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1.
Cancers (Basel) ; 16(10)2024 May 15.
Article in English | MEDLINE | ID: mdl-38791956

ABSTRACT

The overexpression of somatostatin receptor type 2 (SSTR2) is a property of various tumor types. Hybrid imaging utilizing [68Ga]1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra-acetic acid (DOTA) may improve the differentiation between tumor and healthy tissue. We conducted an experimental study on 47 anonymized patient cases including 30 meningiomas, 12 PitNET and 5 SBPGL. Four independent observers were instructed to contour the macroscopic tumor volume on planning MRI and then reassess their volumes with the additional information from DOTA-PET/CT. The conformity between observers and reference volumes was assessed. In total, 46 cases (97.9%) were DOTA-avid and included in the final analysis. In eight cases, PET/CT additional tumor volume was identified that was not detected by MRI; these PET/CT findings were potentially critical for the treatment plan in four cases. For meningiomas, the interobserver and observer to reference volume conformity indices were higher with PET/CT. For PitNET, the volumes had higher conformity between observers with MRI. With regard to SBGDL, no significant trend towards conformity with the addition of PET/CT information was observed. DOTA PET/CT supports accurate tumor recognition in meningioma and PitNET and is recommended in SSTR2-expressing tumors planned for treatment with highly conformal radiation.

2.
Int J Radiat Oncol Biol Phys ; 118(5): 1206-1216, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38244874

ABSTRACT

PURPOSE: Intracerebral radiation-induced contrast enhancement (RICE) can occur after photon as well as proton beam therapy (PBT). This study evaluated the incidence, characteristics, and risk factors of RICE after PBT delivered to, or in direct proximity to, the brain and its effect on health-related quality of life (HRQoL). METHODS AND MATERIALS: Four hundred twenty-one patients treated with pencil beam scanning PBT between 2017 and 2021 were included. Follow-up included clinical evaluation and contrast-enhanced magnetic resonance imaging at 3, 6, and 12 months after treatment completion and annually thereafter. RICE was graded according to Common Terminology Criteria for Adverse Events version 4, and HRQoL parameters were assessed via European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-C30 questionnaires. RESULTS: The median follow-up was 24 months (range, 6-54), and median dose to 1% relative volume of noninvolved central nervous system (D1%CNS) was 54.3 Gy relative biologic effectiveness (RBE; range, 30-76 Gy RBE). The cumulative RICE incidence was 15% (n = 63), of which 10.5% (n = 44) were grade 1, 3.1% (n = 13) were grade 2, and 1.4% (n = 6) were grade 3. No grade 4 or 5 events were observed. Twenty-six of 63 RICE (41.3%) had resolved at the latest follow-up. The median onset after PBT and duration of RICE in patients in whom the lesions resolved were 11.8 and 9.0 months, respectively. On multivariable analysis, D1%CNS > 57.6 Gy RBE, previous in-field radiation, and diabetes mellitus were identified as significant risk factors for RICE development. Previous radiation was the only factor influencing the risk of symptomatic RICE. After PBT, general HRQoL parameters were not compromised. In a matched cohort analysis of 54/50 patients with and without RICE, no differences in global health score or functional and symptom scales were seen. CONCLUSIONS: The overall incidence of clinically relevant RICE after PBT is very low and has no significant negative effect on long-term patient QoL.


Subject(s)
Proton Therapy , Radiation Injuries , Skull Base Neoplasms , Humans , Proton Therapy/adverse effects , Proton Therapy/methods , Skull Base Neoplasms/diagnostic imaging , Skull Base Neoplasms/radiotherapy , Quality of Life , Radiation Injuries/pathology , Radiotherapy Dosage , Brain/radiation effects
3.
Cancers (Basel) ; 15(7)2023 Mar 31.
Article in English | MEDLINE | ID: mdl-37046752

ABSTRACT

BACKGROUND: Skull base chordomas are radio-resistant tumors that require high-dose, high-precision radiotherapy, as can be delivered by particle therapy (protons and carbon ions). We performed a first clinical outcome analysis of particle therapy based on the initial 4-years of operation. METHODS: Between August 2017 and October 2021, 44 patients were treated with proton (89%) or carbon ion therapy (11%). Prior gross total resection had been performed in 21% of lesions, subtotal resection in 57%, biopsy in 12% and decompression in 10%. The average prescription dose was 75.2 Gy RBE in 37 fractions for protons and 66 Gy RBE in 22 fractions for carbon ions. RESULTS: At a median follow-up of 34.3 months (range: 1-55), 2-, and 3-year actuarial local control rates were 95.5% and 90.9%, respectively. The 2-, and 3-year overall and progression-free survival rates were 97.7%, 93.2%, 95.5% and 90.9%, respectively. The tumor volume at the time of particle therapy was highly predictive of local failure (p < 0.01), and currently, there is 100% local control in patients with tumors < 49 cc. No grade ≥3 toxicities were observed. There was no significant difference in outcome or side effect profile seen for proton versus carbon ion therapy. Five patients (11.4%) experienced transient grade ≤2 radiation-induced brain changes. CONCLUSIONS: The first analysis suggests the safety and efficacy of proton and carbon ion therapy at our center. The excellent control of small to mid-size chordomas underlines the effectiveness of particle therapy and importance of upfront maximum debulking of large lesions.

