Moving Second Courses of Radiotherapy Forward: Early Re-Irradiation After Surgical Resection for Recurrent Gliomas Improves Efficacy With Excellent Tolerability

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.

Re-irradiation for high-grade gliomas: Has anything changed?

Optimal management after recurrence or progression of high-grade gliomas is still undefined and remains a challenge for neuro-oncology multidisciplinary teams. Improved radiation therapy techniques, new imaging methods, published experience, and a better radiobiological knowledge of brain tissue have positioned re-irradiation (re-RT) as an option for many of these patients. Decisions must be individualized, taking into account the pattern of relapse, previous treatment, and functional status, as well as the patient’s preferences and expected quality of life. Many questions remain unanswered with respect to re-RT: Who is the most appropriate candidate, which dose and fractionation are most effective, how to define the target volume, which imaging technique is best for planning, and what is the optimal timing? This review will focus on describing the most relevant studies that include re-RT as salvage therapy, with the aim of simplifying decision-making and designing the best available therapeutic strategy.

High-dose re-irradiation of intracranial lesions - Efficacy and safety including dosimetric analysis based on accumulated EQD2Gy dose EQD calculation

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Re-irradiation of the brain is feasible with an encouraging overall survival.

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Treatment related toxicity was low within the reported dose range.

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EQD2 cumulative dose distributions were calculated using rigid registration.

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Dose-Response-Modelling with logistic regression showed a correlation of the D1cc brain with any grade of acute toxicity.

Introduction

The use of cranial re-irradiation is growing with improving overall survival and the advent of high-precision radiotherapy techniques. Still the value of re-irradiation needs careful evaluation regarding safety and efficacy. We analyzed dosimetric and clinical data of patients receiving cranial re-irradiation using EQD2 sum plans.

Methods and material

We retrospectively analyzed the data of 76 patients who received repeated cranial radiotherapy from 02/2013 to 09/2016. 34 patients suffered from recurrent primary brain tumors, 42 from brain metastases. Dosimetric analysis was performed accumulating EQD2 dose distributions based on rigid image registration. Clinical and radiological data was collected at follow-ups including toxicity, local control and overall survival.

Results

In total 76 patients had at least 2 courses of intracranial radiotherapy. The median accumulated prescription EQD2 dose was 96.5 Gy₂ for all radiation courses combined. The median D(0.1 cc) of the brain for patients receiving more than 100 Gy₂ was 114 Gy₂ with a highest dose of 161.5 Gy₂. 74% of patients suffered from low grade (G1–G2) acute toxicity, only two high grade (>G3) toxicities were recorded.

Median overall survival from the time of first re-irradiation was 57 weeks (range 4–186 weeks). The median time to local failure for patients with a primary brain tumor was not reached and 24 weeks (range 1–77 weeks) for patients with brain metastases.

Conclusion

Repeated radiotherapy appears both safe and efficient in patients with recurrent primary or secondary brain tumors with doses to the brain up to 120 Gy₂ EQD2, doses below 100 Gy₂ for brainstem and doses below 75 Gy₂ EQD2 to chiasm and optic nerves.

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.

Italian consensus and recommendations on diagnosis and treatment of low-grade gliomas. An intersociety (SINch/AINO/SIN) document

In 2018, the SINch (Italian Society of Neurosurgery) Neuro-Oncology Section, AINO (Italian Association of Neuro-Oncology) and SIN (Italian Association of Neurology) Neuro-Oncology Section formed a collaborative Task Force to look at the diagnosis and treatment of low-grade gliomas (LGGs). The Task Force included neurologists, neurosurgeons, neuro-oncologists, pathologists, radiologists, radiation oncologists, medical oncologists, a neuropsychologist and a methodologist. For operational purposes, the Task Force was divided into five Working Groups: diagnosis, surgical treatment, adjuvant treatments, supportive therapies, and follow-up. The resulting guidance document is based on the available evidence and provides recommendations on diagnosis and treatment of LGG patients, considering all aspects of patient care along their disease trajectory.

The Role of miRNA for the Treatment of MGMT Unmethylated Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most common high-grade intracranial tumor in adults. It is characterized by uncontrolled proliferation, diffuse infiltration due to high invasive and migratory capacities, as well as intense resistance to chemo- and radiotherapy. With a five-year survival of less than 3% and an average survival rate of 12 months after diagnosis, GBM has become a focus of current research to urgently develop new therapeutic approaches in order to prolong survival of GBM patients. The methylation status of the promoter region of the O⁶-methylguanine–DNA methyltransferase (MGMT) is nowadays routinely analyzed since a methylated promoter region is beneficial for an effective response to temozolomide-based chemotherapy. Furthermore, several miRNAs were identified regulating MGMT expression, apart from promoter methylation, by degrading MGMT mRNA before protein translation. These miRNAs could be a promising innovative treatment approach to enhance Temozolomide (TMZ) sensitivity in MGMT unmethylated patients and to increase progression-free survival as well as long-term survival. In this review, the relevant miRNAs are systematically reviewed.

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.

