Brain metastases are a common and severe complication in patients with lung adenocarcinoma (ADC) harboring epidermal growth factor receptor (EGFR) mutations. Gamma Knife Radiosurgery (GKRS) is a standard treatment for brain metastases, and its efficacy may be influenced by the type of EGFR mutation and the generation of tyrosine kinase inhibitors (TKIs) used. This retrospective study evaluated the impact of EGFR mutation subtypes (exon 19 deletion vs. exon 21 L858R) and TKI generations on clinical outcomes in patients with lung ADC treated with GKRS. A total of 55 patients and 136 brain metastases were analyzed from January 2017 to December 2023. Tumor response was assessed based on local failure and distant brain failure, defined as tumor progression at the treated site and new brain metastases outside the GKRS-treated regions, respectively. The Kaplan-Meier method and univariate and multivariate analyses using Cox proportional hazard regression models were used to identify prognostic factors for local failure, and distant brain failure. The study found that second- and third-generation TKIs, such as afatinib and osimertinib, provided significantly better local control compared to first-generation TKIs (hazard ratio [HR] = 0.12, p = 0.017). Furthermore, tumors with exon 19 deletion demonstrated improved distant brain control compared to those with exon 21 L858R substitution (HR = 2.18, p = 0.048). These findings suggest that mutation type and TKI generation are independent prognostic factors for clinical outcomes following GKRS. This study suggests that both the generation of TKIs and the specific EGFR mutation subtype may influence clinical outcomes following GKRS in lung ADC patients with brain metastases. These findings may aid in stratifying patients and optimizing treatment strategies in clinical practice.

This study evaluated prognostic factors and longitudinal outcomes associated with gamma knife radiosurgery (GKRS) in treating brain metastases from breast cancer, and assessed the efficacy of repeated GKRS in prolonging intracranial disease control. In this retrospective study, we reviewed 159 breast cancer patients involving 640 brain metastases who underwent GKRS at a tertiary medical center. Overall survival (OS), local control (LC), and distant intracranial control were estimated using the Kaplan-Meier method. Prognostic factors were estimated using Cox regression models. The effect of repeat GKRS on intracranial disease control was also examined. The median OS was 19.2 months. In multivariate analysis, the Karnofsky Performance Scale (KPS), HER2 positivity, and ER/PR positivity were independently associated with longer survival. LC rates were 88.9% at 6 months and 83.0% at 12 months. Factors significantly associated with improved LC included a higher margin dose, HER2-negative status, smaller tumor volume, and absence of prior whole-brain radiotherapy (WBRT). Distant intracranial failure within 12 month occurred in 57.0% of patients. Median intracranial control among the 44 patients who underwent repeated GKRS (28.1 months) was significantly longer than those who received single GKRS (8.0 months; p < 0.001). GKRS provides effective local tumor control and favorable survival outcomes for patients with breast cancer brain metastases. KPS score and receptor status (ER/PR and HER2) are significant predictors of overall survival. Repeat GKRS is a promising strategy for prolonging intracranial control and may reduce the need for WBRT or surgical intervention in selected patients.

Craniopharyngiomas are clinically aggressive benign tumors that present a special challenge for clinicians due to high recurrence rates and post operative compilations. Surgical intervention alone poses many challenges and therefore, the use of radiotherapeutic adjuvant modalities has become common. This study aims to evaluate the effectiveness of gamma knife radiosurgery (GKRS) in the management of recurrent and residual craniopharyngiomas and identify the factors that could predict survival and complication rates. PubMed and Cochrane library were screened from inception until September 2024. Fixed effect models (I2 < 50%) and Random effects models (I2 > 50%) were created to study the pooled survival rates and complication rates. Linear Regression models were generated to identify the prognostic factors and F-test was used to check the significance of the models. The meta-analysis included 743 tumors from nine selected studies. Estimated 3, 5 and 10 year OS rates were 96%, 93% and 85% respectively and estimated 3, 5 and 10 year PFS rates were 83%, 68% and 45% respectively. Estimated visual (VD) and endocrinological dysfunction (ED) rates were 5% and 4% respectively. Median marginal dose ≤ 13Gy was the independent predictor of 3 year OS (β = 1.95, p = 0.02), while female patients (β=-0.52, p = 0.023), age (β=-0.36, p = 0.04) and median marginal dose ≤ 13Gy (β = 2.55, p = 0.001) were found to be significant predictors of 5 year OS. F-test revealed that the models generated for 3 year and 5 year OS rates were significant with an excellent R2 values of 0.99 (p = 0.03) and 0.98 (p = 0.008) respectively. Age was the single significant predictor of VD (β=-0.80, p = 0.032) while tumor volume (β = 0.61, p = 0.035) and median marginal dose ≤ 13Gy (β=-1.17, p = 0.039) were significant predictors of ED. GKRS is an effective treatment modality for recurrent and residual craniopharyngiomas, providing comparable to improved survival rates to other modalities and significantly lower complication rates with a safe dose of ≤ 13Gy.

