Adjuvant re-irradiation vs. no early re-irradiation of resected recurrent glioblastoma: pooled comparative cohort analysis from two tertiary centers.

BACKGROUND: The optimal management strategy for recurrent glioblastoma (rGBM) remains uncertain, and the impact of re-irradiation (Re-RT) on overall survival (OS) is still a matter of debate. This study included patients who achieved gross total resection (GTR) after a second surgery after recurrence, following the GlioCave criteria. METHODS: Inclusion criteria include being 18 years or older, having histologically confirmed locally recurrent IDHwt or IDH unknown GBM, achieving MRI-proven GTR after the second surgery, having a Karnofsky performance status of at least 60% after the second surgery, having a minimum interval of 6 months between the first radiotherapy and the second surgery, and a maximum of 8 weeks from second surgery to the start of Re-RT. RESULTS: A total of 44 patients have met the inclusion criteria. The median OS after the second surgery was 14 months. All patients underwent standard treatment after initial diagnosis, including maximum safe resection, adjuvant radiochemotherapy and adjuvant chemotherapy. Re-RT did not significantly impact OS. However, MGMT promoter methylation status and a longer interval (> 12 months) between treatments were associated with better OS. Multivariate analysis revealed the MGMT status as the only significant predictor of OS. CONCLUSION: Factors such as MGMT promoter methylation status and treatment interval play crucial roles in determining patient outcomes after second surgery. Personalized treatment strategies should consider these factors to optimize the management of rGBM. Prospective research is needed to define the value of re-RT after second surgery and to inform decision making in this situation.

Hypofractionated stereotactic radiotherapy (HFSRT) versus single fraction stereotactic radiosurgery (SRS) to the resection cavity of brain metastases after surgical resection (SATURNUS): study protocol for a randomized phase III trial.

BACKGROUND: The brain is a common site for cancer metastases. In case of large and/or symptomatic brain metastases, neurosurgical resection is performed. Adjuvant radiotherapy is a standard procedure to minimize the risk of local recurrence and is increasingly performed as local stereotactic radiotherapy to the resection cavity. Both hypofractionated stereotactic radiotherapy (HFSRT) and single fraction stereotactic radiosurgery (SRS) can be applied in this case. Although adjuvant stereotactic radiotherapy to the resection cavity is widely used in clinical routine and recommended in international guidelines, the optimal fractionation scheme still remains unclear. The SATURNUS trial prospectively compares adjuvant HFSRT with SRS and seeks to detect the superiority of HFSRT over SRS in terms of local tumor control. METHODS: In this single center two-armed randomized phase III trial, adjuvant radiotherapy to the resection cavity of brain metastases with HFSRT (6 - 7 × 5 Gy prescribed to the surrounding isodose) is compared to SRS (1 × 12-20 Gy prescribed to the surrounding isodose). Patients are randomized 1:1 into the two different treatment arms. The primary endpoint of the trial is local control at the resected site at 12 months. The trial is based on the hypothesis that HFSRT is superior to SRS in terms of local tumor control. DISCUSSION: Although adjuvant stereotactic radiotherapy after resection of brain metastases is considered standard of care treatment, there is a need for further prospective research to determine the optimal fractionation scheme. To the best of our knowledge, the SATURNUS study is the only randomized phase III study comparing different regimes of postoperative stereotactic radiotherapy to the resection cavity adequately powered to detect the superiority of HFSRT regarding local control. TRIAL REGISTRATION: The study was retrospectively registered with ClinicalTrials.gov, number NCT05160818, on December 16, 2021. The trial registry record is available on  https://clinicaltrials.gov/study/NCT05160818 . The presented protocol refers to version V1.3 from March 21, 2021.

Innovative radiation oncology Together - Precise, Personalized, Human : Vision 2030 for radiotherapy & radiation oncology in Germany.

