Radiotherapeutic alternatives for previously irradiated recurrent gliomas

Validation of Combs prognostic scoring system in Indian recurrent glioma patients treated with re-radiation

PURPOSE

Retrospective audit of recurrent glioma patients treated by different fractionation schedules and to validate the modified Combs prognostic score in Indian patient cohort.

MATERIALS AND METHODS

Between Jan 2009 and June 2022, 66 recurrent gliomas patients treated with standard adjuvant treatment-radiation (RT) ± temozolomide (chemotherapy)-and re-treated with RT (±chemotherapy) were categorized as per modified Combs prognostic criteria and outcomes were compared.

RESULTS

Sixty-six patients with recurrent gliomas who received reirradiation (re-RT) were audited-53% males; 61% Karnofsky performance status (KPS) ≥80 at time of re-RT; median age 41.5 years (range, 6 to 70 years); 67% <50 years; primary histology low-grade glioma in 33% ; grade III 27%, grade IV 40%; initial median dose of 60 Gy equivalent dose in 2 Gy fractions EQD2; maximum safe resection at recurrence 41%; mean and median follow-up 78 ± 51 months and 66 months. Mean time interval between RT was 46.4 ± 39 months. Mean planning target volume (PTV) volume in conventional RT (Conv-RT), hypofractionated RT (Hypo-RT), and ultra-hypofractionated RT (UF-RT) was 226.1 ± 140.7 mL, 162.8 ± 123.3 mL, and 143.3 ± 145.8 mL. Mean dose for Conv-RT, Hypo-RT, and UF-RT was 50 Gy (range, 40 to 60), 31 Gy (range, 20 to 40), and 20 Gy (range, 10 to 30). Mean overall survival (OS) in Conv-RT, Hypo-RT, and UF-RT cohort was 18.8 months (range, 2.4 to 76.8); 6.6 months (range, 2 to 17.4), and 13.9 months (range, 3 to 131.9). Median OS as per Combs criteria were 16.6 months (Group a), 24.6 months (Group b), 4.6 months (Group c), and 3 months (Group d). Significant survival benefit was with good KPS score (KPS >80 vs. <80; 20.46 vs. 5.25 months; p < 0.001), patients receiving salvage chemotherapy (20.46 vs. 6.96 months; p = 0.001), and patients received re-RT biological equivalent dose BED3 >80 Gy (16.62 vs. 5.48 months; p = 0.03). Median OS in our patient cohort and Combs cohort in Group a was 16.6 and 19.5 months; Group b was 24.6 and 11.3 months; Group c was 4.7 and 8.1 months, and Group d was 2 and 5.5 months, respectively. Six months survival in our patient cohort and Combs cohort in Groups a, b, c, d were 100%, 92%, 34%, 17% and 94%, 79%, 70%, 41%, respectively. Twelve months survival in our patient cohort and Combs cohort in Groups a, b, c, d were 88%, 74%, 22%, 0% and 88%, 47%, 22%, 7%, respectively.

CONCLUSION

Modified Combs prognostic factors predicts OS and is applicable in Indian subcontinent patient population.

Glut-3 Gene Knockdown as a Potential Strategy to Overcome Glioblastoma Radioresistance

The hypoxic pattern of glioblastoma (GBM) is known to be a primary cause of radioresistance. Our study explored the possibility of using gene knockdown of key factors involved in the molecular response to hypoxia, to overcome GBM radioresistance. We used the U87 cell line subjected to chemical hypoxia generated by CoCl2 and exposed to 2 Gy of X-rays, as single or combined treatments, and evaluated gene expression changes of biomarkers involved in the Warburg effect, cell cycle control, and survival to identify the best molecular targets to be knocked-down, among those directly activated by the HIF-1α transcription factor. By this approach, glut-3 and pdk-1 genes were chosen, and the effects of their morpholino-induced gene silencing were evaluated by exploring the proliferative rates and the molecular modifications of the above-mentioned biomarkers. We found that, after combined treatments, glut-3 gene knockdown induced a greater decrease in cell proliferation, compared to pdk-1 gene knockdown and strong upregulation of glut-1 and ldha, as a sign of cell response to restore the anaerobic glycolysis pathway. Overall, glut-3 gene knockdown offered a better chance of controlling the anaerobic use of pyruvate and a better proliferation rate reduction, suggesting it is a suitable silencing target to overcome radioresistance.

Dosimetric Impacts of Source Migration, Radioisotope Type, and Decay with Permanent Implantable Collagen Tile Brachytherapy for Brain Tumors

Introduction: Brachytherapy using permanently implantable collagen tiles containing cesium-131 (Cs-131) is indicated for treatment of malignant intracranial neoplasms. We quantified Cs-131 source migration and modeled the resulting dosimetric impact for Cs-131, iodine-125 (I-125), and palladium-103 (Pd-103). Methods and Materials: This was a retrospective analysis of a subgroup of patients enrolled in a prospective, single-center, nonrandomized, clinical trial (NCT03088579) of Cs-131 collagen tile brachytherapy. Postimplant Cs-131 plans and hypothetical I-125 and Pd-103 calculations were compared for 20 glioblastoma patients for a set seed geometry. Dosimetric impact of decay and seed migration was calculated for 2 hypothetical scenarios: Scenario 1, assuming seed positions on a given image set were unchanged until acquisition of the subsequent set; Scenario 2, assuming any change in seed positions occurred the day following acquisition of the prior images. Seed migration over time was quantified for a subset of 7 patients who underwent subsequent image-guided radiotherapy. Results: Mean seed migration was 1.7 mm (range: 0.7-3.1); maximum seed migration was 4.3 mm. Mean dose to the 60 Gy volume differed by 0.4 Gy (0.6%, range 0.1-1.0) and 0.9 Gy (1.5%, range 0.2-1.7) for Cs-131, 1.2 Gy (2.0%, range 0.1-2.1) and 1.6 Gy (2.6%, range 1.2-2.6) for I-125, and 0.8 Gy (1.3%, range 0.2-1.5) and 1.4 Gy (2.3%, range 0.3-1.9) for Pd-103, for Scenarios 1 and 2, respectively, compared with the postimplant plan. For a set seed geometry mean implant dose was higher for Pd-103 (1.3 times) and I-125 (1.1 times) versus Cs-131. Dose fall-off was steepest for Pd-103: gradient index 1.88 versus 2.23 (I-125) and 2.40 (Cs-131). Conclusions: Dose differences due to source migration were relatively small, suggesting robust prevention of seed migration from Cs-131-containing collagen tiles. Intratarget heterogeneity was greater with Pd-103 and I-125 than Cs-131. Dose fall-off was fastest with Pd-103 followed by I-125 and then Cs-131.