Clinical characteristics and outcomes in participants with screen-detected clinical stage I lung cancer in the Yorkshire lung screening trial: A comparison of surgery versus stereotactic ablative radiotherapy.

Introduction Choroidal metastasis generally has poor prognosis and most commonly originates from breast carcinomas. While systemic chemotherapy offers therapeutic benefits, local therapies are often necessary for symptom management and tumor control. Gamma knife radiosurgery (GKR), which was originally developed for intracranial lesions, has emerged as a promising treatment for choroidal metastasis, offering high precision and minimized toxicity with fewer ocular side effects compared with conventional radiotherapy. This case report explores the use of GKR in a patient with choroidal and brain metastases from breast carcinoma. Case presentation A 44-year-old woman with a history of treated left breast carcinoma presented with 3 months’ gradual vision loss in her left eye. Her visual acuity at presentation was counting fingers (CF). Imaging revealed a choroidal metastasis along with multiple brain metastases. The patient underwent GKR for both choroidal and intracranial metastases, receiving doses ranging from 16 to 18 Gy at 50%–90% isodose. Following treatment, significant tumor regression was observed, with a marked reduction in retinal detachment and vision improvement to 6/18. At 6 months post-GKR, both the choroidal mass and the retinal detachment had fully resolved; however, her visual acuity remained limited due to foveal atrophy. Conclusion This case demonstrates the potential of GKR as a noninvasive and effective modality for the simultaneous treatment of choroidal and intracranial metastases. In palliative settings, especially for patients with limited life expectancy, GKR can provide symptomatic relief and improved quality of life with minimal invasiveness, which is particularly valuable for younger patients facing advanced metastatic cancer. The importance of a multidisciplinary approach in the management of complex metastatic diseases is also highlighted. Future studies are warranted to fully define the role of GKR in choroidal metastasis and its long-term sequelae.

First online real-time motion-including prostate and bladder dose reconstruction during prostate radiotherapy.

Gamma Knife radiosurgery (GKRS) is an established treatment for refractory trigeminal neuralgia, however, predictors of pain relief following treatment remain unclear. We aimed to identify the factors associated with pain relief after the index GKRS session. We retrospectively analyzed 204 patients with trigeminal neuralgia treated with GKRS between 1998 and 2023 (mean age 65.2 years, 68.5% female). Patient variables (pretreatment Roswell Park and Barrow Neurological Institute pain scores, symptom duration, prior therapies, multiple sclerosis status), MRI metrics (neurovascular contact and trigeminal nerve dimensions), and radiosurgery parameters (isocenter location and radiation dose, including biologically effective dose [BED]) were assessed. Responders were defined as BNI<IIIb or RPS<3. At last follow-up (median 20 months, range 6 months to 26 years), 57.3% of patients achieved pain relief. At ≥3-year follow-up, 74.1% of patients maintained adequate pain relief. Multiple sclerosis and prior interventions were associated with lower response rates: MS patients had 27.7% response vs 57.7% without MS (p=0.008), and prior microvascular decompression (MVD) had 34.4% vs 62.7% without prior MVD (p=0.005). GKRS as first-line therapy yielded better outcomes than when used after other treatments (63.9% vs 38.9%, p=0.045). Responders had a smaller trigeminal nerve (mean diameter 3.04 vs 3.42 mm, p=0.007) and a greater isocenter to brainstem orthogonal distance (4.2 vs 3.5 mm, p=0.02). A BED ≥ 2000 Gy was associated with higher response rate (75.8% vs 48.8%, p=0.006). In multivariate analysis, absence of MS, no prior MVD, smaller nerve diameter, and BED ≥ 2000 Gy independently predicted pain relief. Non-modifiable factors that affected response included absence of MS and smaller trigeminal nerve size. Modifiable factors that were associated with higher response rates included no prior MVD, placing the isocenter farther from the brainstem surface, and BED≥ 2000 Gy. These findings support individualized treatment sequencing and GKRS planning to optimize GKRS outcomes in trigeminal neuralgia.

