Hypofractionated stereotactic radiotherapy and continuous low-dose temozolomide in patients with recurrent or progressive malignant gliomas

Reirradiation for recurrent glioblastoma: the significance of the residual tumor volume

PURPOSE

Recurrent glioblastoma has a poor prognosis, and its optimal management remains unclear. Reirradiation (re-RT) is a promising treatment option, but long-term outcomes and optimal patient selection criteria are not well established.

METHODS

This study analyzed 71 patients with recurrent CNS WHO grade 4, IDHwt glioblastoma (GBM) who underwent re-RT at the University of Erlangen-Nuremberg between January 2009 and June 2019. Imaging follow-ups were conducted every 3 months. Progression-free survival (PFS) was defined using RANO criteria. Outcomes, feasibility, and toxicity of re-RT were evaluated. Contrast-enhancing tumor volume was measured using a deep learning auto-segmentation pipeline with expert validation and jointly evaluated with clinical and molecular-pathologic factors.

RESULTS

Most patients were prescribed conventionally fractionated re-RT (84.5%) with 45 Gy in 1.8 Gy fractions, combined with temozolomide (TMZ, 49.3%) or lomustine (CCNU, 12.7%). Re-RT was completed as planned in 94.4% of patients. After a median follow-up of 73.8 months, 88.7% of patients had died. The median overall survival was 9.6 months, and the median progression-free survival was 5.3 months. Multivariate analysis identified residual contrast-enhancing tumor volume at re-RT (HR 1.040 per cm3, p < 0.001) as the single dominant predictor of overall survival.

CONCLUSION

Conventional fractionated re-RT is a feasible and effective treatment for recurrent high-grade glioma. The significant prognostic impact of residual tumor volume highlights the importance of combining maximum-safe resection with re-RT for improved outcomes.

Salvage reirradiation for recurrent glioblastoma: a retrospective case series analysis

PURPOSE

To assess the clinical outcome of patients with recurrent glioblastoma treated with salvage reirradiation.

METHODS

Between 2005 and 2022, data from adult patients with glioblastoma treated with surgery and radio-chemotherapy Stupp regimen who developed a local in-field relapse and received stereotactic radiotherapy (SRT) were retrospectively reviewed.

RESULTS

The study population included 44 patients with recurrent glioblastoma (median of 9.5 months after the first radiotherapy). Reirradiation alone was given to 47.7% of patients. The median maximum diameter of the recurrence was 13.5 mm. The most common SRT regimen (52.3%) was 35 Gy in 10 fractions. Acute toxicity was mild, with transient worsening of previous neurological symptoms in only 15% of patients. After a median follow-up of 15 months, 40% presented radiological response, but a remarkable number of early distant progressions were recorded (32.5%). The median time to progression was 4.8 months, being the dose, the scheme, the size of the recurrence or the strategy (exclusive RT vs. combined) unrelated factors. The median overall survival (OS) was 14.9 months. Karnofsky index < 70 and the size of the recurrence (maximum diameter < 25 mm) were significant factors associated with OS. Radiological changes after reirradiation were commonly seen (> 50% of patients) hindering the response assessment.

CONCLUSIONS

Reirradiation is a feasible and safe therapeutic option to treat localized glioblastoma recurrences, able to control the disease for a few months in selected patients, especially those with good functional status and small lesions. Hypofractionated schemes provided a suitable toxicity profile. Radiological changes were common.

Pattern of recurrence after fractionated stereotactic reirradiation in adult glioblastoma

BACKGROUND

Glioblastomas all eventually relapse after initial treatment, and an option to treat these recurrences is fractionated stereotactic reirradiation (fSRT). The location of recurrences following reirradiation has not been studied for fSRT delivered by a dedicated stereotactic device. We aimed to analyze these locations to better elucidate safety margins, dose and fractionation regimens.

METHODS

We retrospectively analyzed the data of patients with glioblastoma recurrence that had been reirradiated by fSRT in October 2010-December 2020, in 25 Gy in 5 fractions delivered by a CyberKnife® at Institut de Cancérologie de Lorraine. We matched the images of the post-fSRT relapse with the stereotactic radiation treatment planning scan to determine the relapse location.

RESULTS

The location of recurrences after fSRT was "out-field" in 43.5%, "marginal" in 40.3%, and "in-field" in 16.1% of patients (N = 62). A GTV-PTV margin of 1 mm (versus 2-3 mm, HR = 0.38 [0.15-0.95], p = 0.037) and a PTV volume of ≥ 36 cc (HR = 5.18 [1.06-25.3], p = 0.042) were significantly associated with the "marginal" recurrences. Being ≥ 60 years old at initial treatment (HR = 3.06 [1.17-8.01], p = 0.023) and having one or more previous recurrences (HR = 5.29 [1.70-16.5], p = 0.004) were significantly associated with "out-field" recurrences. The median PFS from fSRT was 3.4 months, and OS from diagnosis and from fSRT were 25.7 and 10.8 months respectively.

CONCLUSION

Reirradiation of glioblastoma recurrence by fSRT with 25 Gy in 5 fractions provides good local control.

The efficacy of stereotactic radiotherapy followed by bevacizumab and temozolomide in the treatment of recurrent glioblastoma: a case report

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor among adults. Despite advancements in multimodality therapy for GBM, the overall prognosis remains poor, with an extremely high risk of recurrence. Currently, there is no established consensus on the optimal treatment option for recurrent GBM, which may include reoperation, reirradiation, chemotherapy, or a combination of the above. Bevacizumab is considered a first-line treatment option for recurrent GBM, as is temozolomide. However, in recurrent GBM, it is necessary to balance the risks and benefits of reirradiation in combination with bevacizumab and temozolomide. Herein, we report the case of a patient with recurrent GBM after standard treatment who benefited from stereotactic radiotherapy followed by bevacizumab and temozolomide maintenance therapy. Following 16 months of concurrent chemoradiotherapy (CCRT), the patient was diagnosed with recurrent GBM by a 3-T contrast-enhanced magnetic resonance imaging (MRI). The addition of localized radiotherapy to the ongoing treatment regimen of bevacizumab, in combination with temozolomide therapy, prolonged the patient's disease-free survival to over 2 years, achieving a significant long-term outcome, with no notable adverse effects observed. This clinical case may provide a promising new option for patients with recurrent GBM.

Preferred Imaging for Target Volume Delineation for Radiotherapy of Recurrent Glioblastoma: A Literature Review of the Available Evidence

BACKGROUND

Recurrence in glioblastoma lacks a standardized treatment, prompting an exploration of re-irradiation's efficacy.

METHODS

A comprehensive systematic review from January 2005 to May 2023 assessed the role of MRI sequences in recurrent glioblastoma re-irradiation. The search criteria, employing MeSH terms, targeted English-language, peer-reviewed articles. The inclusion criteria comprised both retrospective and prospective studies, excluding certain types and populations for specificity. The PICO methodology guided data extraction, and the statistical analysis employed Chi-squared tests via MedCalc v22.009.

RESULTS

Out of the 355 identified studies, 81 met the criteria, involving 3280 patients across 65 retrospective and 16 prospective studies. The key findings indicate diverse treatment modalities, with linac-based photons predominating. The median age at re-irradiation was 54 years, and the median time interval between radiation courses was 15.5 months. Contrast-enhanced T1-weighted sequences were favored for target delineation, with PET-imaging used in fewer studies. Re-irradiation was generally well tolerated (median G3 adverse events: 3.5%). The clinical outcomes varied, with a median 1-year local control rate of 61% and a median overall survival of 11 months. No significant differences were noted in the G3 toxicity and clinical outcomes based on the MRI sequence preference or PET-based delineation.