PURPOSE: Scientific and clinical achievements in radiation, medical, and surgical oncology are changing the landscape of interdisciplinary oncology. The German Society for Radiation Oncology (DEGRO) working group of young clinicians and scientists (yDEGRO) and the DEGRO representation of associate and full professors (AKRO) are aware of the essential role of radiation oncology in multidisciplinary treatment approaches. Together, yDEGRO and AKRO endorsed developing a German radiotherapy & radiation oncology vision 2030 to address future challenges in patient care, research, and education. The vision 2030 aims to identify priorities and goals for the next decade in the field of radiation oncology. METHODS: The vision development comprised three phases. During the first phase, areas of interest, objectives, and the process of vision development were defined jointly by the yDEGRO, AKRO, and the DEGRO board. In the second phase, a one-day strategy retreat was held to develop AKRO and yDEGRO representatives' final vision from medicine, biology, and physics. The third phase was dedicated to vision interpretation and program development by yDEGRO representatives. RESULTS: The strategy retreat's development process resulted in conception of the final vision "Innovative radiation oncology Together - Precise, Personalized, Human." The first term "Innovative radiation oncology" comprises the promotion of preclinical research and clinical trials and highlights the development of a national committee for strategic development in radiation oncology research. The term "together" underpins collaborations within radiation oncology departments as well as with other partners in the clinical and scientific setting. "Precise" mainly covers technological precision in radiotherapy as well as targeted oncologic therapeutics. "Personalized" emphasizes biology-directed individualization of radiation treatment. Finally, "Human" underlines the patient-centered approach and points towards the need for individual longer-term career curricula for clinicians and researchers in the field. CONCLUSION: The vision 2030 balances the ambition of physical, technological, and biological innovation as well as a comprehensive, patient-centered, and collaborative approach towards radiotherapy & radiation oncology in Germany.

NG2-Glia Transiently Overcome Their Homeostatic Network and Contribute to Wound Closure After Brain Injury.

In the adult brain, NG2-glia represent a cell population that responds to injury. To further investigate if, how and why NG2-glia are recruited to the injury site, we analyzed in detail the long-term reaction of NG2-glia after a lesion by time-lapse two-photon in vivo microscopy. Live imaging over several weeks of GFP-labeled NG2-glia in the stab wounded cerebral cortex revealed their fast and heterogeneous reaction, including proliferation, migration, polarization, hypertrophy, or a mixed response, while a small subset of cells remained unresponsive. At the peak of the reaction, 2-4 days after the injury, NG2-glia accumulated around and within the lesion core, overcoming the homeostatic control of their density, which normalized back to physiological conditions only 4 weeks after the insult. Genetic ablation of proliferating NG2-glia demonstrated that this accumulation contributed beneficially to wound closure. Thus, NG2-glia show a fast response to traumatic brain injury (TBI) and participate in tissue repair.

Is local radiotherapy a viable option for patients with an opening of the ventricles during surgical resection of brain metastases?

BACKGROUND: Local hypofractionated stereotactic radiotherapy (HFSRT) of the resection cavity is emerging as the standard of care in the treatment of patients with a limited number of brain metastases as it warrants less neurological impairment compared to whole brain radiotherapy. In periventricular metastases surgical resection can lead to an opening of the ventricles and subsequently carries a potential risk of cerebrospinal tumour cell dissemination. The aim of this study was to assess whether local radiotherapy of the resection cavity is viable in these cases. METHODS: From our institutional database we analyzed the data of 125 consecutive patients with resected brain metastases treated in our institution with HFSRT between 2009 and 2017. The incidence of LMD, overall survival (OS), local recurrence (LC) and distant recurrence were evaluated depending on ventricular opening (VO) during surgery. RESULTS: From all 125 patients, the ventricles were opened during surgery in 14 cases (11.2%). None of the patients with VO and 7 patients without VO during surgery developed LMD (p = 0.371). OS (p = 0.817), LC (p = 0.524) and distant recurrence (p = 0.488) did not differ in relation to VO during surgical resection. However, the incidence of distant intraventricular recurrence was slightly increased in patients with VO (14.3% vs. 2.7%, p < 0.01). CONCLUSION: VO during neurosurgical resection did not affect the outcome after HFSRT of the resection cavity in patients with brain metastases. Particularly, the incidence of LMD was not increased in patients receiving local HFSRT after VO. HFSRT can therefore be offered independently of VO as a local treatment of tumor bed after resection of brain metastases.