4.
Strahlenther Onkol ; 199(4): 404-411, 2023 04.
Article in English | MEDLINE | ID: mdl-36471065

ABSTRACT

BACKGROUND: In addition to local tumor control, the aim of any curative radio-oncological treatment is to maintain quality of life. In the treatment of patients with meningioma with a close relationship to optical structures, the preservation of visual performance is a particular challenge. Use of proton therapy can reduce the dose burden to organs at risk immediately adjacent to the tumor. The aim of this study was to score the subjective assessment of visual performance in patients with meningioma involving the optical structures before and after proton therapy. METHODS: All proton-treated patients with meningioma WHO I whose planning target volumes (PTV) included parts of the optic nerve and/or chiasm were included in this study. Subjective assessment of visual performance was evaluated using the Visual Disorder Scale (VDS) of the EORTC QLQ-BN20 questionnaire. This scale includes values from 0 to 100, whereby high values reflect a high degree of subjective symptom burden and thus subjective visual impairment. The visual acuity in externally performed eye tests at baseline and follow-ups (FU) was also evaluated. The timepoints for testing were before the start of radiotherapy, at the end of treatment, and 3, 6, 12, and 24 months in FU (times t1-t6). All patients with at least the first annual postradiation FU at the time of the evaluation were included. The correlation between VDS changes and potential influencing factors such as previous therapies, dosimetric data, initial tumor volume, and tumor shrinkage 1 year after treatment was assessed. RESULTS: A total of 56 patients (45 female/11 male) aged 24-82 years (mean ± SD = 53.9 ± 13.3) treated between March 2017 and September 2019 were included in the analysis. The prescription dose was 54.0 Gy (RBE) with active scanned proton therapy. The mean/D2% dose ± SD for the optic chiasm and ipsilateral optic nerve was 43.4 ± 8.9 Gy (RBE)/49.9 ± 7.1 Gy (RBE) and 35.6 ± 11.7 Gy (RBE)/51.7 ± 4.8 Gy (RBE); the mean/D2% dose ± SD of the contralateral optic nerve was 18.8 ± 12.1 Gy (RBE)/42.4 ± 14.6 Gy (RBE), respectively. A total of 302 data collections were available (t1/t2/t3/t4/t5/t6: n = 56/56/48/56/52/34). Median observation time was 23.6 months. Mean symptom burden decreased over time (mean VDS: t1 29.8 ± 27.9; t2 25.0 ± 27.9; t3 21.8 ± 26.0; t4 22.2 ± 26.0; t5 21.4 ± 26.2; t6 17.3 ± 23.6) with statistically significant improvement at 3­ and 6­month FU as well as 1 year after proton therapy (p = 0.0205; p = 0.0187; p = 0.0054). Objective eye tests available in 41/52 patients confirm the trend towards improved visual acuity (97.5% stable/improved until 24-month FU). However, no potential predictor for VDS changes was revealed. CONCLUSION: Proton treatment of patients with meningioma WHO I with involvement of optical structures does not impair subjective visual performance. After treatment, there is a significant improvement in perceived visual performance.


Subject(s)
Meningeal Neoplasms , Meningioma , Proton Therapy , Humans , Male , Female , Meningioma/radiotherapy , Meningioma/etiology , Meningioma/pathology , Proton Therapy/adverse effects , Protons , Quality of Life , Meningeal Neoplasms/radiotherapy , Meningeal Neoplasms/etiology , Meningeal Neoplasms/pathology , World Health Organization , Radiotherapy Planning, Computer-Assisted
5.
Strahlenther Onkol ; 199(4): 396-403, 2023 04.
Article in English | MEDLINE | ID: mdl-36260109

ABSTRACT

PURPOSE: Overexpression of the somatostatin receptor (SSTR) has led to adoption of SSTR PET/CT for diagnosis and radiotherapy planning in meningioma, but data on SSTR expression during follow-up remain scarce. We investigated PET/CT quantifiers of SSTR tracers in WHO grade I meningioma following fractionated proton beam therapy (PBT) compared to standard response assessment with MRI. METHODS: Twenty-two patients diagnosed with low-grade meningioma treated by PBT were included. Follow-up included clinical visits, MRI, and [68Ga]Ga-DOTATOC PET/CT scans. Radiologic tumor response, MRI and PET volume (VMRI and VPET), maximum and mean standardied uptake value (SUVmax/SUVmean), total lesion activity (TLA), and heterogeneity index (HI) were evaluated. RESULTS: Median follow-up was 35.3 months (range: 6.4-47.9). Nineteen patients (86.4%, p = 0.0009) showed a decrease of SUVmax between baseline and first follow-up PET/CT (median: -24%, range: -53% to +89%) and in 81.8% of all cases, the SUVmax, SUVmean, and TLA at last follow-up were eventually lower than at baseline (p = 0.0043). Ambiguous trends without significance between the timepoints analyzed were observed for VPET. HI increased between baseline and last follow-up in 75% of cases (p = 0.024). All patients remained radiologically and clinically stable. Median VMRI decreased by -9.3% (range 0-32.5%, p < 0.0001) between baseline and last follow-up. CONCLUSION: PET/CT in follow-up of irradiated meningioma showed an early trend towards decreased binding of SSTR-specific tracers following radiation and MRI demonstrated consistently stable or decreasing tumor volume. Translational research is needed to clarify the underlying biology of the subsequent increase in SSTR PET quantifiers.


