Background: Peptide receptor radionuclide therapy (PRRT) could be a therapeutic option for patients with advanced, recurrent or progressing meningiomas overexpressing somatostatin receptors. The aim of this study is to perform an updated meta-analysis to establish the disease control rate of PRRT in these patients. Methods: A comprehensive literature search of studies on PRRT in patients with advanced, recurrent or progressing meningioma was carried out. Four different databases (PubMed/MEDLINE, EMBASE, Cochrane library, Google Scholar) were screened until April 2025. Only original articles about PRRT in advanced, progressive or refractory meningiomas were selected. Case reports were excluded. Three review authors independently performed the literature search, the article selection and the data extraction. Main findings of eligible studies were summarized and a proportion meta-analysis on the disease control rate was carried out using a random-effects model. Results: In total, 18 studies (269 patients) published from 2006 to 2025 were included in the analysis. In most of the included studies, PRRT was performed using [¹⁷⁷Lu]Lu-DOTATATE. The pooled disease control rate was 67.7% (95% confidence interval values: 59.6–75.7%). PRRT was well-tolerated in most patients with advanced, recurrent or progressive meningioma. Moderate statistical heterogeneity was found in the meta-analysis (I-square: 53%). Conclusions: PRRT is an effective and well-tolerated treatment in patients with advanced, progressive or recurrent meningiomas, showing a significant disease control rate (in about two-thirds of patients). Even if well-designed clinical trials are needed to corroborate these findings, evidence-based data seem to support the clinical use of PRRT for this indication.

To evaluate the feasibility and report the preliminary results for stereotactic radiosurgery (SRS) treatments of single or multiple brain metastases delivered with helical tomotherapy (HT) by means of the InterFix™ Radiosurgery kit. Between September 2010 and August 2012, thirty patients underwent SRS for treatment of 46 brain metastases with a median prescription dose of 20 Gy (range 15-21 Gy). Clinical response was assessed with 2-3 month intervals by magnetic resonance imaging (MRI). Dose distribution indexes were computed and compared with published data for SRS performed with dedicated machines. After a median follow-up of 14 months (range 4-31) the estimated overall survival (OS) rate was 70% at 6 months, 60% at 12 months and 44% at 18 months. Local control (LC) was 72% at 6 months, 65% at 12 months and 50% at 18 months. Acute toxicity as headache and epileptic crisis occurred in only two patients. The mean values of conformity, homogeneity and gradient score indexes were 1.36, 1.04 and 50 respectively. HT-SRS for single or multiple brain metastases appears a reliable technique with encouraging clinical outcomes and competitive dosimetrical results.

194 Background: Salvage radiotherapy (RT) is often utilized in case of biochemical progression after radical prostatectomy (RP). Here we report the outcomes of the European SAKK 09/10 randomized phase 3 trial with the aim to compare effectiveness and tolerability of conventional vs. dose-intensified salvage RT. Methods: SAKK 09/10 is an open-label, multicenter, randomized phase 3 trial performed in 24 centers in Switzerland, Germany and Belgium. Men with biochemical progression (two consecutive rises with the final PSA > 0.1 ng/mL or three consecutive rises) after RP with a PSA nadir of ≤ 0.4 ng/mL, with a PSA ≤ 2 ng/mL at randomization and without clinical evidence of macroscopic disease were recruited. Patients were randomly assigned to either conventional dose RT (64 Gy in 32 fractions) or dose-intensified RT (70 Gy in 35 fractions) directed to the prostate bed. Three-dimensional conformal RTor intensity-modulated RT/rotational techniques were used. The primary endpoint was freedom from biochemical progression (PSA ≥ 0.4 ng/mL and rising). Secondary endpoints included clinical progression-free survival, time to hormonal treatment, overall survival, acute and late toxicity (according to the NCI CTCAE v4.0) and quality of life (according to the EORTC QLQ-C30 and PR25). The trial was registered under NCT01272050 in clinicaltrials.gov. Results: Between 02/2011 and 04/2014, 350 patients were randomly assigned to 64 Gy (n = 175) or 70 Gy (n = 175), of whom 344 aged between 48 to 75 years were assessable for the intention-to-treat population. The median PSA at randomization was 0.3 ng/mL (range, 0.03-1.61 ng/mL). At the time of data cutoff (July 3, 2020), the median follow-up was 6.2 years (IQR 5.5-7.2) and a total of 138 biochemical progression events occurred. The estimated freedom from biochemical progression rate at 6 years was 62.3% (95% CI 54.2-69.4%) and 61.3% (95% CI 53.4-68.3%) for the 64 Gy and the 70 Gy arm, respectively, and the hazard ratio adjusted by stratification factors was 1.14 (95% CI 0.82-1.60; log-rank p = 0.44). No significant difference was found for clinical progression-free survival, time to hormonal treatment and overall survival between the two arms, respectively. Late grade 2 and 3 genitourinary toxicity was observed in 35 (21.2%) and 13 (7.9%) patients treated with 64 Gy, and in 46 (26.3%) and 7 (4%) patients with 70 Gy (p = 0.81). Lategrade 2 and 3 gastrointestinal toxicity was observed in 12 (7.3%) and 7 (4.2%) patients with 64 Gy, and in 35 (20%) and 4 (2.3%) patients with 70 Gy(p = 0.009). Quality of life data will be presented. Conclusions: Dose-intensified salvage RT to the prostate bed was not superior to conventional dose RT. However, dose-intensified salvage RT was associated with higher frequencies of late grade ≥ 2 gastrointestinal toxicity. Clinical trial information: NCT01272050.