Intraventricular neuroepithelial tumors: surgical outcome, technical considerations and review of literature.

BACKGROUND: Intraventricular neuroepithelial tumors (IVT) are rare lesions and comprise different pathological entities such as ependymomas, subependymomas and central neurocytomas. The treatment of choice is neurosurgical resection, which can be challenging due to their intraventricular location. Different surgical approaches to the ventricles are described. Here we report a large series of IVTs, its postoperative outcome at a single tertiary center and discuss suitable surgical approaches. METHODS: We performed a retrospective chart review at a single tertiary neurosurgical center between 03/2009-05/2019. We included patients that underwent resection of an IVT emphasizing on surgical approach, extent of resection, clinical outcome and postoperative complications. RESULTS: Forty five IVTs were resected from 03/2009 to 05/2019, 13 ependymomas, 21 subependymomas, 10 central neurocytomas and one glioependymal cyst. Median age was 52,5 years with 55.6% (25) male and 44.4% (20) female patients. Gross total resection was achieved in 93.3% (42/45). 84.6% (11/13) of ependymomas, 100% (12/21) of subependymomas, 90% (9/10) of central neurocytomas and one glioependymal cyst were completely removed. Postoperative rate of new neurological deficits was 26.6% (12/45). Postoperative new permanent cranial nerve deficits occurred in one case with 4th ventricle subependymoma and one in 4th ventricle ependymoma. Postoperative KPSS was 90% (IR 80-100). 31.1% of the patients improved in KPSS, 48.9% remained unchanged and 20% declined. Postoperative adverse events rate was 20.0%. Surgery-related mortality was 2.2%. The rate of shunt/cisternostomy-dependent hydrocephalus was 13.3% (6/45). 15.4% of resected ependymomas underwent adjuvant radiotherapy. Mean follow-up was 26,9 (±30.1) months. CONCLUSION: Our surgical findings emphasize satisfactory complete resection throughout all entities. Surgical treatment can remain feasible, if institutional experience is given. Satisfying long-term survival and cure is possible by complete removal. Gross total resection should always be performed under function-remaining aspects due to mostly benign or slow growing nature of IVTs. Further data is needed to evaluate standard of care and alternative therapy options in rare cases of tumor recurrence or in case of patient collective not suitable for operative resection.

Craniospinal irradiation(CSI) in patients with leptomeningeal metastases: risk-benefit-profile and development of a prognostic score for decision making in the palliative setting.

BACKGROUND: The aim of our study was to assess the feasibility and oncologic outcomes in patients treated with spinal (SI) or craniospinal irradiation (CSI) in patients with leptomeningeal metastases (LM) and to suggest a prognostic score as to which patients are most likely to benefit from this treatment. METHODS: Nineteen patients treated with CSI at our institution were eligible for the study. Demographic data, primary tumor characteristics, outcome and toxicity were assessed retrospectively. The extent of extra-CNS disease was defined by staging CT-scans before the initiation of CSI. Based on outcome parameters a prognostic score was developed for stratification based on patient performance status and tumor staging. RESULTS: Median follow-up and overall survival (OS) for the whole group was 3.4 months (range 0.5-61.5 months). The median overall survival (OS) for patients with LM from breast cancer was 4.7 months and from NSCLC 3.3 months. The median OS was 7.3 months, 3.3 months and 1.5 months for patients with 0, 1 and 2 risk factors according to the proposed prognostic score (KPS < 70 and the presence of extra-CNS disease) respectively. Nonhematologic toxicities were mild. CONCLUSION: CSI demonstrated clinically meaningful survival that is comparable to the reported outcome of intrathecal chemotherapy. A simple scoring system could be used to better select patients for treatment with CSI in this palliative setting. In our opinion, the feasibility of performing CSI with modern radiotherapy techniques with better sparing of healthy tissue gives a further rationale for its use also in the palliative setting.

Neuro-oncology Management During the COVID-19 Pandemic With a Focus on WHO Grade III and IV Gliomas.