CONCLUSIONS

In the setting of recurrent glioblastoma, contrast-enhanced T1-weighted sequences were preferred for target delineation, allowing clinicians to deliver a safe and effective therapeutic option; amino acid PET imaging may represent a useful device to discriminate radionecrosis from recurrent disease. Future investigations, including the ongoing GLIAA, NOA-10, ARO 2013/1 trial, will aim to refine approaches and standardize methodologies for improved outcomes in recurrent glioblastoma re-irradiation.

The evolving role of reirradiation in the management of recurrent brain tumors

Despite aggressive management consisting of surgery, radiation therapy (RT), and systemic therapy given alone or in combination, a significant proportion of patients with brain tumors will experience tumor recurrence. For these patients, no standard of care exists and management of either primary or metastatic recurrent tumors remains challenging.Advances in imaging and RT technology have enabled more precise tumor localization and dose delivery, leading to a reduction in the volume of health brain tissue exposed to high radiation doses. Radiation techniques have evolved from three-dimensional (3-D) conformal RT to the development of sophisticated techniques, including intensity modulated radiation therapy (IMRT), volumetric arc therapy (VMAT), and stereotactic techniques, either stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT). Several studies have suggested that a second course of RT is a feasible treatment option in patients with a recurrent tumor; however, survival benefit and treatment related toxicity of reirradiation, given alone or in combination with other focal or systemic therapies, remain a controversial issue.We provide a critical overview of the current clinical status and technical challenges of reirradiation in patients with both recurrent primary brain tumors, such as gliomas, ependymomas, medulloblastomas, and meningiomas, and brain metastases. Relevant clinical questions such as the appropriate radiation technique and patient selection, the optimal radiation dose and fractionation, tolerance of the brain to a second course of RT, and the risk of adverse radiation effects have been critically discussed.

Re-irradiation with stereotactic radiotherapy for recurrent high-grade glial tumors

Background

Despite the radical treatments applied, recurrence is encountered in the majority of high-grade gliomas (HGG). There is no standard treatment when recurrence is detected, but stereotactic radiotherapy (SRT) is a preferable alternative. The aim of this retrospective study is to evaluate the efficacy of SRT for recurrent HGG, and to investigate the factors that affect survival.

Materials and methods

From 2013 to 2021, a total of 59 patients with 64 lesions were re-irradiated in a single center with the CyberKnife Robotic Radiosurgery System. The primary endpoints of the study were overall survival (OS), progression free survival (PFS) and local control rates (LCR).

Results

The median time to first recurrence was 13 (4-85) months. SRT was performed as a median prescription dose of 30 Gy (range 15-30), with a median of 5 fractions (1-5). The median follow-up time was 4 months (range 1-57). The median OS was 8 (95% CI: 4.66-11.33) months. Age, grade 3, tumor size were associated with better survival. The median PFS was 5 [95% confidence interval (CI): 3.39-6.60] months. Age, grade 3 and time to recurrence > 9 months were associated with improved PFS. Grade 3 gliomas (p = 0.027), size of tumor < 2 cm (p = 0.008) remained independent prognostic factors for OS in multivariate analysis.

Conclusion

SRT is a viable treatment modality with significant survival contribution. Since it may have a favorable prognostic effect on survival in patients with tumor size < 2 cm, we recommend early diagnosis of recurrence and a decision to re-irradiate a smaller tumor during follow-up.

A multi-center prospective study of re-irradiation with bevacizumab and temozolomide in patients with bevacizumab refractory recurrent high-grade gliomas

PURPOSE

Survival is dismal for bevacizumab refractory high-grade glioma patients. We prospectively investigated the efficacy of re-irradiation, bevacizumab, and temozolomide in bevacizumab-naïve and bevacizumab-exposed recurrent high-grade glioma, without volume limitations, in a single arm trial.

METHODS

Recurrent high-grade glioma patients were stratified based on WHO grade (4 vs. < 4) and prior exposure to bevacizumab (yes vs. no). Eligible patients received radiation using a simultaneous integrated boost technique (55 Gy to enhancing disease, 45 Gy to non-enhancing disease in 25 fractions) with bevacizumab 10 mg/kg every 2 weeks IV and temozolomide 75 mg/m² daily followed by maintenance bevacizumab 10 mg/kg every 2 weeks and temozolomide 50 mg/m² daily for 6 weeks then a 2 week holiday until progression. Primary endpoint was overall survival. Quality of life was studied using FACT-Br and FACT-fatigue scales.

RESULTS

Fifty-four patients were enrolled. The majority (n = 36, 67%) were bevacizumab pre-exposed GBM. Median OS for all patients was 8.5 months and 7.9 months for the bevacizumab pre-exposed GBM group. Patients ≥ 36 months from initial radiation had a median OS of 13.3 months compared to 7.5 months for those irradiated < 36 months earlier (p < 0.01). FACT-Br and FACT-Fatigue scores initially declined during radiation but returned to pretreatment baseline. Treatment was well tolerated with 5 patients experiencing > grade 3 lymphopenia and 2 with > grade 3 thrombocytopenia. No radiographic or clinical radiation necrosis occurred.

CONCLUSIONS

Re-irradiation with bevacizumab and temozolomide is a safe and feasible salvage treatment for patients with large volume bevacizumab-refractory high-grade glioma. Patients further from their initial radiotherapy may derive greater benefit with this regimen.

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.

Accelerator-based BNCT for patients with recurrent glioblastoma: a multicenter phase II study

Background

Boron neutron capture therapy (BNCT) utilizes tumor-selective particle radiation. This study aimed to assess the safety and efficacy of accelerator-based BNCT (AB-BNCT) using a cyclotron-based neutron generator (BNCT 30) and ¹⁰B-boronophenylalanine (SPM-011) in patients with recurrent malignant glioma (MG) (primarily glioblastoma [GB]).

Methods

This multi-institutional, open-label, phase II clinical trial involved 27 recurrent MG cases, including 24 GB cases, who were enrolled from February 2016 to June 2018. The study was conducted using the abovementioned AB-BNCT system, with 500 mg/kg SPM-011 (study code: JG002). The patients were bevacizumab-naïve and had recurrent MG after standard treatment. The primary endpoint was the 1-year survival rate, and the secondary endpoints were overall survival (OS) and progression-free survival (PFS). Results were compared to those of a previous Japanese domestic bevacizumab trial for recurrent GB (JO22506).

Results

The 1-year survival rate and median OS of the recurrent GB cases in this trial were 79.2% (95% CI: 57.0–90.8) and 18.9 months (95% CI: 12.9–not estimable), respectively, whereas those of JO22506 were 34.5% (90% CI: 20.0–49.0) and 10.5 months (95% CI: 8.2–12.4), respectively. The median PFS was 0.9 months (95% CI: 0.8–1.0) by the RANO criteria. The most prominent adverse event was brain edema. Twenty-one of 27 cases were treated with bevacizumab following progressive disease.

Conclusions

AB-BNCT demonstrated acceptable safety and prolonged survival for recurrent MG. AB-BNCT may increase the risk of brain edema due to re-irradiation for recurrent MG; however, this appears to be controlled well with bevacizumab.

Role of Hyperbaric Oxygenation Plus Hypofractionated Stereotactic Radiotherapy in Recurrent High-Grade Glioma

BACKGROUND

The presence of hypoxic cells in high-grade glioma (HGG) is one of major reasons for failure of local tumour control with radiotherapy (RT). The use of hyperbaric oxygen therapy (HBO) could help to overcome the problem of oxygen deficiency in poorly oxygenated regions of the tumour. We propose an innovative approach to improve the efficacy of hypofractionated stereotactic radiotherapy (HSRT) after HBO (HBO-RT) for the treatment of recurrent HGG (rHGG) and herein report the results of an ad interim analysis.