Background: Stereotactic body radiation therapy (SBRT) is the most commonly used metastasis-directed therapy (MDT) for oligometastatic urothelial carcinoma (omUC). Despite efforts in defining this disease entity, open questions remain concerning the role of MDT and the use of biomarkers, imaging, and its combination with systemic therapies. The aim of the present systematic review is to provide an updated overview of the current clinical evidence on SBRT for omUC in terms of survival and local control benefits. We also aim to provide updates on controversial areas and future directions in this emerging field. Methods: With a systematic approach, following PRISMA recommendations, we searched two databases to identify and select articles published up until March 2024 reporting the use of SBRT for omUC with or without concomitant systemic therapies. Prospective randomized or non-randomized studies as well as retrospective studies were included. Results: Eight studies were selected for data extraction and 293 omUC patients treated with SBRT were collectively analyzed. In metachronous omUC patients, SBRT delivered with ablative doses (BED10 ≥ 78 Gy) was associated with a 2-year overall survival (OS) rate of 50.7% (95% CI 35.1–64.4%). The use of sub-ablative SBRT doses (BED10 = 43.2 Gy) in combination with immunotherapy did not demonstrate significant clinical outcome improvement in two prospective studies. The overall tolerance was good, with only one study reporting toxicity of grade 3 in up to 18% of the patients treated with SBRT in combination with immunotherapy. Conclusions: SBRT is an effective and widely available MDT option in omUC, although this is based on a limited number of studies. Despite the attempt to use SBRT as an immune response trigger in combination with immunotherapy, no significant improvement in survival outcomes has been observed. The integration of new systemic agents with MDT will likely define a new scenario for the treatment of omUC. The review protocol was registered in PROSPERO, ID: CRD42024522381.

Objective: To evaluate the performance of low dose cone beam CT (CBCT) acquisition protocols for image-guided radiotherapy of prostate cancer. Methods: CBCT images of patients undergoing prostate cancer radiotherapy were acquired with the settings currently used in our department and two low dose settings at 50% and 63% lower exposure. Four experienced radiation oncologists and two radiation therapy technologists graded the images on five image quality characteristics. The scores were analysed through Visual Grading Regression, using the acquisition settings and the patient size as covariates. Results: The low dose acquisition settings have no impact on the image quality for patients with body profile length at hip level below 100 cm. Conclusions: A reduction of about 60% of the dose is feasible for patients with size below 100 cm. The visibility of low contrast features can be compromised if using the low dose acquisition settings for patients with hip size above 100 cm. Advances in knowledge: Low dose CBCT acquisition protocols for the pelvis, based on subjective evaluation of patient images.