BackgroundGamma knife radiosurgery (GKRS) is an established option for cerebral cavernous malformations (CCMs) when microsurgical resection is not feasible. Lesion location strongly influences treatment strategy. The biologically effective dose (BED), introduced by J. F. Fowler, has been widely discussed in radiobiology but not evaluated in CCMs.MethodsA retrospective cohort study was conducted on 107 patients with 123 CCMs treated by GKRS at West China Hospital between June 2020 and December 2022. Post-GKRS hemorrhage was defined as symptomatic bleeding. The annual hemorrhage rate (AHR) quantified bleeding risk, and effective volumetric control was defined as ≥ 20% volume reduction. Clinical outcomes were categorized as improved, stable or worsened.ResultsThe mean age was 41 years, and 59.8% were female. Pre-GKRS hemorrhage was most frequent in brainstem (78.6%) and basal ganglia/thalamic lesions (73.3%). During follow-up, 13 patients (10.6%) experienced hemorrhage and AHR decreased from 13.6 to 4.3% per 100 lesion-years (IRR = 0.314; p < 0.001). BED was an independent protective factor against postoperative hemorrhage (HR = 0.964, p = 0.044) and significantly associated with volumetric and clinical control.ConclusionGKRS significantly reduced hemorrhage risk and promoted lesion regression in CCMs. BED was identified as a strong independent predictor of hemorrhage control, volume response and clinical outcomes, outperforming conventional dose metrics. These findings suggest that BED may guide personalized radiosurgical dose optimization for CCMs.

Abstract OBJECTIVE This study was conducted with the aim to estimate long-term tumor control and hearing preservation rates in patients with neurofibromatosis 2 (NF2)-related vestibular schwannoma (VS), document retreatment success rate, and assess the associated predictive factors. METHODS This was a retrospective analysis of patients with NF2-associated VS who underwent Gamma Knife radiosurgery (GKRS) between 2009 and 2020 and had a minimum follow-up of 1 year. Loss of tumor control was defined as greater than 10% increase in volume in more than one follow-up imaging or the need for retreatment in the form of repeat GKRS or surgery. The Kaplan-Meier method was used to evaluate actuarial tumor control and hearing preservation rates. RESULTS In total, 85 patients with 133 VSs were included in the study. The mean age was 29.8 years. In total, 57 tumors showed tumor regression, 35 showed stable disease, and 23 progressed in size at last follow up. Actuarial tumor control rates after 1, 3, 5, and 9 years were 95%, 79%, 75%, and 55%, respectively, with overall tumor control rate being 85%. Hearing worsened in 39 patients, and facial nerve dysfunction occurred in 4 patients. Five tumors underwent retreatment with GKRS at a median duration of 27.6 months (19-36 months) following the first GKRS. CONCLUSIONS This is the largest radiosurgical series of NF2-associated VS reported to date. GKRS provides a high rate of long-term local tumor control with a low risk of neurologic deprivation for patients with these tumors. The need for retreatment with GKRS, although low, is associated with good tumor control and lesser complications. KEYWORDS Gamma Knife radiosurgery; Neurofibromatosis type 2; Retreatment; Tumor control; Vestibular schwannoma.