METHODS

We enrolled a preliminary cohort of 9 adult patients (aged >18 years) with a diagnosis of rHGG. HSRT was administered in daily 5-Gy fractions for 3-5 consecutive days a week. Each fraction was delivered up to maximum of 60 minutes after HBO.

RESULTS

Median follow-up from re-irradiation was 11.6 months (range: 3.2-11.6 months). The disease control rate (DCR) 3 months after HBO-RT was 55.5% (5 patients). Median progression-free survival (mPFS) for all patients was 5.2 months (95%CI: 1.34-NE), while 3-month and 6-month PFS was 55.5% (95%CI: 20.4-80.4) and 27.7% (95%CI: 4.4-59.1), respectively. Median overall survival (mOS) of HBO-RT was 10.7 months (95% CI: 7.7-NE). No acute or late neurologic toxicity >grade (G)2 was observed in 88.88% of patients. One patient developed G3 radionecrosis.

CONCLUSIONS

HSRT delivered after HBO appears to be effective for the treatment of rHGG, it could represent an alternative, with low toxicity, to systemic therapies for patients who cannot or refuse to undergo such treatments.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, identifier NCT03411408.

Current status and recent advances in reirradiation of glioblastoma

Despite aggressive management consisting of maximal safe surgical resection followed by external beam radiation therapy (60 Gy/30 fractions) with concomitant and adjuvant temozolomide, approximately 90% of WHO grade IV gliomas (glioblastomas, GBM) will recur locally within 2 years. For patients with recurrent GBM, no standard of care exists. Thanks to the continuous improvement in radiation science and technology, reirradiation has emerged as feasible approach for patients with brain tumors. Using stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT), either hypofractionated or conventionally fractionated schedules, several studies have suggested survival benefits following reirradiation of patients with recurrent GBM; however, there are still questions to be answered about the efficacy and toxicity associated with a second course of radiation. We provide a clinical overview on current status and recent advances in reirradiation of GBM, addressing relevant clinical questions such as the appropriate patient selection and radiation technique, optimal dose fractionation, reirradiation tolerance of the brain and the risk of radiation necrosis.

Safety and efficacy of Hypofractionated stereotactic radiosurgery for high-grade Gliomas at first recurrence: a single-center experience

Background

The optimal treatment for recurrent high-grade gliomas (rHGGs) remains uncertain. This study aimed to investigate the efficacy and safety of hypofractionated stereotactic radiosurgery (HSRS) as a first-line salvage treatment for in-field recurrence of high-grade gliomas.

Methods

Between January 2016 and October 2019, 70 patients with rHGG who underwent HSRS were retrospectively analysed. The primary endpoint was overall survival (OS), and secondary endpoints included both progression-free survival (PFS) and adverse events, which were assessed according to Common Toxicity Criteria Adverse Events (CTCAE) version 5. The prognostic value of key clinical features (age, performance status, planning target volume, dose, use of bevacizumab) was evaluated.

Results

A total of 70 patients were included in the study. Forty patients were male and 30 were female. Forty-nine had an initial diagnosis of glioblastoma (GBM), and the rest (21) were confirmed to be WHO grade 3 gliomas. The median planning target volume (PTV) was 16.68 cm³ (0.81–121.96 cm³). The median prescribed dose was 24 Gy (12–30 Gy) in 4 fractions (2–6 fractions). The median baseline of Karnofsky Performance Status (KPS) was 70 (40–90). With a median follow-up of 12.1 months, the median overall survival after salvage treatment was 17.6 months (19.5 and 14.6 months for grade 3 and 4 gliomas, respectively; p = .039). No grade 3 or higher toxicities was recorded. Multivariate analysis showed that concurrent bevacizumab with radiosurgery and KPS > 70 were favourable prognostic factors for grade 4 patients with HGG.

Conclusions

Salvage HSRS showed a favourable outcome and acceptable toxicity for rHGG. A prospective phase II study (NCT04197492) is ongoing to further investigate the value of hypofractionated stereotactic radiosurgery (HSRS) in rHGG.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07856-y.

Re-irradiation of recurrent glioblastoma using helical TomoTherapy with simultaneous integrated boost: preliminary considerations of treatment efficacy

Although there is still no standard treatment for recurrent glioblastoma multiforme (rGBM), re-irradiation could be a therapeutic option. We retrospectively evaluated the efficacy and safety of re-irradiation using helical TomoTherapy (HT) with a simultaneous integrated boost (SIB) technique in patients with rGBM. 24 patients with rGBM underwent HT-SIB. A total dose of 20 Gy was prescribed to the Flair (fluid-attenuated inversion recovery) planning tumor volume (PTV) and 25 Gy to the PTV-boost (T1 MRI contrast enhanced area) in 5 daily fractions to the isodose of 67% (maximum dose within the PTV-boost was 37.5 Gy). Toxicity was evaluated by converting the 3D-dose distribution to the equivalent dose in 2 Gy fractions on a voxel-by-voxel basis. Median follow-up after re-irradiation was 27.8 months (range 1.6-88.5 months). Median progression-free survival (PFS) was 4 months (95% CI 2.0-7.9 months), while 6-month PFS was 41.7% (95% CI 22.2-60.1 months). Median overall survival following re-irradiation was 10.7 months (95% CI 7.4-16.1 months). There were no cases of re-operation due to early or late toxicity. Our preliminary results suggest that helical TomoTherapy with the proposed SIB technique is a safe and feasible treatment option for patients with rGBM, including those large disease volumes, reducing toxicity.

Low Fraction Size Re-irradiation for Large Volume Recurrence of Glial Tumours

The aim of the present study was to evaluate the efficacy of re-irradiation (re-RT) in patients with advanced local relapses of glial tumours and to define the factors influencing the result of the hyper-fractionated external beam therapy on progression after primary management. We have analysed the data of 55 patients with brain tumours (GBM: 28) on progression, who were re-irradiated between January 2007 and December 2018. The mean volume of the recurrent tumour was 118 cm³, and the mean planning target volume (PTV) was 316 cm³, to which 32 Gy was delivered in 20 fractions at least 7.7 months after the first radiotherapy, using 3D conformal radiotherapy (CRT) or intensity modulated radiotherapy (IMRT). The median overall survival (mOS) from the re-RT was 8.4 months, and the 6-month and the 12-month OS rate was 64% and 31%, respectively. The most important factors by univariate analysis, which significantly improved the outcome of re-RT were the longer time interval between the diagnosis and second radiotherapy (p = 0.029), the lower histology grade (p = 0.034), volume of the recurrent tumour (p = 0.006) and Karnofsky performance status (KPS) (p = 0.009) at the re-irradiation. Our low fraction size re-irradiation ≥ 8 months after the first radiotherapy proved to be safe and beneficial for patients with large volume recurrent glial tumours.

Stereotactic reirradiation with temozolomide in patients with recurrent aggressive pituitary tumors and pituitary carcinomas

OBJECTIVES

To evaluate the efficacy of a second course of fractionated stereotactic radiotherapy (re-SRT) and temozolomide (TMZ) as salvage treatment option in patients with aggressive pituitary tumors (APTs) and pituitary carcinomas (PCs).

PATIENTS AND METHODS

Twenty-one patients with recurrent or progressive APTs (n = 17) and PCs (n = 4) who received combined TMZ and re-SRT, 36 Gy/18fractions or 37.5 Gy/15fractions, were retrospectively evaluated. TMZ was given at a dose of 75 mg/m² given concurrently to re-SRT, and then 150-200 mg/m²/day for 5 days every 4 weeks or 50 mg/m² daily for 12 months. Local control (LC) and overall survival (OS) were calculated from the time of re-SRT by Kaplan-Meier method.

