirmed colorectal adenocarcinoma, one to three oligometastases, and a tumor diameter of 5 cm or less. Patients who were inoperable or declined surgery were included. SBRT was delivered with total doses of 50–60 Gy administered over five fractions, covering the planning target volume surface within the 60% isodose line of the maximum dose. The primary endpoint was the 2-year LC rate, while secondary endpoints included overall survival (OS), progression-free survival (PFS), and toxicity. Results: The median follow-up duration was 41.0 months (range: 11.5–77.2). At the time of analysis, five patients had died from CRC, six were alive with disease, and twelve were alive without disease. Only one patient experienced local recurrence of a pulmonary oligometastasis. The 2-year LC, PFS, and OS rates were 95.0% (95% CI: 69.5–99.3), 61.3% (95% CI: 40.0–77.0), and 88.1% (95% CI: 67.6–96.0), respectively. Toxicity was acceptable, with no grade ≥ 3 adverse events. Conclusions: High-central-dose SBRT for LP-OMD from CRC achieved favorable local control with minimal toxicity. These findings should be interpreted cautiously and require validation in larger, multi-institutional studies. Full article

Background. Patients with malignant or benign central nervous system (CNS) tumours are evaluated for suitability of treatment modality based on multiple clinical and tumour-related factors. To obtain multidisciplinary consensus, a patient’s file and imaging are commonly reviewed by a tumour board (TB). There are three relevant weekly TB venues at our institute—gamma knife stereotactic radiosurgery (SRS) intake rounds, CNS rounds, and stereotactic body radiotherapy (SBRT) rounds—which are attended by non-overlapping clinician teams. We explored the clinical parameters prompting multiple TB reviews in patients with complex CNS tumours. Methods. Data were retrospectively obtained from electronic medical records. Patients referred for discussion at SRS rounds (November 2017–June 2020) were cross-referenced with those reviewed in CNS rounds and SBRT rounds. The cohort of interest included patients who underwent review at more than one TB for the same indication. Patient, tumour, and treatment factors were abstracted, and descriptive statistics were calculated. A sub-cohort of patients with pre-plans created for both SRS and conventionally fractionated external beam radiotherapy (EBRT) was identified. Dosimetric data were analyzed. Results. Of 1091 patients, 87 (8.0%) were discussed at more than one TB. 59/87 (67.8%) patients were reviewed at two TBs pertaining to the same CNS lesion and comprised the study cohort. The most common tumour type was meningioma (20/59), and the most common reason for multiple discussions was proximity to optic structures (19/59). After TB discussions, 25/59 patients were seen in consultation by one specialist, 29/59 by two, and 5/59 by none. Overall, the final treatment decisions were conventional EBRT in 21/59; SRS in 18/59; surveillance in 12/59; surgery in 3/59; systemic therapy in 3/59; proton referral in 1/59; and SBRT in 1/59. A total of 20/59 patients were treated with palliative intent. Among all patients who ultimately received radiotherapy, median interval between the first TB discussion and the first RT treatment was 56 days (IQR 7.5–65.5 d). The pre-plan sub-cohort consisted of four patients, all of whom were ultimately treated with conventional EBRT. Conclusions. Evidence to support optimal treatment for some complex CNS tumours can be limited. Multiple radiotherapy modalities may be equally favourable (or unfavourable) options. Proximity to the optic apparatus and previous CNS irradiation are common reasons for clinical equipoise. Tumour board review is an essential tool in formulating a multidisciplinary care plan; however, attention should be paid to ensuring that subsequent consultations and treatment initiation are not unduly delayed. Full article

Magnetic Resonance Imaging (MRI) plays a pivotal role in evaluating treatment response following radiation-based therapies for hepatocellular carcinoma (HCC). As radiation modalities such as stereotactic body radiotherapy (SBRT) and transarterial radioembolization (TARE) gain prominence, understanding the underlying mechanisms of radiation-induced cellular senescence is essential for accurate interpretation of imaging. The physiological changes of radiation treatment manifest as altered diffusion characteristics and delayed regression of enhancement and tumor volumes on MRI, challenging conventional response criteria. Herein, functional and temporal imaging biomarkers are necessary. However, current imaging strategies lack standardization and robust validation, underscoring the need for prospective studies to correlate MRI findings with treatment outcomes. This review synthesizes emerging evidence on MRI-based evaluation of radiation-treated HCC, explores the physiological rationale linking senescence to imaging phenotypes, and advocates for optimized imaging protocols and criteria to enhance post-treatment surveillance and therapeutic decision-making. Full article

Oligometastatic prostate cancer represents a distinct biological state between localized and widely metastatic disease, characterized by a limited number of lesions. Stereotactic body radiotherapy (SBRT) has emerged as a key metastasis-directed therapy (MDT), enabling precise ablation of metastatic lesions with minimal toxicity. Prospective clinical trials such as SABR-COMET, STOMP, ORIOLE, RADIOSA, and EXTEND have shown that SBRT delays disease progression, prolongs progression-free survival, and postpones the need for systemic therapy, while maintaining a favorable safety profile. Nevertheless, methodological limitations persist, including heterogeneity in defining oligometastatic disease, variability in dosing and fractionation, and the lack of predictive biomarkers. Ongoing phase III trials aim to validate the integration of SBRT with modern systemic therapies, including next-generation androgen receptor pathway inhibitors, to optimize clinical outcomes in hormone-sensitive and castration-resistant oligometastatic prostate cancer. This review summarizes current evidence, clinical applications, and future directions for SBRT in this patient population. Full article