GammaTile for Gliomas: A Single-Center Case Series

GammaTile® (GT Medical Technologies, Tempe, Arizona) is a surgically targeted radiation source, approved by FDA for brachytherapy in primary and secondary brain neoplasms. Each GammaTile is composed of a collagen sponge with four seeds of cesium 131 and is particularly useful in recurrent tumors. We report our early experience in seven patients with recurrent gliomas to assess this type of brachytherapy with particular attention to ease of use, complication, and surgical planning. This study represents a retrospective chart review of surgical use and early clinical outcomes of GammaTile in recurrent gliomas. The number of tiles was planned using pre-operative imaging and dosimetry was planned based on post-operative imaging. Patients were followed during their hospital stay and were followed up after discharge. Parameters such as case length, resection extent, complication, ICU length of stay (LOS), hospital LOS, pre-operative Glasgow Coma Scale (GCS), immediate post-operative GCS, post-operative imaging findings, recurrence at follow-up, length of follow-up, and dosimetry were collected in a retrospective manner. Seven patients were identified that met the inclusion criteria. Two patients were diagnosed with recurrent glioblastoma multiforme (GBM), one lower-grade glioma that recurred as a GBM, one GBM that recurred as a gliosarcoma, and two recurrent oligodendrogliomas. We found that operation time, ICU LOS, hospital LOS, pre- and post-operative GCS, and post-operative complications were within the expected ranges for tumor resection patients. Further, dosimetry data suggests that six out of seven patients received adequate radiation coverage, with the seventh having implantation limitations due to nearby organs at risk. We report no postoperative complications that can be attributed to the GammaTiles themselves. In our cohort, we report seven cases where GammaTiles were implanted in recurrent gliomas. No implant-related post-operative complications were identified. This early data suggests that GammaTile can be a safe form of brachytherapy in recurrent gliomas.

Contralateral metastatic cerebellopontine angle glioblastoma: A rare manifestation

Background:

Glioblastoma is the most common glioma presenting within adults with an incidence of 10 per 100,000 people globally. These are mostly supratentorial tumors with rare cases of extra-axial spread. Even rarer is the presentation of glioblastoma within the cerebellopontine angle (CPA). Here, we present a case of a previously resected and irradiated glioblastoma metastasizing from the right temporal lobe region to the contralateral CPA.

Case Description:

A 24-year-old female who previously underwent surgery and concurrent chemoradiotherapy for a right temporal glioblastoma in August 2020, presented to us 6 months later with headaches, vomiting, and dizziness for the past 6 days. She had left-sided dysmetria on examination. MRI of the brain showed an extra-axial, heterogeneously enhancing lesion within the left CPA. The patient subsequently underwent a left retrosigmoid craniotomy and maximum safe resection of the lesion. Histopathology reported the lesion as a glioblastoma.

Conclusion:

Glioblastoma within the CPA is rarely reported within the literature. To date, our case is the first instance of an extra-axial contralateral metastasis of glioblastoma.

Intraoperative radiotherapy for glioblastoma: A systematic review of techniques and outcomes

BACKGROUND

Despite multimodality treatment, the prognosis of glioblastoma (GBM) has remained poor. Intraoperative radiation therapy (IORT) offers additional local control by directly applying a radiation source to the resection margin, where most recurrences occur.

METHODS

We performed a systematic review on the oncologic outcomes and toxicities of IORT for GBM in the era of modern external beam radiation therapy (EBRT) and chemotherapy with temozolamide.

RESULTS

Four studies representing 123 patients were included. Majority (81%) were newly diagnosed, and gross total resection was reported in 13-80% of cases. IORT modalities included electrons from a linear accelerator (LINAC) and photons from a 50-kV x-ray device. Median doses were from 12.5 to 20 Gy for electron-based studies and 10-25 Gy for photon-based studies. Adjuvant treatment consisted of 46-60 Gy post-operative EBRT in electron-based studies and the Stupp protocol in photon-based studies. Complications included radiation necrosis (2.8-33%), infection, hematoma, perilesional edema, and wound dehiscence. Median time to local recurrence was 9.9-16 months and the reported overall progression-free survival was 11.2-12.2 months. Median overall survival was 13-14.2 months for the electron-based studies and 13.8-18 months for the photon-based studies.

CONCLUSION

IORT resulted in improved local control and comparable overall survival rates with the Stupp protocol. Although photon-based IORT had better results than electron IORT, this may be due to improvements in other forms of adjuvant treatment rather than the IORT modality itself. The overall effect of IORT on GBM treatment is still inconclusive due to the small number of patients and heterogeneous reporting of data.

Dosimetric comparison of Gamma Knife® IconTM and linear accelerator-based fractionated stereotactic radiotherapy (FSRT) plans for the re-irradiation of large (>14 cm3) recurrent glioblastomas

Our objective is to investigate dosimetric differences between clinically deliverable Gamma Knife^® (GK) Icon™ and linac-based FSRT plans on the basis of normal brain dose sparing for large (>14 cm³) recurrent glioblastomas (GBM). Sixteen patients with large, recurrent GBM were treated using re-irradiation via linac-based FSRT, 35 Gy in 10 fractions. For each patient, a new GK FSRT plan was created in Leksell GammaPlan^® V11 (LGP). To maintain clinical deliverability, the LGP optimization included a planning goal of treatment time <20 minutes per fraction. Dosimetric comparison of coverage and normal brain dose between the linac and GK treatment plans was performed in MIM. The GK FSRT plans had significantly (p < 0.05) lower mean normal brain dose values (-8.85%), mean values of normal brain V20 (-32.4%) and V12 (-25.9%), and a lower mean V4 (-10.0%). GK FSRT plans have the potential to reduce the risk of radiation-related toxicities.

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.

Radioresistance in Glioblastoma and the Development of Radiosensitizers

Ionizing radiation is a common and effective therapeutic option for the treatment of glioblastoma (GBM). Unfortunately, some GBMs are relatively radioresistant and patients have worse outcomes after radiation treatment. The mechanisms underlying intrinsic radioresistance in GBM has been rigorously investigated over the past several years, but the complex interaction of the cellular molecules and signaling pathways involved in radioresistance remains incompletely defined. A clinically effective radiosensitizer that overcomes radioresistance has yet to be identified. In this review, we discuss the current status of radiation treatment in GBM, including advances in imaging techniques that have facilitated more accurate diagnosis, and the identified mechanisms of GBM radioresistance. In addition, we provide a summary of the candidate GBM radiosensitizers being investigated, including an update of subjects enrolled in clinical trials. Overall, this review highlights the importance of understanding the mechanisms of GBM radioresistance to facilitate the development of effective radiosensitizers.

Proton Reirradiation: Expert Recommendations for Reducing Toxicities and Offering New Chances of Cure in Patients With Challenging Recurrence Malignancies

Local and regional recurrences are common following an initial course of radiotherapy, yet management of these recurrences remains a challenge. Reirradiation may be an optimal treatment approach for providing durable tumor control and even offering select patients with locoregional recurrences or new primary tumors a chance of cure, but photon reirradiation can be associated with considerable risks of high grade acute and late toxicities. The high conformality and lack of exit dose with proton therapy offer significant advantages for reirradiation. By decreasing dose to adjacent normal tissues, proton therapy can more safely deliver definitive instead of palliative doses of reirradiation, more safely dose escalate reirradiation treatment, and more safely allow for concurrent systemic therapy in the reirradiation setting. In this case-based analysis, renowned experts in the fields of proton therapy and of reirradiation present cases for which they recently employed proton reirradiation. This manuscript focuses on case studies in patients with lung cancer, head and neck malignancies, and pelvic malignancies. Considerations for when to deliver proton therapy in the reirradiation setting and the pros and cons of proton therapy are discussed, and the existing literature supporting the use of proton reirradiation for these disease sites is assessed.