RESULTS

With a median follow-up of 27 months (range 12-58 months), 2-year and 4-year LC rates were 73% and 65%, respectively; 2-year and 4-year survival rates were 82% and 66%, respectively. A complete response was achieved in 2 and partial response in 11 patients. Six patients recurred with a median time to progression of 14 months. O(6)-Methylguanine-DNA methyltransferase (MGMT) status and tumor volume emerged as prognostic factors. Grade 3 radiation-related toxicities occurred in 3 (14%) patients. Grade 2 or 3 hematologic toxicities during chemotherapy occurred in 8 (38%) patients.

CONCLUSION

Re-SRT and TMZ is a safe treatment offering high LC in patients with progressive APTs and PCs. The potential advantages of combined chemoradiation as up-front or salvage treatment need to be explored in prospective trials.

Re-Irradiation and Its Contribution to Good Prognosis in Recurrent Glioblastoma Patients

Background

Radiation therapy, one of the strongest anti-cancer treatments, is already performed to treat primary glioblastoma; however, the effect of repeated radiation therapy for recurrent tumors has not been fully explored. The aim of this study was to determine the efficacy of re-irradiation in treating recurrent glioblastoma.

Methods

The study included 36 patients with recurrent glioblastoma treated with repeated radiation therapy between 2002 and 2016. Stereotactic radiosurgery (SRS) and hypo-fractionated stereotactic radiotherapy (HSRT) were performed in these patients.

Results

Fourteen patients received SRS with a median dose of 25 Gy (range, 20–32 Gy) in 1–5 fractions. Twenty-two patients received HSRT with a median dose of 40 Gy (range, 31.5–52 Gy) in 6–20 fractions. There were six treatment-related grade 3 adverse events. Survival analysis showed that re-irradiation significantly prolonged overall survival (OS) and progression-free survival (PFS). The median OS and one-year OS rate after re-irradiation were 17.2 months and 60.4%, respectively. The median PFS and 6-month PFS rate after re-irradiation were 4.4 months and 41.9%, respectively. Of the 36 patients, three survived without any progression in their condition.

Conclusion

Re-irradiation for recurrent glioblastoma showed favorable outcomes. Radiation dose and fractionation should be carefully considered to minimize radiation necrosis.

Digital biomarkers: Importance of patient stratification for re-irradiation of glioma patients - Review of latest developments regarding scoring assessment

PURPOSE

To review scoring assessments in re-irradiation of high-grade glioma (HGG) patients and how to use scoring for patient stratification. The next aim was to investigate the different approaches employed by the scoring systems and the way they can be applied to build homogeneous patient groups for a reliable prognosis.

METHODS

We searched the Medline/Pubmed and Web of science databases for relevant articles regarding scores for re-irradiation of recurrent HGG. All references were divided into the following groups: novel score establishment (n = 5), score validation (n = 6), not relevant to this evaluation (n = 26).

RESULTS

We identified five scoring systems. Two are modifications of an already existing score. Calculations differ immensely from easy point addition to a more complex formula with including three up to 10 individual parameters. Six validation articles were found for three of the scores; one was validated four times. Two scores were never validated.

CONCLUSION

For recurrent HGG, the clinical situation remains demanding. Due to the heterogeneity of data at re-irradiation, patient stratification is important. Several scoring systems have been developed to predict prognosis. As a digital biomarker, scores are of high value regarding quick patient assessment and therapy decision making. For the next generation of digital biomarkers, easy calculation, and inclusion of easily available parameters are crucial.

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

BACKGROUND

Generally, re-irradiation (Re-RT) is offered to patients with glioma recurrences with macroscopic lesions. Results are discussed controversially, and some centers postulate limited benefit of Re-RT. Re-RT is generally offered to tumors up to 4 cm in diameter. Re-resection is also discussed controversially; however, recent studies have shown significant benefit.

OBJECTIVE

To combine proactive re-resection and early Re-RT in patients with recurrent glioma.

METHODS

We included 108 patients treated between 2002 and 2016 for recurrent glioma. All patients underwent surgical resection for recurrence; Re-RT was applied with a median dose of 37.5 Gy (range 25 Gy-57Gy/equivalent dose in 2Gy fractions [EQD2]) with high-precision techniques. All patients were followed prospectively in an interdisciplinary follow-up program.

RESULTS

Median follow-up after Re-RT was 7 mo. Median survival after surgery and Re-RT was 12 mo (range 1-102 mo). Complete resection had a significant impact on the outcome (P = .03). The strongest predictors of outcome were MGMT-promotor methylation and Karnofsky Performance Score and time interval between primary and second RT.

CONCLUSION

Proactive resection of tumor recurrences combined with early Re-RT conveys into promising outcome in recurrent glioma. Complete resection and early Re-RT lead to improved survival. Thus, moving Re-RT to an earlier timepoint during the treatment of recurrent glioma, eg after complete macroscopic removal of the tumor, may be crucial for treatment optimization. Using advanced RT techniques, side effects are low. Currently, this concept is evaluated in the GLIOCAVE/NOA 17 trial.

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.

Hypofractionated stereotactic radiotherapy combined with chemotherapy or not in the management of recurrent malignant gliomas: A systematic review and meta-analysis

Hypofractionated stereotactic radiotherapy (HFSRT) is a common salvage treatment for recurrent malignant glioma (MG). However, it remains controversial whether the combination of HFSRT and chemotherapy could improve survival for patients with recurrent MG compared to HFSRT alone. The present systematic review and meta-analysis aims to investigate this question, and tries to determine to what extent the addition of chemotherapy to HFSRT affects survival. A systematic review was performed to analyse the survival for patients treated with HFSRT combined with chemotherapy or not. Hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) were pooled with random effects; and standard mean difference (MD) with 95% CIs for OS were pooled using the same strategy. A total of 7 studies including 388 patients with recurrent MG were eligible for our study. The OS survival of patients receiving combination therapy ranged from 8.7 to 23 months, and the median OS of patients underwent HFSRT ranged from 3.9 to 12 months. The meta-analyses resulted in the pooled HR of 0.44 (95% CI 0.30-0.65, p < 0.0001) (Cochran Q statistic 4.70, P = 0.320, I² = 14.8%) and pooled standard MD of 0.80 months (95% CI 0.41-1.18, p < 0.001) (Cochran Q statistic 10.16, p = 0.71, I² = 50.8%). The present study suggests that HFSRT + chemotherapy confers a slight survival improvement for patients with recurrent MG as compared with sole HFSRT management. To draw a more solid conclusion, greater investigation is warranted.

Reirradiation of recurrent high-grade glioma and development of prognostic scores for progression and survival

Background

Optimal techniques and patient selection for salvage reirradiation of high-grade glioma (HGG) are unclear. In this study, we identify prognostic factors for freedom from progression (FFP) and overall survival (OS) after reirradiation, risk factors for high-grade toxicity, and validate clinical prognostic scores.

Methods

A total of 116 patients evaluated between 2000 and 2018 received reirradiation for HGG (99 WHO grade IV, 17 WHO grade III). Median time to first progression after initial therapy was 10.6 months. Salvage therapies before reirradiation included surgery (31%) and systemic therapy (41%). Sixty-five patients (56%) received single-fraction stereotactic radiosurgery (SRS) as reirradiation. The median biologically effective dose (BED) was 47.25 Gy, and the median planning target volume (PTV) was 4.8 cc for SRS and 95.0 cc for non-SRS treatments. Systemic therapy was given concurrently to 52% and adjuvantly to 74% of patients.