Appraisal of re-irradiation for the recurrent glioblastoma in the era of MGMT promotor methylation

Despite recent innovation in treatment techniques and subsequently improved outcomes, the majority of glioblastoma (GBL) have relapses, especially in locoregional areas. Local re-irradiation (re-RT) has been established as a feasible option for recurrent GBL of all ages with safety, tolerability, and effectiveness both in survival and quality of life regardless of fractionation schedule. To keep adverse effects under acceptable range, cumulative dose limit in equivalent dose at 2 Gy fractions by the linear-quadratic model at α/β = 2 for normal brain tissue (EQD2) with narrow margin should be observed and single/hypofractionated re-RT should be undertaken very carefully to recurrent tumor with large volume or adjacent to the brainstem. Promising outcome of re-operation (re-Op) plus re-RT (re-Op/RT) need to be validated and result from re-RT with temozolomide/bevacizumab (TMZ/BV) or new strategy is expected. Development of new-concept prognostic scoring or risk group is required to select patients properly and make use of predictive biomarkers such as O(6)-methylguanine-DNA methyltransferase (MGMT) promotor methylation that influence outcomes of re-RT, re-Op/RT, or re-RT with TMZ/BV.

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.

Re-irradiation for malignant glioma: Toward patient selection and defining treatment parameters for salvage

Purpose

Reirradiation for recurrent glioma remains controversial without knowledge of optimal patient selection, dose, fractionation, and normal tissue tolerances. We retrospectively evaluated outcomes and toxicity after conventionally fractionated reirradiation for recurrent high-grade glioma, along with the impact of concurrent chemotherapy.

Methods and materials

We conducted a retrospective review of patients reirradiated for high-grade glioma recurrence between 2007 and 2016 (including patients with initial low-grade glioma). Outcome metrics included overall survival (OS), prognostic factors for survival, and treatment-related toxicity.

Results

Patients (n = 118; median age 47 years; median Karnofsky performance status score: 80) were re-treated at a median of 28 months (range, 5-214 months) after initial radiation therapy. The median reirradiation dose was 41.4 Gy (range, 12.6-54.0 Gy) to a median lesion volume of 202 cm³ (range, 20-901 cm³). The median cumulative (initial radiation and reirradiation combined) potential maximum brainstem dose was 76.9 Gy (range, 5.0-108.3 Gy) and optic apparatus dose was 56.0 Gy (range, 4.5-90.9 Gy). Of the patients, 56% received concurrent temozolomide, 14%, bevacizumab, and 11%, temozolomide plus bevacizumab; 19% had no chemotherapy. The planned reirradiation was completed by 90% of patients. Median OS from the completion of reirradiation was 9.6 months (95% confidence interval [CI], 7.5-11.7 months) for all patients and 14.0, 11.5, and 6.7 months for patients with initial grade 2, 3, and 4 glioma, respectively. On multivariate analysis, better OS was observed with a >24-month interval between radiation treatments (hazard ratio [HR]: 0.3; 95% CI, 0.2-0.5; P < .001), reirradiation dose >41.4 Gy (HR: 0.6; 95% CI, 0.4-0.9; P = .03), and gross total resection before reirradiation (HR: 0.6, 95% CI, 0.3-0.9; P = .02). Radiation necrosis and grade ≥3 late neurotoxicity were both minimal (<5%). No symptomatic persistent brainstem or optic nerve/chiasm injury was identified.

Conclusions

Salvage reirradiation, even at doses >41.4 Gy in conventional fractionation, along with chemotherapy, was safe and well tolerated with meaningful survival duration. These data provide information that may be useful in implementing safe reirradiation treatments for appropriately selected patients and guiding future studies to define optimal reirradiation doses, maximal safe doses to critical structures, and the role of systemic therapy.

Survival gain with re-Op/RT for recurred high-grade gliomas depends upon risk groups

INTRODUCTION

A majority of high-grade gliomas relapse despite combined surgery, radiotherapy and chemotherapy. There is no consensus on standard treatment for recurrent high-grade gliomas, or defined efficacy of adjuvant re-RT after re-Op. This retrospective study evaluated the benefit and safety of re-RT after re-Op (re-Op/RT).

MATERIALS AND METHODS

A total of 84 patients with recurrent high-grade gliomas who underwent reoperation from 2009 to 2015 were analyzed. All patients received neurosurgical intervention and adjuvant radiotherapy previously before recurrence. At recurrence and after reoperation, treatment options were discussed in multidisciplinary clinic or brain tumor joint conference. For re-RT, cumulative EQD₂ (equivalent dose in 2 Gy fractions at α/β = 2) was below 106.9 Gy.

RESULT

Median progression free survival (PFS) was 6.5 months; 3.5 months with re-Op, 9.0 months with re-Op/RT (p = 0.025). Age <50, time interval to recur ≥12 months, WHO pathologic grade III, methylated MGMT promotor, and re-RT were factors enhancing PFS in the multivariate analysis. Median overall survival (OS) was 18.3 months: 12.7 months with re-Op, and 28.1 months with re-Op/RT (p = 0.066). Three risk factors (age >50, WHO grade IV, and unmethylated promoter of MGMT) were significantly associated with poor OS in multivariate analysis. Benefit of re-RT in both OS and PFS was established in patients carrying 2 or more risk factors. During re-RT, 4 patients (8%) had grade 2 or higher toxicity, and 3 patients (6%) did not complete re-RT. No radionecrosis was observed.

CONCLUSION

Re-RT after re-Op was tolerable with a cumulative median EQD₂ of 99.3 Gy and resulted in clear benefit in PFS and marginal gain in OS. Survival gain with re-Op/RT was more prominent in patients with two or more risk factors (age ≥50, WHO pathologic grade IV, unmethylated MGMT promoter), and needs to be validated.