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.

Survival effects of a strategy favoring second-line multimodal treatment compared to supportive care in glioblastoma patients at first progression

OBJECTIVE

Data on the survival effects of supportive care compared to second-line multimodal treatment for glioblastoma progression are scarce. Thus, the authors assessed survival in two population-based, similar cohorts from two European university hospitals with different treatment strategies at first progression.

METHODS

The authors retrospectively identified patients with newly diagnosed glioblastoma treated at two neurooncological centers. After diagnosis, patients from both centers received identical treatments, but at tumor progression each center used a different approach. In the majority of cases, at center A (Greece), supportive care or a single therapeutic modality was offered at progression, whereas center B (Germany) provided multimodal second-line therapy. The main outcome measure was survival after progression (SaP). The influence of the treatment strategy on SaP was assessed by multivariate analysis.

RESULTS

One hundred three patients from center A and 156 from center B were included. Tumor progression was observed in 86 patients (center A) and 136 patients (center B). At center A, 53 patients (72.6%) received supportive care alone, while at center B, 91 patients (80.5%) received second-line treatment. Progression-free survival at both centers was similar (9.4 months [center A] vs 9.0 months [center B]; p = 0.97), but SaP was significantly improved in the patients treated with multimodal second-line therapy at center B (7 months, 95% CI 5.3-8.7 months) compared to those treated with supportive care or a single therapeutic modality at center A (4.5 months, 95% CI 3.5-5.5 months; p = 0.003). In the multivariate analysis, the treatment center was an independent prognostic factor for overall survival (HR 1.59, 95% CI 0.17-2.15; p = 0.002).

CONCLUSIONS

Treatment strategy favoring multimodal second-line treatment over minimal treatment or supportive care at glioblastoma progression is associated with significantly better overall survival.

Patterns of re-irradiation for recurrent gliomas and validation of a prognostic score

PURPOSE OR OBJECTIVE

Re-irradiation is a generally accepted method for salvage treatment in patients with recurrent glioma. However, no standard radiation regimen has been defined. This study aims to compare the efficacy and safety of different treatment regimens and to independently externally validate a recently published reirradiation risk score.

MATERIAL AND METHODS

We retrospectively analyzed a cohort of patients with recurrent malignant glioma treated with salvage conventionally fractionated (CFRT), hypofractionated (HFRT) or stereotactic radiotherapy (SRT) between 2007 and 2017 at the University Medical Centers in Utrecht and Groningen.

RESULTS

Of the 121 patients included, 60 patients (50%) underwent CFRT, 22 (18%) HFRT and 39 (32%) SRT. The primary tumor was grade II-III in 52 patients and grade IV in 69 patients with median Overall Survival (mOS) since first surgery of 113 [Interquartile range: 53.2-137] and 39.7 [24.6-64.9] months respectively (p < 0.01). Overall, mOS from the first day of re-irradiation was 9.7 months [6.5-14.6]. No significant difference in mOS was found between the treatment groups. In multivariate analysis, the Karnofsky performance scale ≥70% (p < 0.01), re-irradiation for first recurrence (p = 0.02), longer time interval between RT start dates (p < 0.01) and smaller planning target volume (p < 0.05) were significant favorable prognostic factors. The reirradiation risk score was validated.

CONCLUSION

In our series, mOS after reirradiation was sufficient to justify use of this modality. Until a reliable treatment decision tool is developed based on larger retrospective research, the decision for re-irradiation schedule should remain personalized and based on a multidisciplinary evaluation of each patient.

Efficacy of Gamma Knife Radiosurgery for Recurrent High-Grade Gliomas with Limited Tumor Volume

Objective

This study aims to determine whether gamma knife radiosurgery (GKR) improves survival in patients with recurrent highgrade gliomas.

Methods

Twenty nine patients with recurrent high-grade glioma underwent 38 GKR. The male-to-female ratio was 10 : 19, and the median age was 53.8 years (range, 20-75). GKR was performed in 11 cases of recurrent anaplastic oligodendrogliomas, five anaplastic astrocytomas, and 22 glioblastomas. The median prescription dose was 16 Gy (range, 10-24), and the median target volume was 7.0 mL (range, 1.1-15.7). Of the 29 patients, 13 (44.8%) received concurrent chemotherapy. We retrospectively analyzed the progression-free survival (PFS) and overall survival (OS) after GKR depending on the Eastern Cooperative Oncology Group (ECOG) performance status (PS), pathology, concurrent chemotherapy, radiation dose, and target tumor volume.

Results

Starting from when the patients underwent GKR, the median PFS and OS were 5.0 months (range, 1.1-28.1) and 13.0 months (range, 1.1-75.1), respectively. On univariate analysis, the median PFS was significantly long in patients with anaplastic oligodendroglioma, ECOG PS 1, and target tumor volume less than 10 mL (p&lt;0.05). Meanwhile, on multivariate analysis, patients with ECOG PS 1 and target tumor volume less than 10 mL showed improved PFS (p=0.043 and p=0.007, respectively). The median OS was significantly increased in patients with ECOG PS 1 and tumor volume less than 10 mL on univariate and multivariate analyses (p&lt;0.05).

Conclusion

GKR could be an additional treatment option in recurrent high-grade glioma, particularly in patients with good PS and limited tumor volume.

Treatment of Glioblastoma

Glioblastoma is the most common and most aggressive form of primary brain tumor in adults and contributes to high social and medical burden as a result of its incurable nature and significant neurologic morbidity. Despite ongoing research, there has not been improvement in survival in glioblastoma. This review discusses recent advances in clinically significant molecular profiling, including IDH mutation status and O⁶-methylguanine-DNA methyltransferase ( MGMT) promoter methylation. We review updates in management of newly diagnosed and recurrent glioblastoma, as well as common difficulties in management, such as pseudoprogression and pseudoresponse. Ongoing translational research in targeted therapy and immunotherapy is briefly discussed.

Treatment of Recurrent Glioblastoma with Stereotactic Radiotherapy: Long-Term Results of a Mono-Institutional Trial

Aims and background

Few clinical data exist concerning normal brain tissue tolerance to re-irradiation. The present study evaluated long-term outcome of 22 recurrent glioblastoma patients re-irradiated with radiosurgery or fractionated stereotactic radiotherapy.

Methods

Twenty-two patients were treated with radiosurgery (13, 59%) or fractionated stereotactic radiotherapy (9, 41%) for 24 lesions of recurrent glioblastoma. The male/female ratio was 14: 8, median age 55 years (range, 27–81), and median Karnofsky performance status 90 (range, 70–100). The majority of the cases (77%) was in recursive partitioning analysis classes III or IV. Radiosurgery or fractionated stereotactic radiotherapy was chosen according to lesion size and location.