BACKGROUND: Because of the increased risk in cancer patients of developing complications caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), physicians have to balance the competing risks of the negative impact of the pandemic and the primary tumor. In this consensus statement, an international group of experts present mitigation strategies and treatment guidance for patients suffering from high grade gliomas (HGG) during the coronavirus disease 2019 (COVID-19) pandemic. METHOD / RESULTS: 16 international experts in the treatment of HGG contributed to this consensus-based practice recommendation including neuro-oncologists, neurosurgeons, radiation -oncologists and a medical physicist. Generally, treatment of neuro-oncological patients cannot be significantly delayed and initiating therapy should not be outweighed by COVID-19. We present detailed interdisciplinary treatment strategies for molecular subgroups in two pandemic scenarios, a scale-up phase and a crisis phase. CONCLUSION: This practice recommendation presents a pragmatic framework and consensus-based mitigation strategies for the treatment of HGG patients during the SARS-CoV-2 pandemic.

A balanced score to predict survival of elderly patients newly diagnosed with glioblastoma.

BACKGROUND: Over the past years, several treatment regimens have been recommended for elderly patients with glioblastoma (GBM), ranging from ultrahypofractionated radiotherapy (RT) over monochemotherapy (ChT) to combined radiochemotherapy (RChT). The current guidelines recommend active treatment in elderly patients in cases with a KPS of at least 60%. We established a score for selecting patients with a very poor prognosis from patients with a better prognosis. METHODS: One hundred eighty one patients ≥65 years old, histologically diagnosed with GBM, were retrospectively evaluated. Clinical characteristics were analysed for their impact on the overall survival (OS). Factors which were significant in univariate analysis (log-rank test, p < 0.05) were included in a multi-variate model (multi-variate Cox regression analysis, MVA). The 9-month OS for the significant factors after MVA (p < 0.05) was included in a prognostic score. Score sums with a median OS of < and > 6 months were summarized as Group A and B, respectively. RESULTS: Age, KPS, MGMT status, the extent of resection, aphasia after surgery and motor dysfunction after surgery were significantly associated with OS on univariate analysis (p < 0.05). On MVA age (p 0.002), MGMT promotor methylation (p 0.013) and Karnofsky performance status (p 0.005) remained significant and were included in the score. Patients were divided into two groups, group A (median OS of 2.7 months) and group B (median OS of 7.8 months). The score was of prognostic significance, independent of the adjuvant treatment regimen. CONCLUSIONS: The score distinguishes patients with a poor prognosis from patients with a better prognosis. Its inclusion in future retrospective or prospective trials could help enhance the comparability of results. Before its employment on a routine basis, external validation is recommended.

Integration of PET-imaging into radiotherapy treatment planning for low-grade meningiomas improves outcome.

PURPOSE: Meningiomas have an excellent survival prognosis, and radiotherapy (RT) is a central component of interdisciplinary treatment. During treatment planning, the definition of the target volume remains challenging using MR and CT imaging alone. This is the first study to analyze the impact of additional PET-imaging on local control (LC) and overall survival (OS) after high-precision RT. METHODS: We analyzed 339 meningiomas treated between 2000 and 2018. For analyses, we divided the patients in low-grade (n = 276) and high-grade (n = 63) cases. We performed RT in an adjuvant setting due to subtotal resection or later due to recurrent tumor growth. The target volumes were delineated based on diagnostic CT and MRI and, if available, additional PET-imaging (low-grade: n = 164, 59.4%; high-grade: n = 39, 61.9%) with either 68Ga-Dotanoc/Dotatoc, 18F-fluoroethyltyrosine or 11C-methionine tracer. Patients were treated with fractionated stereotactic RT with a median total dose and dose per fraction of 54 Gy and 1.8 Gy, respectively. RESULTS: Median follow-up was 5.6 years. For low-grade meningiomas, mean OS was 15.6 years and mean LC was 16.9 years; for high-grade cases mean OS was 11.6 years, and mean LC was 11.1 years. In univariate analyses, PET-imaging had a significant impact on OS (p = 0.035) and LC (p = 0.041) for low-grade meningiomas and remained significant (p = 0.015) for LC in the multivariate analysis. For high-grade cases, PET did not influence both OS and LC. Further prognostic factors could be identified. CONCLUSIONS: For low-grade meningiomas, we showed that the addition of PET-imaging for target volume definition led to a significantly enhanced LC. Thus, PET improves the detection of tumor cells and helps distinguish between healthy tissue and meningioma tissue, especially during the treatment planning process.