Subject(s)
Meningeal Neoplasms , Meningioma , Organometallic Compounds , Proton Therapy , Humans , Positron Emission Tomography Computed Tomography/methods , Meningioma/diagnostic imaging , Meningioma/radiotherapy , Receptors, Somatostatin/metabolism , Follow-Up Studies , Magnetic Resonance Imaging , Meningeal Neoplasms/diagnostic imaging , Meningeal Neoplasms/radiotherapy , Positron-Emission Tomography
6.
Int J Radiat Oncol Biol Phys ; 115(5): 1102-1114, 2023 04 01.
Article in English | MEDLINE | ID: mdl-36372610

ABSTRACT

PURPOSE: Proton beam radiation therapy reduces dose to healthy brain tissue and thereby decreases the risk of treatment-related decline in neurocognition. Considering the paucity of prospective data, this study aimed to evaluate neurocognitive performance in an adult patient population with intracranial tumors. METHODS AND MATERIALS: Between 2017 and 2021, patients enrolled in the MedAustron registry study and irradiated for intracranial tumors were eligible for neurocognitive assessment. Patients with available 1-year follow-up data were included in the analysis. The test battery consisted of a variety of standardized tests commonly used in European Organization for Research and Treatment of Cancer trials. Scores were transformed into z scores to account for demographic effects, and clinically relevant change was defined as a change of ≥1.5 standard deviations. Binary logistic regression analysis and the χ2 test were conducted for clinical parameters and dosimetric hippocampal parameters to evaluate the relationship with overall cognitive decline and changes in memory. RESULTS: One hundred twenty-three patients with mostly nonprogressive, extra-axial tumors and neurocognitive assessment at baseline and treatment end as well as 3, 6, and 12 months after completion of proton beam radiation therapy were analyzed. Overall, 7 test scores revealed stability in neurocognitive function with minimal positive changes 1 year after treatment completion (statistically significant in 6 of 7 tests), whereas the majority had no or minimal baseline deficits. At 1-year follow-up, 89.4% of all patients remained stable in their overall cognitive functioning without clinically relevant deterioration in 2 or more tests. None of them showed disease progression. Of the patients, 8.1% presented with radiation-induced brain lesions and exhibited a higher percentage of overall cognitive deterioration without reaching statistical significance. Multivariate binary logistic regression analysis revealed higher age at baseline as the only independent parameter to be associated with an overall clinically relevant cognitive decline. There was no significant correlation of hippocampal doses and memory functioning. CONCLUSIONS: One year after proton therapy, we observed preservation of cognitive functioning in the vast majority of our patients with intracranial tumors.


Subject(s)
Brain Neoplasms , Proton Therapy , Adult , Humans , Proton Therapy/adverse effects , Prospective Studies , Brain Neoplasms/pathology , Brain/pathology , Cognition/radiation effects , Neuropsychological Tests
7.
Radiother Oncol ; 177: 21-32, 2022 12.
Article in English | MEDLINE | ID: mdl-36252635

ABSTRACT

PURPOSE: To systematically review all dosimetric studies investigating the impact of deep inspiration breath hold (DIBH) compared with free breathing (FB) in mediastinal lymphoma patients treated with proton therapy as compared to IMRT (intensity-modulated radiation therapy)-DIBH. MATERIALS AND METHODS: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline using the PubMed database to identify studies of mediastinal lymphoma patients with dosimetric comparisons of proton-FB and/or proton-DIBH with IMRT-DIBH. Parameters included mean heart (MHD), lung (MLD), and breast (MBD) doses, among other parameters. Case reports were excluded. Absolute differences in mean doses > 1 Gy between comparators were considered to be clinically meaningful. RESULTS: As of April 2021, eight studies fit these criteria (n = 8), with the following comparisons: proton-FB vs IMRT-DIBH (n = 5), proton-DIBH vs proton-FB (n = 5), and proton-DIBH vs IMRT-DIBH (n = 8). When comparing proton-FB with IMRT-DIBH in 5 studies, MHD was reduced with proton-FB in 2 studies, was similar (<1 Gy difference) in 2 studies, and increased in 1 study. On the other hand, MLD and MBD were reduced with proton-FB in 3 and 4 studies, respectively. When comparing proton-DIBH with proton-FB, MHD and MLD were reduced with proton DIBH in 4 and 3 studies, respectively, while MBD remained similar. Compared with IMRT-DIBH in 8 studies, proton-DIBH reduced the MHD in 7 studies and was similar in 1 study. Furthermore, MLD and MBD were reduced with proton-DIBH in 8 and 6 studies respectively. Integral dose was similar between proton-FB and proton-DIBH, and both were substantially lower than IMRT-DIBH. CONCLUSION: Accounting for heart, lung, breast, and integral dose, proton therapy (FB or DIBH) was superior to IMRT-DIBH. Proton-DIBH can lower dose to the lungs and heart even further compared with proton-FB, depending on disease location in the mediastinum, and organ-sparing and target coverage priorities.