Results

Median time between primary radiotherapy and re-irradiation was 9 months. Median doses were 17 Gy and 30 Gy, whereas median cumulative normalized total dose was 141 Gy and 98 Gy for radiosurgery and fractionated stereotactic radiotherapy, respectively. All patients submitted to radiosurgery had a cumulative normalized total dose of more than 100 Gy, whereas only a few (44%) of fractionated stereotactic radiotherapy patients had a cumulative normalized total dose exceeding 100 Gy. Median follow-up from re-irradiation was 54 months. At the time of analysis, all patients had died. After re-irradiation, 1 (4%) lesion was in partial remission, 16 (67%) lesions were stable, and the remaining 7 (29%) were in progression. Median duration of response was 6 months, and median survival from re-irradiation 11 months. Three of 13 (23%) patients submitted to radiosurgery developed asymptomatic brain radionecrosis. The cumulative normalized total dose for the 3 patients was 122 Gy, 124 Gy, and 141 Gy, respectively. In one case, the volume of the lesion was large (14 cc), and in the other 2 the interval between the first and second cycle of radiotherapy was short (5 months).

Conclusions

Re-irradiation with radiosurgery and fractionated stereotactic radiotherapy is feasible and effective in recurrent glioblastoma patients. Apart from the importance of an accurate patient selection, cumulative radiotherapy dose and a correct indication for radiosurgery or fractionated stereotactic radiotherapy must be taken into account to avoid brain toxicity. Free full text available at www.tumorionline.it

Indications and Efficacy of Gamma Knife Stereotactic Radiosurgery for Recurrent Glioblastoma: 2 Decades of Institutional Experience

BACKGROUND

The role of stereotactic radiosurgery (SRS) for recurrent glioblastoma and the radionecrosis risk in this setting remain unclear.

OBJECTIVE

To perform a large retrospective study to help inform proper indications, efficacy, and anticipated complications of SRS for recurrent glioblastoma.

METHODS

We retrospectively analyzed patients who underwent Gamma Knife SRS between 1991 and 2013. We used the partitioning deletion/substitution/addition algorithm to identify potential predictor covariate cut points and Kaplan-Meier and proportional hazards modeling to identify factors associated with post-SRS and postdiagnosis survival.

RESULTS

One hundred seventy-four glioblastoma patients (median age, 54.1 years) underwent SRS a median of 8.7 months after initial diagnosis. Seventy-five percent had 1 treatment target (range, 1-6), and median target volume and prescriptions were 7.0 cm 3 (range, 0.3-39.0 cm 3 ) and 16.0 Gy (range, 10-22 Gy), respectively. Median overall survival was 10.6 months after SRS and 19.1 months after diagnosis. Kaplan-Meier and multivariable modeling revealed that younger age at SRS, higher prescription dose, and longer interval between original surgery and SRS are significantly associated with improved post-SRS survival. Forty-six patients (26%) underwent salvage craniotomy after SRS, with 63% showing radionecrosis or mixed tumor/necrosis vs 35% showing purely recurrent tumor. The necrosis/mixed group had lower mean isodose prescription compared with the tumor group (16.2 vs 17.8 Gy; P = .003) and larger mean treatment volume (10.0 vs 5.4 cm 3 ; P = .009).

CONCLUSION

Gamma Knife may benefit a subset of focally recurrent patients, particularly those who are younger with smaller recurrences. Higher prescriptions are associated with improved post-SRS survival and do not seem to have greater risk of symptomatic treatment effect.

Modification and optimization of an established prognostic score after re-irradiation of recurrent glioma

Introduction

For about 30 years, researchers developed prognostic scores and searched for prognostic factors to predict outcomes for cancer patients. The “Combs Prognostic Score” for re-irradiation in recurrent glioma was recently validated and results showed that the score is a significant (p < .001) and reliable predictor for patients undergoing re-irradiation (re-RT). We sought to enhance the score and generated a novel scoring approach, taking into account the information on resection of recurrent tumors, KPS, and tumor volume.

Patients and methods

The prognostic score was generated based on 209 patients treated between 2002 and 2016 for recurrent glioma at the department of radiation oncology at the Klinikum rechts der Isar, Munich. To further enhance the previously validated Combs Prognostic Score, which uses the prognostic factors primary histology, time between primary RT and re-RT, and age, we added KPS, tumor volume (PTV) and re-resection into the scoring scheme.

Results

The median follow-up time was 3.5 months. 67.5% were WHO IV gliomas with a median OS after re-RT of 7.9 months, 17.7% were WHO III gliomas with an OS of 11.3 months and 14.8% were WHO I/II gliomas with an OS of 14.7 months. Multivariate analyses confirmed the prognostic factors KPS (p < .001) and showed a tendency to significance for tumor volume (p = .067) and re-resection (p = .064). The new prognostic score demonstrated a high significance (p < .001).

Conclusion

The “New Combs Prognostics Score” is a significant and useful tool to predict the overall effect of re-RT in patients with recurrence gliomas. This modified score offers an even better way to classify patients in clinical routine and prospective clinical trials investigating re-irradiation.

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.

Validation of an established prognostic score after re-irradiation of recurrent glioma

BACKGROUND

Re-irradiation (Re-RT) is offered widely in clinical routine, and has been established as a key element in the treatment of recurrent gliomas. At our center, generally re-resection is performed widely by an experienced neurosurgical team. Thus, Re-RT mostly offered to patients with macroscopic residuals or irresectable lesions, is applied later compared to other centers. Therefore, we sought to validate the Combs Prognostic Score developed in 2012 using our independent patient cohort.

PATIENTS AND METHODS

We included 199 patients treated from 2002 until April 2016 for recurrent glioma at the Department of Radiation Oncology at the Klinikum Rechts der Isar, Munich. Different concepts of Re-RT were applied.

RESULTS

Median follow-up after Re-RT was 2.5 months. Median overall survival (OS) after Re-RT was 7.9 months for WHO IV gliomas, 11.3 months for WHO III gliomas, and 13.6 months for low-grade gliomas (WHO I/II). Univariate analyses confirmed the prognostic factors primary histology (p = 0.001), age (p = 0.002), and time between primary radiotherapy and Re-RT (p < 0.001). We also tested Karnofsky Performance Score (KPS), gender, and neurological symptoms before Re-RT as well as planning target volume and found only KPS also significant at p < 0.001. Comparing the prognostic score groups, the outcome was highly statistically significant at p < 0.001.

CONCLUSION

In our analysis, we validated the Combs Prognostic Score. Validation in this independent large patient cohort confirms the significance of the score for glioma recurrences. Thus, the role of the Combs Prognostic Score might be an essential component of future clinical decision making and patient stratification.

Chemotherapy with BCNU in recurrent glioma: Analysis of clinical outcome and side effects in chemotherapy-naïve patients

Background

To date, standardized strategies for the treatment of recurrent glioma are lacking. Chemotherapy with the alkylating agent BCNU (1,3-bis (2-chloroethyl)-1-nitroso-urea) is a therapeutic option even though its efficacy and safety, particularly the risk of pulmonary fibrosis, remains controversial. To address these issues, we performed a retrospective analysis on clinical outcome and side effects of BCNU-based chemotherapy in recurrent glioma.