Abstract BACKGROUND 20-40% of all patients with cancer develop brain metastases. Stereotactic radiotherapy (SRT) has become the preferred standard of care after surgical resection, with improved local control (LC) rates over resection alone. However, even with this paradigm, there is a significant risk of local failure as well as a significant incidence of adverse radiation effect (ARE) with fractionated SRT (FSRT), both of which increase with tumor size. Thus, there is an unmet need for improved adjunctive radiation therapy. Surgically Targeted Radiation Therapy (STaRT) using collagen-tile Cesium-131 brachytherapy (GammaTile®, GT Medical Technologies, Tempe, Arizona, USA) is FDA cleared for the treatment of newly diagnosed malignant brain tumors and may offer an advantage in the rate of LC and/or ARE. OBJECTIVE The primary objective is to compare surgical bed recurrence free survival (SBRFS) after surgical tumor removal plus SRT, versus surgical tumor removal plus STaRT. Key secondary objectives include assessments of overall survival, occurrence of leptomeningeal tumors (classical and nodular), quality of life, neurocognitive function, and radiation necrosis, among others. METHODS Prospective, randomized, parallel, open-label, multi-site 230 patient study with 2 study arms: Patients with 1 tumor for resection + SRT to resection bed versus patients with resection of 1 tumor + STaRT to resection bed. Randomization is 1:1 done preoperatively, ≤7 cm preoperative maximum dimension, and 5 additional unresected metastases are allowed, with patients in both arms receiving FSRT/ radiosurgery to any unresected, previously untreated metastases. An interim analysis is planned for August 2025, pending central review.

Abstract Retinoblastoma is the most common intraocular malignancy in children. Heritable cases, often due to germline RB1mutations, typically present bilaterally. Trilateral retinoblastoma refers to intraocular retinoblastoma with an associated intracranial primitive neuroectodermal tumor (PNET), usually in the pineal gland, and occurs in 3–9% of heritable cases. This report describes a male infant with 13q deletion syndrome diagnosed at four months with bilateral retinoblastoma. He initially received six cycles of systemic chemotherapy (vincristine, etoposide, carboplatin) plus cyclosporine, followed by five cycles of intra-arterial melphalan and laser ablation to the left eye. A pineal lesion observed since infancy showed progression at age two. Biopsy confirmed PNET. Treatment included multiagent chemotherapy (vincristine, cyclophosphamide, cisplatin, etoposide) and autologous stem cell rescue with conditioning (carboplatin, etoposide, thiotepa). He engrafted by day +12 and remained stable for three years. At age seven, pineal tumor regrowth was treated with Gamma Knife radiosurgery. Two years later, subsequent progression led to an endoscopic third ventriculostomy and another Gamma Knife procedure. Later that same year, leptomeningeal spread developed. He began bridging chemotherapy (vincristine, cyclophosphamide), followed by proton beam craniospinal irradiation (3600 Gy with boost to pineal area), and 12 cycles of bevacizumab, irinotecan, and temozolomide. As of three years post-radiation, the patient remains without active disease. MRI shows a stable residual pineal lesion and stable post-treatment changes in both eyes. This case highlights the complex, multimodal management of trilateral retinoblastoma in a patient with 13q deletion syndrome. Prolonged disease control is possible with chemotherapy, focal therapies, stem cell transplantation, radiosurgery, and proton beam radiation. However, long-term surveillance and flexible salvage strategies remain critical for sustained outcomes.

Abstract INTRODUCTION Spinal metastases from prevalent cancers—such as breast, prostate, and lung—affect over 100,000 patients annually. Metastatic epidural spinal cord compression (MESCC) is a severe complication that can lead to significant neurological deficits and requires urgent intervention. Although stereotactic radiation therapy effectively controls spinal metastases, MESCC often necessitates “separation surgery” to physically distance the tumor from the spinal cord to prevent radiation-induced injury. However, separation surgery is invasive, prolongs hospitalization, interrupts systemic therapy, and delays radiation. Laser Interstitial Thermal Therapy (LITT) presents a minimally invasive alternative, but its clinical adoption is limited by challenges in MRI thermography and precise laser fiber placement in the spine. Here, we introduce a novel porcine model of MESCC to address these limitations. METHODS We established a porcine xenograft spine tumor model by implanting human breast cancer (HCC70) or osteosarcoma (143B) cells into the vertebral bodies of immunosuppressed Yucatan mini pigs. Tumor progression was monitored using serial CT and MRI. For LITT, commercial laser fibers were percutaneously placed under image guidance. To improve real-time MRI thermography during ablation, we developed motion compensation techniques that eliminate the need for breath holding, and we compared MRI-derived tissue damage estimates with histopathological findings. RESULTS The model demonstrated consistent, radiographically evident tumor growth. Breath-holding during thermography introduced significant noise and caused unreliable tissue damage estimates, whereas multi-baseline and reference-less algorithms substantially reduced motion artifacts. Discrepancies between MRI damage estimates and histopathology highlight the necessity for further validation of MRI thermography in the spine. DISCUSSION LITT is a promising, minimally invasive alternative to separation surgery for MESCC. Its successful clinical translation depends on the development of robust, motion-compensated MRI thermography algorithms and the absolute validation of MRI-based damage assessments. Our porcine model offers an ideal platform for overcoming these challenges.