Subject(s)
Lymphoma , Mediastinal Neoplasms , Proton Therapy , Unilateral Breast Neoplasms , Humans , Breath Holding , Organs at Risk , Radiotherapy Planning, Computer-Assisted , Protons , Mediastinal Neoplasms/radiotherapy , Heart , Radiotherapy Dosage , Unilateral Breast Neoplasms/radiotherapy
8.
Eur J Cancer Care (Engl) ; 31(6): e13737, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36254927

ABSTRACT

OBJECTIVE: End of life communication (EOLC) is generally regarded as a challenging aspect of the medical profession, with high influences of culture, the physician's experience and awareness. The aim of the current study was to assess the awareness of Austrian oncologists towards EOLC practices in their daily clinical routine and to identify limiting and supporting factors of these conversations. METHODS: Overall, 45 oncologists participated in the assessment in this cross-sectional, mixed-method design using semi-structured interviews and questionnaire. RESULTS: Themes that occurred during the interviews included the initiation of EOLC, EOLC in practice, strategies for EOLC, limiting and supporting factors and consequences of EOLC. There were several variations in the EOLC approach, that is, the use of time frames, timing, initiation and the amount of details given to the patient. CONCLUSION: Oncologists agreed that EOLC is important in their daily clinical routine and for their patients. Nevertheless, there seems to be an underlying variation in approaches chosen by Austrian oncologists. This variation might be reduced by asking patients about their information preferences in advance and by routine implementation of communication guidelines, nomograms and prognostic calculators to reduce uncertainty.


Subject(s)
Courage , Oncologists , Terminal Care , Humans , Terminal Care/methods , Cross-Sectional Studies , Attitude of Health Personnel , Communication , Death
9.
Front Oncol ; 12: 962697, 2022.
Article in English | MEDLINE | ID: mdl-36052240

ABSTRACT

Aim: Data on the safety of moderately hypofractionated proton beam therapy (PBT) are limited. The aim of this study is to compare the acute toxicity and early quality of life (QoL) outcomes of normofractionated (nPBT) and hypofractionated PBT (hPBT). Material and methods: We prospectively compared acute toxicity and QoL between patients treated with nPBT (dose per fraction 1.8-2.3 Gy, n = 90) and hPBT (dose per fraction 2.5-3.1 Gy, n = 49) in following locations: head and neck (H&N, n = 85), abdomen and pelvis (A&P, n = 43), and other soft tissue (ST, n = 11). The toxicities were grouped into categories-mucosal, skin, and other sites-and evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4.03 at baseline, treatment completion, and 3 months after PBT completion. QoL was evaluated with the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 scale for all locations and additionally with EORTC QLQ-HN35 for H&N patients. Results: Overall, the highest toxicity grades of G0, G1, G2, and G3 were observed in 7 (5%), 40 (28.8%), 78 (56.1%), and 15 (10.8%) patients, respectively. According to organ and site, no statistically significant differences were detected in the majority of toxicity comparisons (66.7%). For A&P, hPBT showed a more favorable toxicity profile as compared to nPBT with a higher frequency of G0 and G1 and a lower frequency of G2 and G3 events (p = 0.04), more patients with improvement (95.7% vs 70%, p = 0.023), and full resolution of toxicities (87% vs 50%, p = 0.008). Skin toxicity was unanimously milder for hPBT compared to nPBT in A&P and ST locations (p = 0.018 and p = 0.025, respectively). No significant differences in QoL were observed in 97% of comparisons for QLQ-C30 scale except for loss of appetite in H&N patients (+33.3 for nPBT and 0 for hPBT, p = 0.02) and role functioning for A&P patients (0 for nPBT vs +16.7 hPBT, p = 0.003). For QLQ-HN35, 97.9% of comparisons did not reveal significant differences, with pain as the only scale varying between the groups (-8.33 vs -25, p = 0.016). Conclusion: Hypofractionated proton therapy offers non-inferior early safety and QoL as compared to normofractionated irradiation and warrants further clinical investigation.