Methods

Survival data of 34 mostly chemotherapy-naïve glioblastoma patients treated with BCNU at 1^st relapse were compared to 29 untreated control patients, employing a multiple Cox regression model which considered known prognostic factors including MGMT promoter hypermethylation. Additionally, medical records of 163 patients treated with BCNU for recurrent glioma WHO grade II to IV were retrospectively evaluated for BCNU-related side effects classified according to the National Cancer Institute Common Toxicity Criteria for Adverse Events (CTCAE) version 2.0.

Results

In recurrent glioblastoma, multiple regression survival analysis revealed a significant benefit of BCNU-based chemotherapy on survival after relapse (p = 0.02; HR = 0.48; 95 % CI = 0.26–0.89) independent of known clinical and molecular prognostic factors. Exploratory analyses suggested that survival benefit was most pronounced in MGMT-hypermethylated, BCNU-treated patients. Moreover, BCNU was well tolerated by 46 % of the 163 patients analyzed for side effects; otherwise, predominantly mild side effects occurred (CTCAE I/II; 45 %). Severe side effects CTCAE III/IV were observed in 9 % of patients including severe hematotoxicity, thromboembolism, intracranial hemorrhage and injection site reaction requiring surgical intervention. One patient presented with a clinically apparent pulmonary fibrosis CTCAE IV requiring temporary mechanical ventilation.

Conclusion

In this study, BCNU was rarely associated with severe side effects, particularly pulmonary toxicity, and, in case of recurrent glioblastoma, even conferred a favorable outcome. Therefore BCNU appears to be an appropriate alternative to other nitrosoureas although the efficacy against newer drugs needs further evaluation.

Therapeutic options in recurrent glioblastoma--An update

INTRODUCTION

Standards of care are not yet defined in recurrent glioblastoma.

METHODS

We reviewed the literature on clinical trials for recurrent glioblastoma available in PubMed and American Society of Clinical Oncology (ASCO) abstracts until June 2015.

RESULTS

Evidence is limited due to the paucity of randomized controlled studies. Second surgery or re-irradiation are options for selected patients. Alkylating chemotherapy such as nitrosoureas or temozolomide and the vascular endothelial growth factor (VEGF) antibody, bevacizumab, exhibit comparable single agent activity. Phase III data exploring the benefit of combining bevacizumab and lomustine are emerging. Novel approaches in the fields of targeted therapy, immunotherapy, and tumor metabolism are coming forward. Several biomarkers are being explored, but, except for O(6)-methylguanine DNA methyltransferase (MGMT) promoter methylation, none has assumed a role in clinical practice.

CONCLUSION

Proper patient selection, development of predictive biomarkers and randomized controlled studies are required to develop evidence-based concepts for recurrent glioblastoma.

Glioblastoma

Glioblastoma is the most common and aggressive primary brain tumor in adults. Defining histopathologic features are necrosis and endothelial proliferation, resulting in the assignment of grade IV, the highest grade in the World Health Organization (WHO) classification of brain tumors. The classic clinical term "secondary glioblastoma" refers to a minority of glioblastomas that evolve from previously diagnosed WHO grade II or grade III gliomas. Specific point mutations of the genes encoding isocitrate dehydrogenase (IDH) 1 or 2 appear to define molecularly these tumors that are associated with younger age and more favorable outcome; the vast majority of glioblastomas are IDH wild-type. Typical molecular changes in glioblastoma include mutations in genes regulating receptor tyrosine kinase (RTK)/rat sarcoma (RAS)/phosphoinositide 3-kinase (PI3K), p53, and retinoblastoma protein (RB) signaling. Standard treatment of glioblastoma includes surgery, radiotherapy, and alkylating chemotherapy. Promoter methylation of the gene encoding the DNA repair protein, O(6)-methylguanyl DNA methyltransferase (MGMT), predicts benefit from alkylating chemotherapy with temozolomide and guides choice of first-line treatment in elderly patients. Current developments focus on targeting the molecular characteristics that drive the malignant phenotype, including altered signal transduction and angiogenesis, and more recently, various approaches of immunotherapy.

Recurrent Glioblastoma: Where we stand

Current first-line treatment regimens combine surgical resection and chemoradiation for Glioblastoma that provides a slight increase in overall survival. Age on its own should not be used as an exclusion criterion of glioblastoma multiforme (GBM) treatment, but performance should be factored heavily into the decision-making process for treatment planning. Despite aggressive initial treatment, most patients develop recurrent diseases which can be treated with re-resection, systemic treatment with targeted agents or cytotoxic chemotherapy, reirradiation, or radiosurgery. Research into novel therapies is investigating alternative temozolomide regimens, convection-enhanced delivery, immunotherapy, gene therapy, antiangiogenic agents, poly ADP ribose polymerase inhibitors, or cancer stem cell signaling pathways. Given the aggressive and resilient nature of GBM, continued efforts to better understand GBM pathophysiology are required to discover novel targets for future therapy.

Multimodality therapy approaches, local and systemic treatment, compared with chemotherapy alone in recurrent glioblastoma

BACKGROUND

Long-term local control in Glioblastoma is rarely achieved and nearly all patients relapse. In this study we evaluated the clinical effect of different treatment approaches in recurrent patients.

METHODS

Forty-three patients, with median age of 51 years were evaluated for salvage treatment: re-resection and/or re-irradiation plus chemotherapy or chemotherapy alone. Response was recorded using the Response Assessment in Neuro-Oncology criteria. Hematologic and non-hematologic toxicities were graded according to Common Terminology Criteria for Adverse Events 4.0. Twenty-one patients underwent chemotherapy combined with local treatment, surgery and/or radiation therapy, and 22 underwent chemotherapy only.

RESULTS

The median follow up was 7 months (range 3-28 months). The 1 and 2-years Progression Free Survival was 65 and 10 % for combined treatment and 22 and 0 % for chemotherapy alone (p < 0.01). The 1 and 2-years overall survival was 69 and 29 % for combined and 26 and 0 % for chemotherapy alone (p < 0.01). No toxicity greater than grade 2 was recorded.

CONCLUSION

These data showed that in glioblastoma recurrence the combination of several approaches in a limited group of patients is more effective than a single treatment alone. This stress the importance of multimodality treatment whenever clinically feasible.

Radiosurgery reirradiation for high-grade glioma recurrence: a retrospective analysis

Despite various treatment strategies being available, recurrent high-grade gliomas (r-HGG) are difficult to manage. To obtain local control, radiosurgery (SRS) reirradiation has been considered as potential treatment. In the present study, a retrospective analysis was performed on r-HGG patients treated with salvage single- (s-SRS) or multi-fraction SRS (m-SRS). The aim of this study was to evaluate the effectiveness of salvage SRS in terms of overall survival (OS); toxicity was analyzed as well. Between 2004 May and 2011 December, 128 r-HGG patients (161 lesions) treated with CyberKnife(®) SRS reirradiation were retrospectively analyzed. Toxicity was graded according to Radiation Therapy Oncology Group and by Common Terminology Criteria for Adverse Events v.3 criteria. OS from the diagnosis date and OS from reirradiation were estimated using the Kaplan-Meier method. Median follow-up was 9 months (range 15 days-82 months). All patients completed SRS without high-grade toxicity. Radiation necrosis was observed in seven patients (6 %) with large volume lesions. The median survival from initial diagnosis was 32 months. The 1-, 2-, and 3-years survival rates from diagnosis were 95, 62, and 45 % respectively. Median survival following SRS was 11.5 months. The 1-, 2-, and 3-years survival rate following SRS was 48, 20, and 17 % respectively. On multivariate analysis, age <40 years, salvage surgery before SRS, and other post-SRS therapies (second-line chemotherapy and/or surgery) were found to significantly improve survival (p = 0.03). SRS represents a safe and feasible option to treat r-HGG patients with low complication rates and potential survival benefit.