Abstract Brain metastases significantly impact neurocognitive function and overall survival. Stereotactic radiosurgery (SRS) is a cornerstone of treatment for patients with limited metastases and expected survival beyond three months. Despite current guidelines, up to 20% of patients with brain metastases undergoing SRS have been reported to die within 90 days. This study retrospectively evaluates prognostic factors associated with 90-day survival after SRS, aiming to improve patient selection. We retrospectively analyzed a cohort of 1,546 patients who underwent Gamma Knife SRS for brain metastases at our institution between 2015 and 2023. One hundred seventy patients who survived fewer than 90 days post-SRS were identified and case-matched to 170 patients who survived over 90 days. Measured variables included patient demographics, tumor characteristics, treatment history, functional status, and control of the primary cancer. We modeled post-SRS 90-day survival using binomial and multivariate logistic regression. Multivariate analysis highlighted Karnofsky Performance Status (KPS) &amp;lt; 70 (OR: 17.4, p &amp;lt; 0.001), prior whole brain radiation (OR: 6, p = 0.004), and focal neurological deficits (OR: 3.02, p = 0.003) as significant predictors of early deaths, while CNS progression before SRS (OR: 0.22, p &amp;lt; 0.001) and control of systemic cancer (OR: 0.556, p = 0.002) were associated with a less than 90-day survival. The predictive model demonstrated acceptable performance with an area under the curve (AUC) of 0.85, accuracy of 80%, sensitivity of 87%, and specificity of 71%. Key predictors of 90-day survival following SRS for brain metastases include functional status (KPS), control of systemic cancer, CNS progression status, and focal neurologic deficits. These findings are complementary factors that can assist in making decisions and SRS patient selection.

Abstract BACKGROUND Tracking metastatic brain cancer progression over time presents significant clinical challenges. Accurate detection of brain metastases on magnetic resonance imaging (MRI) is essential for determining correct tumor resection margins and distinguishing tumor progression from treatment response. METHODS We adapted the VALE method—a satellite imaging technique that generates color-coded change maps—to highlight tumor margins in longitudinal brain MRI scans. We used the publicly available NYUMets dataset (1,429 patients with stage IV metastatic cancer, each with on average 6 longitudinal MRIs including T1-weighted pre-contrast, T1-weighted post-contrast, and FLAIR sequences), and selected three timepoints approximately six months apart. Our processing pipeline involved four key steps: (1) registering FLAIR and T1 post-contrast images to the baseline T1 pre-contrast scan, (2) normalizing median pixel intensities across timepoints using white matter intensity from the baseline scan, (3) performing histogram clipping, and (4) creating color-coded change maps by overlaying the three timepoints in the RGB color channels. In the resulting maps, blue indicates new lesions, pink shows tissue changes, and white represents lesion stability. RESULTS Color-coded change maps significantly improved visualization of small brain tumors and metastases compared to standard imaging. The maps revealed clear associations between edema progression and lesion development in corresponding regions. Most importantly, they enhanced delineation of tumor boundaries that were not apparent in conventional T1 post-contrast images. Clinical Implications: This method has the potential to improve tumor resection accuracy during gamma knife surgery, thereby reducing recurrence risk. The enhanced boundary visualization could be particularly valuable for surgical planning and treatment monitoring. Future Directions: We are currently processing the complete NYUMets dataset to validate our technique across all cases. Future work will explore using these color-coded change maps as saliency maps in neural networks to better predict treatment response versus cancer progression.

