Background In this dosimetric study, a dedicated planning tool for single isocenter stereotactic radiosurgery for multiple brain metastases using dynamic conformal arc therapy (DCAT) was compared to standard volumetric modulated arc therapy (VMAT). Methods Twenty patients with a total of 66 lesions who were treated with the DCAT tool were included in this study. Single fraction doses of 15–20 Gy were prescribed to each lesion. Patients were re-planned using non-coplanar VMAT. Number of monitor units as well as V 4Gy , V 5Gy and V 8Gy were extracted for every plan. Using a density-based clustering algorithm, V 10Gy and V 12Gy and the volume receiving half of the prescribed dose were extracted for every lesion. Gradient indices and conformity indices were calculated. The correlation of the target sphericity, a measure of how closely the shape of the target PTV resembles a sphere, to the difference in V 10Gy and V 12Gy between the two techniques was assessed using Spearman’s correlation coefficient. Results The automated DCAT planning tool performed significantly better in terms of all investigated metrics ( p < 0.05), in particular healthy brain sparing (V 10Gy : median 3.2 cm 3 vs. 4.9 cm 3 ), gradient indices (median 5.99 vs. 7.17) and number of monitor units (median 4569 vs. 5840 MU). Differences in conformity indices were minimal (median 0.75 vs. 0.73) but still significant ( p < 0.05). A moderate correlation between PTV sphericity and the difference of V 10Gy and V 12Gy between the two techniques was found (Spearman’s rho = 0.27 and 0.30 for V 10Gy and V 12Gy , respectively, p < 0.05). Conclusions The dedicated DCAT planning tool performed better than VMAT in terms of healthy brain sparing and treatment efficiency, in particular for nearly spherical lesions. In contrast, VMAT can be superior in cases with irregularly shaped lesions.

Background: There is limited data on the use of targeted or immunotherapy (TT/IT) in combination with single fraction stereotactic radiosurgery (SRS) in patients with melanoma brain metastasis (MBM). Therefore, we analyzed the outcome and toxicity of SRS alone compared to SRS in combination with TT/IT. Methods: Patients with MBM treated with single session SRS at our department between 2014 and 2017 with a minimum follow-up of 3 months after first SRS were included. The primary endpoint of this study was local control (LC). Secondary endpoints were distant intracranial control, radiation necrosis-free survival (RNFS), and overall survival (OS). The local/ distant intracranial control rates, RNFS and OS were analyzed using the Kaplan-Meier method. The log-rank test was used to test differences between groups. Cox proportional hazard model was performed for univariate continuous variables and multivariate analyses. Results: Twenty-eight patients (17 male and 11 female) with 52 SRS-lesions were included. The median follow-up was 19 months (range 14-24 months) after first SRS. Thirty-six lesions (69.2%) were treated with TT/IT simultaneously (4 weeks before and 4 weeks after SRS), while 16 lesions (30.8%) were treated with SRS alone or with sequential TT/ IT. The 1-year local control rate was 100 and 83.3% for SRS with TT/IT and SRS alone (p = 0.023), respectively. The estimated 1-year RNFS was 90.0 and 82.1% for SRS in combination with TT/IT and SRS alone (p = 0.935). The distant intracranial control rate after 1 year was 47.7 and 50% for SRS in combination with TT/IT and SRS alone (p = 0.933). On univariate analysis, the diagnosis-specific Graded Prognostic Assessment including the BRAF status (Melanoma-molGPA) was associated with a significantly improved LC. Neither gender nor SRS-PTV margin had a prognostic impact on LC. V10 and V12 were significantly associated with RNFS (p < 0.001 and p = 0.004). Conclusion: SRS with simultaneous TT/IT significantly improved LC with no significant difference in radiation necrosis rate. The therapy combination appears to be effective and safe. However, prospective studies on SRS with simultaneous TT/IT are necessary and ongoing. Trial registration: The institutional review board approved this analysis on 10th of February 2015 and all patients signed informed consent (UE nr. 128-14).