Hypofractionated Stereotactic Radiation Therapy in Recurrent High-Grade Glioma: A New Challenge

Purpose

The aim of this study was to evaluate outcomes of hypofractionated stereotactic radiation therapy (HSRT) in patients re-treated for recurrent high-grade glioma.

Materials and Methods

From January 2006 to September 2013, 25 patients were treated. Six patients underwent radiation therapy alone, while 19 underwent combined treatment with surgery and/or chemotherapy. Only patients with Karnofsky Performance Status (KPS) > 70 and time from previous radiotherapy greater than 6 months were re-irradiated. The mean recurrent tumor volume was 35 cm³ (range, 2.46 to 116.7 cm³), and most of the patients (84%) were treated with a total dose of 25 Gy in five fractions (range, 20 to 50 Gy in 5-10 fractions).

Results

The median follow-up was 18 months (range, 4 to 36 months). The progression-free survival (PFS) at 1 and 2 years was 72% and 34% and the overall survival (OS) 76% and 50%, respectively. No severe toxicity was recorded. In univariate and multivariate analysis extent of resection at diagnosis significantly influenced PFS and OS (p < 0.01). Patients with smaller recurren tumor volume treated had better local control and survival. Indeed, the 2-year PFS was 40% (≤ 50 cm³) versus 11% (p=0.1) and the 2-year OS 56% versus 33% (> 50 cm³), respectively (p=0.26).

Conclusion

In our experience, HSRT could be a safe and feasible therapeutic option for recurrent high grade glioma even in patients with larger tumors. We believe that a multidisciplinary evaluation is mandatory to assure the best treatment for selected patients. Local treatment should also be considered as part of an integrated approach.

Standard of care and future pharmacological treatment options for malignant glioma: an urgent need for screening and identification of novel tumor-specific antigens

INTRODUCTION

Malignant gliomas (MGs) represent the most common primary brain tumors in adults, the most deadly of which is grade IV glioblastoma. Patients with glioblastoma undergoing current standard-of-care therapy have a median survival of 12 - 15 months.

AREAS COVERED

Over the past 25 years, there have been modest advancements in the treatment of MGs. Assessment of therapeutic responses has continued to evolve to account for the increasing number of agents being tested in the clinic. Currently approved therapies for primary tumors have been extended for use in the setting of recurrent disease with modest efficacy. Agents initially approved for recurrent gliomas have begun to demonstrate efficacy against de novo tumors but will ultimately need to be evaluated in future studies for scheduling, timing and dosing relative to chemotherapy.

EXPERT OPINION

Screening and identification of tumor-specific mutations is critical for the advancement of effective therapy that is both safe and precise for the patient. Two unique antigens found in glioblastoma are currently being employed as targets for immunotherapeutic vaccines, one of which has advanced to Phase III testing. Whole genome sequencing of MGs has yielded two other novel mutations that offer great promise for the development of molecular inhibitors.

Reirradiation as part of a salvage treatment approach for progressive non-pontine pediatric high-grade gliomas: preliminary experiences from the German HIT-HGG study group

BACKGROUND AND PURPOSE

The aim of the present analysis was to assess the feasibility, toxicity, and the tumor control of reirradiation as a salvage treatment for progressive pediatric non-pontine high-grade gliomas (HGG).

PATIENTS AND METHODS

The database of the Reference Center for Radiation Oncology of the German HIT (HIT = German acronym for brain tumor) treatment network for childhood brain tumors was screened for children who were reirradiated for progressive non-pontine HGG.

RESULTS

We identified eight patients (WHO grade III: n = 5; WHO grade IV: n = 3) who underwent reirradiation between April 2006 and July 2012. Median age was 13.5 years at primary diagnosis and 14.8 years at first progression. All patients initially underwent surgery (incomplete resection, n = 7; biopsy, n = 1) followed by radiochemotherapy. Relapses occurred inside (n = 2), at the margin (n = 4), and outside of the preirradiated area (n = 2). In all patients, reirradiation was tolerated well without significant acute toxicity. Temporary clinical improvement and tumor regression on magnetic resonance imaging (MRI) following reirradiation was reported (n = 3). However, all patients finally died by disease progression. Median survival time was 26.2 months from initial diagnosis and 11.4 months after first progression. Median time interval between initial radiotherapy and first reirradiation was 9.0 months. In six patients, all macroscopic tumor deposits were reirradiated. In these patients, median progression-free (overall) survival from the start of reirradiation was 2.4 (4.6) months.

CONCLUSION

Our analysis, although based on a limited patient number, suggests that reirradiation of progressive non-pontine HGG is feasible in children. Benefit in terms of quality of life and/or survival needs to be assessed in a prospective and ideally in a randomized manner.

Central nervous system cancers

Primary and metastatic tumors of the central nervous system are a heterogeneous group of neoplasms with varied outcomes and management strategies. Recently, improved survival observed in 2 randomized clinical trials established combined chemotherapy and radiation as the new standard for treating patients with pure or mixed anaplastic oligodendroglioma harboring the 1p/19q codeletion. For metastatic disease, increasing evidence supports the efficacy of stereotactic radiosurgery in treating patients with multiple metastatic lesions but low overall tumor volume. These guidelines provide recommendations on the diagnosis and management of this group of diseases based on clinical evidence and panel consensus. This version includes expert advice on the management of low-grade infiltrative astrocytomas, oligodendrogliomas, anaplastic gliomas, glioblastomas, medulloblastomas, supratentorial primitive neuroectodermal tumors, and brain metastases. The full online version, available at NCCN. org, contains recommendations on additional subtypes.

Analysis of equivalent uniform dose (EUD) and conventional radiation treatment parameters after primary and re-irradiation of malignant glioma

BACKGROUND

Re-irradiation is a reasonable second treatment option for patients with recurrent malignant glioma (MG) after previous radio(chemo)therapy. However, only limited data is available allowing for a precise selection of patients suitable for re-treatment in regard to safety and efficacy.

METHODS

Using the department database, 58 patients with two courses of percutaneous radiation were identified. Besides classical dose-volume histogram (DVH) parameters equivalent uniform dose (EUD) values were calculated for the tumor and organs at risk (OARs), retrospectively analyzed and correlated to survival outcome parameters. Cumulative EUD values were also calculated in all cases where previous OAR DVHs were available.