Abstract BACKGROUND The standard of care treatment for glioblastoma multiforme (GBM) is maximal safe resection followed by postoperative radiation with concurrent and adjuvant temozolomide. The adjuvant radiotherapy dose is 60Gy in 30 fractions, 2Gy per fraction over 6 weeks with concurrent temozolomide 75mg/m2. The median overall survival is 14.6 months. Hypofractionated stereotactic radiotherapy enables to deliver high biological effective dose with shorter treatment duration.Aims: In this prospective study, we aimed to evaluate the safety and feasibility of adjuvant hypofractionated stereotactic radiotherapy technique(HFSRT)with conventional fractionated radiotherapy (CRT) with concurrent and adjuvant temozolomide. METHODS Fifteen adult patients diagnosed with GBM and ECOG performance status of 0-1 were include in the study from August 2019 to April 2021. All patients underwent maximal safe resection. Seven patients received adjuvant HFSRT to a dose of 42Gy in six fractions, 7Gy per fraction on alternate days over 2 weeks with concurrent and adjuvant temozolomide. Eight patients received conventional radiotherapy to a dose of 60Gy in 30 fractions over six weeks with concurrent and adjuvant temozolomide. All patients received adjuvant radiotherapy with VMAT technique. Concurrent temozolomide was given at a dose of 75mg/m2 daily during treatment. Adjuvant temozolomide at a dose of 150mg/m2 for first cycle and 200mg/m2 afterwards for a total of 6 cycles. RESULTS The mean age of all patients included in the study was 39.9 years. Eight patients were males and seven were females. Seven out of 15 patients underwent gross total resection. All patients completed adjuvant radiotherapy treatment without any interruptions. The commonly observed side effects of CTCAE grade1cognitive impairment, grade1seizures, Grade 1 and 2 muscle weakness, grade 1 somnolence and grade 1 thrombocytopenia were not significantly different among two treatment groups. However, Grade 3 hyponatremia was observed in two patients who received conventional treatment during adjuvant temozolomide. CONCLUSION Adjuvant hypofractionated stereotactic radiotherapy with concurrent and adjuvant temozolomide appears to be safe and feasible treatment option, which requires further studies in patients with GBM.

Background: Trigeminal neuralgia (TN) is a debilitating facial pain disorder commonly associated with neurovascular compression (NVC), frequent radiological finding, often asymptomatic and insufficient for diagnosis without clinical correlation. We present a case in which Gamma Knife radiosurgery (GKRS) was performed for presumed TN based on incidental imaging findings, leading to the development of trigeminal neuropathy. According to the International Classification of Headache Disorders (ICHD-3), secondary trigeminal neuropathy refers to facial pain or sensory deficits resulting from a structural lesion, commonly due to tumors, multiple sclerosis, or iatrogenic injury. Methods: A 50-year-old male with a history of two self-limited episodes of right facial nerve palsy underwent brain MRI, which incidentally showed vascular contact with the right trigeminal nerve. Despite the absence of classic TN symptoms, the patient underwent GKRS in March 2024. By July 2024, the patient developed progressive right-sided trigeminal hypoesthesia and dysesthesia of ophthalmic and maxillary divisions. By the end of 2024, he reported paroxysmal, electric shock-like pain (NRS 10/10) in the right frontal, periorbital, and genian regions, up to five times daily. Brain MRI in December 2024 demonstrated a small enhancing lesion in the cisternal segment of the right trigeminal nerve and mild T2-FLAIR hyperintensity near the root entryzone. Pharmacologic treatment provided no significant benefit. Results: The absence of prior symptoms, the temporal association of symptom onset with the procedure, and the lack of alternative neuroimaging findings strongly support an iatrogenic etiology. Secondary causes - including neoplasms, multiple sclerosis, neuroborreliosis, neurosarcoidosis, and varicella-zoster virus reactivation - were excluded by clinical and laboratory evaluation. Conclusion: This case underscores the potential harm of relying solely on imaging findings such as NVC in the absence of clinical features. GKRS should be reserved for patients with clear symptomatic TN who are refractory to medical therapy and not suitable candidates for microvascular decompression. The patient’s clinical course is consistent with a radiosurgery-induced trigeminal neuropathy, fulfilling the criteria for post-traumatic painful trigeminal neuropathy (ICHD-3 code 13.1.2.3). This report highlights the importance of thorough clinical evaluation in facial pain syndromes. Overreliance on radiologic findings without adequate clinical correlation may result in misdiagnosis and unnecessary, potentially harmful interventions.