Neoadjuvant stereotactic radiosurgery for intracerebral metastases of solid tumors (NepoMUC): a phase I dose escalation trial.

BACKGROUND: More than 25% of patients with solid cancers develop intracerebral metastases. Aside of surgery, radiation therapy (RT) is a mainstay in the treatment of intracerebral metastases. Postoperative fractionated stereotactic RT (FSRT) to the resection cavity of intracerebral metastases is a treatment of choice to reduce the risk of local recurrence. However, FSRT has to be delayed until a sufficient wound healing is attained; hence systemic therapy might be postponed. Neoadjuvant stereotactic radiosurgery (SRS) might offer advantages over adjuvant FSRT in terms of better target delineation and an earlier start of systemic chemotherapy. Here, we conducted a study to find the maximum tolerated dose (MTD) of neoadjuvant SRS for intracerebral metastases. METHODS: This is a single-center, phase I dose escalation study on neoadjuvant SRS for intracerebral metastases that will be conducted at the Klinikum rechts der Isar Hospital, Technical University of Munich. The rule-based traditional 3 + 3 design for this trial with 3 dose levels and 4 different cohorts depending on lesion size will be applied. The primary endpoint is the MTD for which no dose-limiting toxicities (DLT) occur. The adverse events of each participant will be evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 continuously during the study until the first follow-up visit (4-6 weeks after surgery). Secondary endpoints include local control rate, survival, immunological tumor characteristics, quality of life (QoL), CTCAE grade of late clinical, neurological, and neurocognitive toxicities. In addition to the intracerebral metastasis which is treated with neoadjuvant SRS and resection up to four additional intracerebral metastases can be treated with definitive SRS. Depending on the occurrence of DLT up to 72 patients will be enrolled. The recruitment phase will last for 24 months. DISCUSSION: Neoadjuvant SRS for intracerebral metastases offers potential advantages over postoperative SRS to the resection cavity, such as better target volume definition with subsequent higher efficiency of eliminating tumor cells, and lower damage to surrounding healthy tissue, and much-needed systemic chemotherapy could be initiated more rapidly. Trial registration The local ethical review committee of Technical University of Munich (199/18S) approved this study on September 05, 2018. This trial was registered on German Clinical Trials Register (DRKS00016613; https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00016613) on January 29, 2019.

Stereotactic irradiation of the resection cavity after surgical resection of brain metastases - when is the right timing?

Purpose: This study aimed to evaluate whether an early beginning of the adjuvant stereotactic radiotherapy after macroscopic complete resection of 1-3 brain metastases is essential or whether longer intervals between surgery and radiotherapy are feasible.Material and methods: Sixty-six patients with 69 resection cavities treated with HFSRT after macroscopic complete resection of 1-3 brain metastases between 2009 and 2016 in our institution were included in this study. Overall survival, local recurrence and locoregional recurrence were evaluated depending on the time interval from surgery to the start of radiation therapy.Results: Patients that started radiotherapy within 21 days from surgery had a significantly decreased OS compared to patients treated after a longer interval from surgery (p < .01). There was no significant difference between patients treated ≥ 34 and 22-33 days from surgery (p = .210). In the univariate analysis, local control was superior for patients starting treatment 22-33 days from surgery compared to a later start (p = .049). This effect did not prevail in a multivariate model. There was no significant difference between patients treated within 21 days and patients treated more than 33 days after surgery (p = .203). Locoregional control was not influenced by RT timing (p = .508).Conclusion: A short delay in the start of radiotherapy does not seem to negatively impact the outcome in patients with resected brain metastases. We even observed an unexpected reduction in OS in patients treated within 21 days from surgery. Further studies are needed to define the optimal timing of postoperative radiotherapy to the resection cavity.

A Second Course of Radiotherapy in Patients with Recurrent Malignant Gliomas: Clinical Data on Re-irradiation, Prognostic Factors, and Usefulness of Digital Biomarkers.