RESULTS

Median follow-up was 265 days and no relevant toxicity was observed after re-irradiation in our patient cohort during follow-up. Time interval between first and second irradiation was regularly above 6 months. As a conservative estimation of the cumulative EUD to the OARs, the EUDs of first and second irradiation were added. Median cumulative EUD to the optic chiasm was 48.8 Gy (range, 2.5-76.5 Gy), 57.4 Gy (range, 2.7-75.3 Gy) to the brainstem, 20.9/22.1 Gy (range, 0.0-68.3 Gy) to the right/left optic nerve and 73.8 Gy (range, 64.9-77.3 Gy) to the brain. No correlation between treated volume and survival was seen.

CONCLUSIONS

This study provides retrospective estimates on cumulative doses at the OARs. EUD values are derived and may serve as reference for further studies, including planning studies where specific constraints are needed.

Hypofractionated stereotactic radiation therapy for recurrent glioblastoma: single institutional experience

BACKGROUND

Glioblastoma (GBM) is the most common malignant primary brain tumor in adults. Tumor control and survival have improved with the use of radiotherapy (RT) plus concomitant and adjuvant chemotherapy, but the prognosis remain poor. In most cases the recurrence occurs within 7-9 months after primary treatment. Currently, many approaches are available for the salvage treatment of patients with recurrent GBM, including resection, re-irradiation or systemic agents, but no standard of care exists.

METHODS

We analysed a cohort of patients with recurrent GBM treated with frame-less hypofractionated stereotactic radiation therapy with a total dose of 25 Gy in 5 fractions.

RESULTS

Of 91 consecutive patients with newly diagnosed GBM treated between 2007 and 2012 with conventional adjuvant chemo-radiation therapy, 15 underwent salvage RT at recurrence. The median time interval between primary RT and salvage RT was 10.8 months (range, 6-54 months). Overall, patients undergoing salvage RT showed a longer survival, with a median survival of 33 vs. 9.9 months (p= 0.00149). Median overall survival (OS) from salvage RT was 9.5 months. No patients demonstrated clinically significant acute morbidity, and all patients were able to complete the prescribed radiation therapy without interruption.

CONCLUSION

Our results suggest that hypofractionated stereotactic radiation therapy is effective and safe in recurrent GBM. However, until prospective randomized trials will confirm these results, the decision for salvage treatment should remain individual and based on a multidisciplinary evaluation of each patient.

Frameless stereotactic radiosurgery for the treatment of primary intracranial tumours in dogs

Stereotactic radiosurgery (SRS) is a procedure that delivers a single large radiation dose to a well-defined target. Here, we describe a frameless SRS technique suitable for intracranial targets in canines. Medical records of dogs diagnosed with a primary intracranial tumour by imaging or histopathology that underwent SRS were retrospectively reviewed. Frameless SRS was used successfully to treat tumours in 51 dogs with a variety of head sizes and shapes. Tumours diagnosed included 38 meningiomas, 4 pituitary tumours, 4 trigeminal nerve tumours, 3 gliomas, 1 histiocytic sarcoma and 1 choroid plexus tumour. Median survival time was 399 days for all tumours and for dogs with meningiomas; cause-specific survival was 493 days for both cohorts. Acute grade III central nervous system toxicity (altered mentation) occurred in two dogs. Frameless SRS resulted in survival times comparable to conventional radiation therapy, but with fewer acute adverse effects and only a single anaesthetic episode required for therapy.

Current status of local therapy in malignant gliomas--a clinical review of three selected approaches

Malignant gliomas are the most frequently occurring, devastating primary brain tumors, and are coupled with a poor survival rate. Despite the fact that complete neurosurgical resection of these tumors is impossible in consideration of their infiltrating nature, surgical resection followed by adjuvant therapeutics, including radiation therapy and chemotherapy, is still the current standard therapy. Systemic chemotherapy is restricted by the blood-brain barrier, while methods of local delivery, such as with drug-impregnated wafers, convection-enhanced drug delivery, or direct perilesional injections, present attractive ways to circumvent these barriers. These methods are promising ways for direct delivery of either standard chemotherapeutic or new anti-cancer agents. Several clinical trials showed controversial results relating to the influence of a local delivery of chemotherapy on the survival of patients with both recurrent and newly diagnosed malignant gliomas. Our article will review the development of the drug-impregnated release, as well as convection-enhanced delivery and the direct injection into brain tissue, which has been used predominantly in gene-therapy trials. Further, it will focus on the use of convection-enhanced delivery in the treatment of patients with malignant gliomas, placing special emphasis on potential shortcomings in past clinical trials. Although there is a strong need for new or additional therapeutic strategies in the treatment of malignant gliomas, and although local delivery of chemotherapy in those tumors might be a powerful tool, local therapy is used only sporadically nowadays. Thus, we have to learn from our mistakes in the past and we strongly encourage future developments in this field.

Survival analysis of HDR brachytherapy versus reoperation versus temozolomide alone: a retrospective cohort analysis of recurrent glioblastoma multiforme

OBJECTIVES

Tumour recurrence of glioblastoma multiforme (GBM) after initial treatment with surgical resection, radiotherapy and chemotherapy is an inevitable phenomenon. This retrospective cohort study compared the efficacy of interstitial high dose rate brachytherapy (HDR-BRT), re-resection and sole dose dense temozolomide chemotherapy (ddTMZ) in the treatment of recurrent glioblastoma after initial surgery and radiochemotherapy.

DESIGN

Retropective cohort study.

SETTING

Primary level of care with two participating centres. The geographical location was central Germany.

PARTICIPANTS

From January 2005 to December 2010, a total of 111 patients developed recurrent GBM after initial surgery and radiotherapy with concomitant temozolomide. The inclusion criteria were as follows: (1) histology-proven diagnosis of primary GBM (WHO grade 4), (2) primary treatment with resection and radiochemotherapy, and (3) tumour recurrence/progression.

INTERVENTIONS

This study compared retrospectively the efficacy of interstitial HDR-BRT, re-resection and ddTMZ alone in the treatment of recurrent glioblastoma.

PRIMARY AND SECONDARY OUTCOME MEASURES

Median survival, progression free survival and complication rate.

RESULTS

Median survival after salvage therapy of the recurrence was 37, 30 and 26 weeks, respectively. The HDR-BRT group did significantly better than both the reoperation (p<0.05) and the ddTMZ groups (p<0.05). Moderate to severe complications in the HDR-BRT, reoperation and sole chemotherapy groups occurred in 5/50 (10%), 4/36 (11%) and 9/25 (36%) cases, respectively.

CONCLUSIONS

CT-guided interstitial HDR-BRT attained higher survival benefits in the management of recurrent glioblastoma after initial surgery and radiotherapy with concurrent temozolomide in comparison with the other treatment modalities. The low risk of complications of the HDR-BRT and the fact that it can be delivered percutaneously in local anaesthesia render it a promissing treatment option for selected patients which should be further evaluated.