Objective.Anatomy continuously deforms during radiation therapy. Although real-time volumetric imaging approaches are emerging, there is a lack of adaptive strategies that account for intrafraction deformations. The purpose of this study was to develop a multileaf collimator (MLC) tracking method that adapts to deformations and evaluate the performance for lung cancer with multiple lesions.Approach.Dose-optimised deformable MLC tracking was developed using a fast dose calculation to accumulate dose at each timestep. The accumulated planned doses were deformed to represent the desired dose distribution for the deformed anatomy and the MLC leaf positions were optimised to minimise the difference between the delivered and deformed planned dose. Dose-optimised deformable MLC tracking was evaluated using four lung cancer cases generated using the 4D XCAT digital phantom. Stereotactic ablative radiotherapy treatment plans were created using a planning target volume (PTV) margin expansion of 5 mm on the gross tumour volumes (GTV). Treatments were simulated using three patient-measured motions for each phantom. The doses accumulated using the fast dose calculation model with MLC tracking were compared to an internal target volume (ITV)-based approach.Main results.The volume of the PTVs were reduced by an average of 34% using dose-optimised deformable MLC tracking compared to the ITV-based approach. The mean differences and standard deviations from the planned doses were -0.5% ± 0.6% for the GTV D100%and -1.1% ± 0.6% for the PTV D98%when dose-optimised deformable MLC tracking was used, and -5.2% ± 8.8% for the ITV D100%and -13.8% ± 12.9% for the PTV D98%when no tracking was used.Significance.The study demonstrated a proof of concept for dose-optimised deformable MLC tracking to reduce dosimetric errors for deforming anatomy. The proposed method could enable the safe reduction of treatment margins for multiple independently moving targets in the lung compared to the standard of care.

Introduction. Despite advances in the surgical management of prostate cancer (PCa), postoperative recurrence remains a significant clinical challenge. Contemporary approaches to postoperative radiation therapy, including stereotactic body radiation therapy (SBRT), offer promising opportunities to enhance therapeutic efficacy and reduce treatment duration while maintaining an acceptable toxicity profile. Aim. To evaluate the long-term efficacy and safety of postoperative SBRT directed to the prostate bed (PB) in patients with recurrent PCa following radical prostatectomy (RP). Materials and Methods. A prospective single-center study enrolled 56 patients with biochemical recurrence of PCa after RP. All patients received SBRT to the PB with a total dose of 35 Gy delivered in five fractions. The median follow-up duration was 38 months. Oncological outcomes, radiation-induced toxicity (assessed using RTOG criteria), and quality of life parameters were evaluated. Results. Biochemical recurrence occurred in 13 patients (23.2 %), including three cases (5.4 %) of local relapse within the PB. Disease-free survival was maintained in 76.8 % of patients at the final follow-up, with local control achieved in 94.6 % of cases. Acute grade I genitourinary toxicity was observed in 11 patients (19.6 %). Late toxicities included grade I–II genitourinary effects in 25 patients (44.6 %) and grade I–II gastrointestinal effects in five patients (8.9 %). No grade III or higher radiation-related complications were reported. Quality of life measures remained stable compared to baseline values. Conclusion. Postoperative SBRT targeting the PB provides excellent local control and is well tolerated. This treatment approach represents an effective and safe therapeutic option for patients with recurrent PCa following surgical intervention.