10.
Cancers (Basel) ; 14(18)2022 Sep 13.
Article in English | MEDLINE | ID: mdl-36139596

ABSTRACT

Aim: The aim of this study was to assess the effects of including somatostatin receptor agonist (SSTR) PET imaging in meningioma radiotherapy planning by means of changes in inter-observer variability (IOV). Further, the possibility of using threshold-based delineation approaches for semiautomatic tumor volume definition was assessed. Patients and Methods: Sixteen patients with meningioma undergoing fractionated radiotherapy were delineated by five radiation oncologists. IOV was calculated by comparing each delineation to a consensus delineation, based on the simultaneous truth and performance level estimation (STAPLE) algorithm. The consensus delineation was used to adapt a threshold-based delineation, based on a maximization of the mean Dice coefficient. To test the threshold-based approach, seven patients with SSTR-positive meningioma were additionally evaluated as a validation group. Results: The average Dice coefficients for delineations based on MRI alone was 0.84 ± 0.12. For delineation based on MRI + PET, a significantly higher dice coefficient of 0.87 ± 0.08 was found (p < 0.001). The Hausdorff distance decreased from 10.96 ± 11.98 mm to 8.83 ± 12.21 mm (p < 0.001) when adding PET for the lesion delineation. The best threshold value for a threshold-based delineation was found to be 14.0% of the SUVmax, with an average Dice coefficient of 0.50 ± 0.19 compared to the consensus delineation. In the validation cohort, a Dice coefficient of 0.56 ± 0.29 and a Hausdorff coefficient of 27.15 ± 21.54 mm were found for the threshold-based approach. Conclusions: SSTR-PET added to standard imaging with CT and MRI reduces the IOV in radiotherapy planning for patients with meningioma. When using a threshold-based approach for PET-based delineation of meningioma, a relatively low threshold of 14.0% of the SUVmax was found to provide the best agreement with a consensus delineation.

11.
Front Neurosci ; 16: 810645, 2022.
Article in English | MEDLINE | ID: mdl-35401087

ABSTRACT

Neuroendocrine tumors (NETs) are rare neoplasms predominantly arising in the gastrointestinal-tract or the lungs of adults. To date, only ten cases of primary central nervous system (CNS) NETs have been reported, with just three of them describing a neuroendocrine carcinoma (NECA) and none occurring in a child. We report on a previously healthy 5-year-old boy, who presented with headaches, nausea and vomiting, and was diagnosed with a left cerebellar solid mass with a cystic component. After gross-total resection, histology revealed a neuroendocrine carcinoma. Molecular analysis of the tumor tissue showed a KRAS-splice-site mutation (c451-3C > T). The KRAS-mutation was discovered to be a maternal germline mutation, previously described as likely benign. After extensive search for an extracranial primary tumor, including Ga-68 DOTANOC-PET-CT, the diagnosis of a primary CNS NECA was established, and proton irradiation was performed. Unfortunately, the patient developed an in-field recurrence just 5 weeks after the end of radiotherapy. The tumor was re-resected with vital tumor tissue. Six cycles of chemotherapy were initiated, consisting of cisplatin, carboplatin, etoposide and ifosfamide. The patient remains disease free 22 months after the end of treatment, supporting the beneficial effect of platinum- and etoposide-based chemotherapy for this tumor entity.

12.
Z Med Phys ; 32(1): 39-51, 2022 Feb.
Article in English | MEDLINE | ID: mdl-33640219

ABSTRACT

In December 2016 the clinical operation has started at the particle therapy centre MedAustron, Wiener Neustadt, Austria. Different commercial immobilisation devices are used for head patients. These immobilisation devices are a combination of table tops (Qfix BoS™ Headframe, Elekta HeadStep™), pillows (BoS™ Standard pillow, Moldcare®, HeadStep™ pillow) and thermoplastic masks (Klarity Green™, Qfix Fibreplast™, HeadStep™ iCAST double). For each patient image-guided radiotherapy (IGRT) is performed by acquiring orthogonal X-ray imaging and 2D3D registration and the application of the resulting 6-degree of freedom (DOF) position correction on the robotic couch. The inter- and intrafraction displacement of 101 adult head patients and 27 paediatric sedated head patients were evaluated and compared among each other regarding reproducibility during the entire treatment and stability during each fraction. For the comparison, statistical methods (Shapiro-Wilk test, Mann-Whitney U-test) were applied on the position corrections as well as on the position verifications. The actual planning target volume margins of 3mm (adults) and 2mm (children) were evaluated by applying the van Herk formula on the intrafraction displacement results and performing treatment plan robustness simulations of twelve different translational offset scenarios including a HU uncertainty of 3.5%. Statistically significant differences between the immobilisation devices were found, but they turned out to be clinically irrelevant. The margin calculation for adult head patients resulted in 0.8mm (lateral), 1.2mm (cranio-caudal) and 0.6mm (anterior-posterior), and for paediatric head patients under anaesthesia in 0.8mm (lateral), 0.5mm (cranio-caudal) and 0.9mm (anterior-posterior). Based on these values, robustness evaluations of selected adult head patients and sedated children showed the validity of the currently used PTV margins.