Results

Median FFP was 4.9 months, and median OS was 11.0 months. Significant multivariable prognostic factors for FFP were performance status, time to initial progression, and BED; for OS they were age, time to initial progression, and PTV volume at recurrence. High-grade toxicity was correlated to PTV size at recurrence. Three-level prognostic scores were generated for FFP and OS, with cross-validated receiver operating characteristic area under the curve (AUC) of 0.640 and 0.687, respectively.

Conclusions

Clinical variables at the time of reirradiation for HGG can be used to prognosticate FFP and OS.

Hypofractionated Stereotactic Radiotherapy as a Salvage Therapy for Recurrent High-Grade Gliomas: Single-Center Experience

Background and Purpose:

The aim of this study was to investigate the survival outcomes and safety of hypofractioned stereotactic radiotherapy as a salvage treatment for recurrent high-grade glioma.

Patients and Methods:

Between March 2012 and March 2017, 32 consecutive patients (12 women, 20 men) treated in a single center were retrospectively included in this study. Grade III gliomas were diagnosed in 14 patients and grade IV in 18 patients. Thirty-four lesions were treated with hypofractionated stereotactic radiotherapy on a linear accelerator. Hypofractionated stereotactic radiotherapy delivered a median dose of 30 Gy (27-30) in 6 fractions (3-6) of 5 Gy (5-9). The treatment plans were normalized to 100% at the isocenter and prescribed to the 80% isodose line. Clinical outcomes and prognostic factors were analyzed.

Results:

Median follow-up was 20.9 months. Median overall survival following hypofractionated stereotactic radiotherapy was 15.6 months (median overall survival for patients with glioblastoma and grade III glioma was 8.2 and 19.5 months, respectively; P = .0496) and progression-free survival was 3.7 months (median progression-free survival for patients with glioblastoma and grade III glioma was 3.6 and 4.5 months, respectively; P = .2424). In multivariate analysis, tumor grade III (P = .0027), an Eastern Cooperative Oncology Group status <2 at the time of reirradiation (P = .0023), and a mean dose >35 Gy (P = .0055) significantly improved overall survival. A maximum reirradiation dose above 38 Gy (P = .0179) was significantly associated with longer progression-free survival.

Conclusion:

Hypofractionated stereotactic radiotherapy is well tolerated and offers an effective salvage option for the treatment of recurrent high-grade gliomas with encouraging overall survival. Our results suggest that the dose distribution had an impact on survival.

Re-irradiation for recurrent glioma: outcome evaluation, toxicity and prognostic factors assessment. A multicenter study of the Radiation Oncology Italian Association (AIRO)

INTRODUCTION

The prognosis of glioma is dismal, and almost all patients relapsed. At recurrence time, several treatment options are considered, but to date there is no a standard of care. The Neurooncology Study Group of the Italian Association of Radiation Oncology (AIRO) collected clinical data regarding a large series of recurrent glioma patients who underwent re-irradiation (re-RT) in Italy.

METHODS

Data regarding 300 recurrent glioma patients treated from May 2002 to November 2017, were analyzed. All patients underwent re-RT. Surgical resection, followed by re-RT with concomitant and adjuvant chemotherapy was performed. Clinical outcome was evaluated by neurological examination and brain MRI performed, 1 month after radiation therapy and then every 3 months.

RESULTS

Re-irradiation was performed at a median interval time (IT) of 16 months from the first RT. Surgical resection before re-RT was performed in 19% of patients, concomitant temozolomide (TMZ) in 16.3%, and maintenance chemotherapy in 29%. Total doses ranged from 9 Gy to 52.5 Gy, with a median biological effective dose of 43 Gy. The median, 1, 2 year OS were 9.7 months, 41% and 17.7%. Low grade glioma histology (p  ≪ 0.01), IT > 12 months (p = 0.001), KPS > 70 (p = 0.004), younger age (p = 0.001), high total doses delivered (p = 0.04), and combined treatment performed (p = 0.0008) were recorded as conditioning survival.

CONCLUSION

our data underline re-RT as a safe and feasible treatment with limited rate of toxicity, and a combined ones as a better option for selected patients. The identification of a BED threshold able to obtain a greater benefit on OS, can help in designing future prospective studies.

Re-irradiation for recurrent high-grade gliomas: a systematic review and analysis of treatment technique with respect to survival and risk of radionecrosis

Background

Re-irradiation may be considered for select patients with recurrent high-grade glioma. Treatment techniques include conformal radiotherapy employing conventional fractionation, hypofractionated stereotactic radiotherapy (FSRT), and single-fraction stereotactic radiosurgery (SRS).

Methods

A pooled, population-weighted, multiple linear regression analysis of publications from 1992 to 2016 was performed to evaluate the relationships between re-irradiation technique and median overall survival (OS) and radionecrosis outcomes.

Results

Seventy published articles were analyzed, yielding a total of 3302 patients. Across all studies, initial treatment was external beam radiotherapy to a median dose of 60 Gy in 30 fractions, with or without concurrent chemotherapy. On multivariate analysis, there was a significant correlation between OS and radiotherapy technique after adjusting for age, re-irradiation biologically equivalent dose (EQD2), interval between initial and repeat radiotherapy, and treatment volume (P < .0001). Adjusted mean OS was 12.2 months (95% CI, 11.8-12.5) after SRS, 10.1 months (95% CI, 9.7-10.5) after FSRT, and 8.9 months (95% CI, 8.4-9.4) after conventional fractionation. There was also a significant association between radionecrosis and treatment technique after adjusting for age, re-irradiation EQD2, interval, and volume (P < .0001). Radionecrosis rate was 7.1% (95% CI, 6.6-7.7) after FSRT, 6.1% (95% CI, 5.6-6.6) after SRS, and 1.1% (95% CI, 0.5-1.7) after conventional fractionation.

Conclusions

The published literature suggests that OS is highest after re-irradiation using SRS, followed by FSRT and conventionally fractionated radiotherapy. Whether this represents superiority of the treatment technique or an uncontrolled selection bias is uncertain. The risk of radionecrosis was low for all modalities overall. Re-irradiation is a feasible option in appropriately selected patients.

Stereotactic Radiosurgery and Hypofractionated Radiotherapy for Glioblastoma

Glioblastoma is the most common primary brain tumor in adults. Standard therapy depends on patient age and performance status but principally involves surgical resection followed by a 6-wk course of radiation therapy given concurrently with temozolomide chemotherapy. Despite such treatment, prognosis remains poor, with a median survival of 16 mo. Challenges in achieving local control, maintaining quality of life, and limiting toxicity plague treatment strategies for this disease. Radiotherapy dose intensification through hypofractionation and stereotactic radiosurgery is a promising strategy that has been explored to meet these challenges. We review the use of hypofractionated radiotherapy and stereotactic radiosurgery for patients with newly diagnosed and recurrent glioblastoma.

Re-irradiation as salvage treatment in recurrent glioblastoma: A comprehensive literature review to provide practical answers to frequently asked questions

The primary aim of this review is to provide practical recommendations in terms of fractionation, dose, constraints and selection criteria to be used in the daily clinical routine. Based on the analysis of the literature reviewed, in order to keep the risk of severe side effects ≤3,5%, patients should be stratified according to the target volume. Thus, patients should be treated with different fractionation and total EQD2 (<12.5 ml: EQD2 < 65 Gy with radiosurgery; >12.5 ml and <35 ml: EQD2 < 50 Gy with hypofractionated stereotactic radiotherapy; >35 ml and <50 ml: EQD2 < 36 Gy with conventionally fractionated radiotherapy). Concurrent approaches with temozolomide or bevacizumab do not seem to improve the outcomes of reirradiation and may lead to a higher risk of toxicity but these findings need to be confirmed in prospective series.