OPINION STATEMENT: The treatment of malignant gliomas has undergone a significant intensification during the past decade, and the interdisciplinary treatment team has learned that all treatment opportunities, including surgery and radiotherapy (RT), also have a central role in recurrent gliomas. Throughout the decades, re-irradiation (re-RT) has achieved a prominent place in the treatment of recurrent gliomas. A solid body of evidence supports the safety and efficacy of re-RT, especially when modern techniques are used, and justifies the early use of this regimen, especially in the case when macroscopic disease is present. Additionally, a second adjuvant re-RT to the resection cavity is currently being investigated by several investigators and seems to offer promising results. Although advanced RT technologies, such as stereotactic radiosurgery (SRS), fractionated stereotactic radiotherapy (FSRT), intensity-modulated radiotherapy (IMRT), and image-guided radiotherapy (IGRT) have become available in many centers, re-RT should continue to be kept in experienced hands so that they can select the optimal regimen, the ideal treatment volume, and the appropriate techniques from their tool-boxes. Concomitant or adjuvant use of systemic treatment options should also strongly be taken into consideration, especially because temozolomide (TMZ), cyclohexyl-nitroso-urea (CCNU), and bevacizumab have shown a good safety profile; they should be considered, if available. Nonetheless, the selection of patients for re-RT remains crucial. Single factors, such as patient age or the progression-free interval (PFI), fall too short. Therefore, powerful prognostic scores have been generated and validated, and these scores should be used for patient selection and counseling.

Deep learning derived tumor infiltration maps for personalized target definition in Glioblastoma radiotherapy.

PURPOSE: Glioblastoma is routinely treated by concomitant radiochemotherapy. Current target definition guidelines use anatomic MRI (magnetic resonance imaging) scans, taking into account contrast enhancement and the rather unspecific hyperintensity on the fluid-attenuated inversion recovery (FLAIR) sequence. METHODS AND MATERIALS: We applied deep learning based free water correction of diffusion tensor imaging (DTI) scans to estimate the infiltrative gross tumor volume (iGTV) inside of the FLAIR hyperintense region. We analyzed the resulting iGTVs and their impact on target volume definition in a retrospective cohort of 33 GBM patients. RESULTS: iGTVs were significantly smaller compared to standard pre- and post-operative gross tumor volume (GTV) definitions. Two novel infiltrative tumor GTVs (nGTVPRE-OP and nGTVPOST-OP) defined as the conjunction volume of the standard GTV and the iGTV showed only a moderate increase in size compared to standard GTV definitions. On postoperative scans, the iGTV was predominantly covered by the two clinical target volume (CTV) concepts CTVEORTC and CTVROTG1. A novel infiltrative tumor CTV (nCTV) [nGTVPOST-OP + 2 cm margin] was significantly smaller compared to CTVROTG1 but larger than CTVEORTC. The overlap volume and conformity index demonstrated a distinct spatial configuration of the nCTV. Tumor recurrences overlapped with the iGTV in all but one patients and were completely covered by the nCTV in all patients. After reducing the margin to 1 cm recurrences coverage was at least in-field in all patients. CONCLUSION: To conclude, free water corrected DTI scans may help to define infiltrative tumor areas of GBM that could ultimately be used to individualize RT treatment planning in terms of dose sparing or dose escalation.

Re-irradiation in elderly patients with glioblastoma: a single institution experience.

BACKGROUND: Re-Irradiation (Re-RT) is an established treatment option for young patients with recurrent glioblastoma (GBM). Multiple reports show a low risk of side-effects as well as a good efficacy resulting in median survival times ranging from 5 to 18 months. Elderly patients, however, are underrepresented in reports about Re-RT. Even in the elderly, with concomitant radiochemotherapy and adjuvant chemotherapy, progression-free survival times now are approaching 6 months or even longer. METHODS: We report on 25 consecutive patients with at least 65 years of age treated with Re-RT for recurrent GBM. We analyzed the patient's files for the treatment regimens, side-effects and survival times. Survival times, as well as hazards, were calculated by the Kaplan Meier method as well as Cox-regression method, respectively. RESULTS: The median overall survival was 6.9 months, treatment was well tolerated with only minor side effects. Use of systemic treatments as well as the length of the interval between 1st -line radiotherapy and re-irradiation were associated with a favorable prognosis. The latter remained significant after multivariate analysis. CONCLUSION: Re-RT of elderly GBM patients should not be withheld based purely on age since the treatment is safe and results in comparable survival times to younger patients. When counseling elderly patients with recurrent GBM, especially the length of the interval since 1st line radiotherapy should be considered as a prognostic factor and an additional systemic treatment option should be considered.