Subject(s)
Immobilization , Radiotherapy, Image-Guided , Child , Humans , Immobilization/methods , Masks , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Image-Guided/methods , Reproducibility of Results
13.
Z Med Phys ; 32(2): 218-227, 2022 May.
Article in English | MEDLINE | ID: mdl-34920940

ABSTRACT

A magnetic resonance imaging (MRI) sequence independent deep learning technique was developed and validated to generate synthetic computed tomography (sCT) scans for MR guided proton therapy. 47 meningioma patients previously undergoing proton therapy based on pencil beam scanning were divided into training (33), validation (6), and test (8) cohorts. T1, T2, and contrast enhanced T1 (T1CM) MRI sequences were used in combination with the planning CT (pCT) data to train a 3D U-Net architecture with ResNet-Blocks. A hyperparameter search was performed including two loss functions, two group sizes of normalisation, and depth of the network. Training outcome was compared between models trained for each individual MRI sequence and for all sequences combined. The performance was evaluated based on a metric and dosimetric analysis as well as spot difference maps. Furthermore, the influence of immobilisation masks that are not visible on MRIs was investigated. Based on the hyperparameter search, the final model was trained with fixed features per group for the group normalisation, six down-convolution steps, an input size of 128×192×192, and feature loss. For the test dataset for body/bone the mean absolute error (MAE) values were on average 79.8/216.3Houndsfield unit (HU) when trained using T1 images, 71.1/186.1HU for T2, and 82.9/236.4HU for T1CM. The structural similarity metric (SSIM) ranged from 0.95 to 0.98 for all sequences. The investigated dose parameters of the target structures agreed within 1% between original proton treatment plans and plans recalculated on sCTs. The spot difference maps had peaks at ±0.2cm and for 98% of all spots the difference was less than 1cm. A novel MRI sequence independent sCT generator was developed, which suggests that the training phase of neural networks can be disengaged from specific MRI acquisition protocols. In contrast to previous studies, the patient cohort consisted exclusively of actual proton therapy patients (i.e. "real-world data").


Subject(s)
Proton Therapy , Head , Humans , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Neural Networks, Computer , Proton Therapy/methods , Radiotherapy Planning, Computer-Assisted/methods , Tomography, X-Ray Computed
14.
Cancers (Basel) ; 13(18)2021 Sep 20.
Article in English | MEDLINE | ID: mdl-34572933

ABSTRACT

Grade I meningioma is the most common intracranial tumor in adults. The standard imaging for its radiation treatment planning is MRI, and [68Ga]1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-conjugated PET/CT can further improve delineation. We investigated the impact of PET/CT on interobserver variability in identifying the tumor in 30 anonymized patients. Four radiation oncologists independently contoured residual tumor volume, first using only MRI and subsequently with the addition of PET/CT. Conformity indices (CIs) were calculated between common volumes, observer pairs and compared to the volumes previously used. Overall, 29/30 tumors (96.6%) showed [68Ga]Ga-DOTA avidity. With help of PET/CT, the participants identified six cases with new lesions not recognized in MRI, including two where new findings would critically alter the target volume used for radiation. The PET/CT-aided series demonstrated superior conformity, as compared to MRI-only between observer pairs (median CI = 0.58 vs. 0.49; p = 0.002), common volumes (CI = 0.34; vs. 0.29; p = 0.002) and matched better the reference volumes actually used for patient treatment (CI = 0.55 vs. 0.39; p = 0.008). Cis in the PET/CT-aided series were lower for meningiomas outside of the skull base (0.2 vs. 0.44; p = 0.03). We conclude that SSTR2 receptor-targeted PET/CT is a valuable tool for planning particle therapy of incompletely resected meningioma. It serves both as a workup procedure and an aid for delineation process that reduces the likelihood of marginal misses.

15.
Curr Oncol Rep ; 22(9): 93, 2020 07 10.
Article in English | MEDLINE | ID: mdl-32651730

ABSTRACT

PURPOSE OF REVIEW: The incidence of glioblastoma multiforme (GBM) increases with age; more than half of newly diagnosed patients are older than 65 years. Due to age-dependent decreasing organ functions, comorbidities, functional decline, and increasing risk of social isolation, not all patients are able to tolerate standard therapy of GBM with 6 weeks of radiochemotherapy. RECENT FINDINGS: A set of alleviated therapies, e.g., chemotherapy or radiotherapy alone, hypofractionated radiotherapies with different total doses and variable fractionation regimens as well as hypofractionated radiotherapy with concomitant and adjuvant chemotherapy, have been evaluated during the last years. However, clinicians are still unsure which therapy would fit best to a given patient. Recently, the predictive value of comprehensive geriatric assessment regarding tolerance of chemotherapy and prediction of early mortality has been validated for older GBM patients in a retrospective trial. Thus, it appears that neuro-oncology is now ready for the prospective implementation of geriatric assessment to guide treatment planning for elderly GBM patients.