Re-irradiation of recurrent gliomas: pooled analysis and validation of an established prognostic score-report of the Radiation Oncology Group (ROG) of the German Cancer Consortium (DKTK)

The heterogeneity of high‐grade glioma recurrences remains an ongoing challenge for the interdisciplinary neurooncology team. Response to re‐irradiation (re‐RT) is heterogeneous, and survival data depend on prognostic factors such as tumor volume, primary histology, age, the possibility of reresection, or time between primary diagnosis and initial RT and re‐RT. In the present pooled analysis, we gathered data from radiooncology centers of the DKTK Consortium and used it to validate the established prognostic score by Combs et al. and its modification by Kessel et al. Data consisted of a large independent, multicenter cohort of 565 high‐grade glioma patients treated with re‐RT from 1997 to 2016 and a median dose of 36 Gy. Primary RT was between 1986 and 2015 with a median dose of 60 Gy. Median age was 54 years; median follow‐up was 7.1 months. Median OS after re‐RT was 7.5, 9.5, and 13.8 months for WHO IV, III, and I/II gliomas, respectively. All six prognostic factors were tested for their significance on OS. Aside from the time from primary RT to re‐RT (P = 0.074) and the reresection status (P = 0.101), all factors (primary histology, age, KPS, and tumor volume) were significant. Both the original and new score showed a highly significant influence on survival with P < 0.001. Both prognostic scores successfully predict survival after re‐RT and can easily be applied in the routine clinical workflow. Now, further prognostic features need to be found to even improve treatment decisions regarding neurooncological interventions for recurrent glioma patients.

Reirradiation of gliomas under stereotactic conditions: Prognostic factors for survival without relapse or side effects, a retrospective study at Tours regional university hospital (France)

PURPOSE

To search for factors correlated with relapse-free survival following stereotactic reirradiation in patients with recurrent glioma following radiochemotherapy and evaluate tolerance to this treatment.

PATIENTS AND METHODS

Initial radiotherapy was given according to the protocol of Stupp and al. Reirradiation was performed using the CyberKnife^® system. Patients could have had surgical resection initially and at the time of recurrence. We analysed 13 patients treated between July 2010 and September 2014. The median age was 55 years. The doses delivered ranged from 20 to 36Gy, in one to ten fractions.

RESULTS

Median survival after stereotactic radiotherapy was 14 months. Survival without relapse was 3.7 months. Factors significantly influencing duration of relapse-free survival were: age (P=0.04), total dose (P=0.02), dose per fraction (P=0.04) and number of fractions (P=0.01). We found no correlation between gross tumour volume, clinical target volume, grade of tumour or prescription isodose and relapse-free survival following radiochemotherapy. Three patients developed radionecrosis.

CONCLUSION

Reirradiation under stereotactic conditions is well tolerated. A dose of more than 30Gy delivered in 5 or more fractions seems to prolong relapse-free survival.

Survival and complications of stereotactic radiosurgery: A systematic review of stereotactic radiosurgery for newly diagnosed and recurrent high-grade gliomas

BACKGROUND

Utilization of stereotactic radiosurgery (SRS) for treatment of high-grade gliomas (HGGs) has been slowly increasing with variable reported success rates.

OBJECTIVE

Systematic review of the available data to evaluate the efficacy of SRS as a treatment for HGG with regards to median overall survival (OS) and progression-free survival (PFS), in addition to ascertaining the rate of radiation necrosis and other SRS-related major neurological complications.

METHODS

Literature searches were performed for publications from 1992 to 2016. The pooled estimates of median PFS and median OS were calculated as a weighted estimate of population medians. Meta-analyses of published rates of radiation necrosis and other major neurological complications were also performed.

RESULTS

Twenty-nine studies reported the use of SRS for recurrent HGG, and 16 studies reported the use of SRS for newly diagnosed HGG. For recurrent HGG, the pooled estimates of median PFS and median OS were 5.42 months (3-16 months) and 20.19 months (9-65 months), respectively; the pooled radiation necrosis rate was 5.9% (0-44%); and the pooled estimates of major neurological complications rate was 3.3% (0-23%). For newly diagnosed HGG, the pooled estimates of median PFS and median OS were 7.89 months (5.5-11 months) and 16.87 months (9.5-33 months) respectively; the pooled radiation necrosis rate was 6.5% (0-33%); and the pooled estimates of other major neurological complications rate was 1.5% (0-25%).

CONCLUSION

Our results suggest that SRS holds promise as a relatively safe treatment option for HGG. In terms of efficacy at this time, there are inadequate data to support routine utilization of SRS as the standard of care for newly diagnosed or recurrent HGG. Further studies should be pursued to define more clearly the therapeutic role of SRS.

Multicenter, Phase 1, Dose Escalation Study of Hypofractionated Stereotactic Radiation Therapy With Bevacizumab for Recurrent Glioblastoma and Anaplastic Astrocytoma

PURPOSE

To establish the maximum tolerated dose of a 3-fraction hypofractionated stereotactic reirradiation schedule when delivered with concomitant bevacizumab to treat recurrent high-grade gliomas.

METHODS AND MATERIALS

Patients with recurrent high-grade glioma with Karnofsky performance status ≥60, history of standard fractionated initial radiation, tumor volume at recurrence ≤40 cm³, and absence of brainstem or corpus callosum involvement were eligible. A standard 3+3 phase 1 dose escalation trial design was utilized, with dose-limiting toxicities defined as any grade 3 to 5 toxicities possibly, probably, or definitely related to radiation. Bevacizumab was given at a dose of 10 mg/kg every 2 weeks. Hypofractionated stereotactic reirradiation was initiated after 2 bevacizumab doses, delivered in 3 fractions every other day, starting at 9 Gy per fraction.

RESULTS

A total of 3 patients were enrolled at the 9 Gy × 3 dose level cohort, 5 in the 10 Gy × 3 cohort, and 7 in the 11 Gy × 3 cohort. One dose-limiting toxicity of grade 3 fatigue and cognitive deterioration possibly related to hypofractionated stereotactic reirradiation was observed in the 11 Gy × 3 cohort, and this dose was declared the maximum tolerated dose in combination with bevacizumab. Although no symptomatic radionecrosis was observed, substantial treatment-related effects and necrosis were observed in resected specimens. The intent-to-treat median overall survival was 13 months.

CONCLUSIONS

Reirradiation using a 3-fraction schedule with bevacizumab support is feasible and reasonably well tolerated. Dose-escalation was possible up to 11 Gy × 3, which achieves a near doubling in the delivered biological equivalent dose to normal brain, in comparison with our previous 6 Gy × 5 schedule. Promising overall survival warrants further investigation.

The radiosurgery fractionation quandary: single fraction or hypofractionation?

Stereotactic radiosurgery (SRS), typically administered in a single session, is widely employed to safely, efficiently, and effectively treat small intracranial lesions. However, for large lesions or those in close proximity to critical structures, it can be difficult to obtain an acceptable balance of tumor control while avoiding damage to normal tissue when single-fraction SRS is utilized. Treating a lesion in 2 to 5 fractions of SRS (termed "hypofractionated SRS" [HF-SRS]) potentially provides the ability to treat a lesion with a total dose of radiation that provides both adequate tumor control and acceptable toxicity. Indeed, studies of HF-SRS in large brain metastases, vestibular schwannomas, meningiomas, and gliomas suggest that a superior balance of tumor control and toxicity is observed compared with single-fraction SRS. Nonetheless, a great deal of effort remains to understand radiobiologic mechanisms for HF-SRS driving the dose-volume response relationship for tumors and normal tissues and to utilize this fundamental knowledge and the results of clinic studies to optimize HF-SRS. In particular, the application of HF-SRS in the setting of immunomodulatory cancer therapies offers special challenges and opportunities.