Background: In recent years, structured reporting has been shown to be beneficial with regard to report completeness and clinical decision-making as compared to free-text reports (FTR). However, the impact of structured reporting on reporting efficiency has not been thoroughly evaluted yet. The aim of this study was to compare reporting times and report quality of structured reports (SR) to conventional free-text reports of dualenergy x-ray absorptiometry exams (DXA). Methods: FTRs and SRs of DXA were retrospectively generated by 2 radiology residents and 2 final-year medical students. Time was measured from the first view of the exam until the report was saved. A random sample of DXA reports was selected and sent to 2 referring physicians for further evaluation of report quality. Results: A total of 104 DXA reports (both FTRs and SRs) were generated and 48 randomly selected reports were evaluated by referring physicians. Reporting times were shorter for SRs in both radiology residents and medical students with median reporting times of 2.7 min (residents: 2.7, medical students: 2.7) for SRs and 6.1 min (residents: 5.0, medical students: 7.5) for FTRs. Information extraction was perceived to be significantly easier from SRs vs FTRs (P < 0.001). SRs were rated to answer the clinical question significantly better than FTRs (P < 0.007). Overall report quality was rated significantly higher for SRs compared to FTRs (P < 0.001) with 96% of SRs vs 79% of FTRs receiving high or very high-quality ratings. All readers except for one resident preferred structured reporting over free-text reporting and both referring clinicians preferred SRs over FTRs for DXA. Conclusions: Template-based structured reporting of DXA might lead to shorter reporting times and increased report quality.

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Background Multifocal manifestation of high-grade glioma is a rare disease with very unfavourable prognosis. The pathogenesis of multifocal glioma and pathophysiological differences to unifocal glioma are not fully understood. The optimal treatment of patients suffering from multifocal high-grade glioma is not defined in the current guidelines, therefore individual case series may be helpful as guidance for clinical decision-making. Methods Patients with multifocal high-grade glioma treated with conventionally fractionated radiation therapy (RT) in our institution with or without concomitant chemotherapy between April 2011 and April 2019 were retrospectively analysed. Multifocality was neuroradiologically assessed and defined as at least two independent contrast-enhancing foci in the MRI T1 contrast-enhanced sequence. IDH mutational status and MGMT methylation status were assessed from histopathology records. GTV, PTV as well as the V30Gy, V45Gy and D2% volumes of the brain were analysed. Overall and progression-free survival were calculated from the diagnosis until death and from start of radiation therapy until diagnosis of progression of disease in MRI for all patients. Results 20 multifocal glioma cases (18 IDH wild-type glioblastoma cases, one diffuse astrocytic glioma, IDH wild-type case with molecular features of glioblastoma and one anaplastic astrocytoma, IDH wild-type case) were included into the analysis. Resection was performed in two cases and stereotactic biopsy only in 18 cases before the start of radiation therapy. At the start of radiation therapy patients were 61 years old in median (range 42–84 years). Histopathological examination showed IDH wild-type in all cases and MGMT promotor methylation in 11 cases (55%). Prescription schedules were 60 Gy (2 Gy × 30), 59.4 Gy (1.8 Gy × 33), 55 Gy (2.2 Gy × 25) and 50 Gy (2.5 Gy × 20) in 15, three, one and one cases, respectively. Concomitant temozolomide chemotherapy was applied in 16 cases, combined temozolomide/lomustine chemotherapy was applied in one case and concomitant bevacizumab therapy in one case. Median number of GTVs was three. Median volume of the sum of the GTVs was 26 cm3. Median volume of the PTV was 425.7 cm3 and median PTV to brain ratio 32.8 percent. Median D2% of the brain was 61.5 Gy (range 51.2–62.7) and median V30Gy and V45 of the brain were 59.9 percent (range 33–79.7) and 40.7 percent (range 14.9–64.1), respectively. Median survival was eight months (95% KI 3.6–12.4 months) and median progression free survival after initiation of RT five months (95% CI 2.8–7.2 months). Grade 2 toxicities were detected in eight cases and grade 3 toxicities in four cases consisting of increasing edema in three cases and one new-onset seizure. One grade 4 toxicity was detected, which was febrile neutropenia related to concomitant chemotherapy. Conclusion Conventionally fractionated RT with concomitant chemotherapy could safely be applied in multifocal high-grade glioma in this case series despite large irradiation treatment fields.