Cavity volume changes after surgery of a brain metastasis-consequences for stereotactic radiation therapy.

PURPOSE: For a large or symptomatic brain metastasis, resection and adjuvant radiotherapy are recommended. Hypofractionated stereotactic radiotherapy (HFSRT) is increasingly applied in patients with a limited number of lesions. Exact target volume definition is critical given the small safety margins. Whilst technical advances have minimized inaccuracy due to patient positioning and radiation targeting, little is known about changes in target volume. This study sought to evaluate potential changes in the resection cavity of a brain metastasis. METHODS: In all, 57 patients treated with HFSRT after surgical resection of one brain metastasis between 2008 and 2015 in our institution were included in this study. Gross tumor volume (GTV) of the initial metastasis and the volume of the resection cavity in the post-operative, planning, and follow-up MRIs were measured and compared. RESULTS: The mean cavity size decreased after surgery with the greatest change of -23.4% (±41.5%) occurring between post-operative MRI and planning MRI (p < 0.01). During this time period, the cavity volume decreased, remained stable, and increased in 79.1, 3.5, and 17.4%, respectively. A further decrease of -20.7% (±58.1%) was perceived between planning MRI and first follow-up (p < 0.01). No significant difference in pattern of change could be observed depending on the volume of initial GTV, size of the post-operative resection cavity, initial or post-resection FLAIR (fluid-attenuated inversion recovery) hyper-intensity, postsurgical ischemia, or primary tumor. The resection cavities of patients with post-operative ischemia were significantly larger than resection cavities of patients without ischemia. CONCLUSION: The resection cavity seems to be very dynamic after surgery. Hence, it remains necessary to use very recent scans for treatment planning.

The algorithms of adjuvant therapy in gliomas and their effect on survival.

The treatment of gliomas became more sophisticated during the last decades. As by now, adjuvant treatment after maximum safe resection is considered an important and effective treatment strategy in most gliomas, yet the decision is based on several factors. This review summarizes the available evidence for the current adjuvant treatment algorithms with a focus on the impact on the survival of glioma patients. The review is based on the current guidelines, but it also includes new insights which have not yet been included into the official guidelines.

A trend towards a more intense adjuvant treatment of low-grade-gliomas in tertiary centers in Germany after RTOG 9802 - results from a multi-center survey.

BACKGROUND: The treatment recommendations for Low-grade Gliomas (LGG) underwent profound changes due to results from RTOG 9802 published in April 2016. This work aims to investigate whether the results from the trial were already incorporated into the treatment recommendations at German oncology centers before an update of the official guidelines. METHODS: An online based questionnaire with questions covering all aspects of adjuvant treatments of LGGs was generated, including three cases with distinct clinical situations. We contacted all members of the neuro-oncologic working group (NOA) of the German Cancer Society (DKG) as well as all German-speaking members of the European Low-Grade Glioma Network via E-mail. RESULTS: We collected 38 responses. All responders were at least specialists; they predominantly worked at tertiary hospitals with a high volume of LGGs treated annually (75% with more than 10 cases per year). All responders stated to consent treatment recommendation for LGGs within interdisciplinary oncologic boards. The treatment recommendations for LGGs changed profoundly between 2015 and 12/2016. There is a trend towards PCV-based multimodal treatments, especially for oligodendroglial LGGs, as well as a trend away from watchful-waiting-policies for astrocytic LGGs. CONCLUSION: Neurooncologists do adapt results from clinical trials quickly. None the less, there is still an immense heterogeneity within the treatment recommendations, predominantly for astrocytic LGGs. Well planned clinical trials and concise treatment recommendations are warranted; additionally, individual counseling of patients is essential.