Re-irradiation after gross total resection of recurrent glioblastoma : Spatial pattern of recurrence and a review of the literature as a basis for target volume definition

BACKGROUND

Currently, patients with gross total resection (GTR) of recurrent glioblastoma (rGBM) undergo adjuvant chemotherapy or are followed up until progression. Re-irradiation, as one of the most effective treatments in macroscopic rGBM, is withheld in this situation, as uncertainties about the pattern of re-recurrence, the target volume, and also the efficacy of early re-irradiation after GTR exist.

METHODS

Imaging and clinical data from 26 consecutive patients with GTR of rGBM were analyzed. The spatial pattern of recurrences was analyzed according to the RANO-HGG criteria ("response assessment in neuro-oncology criteria for high-grade gliomas"). Progression-free (PFS) and overall survival (OS) were analyzed by the Kaplan-Meier method. Furthermore, a systematic review was performed in PubMed.

RESULTS

All but 4 patients underwent adjuvant chemotherapy after GTR. Progression was diagnosed in 20 of 26 patients and 70% of recurrent tumors occurred adjacent to the resection cavity. The median extension beyond the edge of the resection cavity was 20 mm. Median PFS was 6 months; OS was 12.8 months. We propose a target volume containing the resection cavity and every contrast enhancing lesion as the gross tumor volume (GTV), a spherical margin of 5-10 mm to generate the clinical target volume (CTV), and a margin of 1-3 mm to generate the planning target volume (PTV). Re-irradiation of this volume is deemed to be safe and likely to prolong PFS.

CONCLUSION

Re-irradiation is worth considering also after GTR, as the volumes that need to be treated are limited and re-irradiation has already proven to be a safe treatment option in general. The strategy of early re-irradiation is currently being tested within the GlioCave/NOA 17/Aro 2016/03 trial.

The evolving role for re-irradiation in the management of recurrent grade 4 glioma

Although significant gains have been realized in the management of grade 4 glioma, the majority of these patients will ultimately suffer local recurrence within the prior field of treatment. Clearly, novel local treatment strategies are required to improve patient outcomes. Concerns of toxicity have limited enthusiasm for the utilization of re-irradiation as a treatment option. However, using modern imaging technology and precision radiotherapy delivery techniques re-irradiation has proven a feasible option achieving both a palliative benefit and prolongation of survival with low toxicity rates. The evolution of re-irradiation as a treatment modality for recurrent grade 4 glioma is reviewed. In addition, potential targeted radiosensitizers to be used in conjunction with re-irradiation are also discussed.

Management of GBM: a problem of local recurrence

Forty years ago, adjuvant treatment of patients with GBM using fractionated radiotherapy following surgery was shown to substantially improve survival compared to surgery alone. However, even with the addition of temozolomide to radiotherapy, overall survival is quite limited and local failure remains a fundamental problem, despite multiple attempts to increase dose to the tumor target. This review presents the historical background and clinical rationale leading to the current standard of care consisting of 60 Gy total dose in 2 Gy fractions to the MRI-defined targets in younger, high performance status patients and more hypofractionated regimens in elderly and/or debilitated patients. Particle therapies offer the potential to increase local control while reducing dose and, potentially, long-term neurocognitive toxicity. However, improvements in systemic therapies for GBM will need to be implemented before the full benefits of improved local control can be realized.

Re-irradiation alternatives for recurrent high-grade glioma

Despite advances in the fields of surgery, chemotherapy and radiotherapy, the prognosis for high-grade glioma (HGG) remains unsatisfactory. The majority of HGG patients experience disease recurrence. To date, no standard treatments have been established for recurrent HGG. Repeat surgery and chemotherapy demonstrate moderate efficacy. As recurrent lesions are usually located within the previously irradiated field, a second course of irradiation was once considered controversial, as it was considered to exhibit unsatisfactory efficacy and radiation-related toxicities. However, an increasing number of studies have indicated that re-irradiation may present an efficacious treatment for recurrent HGG. Re-irradiation may be delivered via conventionally fractionated stereotactic radiotherapy, hypofractionated stereotactic radiation therapy, stereotactic radiosurgery and brachytherapy techniques. In the present review, the current literature regarding re-irradiation treatment for recurrent HGG is summarized with regard to survival outcome and side effects.

Innovative Hypofractionated Stereotactic Regimen Achieves Excellent Local Control with No Radiation Necrosis: Promising Results in the Management of Patients with Small Recurrent Inoperable GBM

Management of recurrent glioblastoma multiforme (GBM) remains a challenge. Several institutions reported that a single fraction of ≥ 20 Gy for small tumor burden results in excellent local control; however, this is at the expense of a high incidence of radiation necrosis (RN). Therefore, we developed a hypofractionation pattern of 33 Gy/3 fractions, which is a radiobiological equivalent of 20 Gy, with the aim to lower the incidence of RN. We reviewed records of 21 patients with recurrent GBM treated with hypofractionated stereotactic radiation therapy (HFSRT) to their 22 respective lesions. Sixty Gy fractioned external beam radiotherapy was performed as first-line treatment. Median time from primary irradiation to HFSRT was 9.6 months (range: 3.1 – 68.1 months). In HFSRT, a median dose of 33 Gy in 11 Gy fractions was delivered to the 80% isodose line that encompassed the target volume. The median tumor volume was 1.07 cm3 (range: 0.11 – 16.64 cm3). The median follow-up time after HFSRT was 9.3 months (range: 1.7 – 33.6 months). Twenty-one of 23 lesions treated (91.3%) achieved local control while 2/23 (8.7%) progressed. Median time to progression outside of the treated site was 5.2 months (range: 2.2 – 9.6 months). Progression was treated with salvage chemotherapy. Five of 21 patients (23.8%) were alive at the end of this follow-up; two patients remain disease-free. The remaining 16/21 patients (76.2%) died of disease. Treatment was well tolerated by all patients with no acute CTC/RTOG > Grade 2. There was 0% incidence of RN. A prospective trial will be underway to validate these promising results.

Stereotactic Radiosurgery for Glioblastoma

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults and one of the most aggressive of all human cancers. GBM tumors are highly infiltrative and relatively resistant to conventional therapies. Aggressive management of GBM using a combination of surgical resection, followed by fractionated radiotherapy and chemotherapy has been shown to improve overall survival; however, GBM tumors recur in the majority of patients and the disease is most often fatal. There is a need to develop new treatment regimens and technological innovations to improve the overall survival of GBM patients. The role of stereotactic radiosurgery (SRS) for the treatment of GBM has been explored and is controversial. SRS utilizes highly precise radiation techniques to allow dose escalation and delivery of ablative radiation doses to the tumor while minimizing dose to the adjacent normal structures. In some studies, SRS with concurrent chemotherapy has shown improved local control with acceptable toxicities in select GBM patients. However, because GBM is a highly infiltrative disease, skeptics argue that local therapies, such as SRS, do not improve overall survival. The purpose of this article is to review the literature regarding SRS in both newly diagnosed and recurrent GBM, to describe SRS techniques, potential eligible SRS candidates, and treatment-related toxicities. In addition, this article will propose promising areas for future research for SRS in the treatment of GBM.

Recurrent malignant gliomas

In almost all patients, malignant glioma recurs following initial treatment with maximal safe resection, conformal radiotherapy, and temozolomide. This review describes the many options for treatment of recurrent malignant gliomas, including reoperation, alternating electric field therapy, chemotherapy, stereotactic radiotherapy or radiosurgery, or some combination of these modalities, presenting the evidence for each approach. No standard of care has been established, though the antiangiogenic agent, bevacizumab; stereotactic radiotherapy or radiosurgery; and, perhaps, combined treatment with these 2 modalities appear to offer modest benefits over other approaches. Clearly, randomized trials of these options would be advantageous, and novel, more efficacious approaches are urgently needed.