Subject(s)
Geriatric Assessment , Glioblastoma/therapy , Aged , Bevacizumab/therapeutic use , Chemoradiotherapy , Chemotherapy, Adjuvant , Dose Fractionation, Radiation , Humans , Radiation Dose Hypofractionation
16.
J Cancer Educ ; 34(4): 743-748, 2019 Aug.
Article in English | MEDLINE | ID: mdl-29687186

ABSTRACT

Medical students have to acquire theoretical knowledge, practical skills, and a personal attitude to meet the emerging needs of palliative care. The present study aimed to assess the personal attitude of Austrian medical students towards end of life communication (EOLC), as key part of palliative care. This cross-sectional, mono-institutional assessment invited all medical students at the Medical University of Vienna in 2015. The assessment was conducted web-based via questionnaire about attitudes towards EOLC. Additional socio-demographic and medical education-related parameters were collected. Overall, 743 medical students participated in the present report. Differences regarding the agreement or disagreement to several statements concerning the satisfaction of working with chronically ill patients, palliative care, and health care costs, as well as the extent of information about palliative disease, were found for age, gender, and academic years. The overall attitude towards EOLC in the present sample can be regarded as quite balanced. Nevertheless, a considerable number of medical students are still reluctant to inform patients about their incurable disease. Reservations towards palliative care as part of the health care system seem to exist. The influence of the curriculum as well as practical experiences seems to be important but needs further investigation.


Subject(s)
Attitude of Health Personnel , Curriculum/standards , Health Communication , Students, Medical/psychology , Terminal Care/organization & administration , Adolescent , Adult , Austria , Cross-Sectional Studies , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Middle Aged , Surveys and Questionnaires , Terminal Care/psychology , Young Adult
17.
BMC Med Educ ; 17(1): 100, 2017 Jun 06.
Article in English | MEDLINE | ID: mdl-28587603

ABSTRACT

BACKGROUND: Clinical decision making in oncology is based on both inter- and multidisciplinary approach. Hence teaching future doctors involved in oncology or general health practice is crucial. The aim of the Vienna Summer School on Oncology (VSSO) as an international, integrated, undergraduate oncology course is to teach medical students interdisciplinary team communication and application of treatment concepts/algorithms in a multidisciplinary setting. METHOD: The teaching is based on an inter- and multidisciplinary faculty and a multimodal education approach to address different learning styles. The participants rated their satisfaction of the program voluntarily after finishing the course according to a grading scale from one (not good) to five (very good). The learning success was assessed by a compulsory pre-VSSO and post-VSSO single choice questionnaire. RESULTS: Program organisation was rated with a mean score of 4.47 out of 5.0 (SD 0.51), composition of the program and range of topics with a mean score of 4.68 (SD 0.58) and all teachers with a mean score of 4.36 (SD 0.40) points. Student evaluation at the beginning and end of the program indicated significant knowledge acquisition -i.e., general aspects of cancer: median 8.75 points (IQR 7.5-9.4) vs.10.0 points (IQR 9.4-10.0) p = 0.005; specific aspects of cancer: median 4.87 points (IQR 3.33-5.71) vs. 8.72 points (IQR 6.78-9.49) p ≤ 0.001, respectively. CONCLUSION: Even though the participants represent a selection of students with special interest in cancer, the results of the VSSO indicate the benefit of an inter- and multidisciplinary teaching approach within an oncology module.


Subject(s)
Clinical Decision-Making/methods , Education, Medical, Undergraduate , Interdisciplinary Communication , Interdisciplinary Studies , Medical Oncology/education , Seasons , Students, Medical , Austria , Education, Medical, Undergraduate/standards , Health Services Research , Humans , Program Evaluation
18.
J Neurosurg ; 127(6): 1249-1256, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28156245

ABSTRACT

OBJECTIVE Treatment of parasagittal meningiomas is still considered a challenge in modern microsurgery. The use of microsurgical resection, radiosurgery, or a microsurgery-radiosurgery combination treatment strategy is often debated. The aim of this study was to evaluate the treatment of parasagittal meningioma and provide evidence that a multimodal approach reduces complication rates and achieves good tumor control rates. METHODS The authors retrospectively reviewed long-term follow-up data on 117 patients who had been treated for parasagittal meningiomas at their institution between 1993 and 2013. Treatment included microsurgery, Gamma Knife radiosurgery (GKRS), and radiotherapy. RESULTS The median tumor volume prior to the first microsurgical resection was largest in the microsurgery-radiosurgery combination treatment group. Invasion of the superior sagittal sinus was significantly associated with a Simpson Grade IV resection and subsequent radiosurgery treatment. The Simpson resection grade did not influence time to progression or recurrence in benign meningioma cases. Complete sinus occlusion was followed by microsurgical resection of the occluded sinus, by tumor resection without resection of the sinus, or by GKRS. Histopathology revealed WHO Grade I tumors in most patients. However, a high percentage (33%) of atypical or malignant meningiomas were diagnosed after the last microsurgical resection. The time to recurrence or progression after microsurgery was significantly longer in patients with WHO Grade I meningiomas than in those with Grade II or III meningiomas. At follow-up, tumor control rates after GKRS were 91% for presumed meningioma, 85% for benign meningioma, 71% for atypical meningioma, and 38% for malignant meningioma. CONCLUSIONS A multimodal treatment approach to parasagittal meningiomas reduces the rate of complications. Thus, microsurgery, radiotherapy, and radiosurgery are complementary treatment options. Gamma Knife radiosurgery is safe and effective in patients with meningiomas invading the superior sagittal sinus. The procedure can be part of a multimodal treatment plan or administered as a single treatment in well-selected patients.