We conclude that tumor infiltration of the hippocampus has an impact on neurocognitive function. However, treatment with radiotherapy seems to have less influence on cognitive outcome than expected.

BackgroundRadiation delivery for malignant brain tumors is gradually becoming more precise. Particularly the possibilities of sparing adjacent normal structures such as the hippocampus are increasing. To determine its radiation exposure more exactly, the equivalent uniform dose (EUD) of the hippocampus was compared with further treatment parameters. This way sparing options could be found.MethodsFrom the database of the University hospital of Munich 61 glioblastoma patients were selected who received primary radiotherapy in 2011. General data about the etiology, treatment course, survival of the patients and dose parameters were retrieved.ResultsIn a linear regression analysis the side of the tumor (left hippocampus: p < 0.001/right hippocampus: p = 0.009) and its temporal location (left hippocampus: p = 0.015/right hippocampus: p = 0.033) were identified as factors with a significant influence on the EUD of the respective hippocampus. Besides this, the size of the planning target volume (PTV) and the EUD of the hippocampus correlated significantly (p = 0.027; Pearson correlation = 0.291). The median PTV size of the tumor in the right hemisphere was 386.1 ml (range 131.2–910.7 ml), and in the left hemisphere 291.3 ml (range 146.0–588.9 ml) (Kruskal–Wallis test: p = 0.048). A dose quartile analysis showed that 31 patients had a high dose exposure of the hippocampus on one side while having a moderate dose exposure in the other side.ConclusionsThe radiation exposure of the respective hippocampus is dependent on the side where the tumor is located as well as on whether it is temporally located. The exposure of the contralateral hippocampus is further dependent on multiple additional factors – nevertheless a reasonable protection seems to be possible in about half of all cases.

Background Single-isocenter dynamic conformal arc (SIDCA) therapy is a technically efficient way of delivering stereotactic radiosurgery (SRS) to multiple metastases simultaneously. This study reports on the safety and feasibility of linear accelerator (LINAC) based SRS with SIDCA for patients with multiple brain metastases. Methods All patients who received SRS with this technique between November 2017 and June 2019 within a prospective registry trial were included. The patients were irradiated with a dedicated planning tool for multiple brain metastases using a LINAC with a 5 mm multileaf collimator. Follow-up was performed every 3 months, including clinical and radiological examination with cranial magnetic resonance imaging (MRI). These early data were analyzed using descriptive statistics and the Kaplan–Meier method. Results A total of 65 patients with 254 lesions (range 2–12) were included in this analysis. Median beam-on time was 23 min. The median follow-up at the time of analysis was 13 months (95% CI 11.1–14.9). Median overall survival and median intracranial progression-free survival was 15 months (95% CI 7.7–22.3) and 7 months (95% CI 3.9–10.0), respectively. Intracranial and local control after 1 year was 64.6 and 97.5%, respectively. During follow-up, CTCAE grade I adverse effects (AE) were experienced by 29 patients (44.6%; 18 of them therapy related, 27.7%), CTCAE grade II AEs by four patients (6.2%; one of them therapy related, 1.5%), and CTCAE grade III by three patients (4.6%; none of them therapy related). Two lesions (0.8%) in two patients (3.1%) were histopathologically proven to be radiation necrosis. Conclusion Simultaneous SRS using SIDCA seems to be a feasible and safe treatment for patients with multiple brain metastases.