Management of patients with recurrent glioblastoma using hypofractionated stereotactic radiotherapy

BACKGROUND

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. The chance of cure is very limited due to treatment-refractory disease course with frequent recurrences despite aggressive multimodality management. In this retrospective study, we evaluated treatment outcomes of hypofractionated stereotactic radiotherapy (HFSRT) in the management of recurrent GBM and report our single-center experience.

METHODS

Twenty-eight patients receiving HFSRT for recurrent GBM between September 2008 and February 2014 were retrospectively assessed. Total radiotherapy dose was 25 Gy delivered in 5 fractions over 5 consecutive days for all patients. High-precision, image-guided volumetric modulated arc therapy was delivered with a linear accelerator using 6-MV photons using the frameless technique. Analyzed prognostic factors were age, gender, Karnofsky performance status (KPS), tumor location, planning target volume (PTV) size, overall survival (OS), progression-free survival (PFS), time interval between completion of treatment with Stupp protocol at primary diagnosis and recurrence.

RESULTS

Median follow-up time was 42 months (range 2-68). Median time interval between primary chemoradiotherapy and HFSRT was 11.2 months (range 4-57.9). Median OS and PFS calculated from reirradiation was 10.3 months and 5.8 months, respectively. Longer interval between initial treatment and recurrence (p = 0.01), smaller PTV size (p = 0.001), KPS ≥70 (p = 0.005) and younger age (p = 0.004) were associated with longer OS on statistical analysis.

CONCLUSION

HFSRT offers a feasible and effective salvage treatment option for recurrent GBM management. Prognostic factors associated with longer OS in our study were longer interval between initial treatment and recurrence, smaller PTV size, KPS ≥70 and younger age.

Gamma Knife Radiosurgery for High Grade Glial Neoplasms: A Canadian Experience

Object:

To review our institutional experience with Gamma Knife (GK) stereotactic radiosurgery in treating focally recurrent high grade glial neoplasms of World Health Organization (WHO) grade III or IV.

Methods:

We conducted a retrospective cohort review of all patients treated with GK for focally recurrent high grade gliomas at our institution between November 2003 and April 2013. Data on age, sex, tumor volume, location and maximal diameter, presenting clinical status, complications and clinical outcome was recorded.

Results:

A total of 33 patients were identified. Four were lost to follow-up. Average post-GK and overall survival was 20.4 months (range: 3 – 72) and 63.3 months (range: 10 – 214) respectively. For WHO grade IV gliomas, the average post-GK and overall survival was 15.8 months (range: 3 – 77) and 40.1 months (range: 13 – 148) respectively. Similarily, for WHO grade III gliomas, the average post-GK and overall survival was 34.9 months (range: 6 – 72) and 136.4 months (range: 22 – 214) respectively. Twenty-two patients (75.9%) had post-GK edema, with 14 requiring dexamethasone and eight being asymptomatic. Four patients (13.8%) had imaging defined radiation necrosis.

Conclusions:

Gamma Knife SRS affords an extension of local tumor control, acceptable morbidity, and potentially prolonged survival, for highly selected patients with focally recurrent high grade glial neoplasms.

[Management of gliomas]

Gliomas are the most frequent primary brain tumors. Their care is difficult because of the proximity of organs at risk. The treatment of glioblastoma includes surgery followed by chemoradiation with the protocol of Stupp et al. The addition of bevacizumab allows an increase in progression-free survival by 4 months but it does not improve overall survival. This treatment is reserved for clinical trials. Intensity modulation radiotherapy may be useful to reduce the neurocognitive late effects in different types of gliomas. In elderly patients an accelerated radiotherapy 40 Gy in 15 fractions allows a similar survival to standard radiotherapy. O(6)-methylguanine-DNA methyltransferase (MGMT) status may help to choose between chemotherapy and radiotherapy. There is no standard for the treatment of recurrent gliomas. Re-irradiation in stereotactic conditions allows a median survival of 8 to 12.4 months. Anaplastic gliomas with 1p19q mutation have a greater sensibility to chemotherapy by procarbazine, lomustine and vincristine. Chemoradiotherapy in these patients has become the standard treatment. Many studies are underway testing targeted therapies, their place in the therapeutic management and new radiotherapy techniques.

Efficacy of salvage stereotactic radiotherapy for recurrent glioma: impact of tumor morphology and method of target delineation on local control

In this study, we assessed the efficacy of salvage stereotactic radiotherapy (SRT) for recurrent glioma. From August 2008 to December 2012, 30 patients with recurrent glioma underwent salvage SRT. The initial histological diagnoses were World Health Organization (WHO) grades II, III, and IV in 6, 9, and 15 patients, respectively. Morphologically, the type of recurrence was classified as diffuse or other. Two methods of clinical target delineation were used: A, a contrast-enhancing tumor; or B, a contrast-enhancing tumor with a 3–10-mm margin and/or surrounding fluid attenuation inversion recovery (FLAIR) high-intensity areas. The prescribed dose was 22.5–35 Gy delivered in five fractions at an isocenter using a dynamic conformal arc technique. The overall survival (OS) and local control probability (LCP) after SRT were calculated using the Kaplan–Meier method. A univariate analysis was used to test the effect of clinical variables on OS/LCP. The median follow-up period was 272 days after SRT. The OS and LCP were 83% and 56% at 6 months after SRT, respectively. Morphologically, the tumor type correlated significantly with both OS and LCP (P = 0.006 and <0.001, respectively). The method of target delineation also had a significant influence on LCP (P = 0.016). Grade 3 radiation necrosis was observed in two patients according to Common Terminology Criteria for Adverse Events, version 3. Salvage SRT was safe and effective for recurrent glioma, especially non-diffuse recurrences. Improved local control might be obtained by adding a margin to contrast-enhancing tumors or including increased FLAIR high-intensity areas.

Reirradiation in progressive high-grade gliomas: outcome, role of concurrent chemotherapy, prognostic factors and validation of a new prognostic score with an independent patient cohort

Purposes

First, to evaluate outcome, the benefit of concurrent chemotherapy and prognostic factors in a cohort of sixty-four high-grade glioma patients who underwent a second course of radiation therapy at progression. Second, to validate a new prognostic score for overall survival after reirradiation of progressive gliomas with an independent patient cohort.

Patients and methods

All patients underwent fractionated reirradiation with a median physical dose of 36 Gy. Median planned target volume was 110.4 ml. Thirty-six patients received concurrent chemotherapy consisting in 24/36 cases (67%) of carboplatin and etoposide and in 12/36 cases (33%) of temozolomide. We used the Kaplan Meier method, log rank test and proportional hazards regression analysis for statistical assessment.

Results

Median overall survival from the start of reirradiation was 7.7 ± 0.7 months. Overall survival rates at 6 and 12 months were 60 ± 6% and 24 ± 6%, respectively. Despite relatively large target volumes we did not observe any major acute toxicity. Concurrent chemotherapy did not appear to improve outcome. In contrast, female gender, young age, WHO grade III histology, favorable Karnofsky performance score and complete resection of the tumor prior to reirradiation were identified as positive prognostic factors for overall survival. We finally validated a recent suggestion for a prognostic score with our independent but small patient cohort. Our preliminary findings suggest that its ability to discriminate between different prognostic groups is limited.

Conclusions

Outcome of our patients was comparable to previous studies. Even in case of large target volumes reirradiation seems to be feasible without observing major toxicity. The benefit of concurrent chemotherapy is still elusive. A reassessment of the prognostic score, tested in this study, using a larger patient cohort is needed.