Введение. Менингиома зрительного нерва — редко встречающаяся опухоль у пациентов преимущественно взрослого возраста, в том числе, с нейрофиброматозом II типа, сопровождающаяся снижением зрительных функций и экзофтальмом. Возможные варианты ведения пациентов: динамическое наблюдение, хирургическое удаление опухоли или декомпрессия зрительного нерва, лучевая терапия, а также комбинация данных методов. Лучевая терапия может быть рекомендована пациентам с сохранными зрительными функциями, при отсутствии выраженного экзофтальма и трофических изменений глаза. Стандартом лучевого лечения является классический режим фракционирования. В настоящей работе рассматривается наш опыт применения режима гипофракционирования на менингиомы зрительного нерва. Цель. Оценить безопасность и эффективность лучевого лечения пациентов с менингиомой зрительного нерва в режиме гипофракционирования. Материалы и методы. С марта 2010 по май 2020 г. 18 пациентов с менингиомами зрительного нерва прошли лечение на линейных ускорителях Cyber-Knife и Novalis в режиме гипофракционирования с разовой очаговой дозой 5,5 Гр, пять фракций до суммарной очаговой дозы 27,5 Гр: 16 взрослых пациентов в возрасте от 25 до 70 лет (медиана — 51 год; IQR — 21) и двое детей 8 и 14 лет. Медиана объема опухоли составила 1,5 см3 (от 0,34 до 6,49 см3). Результаты. Медиана наблюдения составила 57 мес. (от 11 до 102 мес.; IQR — 49). Контроль роста опухоли достигнут у всех 18 пациентов, частичный ответ опухоли, в виде уменьшения объема на 40 % и более, наблюдался у пяти (27,8 %) больных. Ухудшения зрительных функций не было ни у одного пациента; улучшение остроты зрения отмечено в 6/14 (42,9 %) случаях. Расширение границ полей зрения наблюдалось у пяти (62,5 %) из восьми пациентов, у которых изначально была возможность оценки границ полей зрения. После облучения у семи (50 %) из 14 пациентов размеры экзофтальма уменьшились на 1 мм и более. Выводы. Лучевое лечение в режиме гипофракционирования показало свою безопасность и эффективность при лечении пациентов с менингиомой зрительного нерва.

Введение. Частота развития радионекроза (РН) после проведения курса стереотаксической радиохирургии (СРХ) или стереотаксической лучевой терапии (СТЛТ) посредством линейных ускорителей электронов (ЛУЭ) или роботизированных методик проведения курса лучевой терапии (ЛТ) остается до конца неопределенной. В отличии от результатов исследований по применению гамма-терапевтических установок, количество литературных данных, посвященных применению данных методов ЛТ, остается ограниченным. Подобное может являться причиной искусственного экстраполирования результатов частоты развития РН, полученных посредством гамма-ЛТ, на популяцию пациентов, пролеченных посредством ЛУЭ или роботизированных методик проведения курса ЛТ, и не отражать истинную частоту проявления данного нежелательного явления. Цель. Оценка частоты развития РН после курса СРХ/СТЛТ посредством ЛУЭ или роботизированных методик проведения курса ЛТ у пациентов с метастатическим поражением головного мозга. Материалы и методы. В данный метаанализ были включены исследования, опубликованные с 2015 по 2025 г. на поисковых ресурсах PubMed и ScienceDirect. Интересующим результатом была частота развития РН по очагам и/или по пациентам. Поиск, отбор и включение публикаций были осуществлены согласно рекомендациям Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Статистическая обработка полученных данных была выполнена посредством программного обеспечения Comprehensive Meta-Analysis v.3, v.4. Результаты. В метаанализ включено 10 публикаций, удовлетворяющих критериям включения. После статистической обработки данных частота развития РН по облученным очагам составила 7,1 % (95 % ДИ: 4,1-12,2) и 10,5 % (95 % ДИ: 6,8-15,8) по пациентам при использовании модели случайных эффектов. Выводы. При непрямом сравнении с результатами лечения метастатических очагов посредством гамма-терапевтических установок частота развития РН после проведения курса СРХ/СТЛТ с применением ЛУЭ или роботизированных методик проведения курса ЛТ может считаться сопоставимой. Для формирования более точных данных необходимо большее количество научных работ, рассматривающих применение этих методов ЛТ у пациентов с метастазами в головном мозге.