Association between genetic variants of DNA repair genes and coronary artery disease

Polymorphisms in DNA repair genes may be associated with differences in the repair efficiency of DNA damage and may influence an individual's risk of atherosclerosis. Genetic research on coronary artery disease (CAD) has traditionally focused on investigation aimed at identifying disease-susceptibility genes. The aim of this study was to investigate the relationship between AP-endonuclease-1 (Asp148Glu), XRCC1 (Arg399Gln), XRCC3 (Thr241Met), XPD (Lys751Gln), XPG (Asp1104His), and hOGG1 (Ser326Cys), gene polymorphisms and the risk of developing CAD in a Turkish population. The study population consisted of 197 patients with acute coronary syndrome (ACS) with chronic CAD and 135 healthy subjects' age and sex matched. Gene polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism method. We demonstrated for the first time, a positive association of XRCC3 and hOGG1 DNA repair gene variants with CAD risk. XRCC3 Thr/Thr genotype and Thr allele frequencies were significantly increased in ACS and chronic CAD patients compared with the control group (p<0.05). It was also observed that there is a protective role of XRCC3 Met alleles against both ACS and chronic CAD (p<0.05). hOGG1 Cys alleles were found significantly higher in ACS patients than in the control group and carriers of the Cys allele had a 1.7-fold increased risk for ACS. In addition, we confirmed the association of XRCC3 Thr241Met and hOGG1 Ser326Cys gene variants with CAD by haplotype analysis. We found that CAD risk is associated with XRCC3 Thr: hOGG1 Cys haplotype, whereas XRCC3 Met: hOGG1 Ser haplotype was found to be protective against the disease. The preliminary results suggested that XRCC3 and hOGG1 genetic variants may be risk factors by affecting the enzyme's function that may lead to development of CAD.

Standards of care for treatment of recurrent glioblastoma--are we there yet?

Newly diagnosed glioblastoma is now commonly treated with surgery, if feasible, or biopsy, followed by radiation plus concomitant and adjuvant temozolomide. The treatment of recurrent glioblastoma continues to be a moving target as new therapeutic principles enrich the standards of care for newly diagnosed disease. We reviewed PubMed and American Society of Clinical Oncology abstracts from January 2006 to January 2012 to identify clinical trials investigating the treatment of recurrent or progressive glioblastoma with nitrosoureas, temozolomide, bevacizumab, and/or combinations of these agents. At recurrence, a minority of patients are eligible for second surgery or reirradiation, based on appropriate patient selection. In temozolomide-pretreated patients, progression-free survival rates at 6 months of 20%-30% may be achieved either with nitrosoureas, temozolomide in various dosing regimens, or bevacizumab. Combination regimens among these agents or with other drugs have not produced evidence for superior activity but commonly produce more toxicity. More research is needed to better define patient profiles that predict benefit from the limited therapeutic options available after the current standard of care has failed.

Management of malignant gliomas and primary CNS lymphoma: standard of care and future directions

PURPOSE OF REVIEW

This article review the current standard of care of astrocytic gliomas and primary CNS lymphoma and discusses promising new therapeutic targets.

RECENT FINDINGS

Standard treatment modalities for primary malignant brain tumors include resection, radiation, local or systemic chemotherapy, and, most recently, antiangiogenic agents. However, these tumors often have a rapid course, and patients usually die within a few years of diagnosis. Improved surgical techniques and radiation and chemotherapy can prolong survival while maintaining quality of life, but these therapies remain inadequate.

SUMMARY

The care of patients with malignant brain tumors is challenging. A better understanding of the pathogenesis of primary malignant brain tumors and the elucidation of aberrant molecular pathways are leading to novel treatment strategies and the ability to identify patients who may benefit from specific treatments.

Initial experience of hypofractionated radiation retreatment with true beam and flattening filter free beam in selected case reports of recurrent nasopharyngeal carcinoma

AIM

To show our preliminary experience in using TrueBeam with RapidArc technology and FFF beam for stereotactic re-irradiation of nasopharyngeal carcinoma.

BACKGROUND

Thanks to new advanced techniques, as well as intensity modulated radiation therapy, it is possible to approach head and neck recurrences in selected patients. Volumetric Modulated Arc Therapy (VMAT) in its RapidArc(®) format, permits to reduce significantly the time to deliver complex intensity modulated plans, allowing to treat hypofractionated regimes within a few minutes. With TrueBeam it is possible to perform photon beams without usage of the flattening filter. It seems possible to expect a reduction of out-of-field dose when flattening filter free (FFF) beams are used. While research into the physics domain for FFF beams is increasing, there are very few clinical data where FFF beams are applied in clinical practice.

MATERIALS AND METHODS

We present here the cases of 4 patients with local or regional recurrence of nasopharyngeal carcinoma. All patients were treated using TrueBeam with RapidArc technology and FFF beam for stereotactic hypofractionated re-irradiation.

RESULTS

All patients concluded SBRT and showed good tolerability. During follow-up, complete response at imaging evaluation (PET and/or MRI) for all treated patients was documented.

CONCLUSIONS

Our preliminary experience using TrueBeam with RapidArc technology and FFF beam for stereotactic hypofractionated re-irradiation of nasopharyngeal carcinoma was safe and effective in all 4 treated patients. Longer follow-up and a larger population of study is needed to confirm these promising results.

Intra-operative electron beam radiotherapy for newly diagnosed and recurrent malignant gliomas: feasibility and long-term outcomes

INTRODUCTION

Intra-operative electron beam radiotherapy (IOERT) is an alternative to dose escalation for the treatment of central nervous system tumors. The objective of this study was to describe the feasibility and long-term outcomes of IOERT in the treatment of primary and recurrent gliomas.

MATERIALS AND METHODS

From January 1992 through December 2002, all patients treated with IOERT at the Hospital San Francisco de Asis, Madrid/Spain were retrospectively reviewed. The selection criteria included patients with superficial tumors, KPS >70 % and lesions <6 cm. Irradiation was administered in one section. The prescribed dose considered the amount of post-resection residual tumor, previous radiotherapy and the tolerance level of brain structures exposed to IOERT.

RESULTS

There were 17 patients (53 %) with newly diagnosed malignant brain gliomas and 15 patients with recurrent tumors. The delivered dose varied from 8 to 20 Gy (median 12.5 Gy) for primary and from 8 to 16 Gy (median 10 Gy) for recurrent tumors. The median overall survival for the entire cohort was 13 months (14 and 10.4 months for the primary and recurrent, respectively). Three patients presented with radionecrosis, one patient with osteomyelitis at the craniotomy bone flap, one with intracerebral hemorrhage, and another patient experienced a pulmonary embolism.

CONCLUSIONS

IOERT is a feasible technique and can be viewed as a tool in the treatment of newly diagnosed or recurrent brain gliomas.

Evolution of care for patients with relapsed glioblastoma

Glioblastoma is the most common and aggressive form of brain tumor in adults and has a poor prognosis and a high recurrence rate despite optimal care. The management of patients with relapsed glioblastoma is challenging, with no widely agreed standard of care. Different chemotherapy and radiotherapy combination treatment strategies provide only modest benefits. Recently, several novel agents, including bevacizumab and XL-184, have demonstrated promising results in Phase II trials with their further evaluation ongoing in Phase III randomized trials. Interpreting the data from such trials is a key challenge in glioblastoma, highlighting the need for relevant and standardized patient assessment techniques. Data from ongoing and planned trials should help to define optimal treatment strategies for this disease.