Subject(s)
Meningeal Neoplasms/therapy , Meningioma/therapy , Adult , Aged , Aged, 80 and over , Combined Modality Therapy , Female , Humans , Male , Meningeal Neoplasms/radiotherapy , Meningeal Neoplasms/surgery , Meningioma/radiotherapy , Meningioma/surgery , Microsurgery , Middle Aged , Radiosurgery , Treatment Outcome
19.
Strahlenther Onkol ; 191(7): 549-56, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25690939

ABSTRACT

INTRODUCTION: Due to concerns about patients' wellbeing, open end-of-life communication is associated with reservation. Furthermore, sociocultural differences must be considered. The objective of this pilot study was therefore to investigate the information preferences of Austrian patients regarding cure rates and prognosis. PATIENTS AND METHODS: The information preferences of 50 advanced lung cancer patients were assessed at their first visit to the Department of Radiation Oncology, Medical University of Vienna. Preferences in terms of content (cure rates and/or prognosis) and depth of the information (additional quantitative estimates) were addressed. After the individually adapted medical consultation, patients' satisfaction with the consultation and the emotional responses to the information were evaluated. RESULTS: The majority of patients (76 %) requested information about cure rates and/or prognosis; nearly half of these (47 %) wanted additional quantitative estimates. Neither sociodemographic variables, disease characteristics, nor time since diagnosis had an impact on the information preferences. The individually adapted medical information showed no overall negative influence on the emotional responses; only patients receiving prognostic information had significantly higher distress scores after the consultation. High satisfaction with the individually adapted medical consultation was reported by 92 % of patients. CONCLUSION: Austrian physicians may offer end-of-life communication and directly ask patients about their information preferences, since patients seem able to decide whether or not prognostic information would overwhelm their emotional capacity and therefore to accept or reject the invitation. The disclosure of cure rates and/or prognosis with or without quantitative estimates-according to the patients' preferences-shows overall no negative impact on emotional reactions. The individually adapted consultation results in high patient satisfaction. Nevertheless, prognostic information may lead to higher distress.


Subject(s)
Lung Neoplasms/mortality , Lung Neoplasms/radiotherapy , Patient Education as Topic , Patient Preference , Adaptation, Psychological , Adult , Aged , Aged, 80 and over , Austria , Disease-Free Survival , Female , Humans , Lung Neoplasms/pathology , Lung Neoplasms/psychology , Male , Middle Aged , Neoplasm Staging/psychology , Palliative Care/psychology , Patient Participation/psychology , Pilot Projects , Prognosis , Quality of Life/psychology , Surveys and Questionnaires
20.
Z Med Phys ; 23(4): 279-90, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23969092

ABSTRACT

We present an evaluation of various non-rigid registration algorithms for the purpose of compensating interfractional motion of the target volume and organs at risk areas when acquiring CBCT image data prior to irradiation. Three different deformable registration (DR) methods were used: the Demons algorithm implemented in the iPlan Software (BrainLAB AG, Feldkirchen, Germany) and two custom-developed piecewise methods using either a Normalized Correlation or a Mutual Information metric (featureletNC and featureletMI). These methods were tested on data acquired using a novel purpose-built phantom for deformable registration and clinical CT/CBCT data of prostate and lung cancer patients. The Dice similarity coefficient (DSC) between manually drawn contours and the contours generated by a derived deformation field of the structures in question was compared to the result obtained with rigid registration (RR). For the phantom, the piecewise methods were slightly superior, the featureletNC for the intramodality and the featureletMI for the intermodality registrations. For the prostate cases in less than 50% of the images studied the DSC was improved over RR. Deformable registration methods improved the outcome over a rigid registration for lung cases and in the phantom study, but not in a significant way for the prostate study. A significantly superior deformation method could not be identified.


Subject(s)
Algorithms , Cone-Beam Computed Tomography/methods , Pattern Recognition, Automated/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Radiotherapy, Conformal/methods , Radiotherapy, Image-Guided/methods , Subtraction Technique , Humans , Phantoms, Imaging , Reproducibility of Results , Sensitivity and Specificity
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