Short-course radiotherapy in elderly patients with glioblastoma: feasibility and efficacy of results from a single centre

The role of radiation therapy in treatment of adults with newly diagnosed glioblastoma multiforme: a systematic review and evidence-based clinical practice guideline update

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma. QUESTION 1 : In adult patients (aged 65 and under) with newly diagnosed glioblastoma, is the addition of radiation therapy (RT) more beneficial than management without RT in improving survival?

RECOMMENDATIONS

Level I: Radiation therapy (RT) is recommended for the treatment of newly diagnosed malignant glioblastoma in adults. QUESTION 2 : In adult patients (aged 65 and under) with newly diagnosed glioblastoma, is the RT regimen of 60 Gy given in 2 Gy daily fractions more beneficial than alternative regimens in providing survival benefit while minimizing toxicity?

RECOMMENDATIONS

Level I: Treatment schemes should include dosage of up to 60 Gy given in 2 Gy daily fractions that includes the enhancing area. QUESTION 3 : In adult patients (aged 65 and under) with newly diagnosed glioblastoma, is a tailored target volume superior to regional RT for reduction of radiation-induced toxicity while maintaining efficacy?

RECOMMENDATION

Level II: It is recommended that radiation therapy planning include 1-2 cm margin around the radiographically T1 weighted contrast-enhancing tumor volume or the T2 weighted abnormality on MRI. Level III: Recalculation of the radiation volume during RT treatment may be necessary to reduce the radiated volume of normal brain since the volume of surgical defect will change during the long period of RT. QUESTION 4 : In adult patients (aged 65 and under) with newly diagnosed glioblastoma, does the addition of RT of the subventricular zone to standard tumor volume treatment improve tumor control and overall survival?

RECOMMENDATION

No recommendation can be formulated as there is contradictory evidence in favor of and against intentional radiation of the subventricular zone (SVZ) QUESTION 5 : In elderly (age > 65 years) and/or frail patients with newly diagnosed glioblastoma, does the addition of RT to surgical intervention improve disease control and overall survival?

RECOMMENDATION

Level I: Radiation therapy is recommended for treatment of elderly and frail patients with newly diagnosed glioblastoma to improve overall survival. QUESTION 6 : In elderly (age > 65 years) and/or frail patients with newly diagnosed glioblastoma, does modification of RT dose and fractionation scheme from standard regimens decrease toxicity and improve disease control and survival?

RECOMMENDATION

Level II: Short RT treatment schemes are recommended in frail and elderly patients as compared to conventional 60 Gy given in 2 daily fractions because overall survival is not different while RT risk profile is better for the short RT scheme. Level II: The 40.05 Gy dose given in 15 fractions or 25 Gy dose given in 5 fractions or 34 Gy dose given in 10 fractions should be considered as appropriate doses for Short RT treatments in elderly and/or frail patients. QUESTION 7 : In adult patients with newly diagnosed glioblastoma is there advantage to delaying the initiation of RT instead of starting it 2 weeks after surgical intervention in decreasing radiation-induced toxicity and improving disease control and survival?

RECOMMENDATION

Level III: It is suggested that RT for patients with newly diagnosed GBM starts within 6 weeks of surgical intervention as compared to later times. There is insufficient evidence to recommend the optimal specific post-operative day within the 6 weeks interval to start RT for adult patients with newly diagnosed glioblastoma that have undergone surgical resection. QUESTION 8 : In adult patients with newly diagnosed supratentorial glioblastoma is Image-Modulated RT (IMRT) or similar techniques as effective as standard regional RT in providing tumor control and improve survival?

RECOMMENDATION

Level III: There is no evidence that IMRT is a better RT delivering modality when compared to conventional RT in improving overall survival in adult patients with newly diagnosed glioblastoma. Hence, IMRT should not be preferred over the Conventional RT delivery modality. QUESTION 9 : In adult patients with newly diagnosed glioblastoma does the use of radiosensitizers with RT improve the efficacy of RT as determined by disease control and overall survival?

RECOMMENDATION

Level III: Iododeoxyuridine is not recommended to be used as radiosensitizer during RT treatment for patients with newly diagnosed GBM QUESTION 10 : In adult patients with newly diagnosed glioblastoma is the use of Ultrafractionated RT superior to standard fractionation regimens in improving disease control and survival?

RECOMMENDATION

There is insufficient evidence to formulate a recommendation regarding the use of ultrafractionated RT schemes and patient population that could benefit from it. QUESTION 11 : In patients with poor prognosis with newly diagnosed glioblastoma is hypofractionated RT indicated instead of a standard fractionation regimen as measured by extent of toxicity, disease control and survival?

RECOMMENDATION

Level I: Hypofractionated RT schemes may be used for patients with poor prognosis and limited survival without compromising response. There is insufficient evidence in the literature for us to be able to recommend the optimal hypofractionated RT scheme that will confer longest overall survival and/or confer the same overall survival with less toxicities and shorter treatment time. QUESTION 12 : In adult patients with newly diagnosed glioblastoma is the addition of brachytherapy to standard fractionated RT indicated to improve disease control and survival?

RECOMMENDATION

Level I: Brachytherapy as a boost to external beam RT has not been shown to be beneficial and is not recommended in the routine management of patients with newly diagnosed GBM. QUESTION 13 : In elderly patients (> 65 year old) with newly diagnosed glioblastoma under what circumstances is accelerated hyperfractionated RT indicated instead of a standard fractionation regimen as measured by extent of toxicity, disease control and survival?

RECOMMENDATION

Level III: Accelerated Hyperfractionated RT with a total RT dose of 45 Gy or 48 Gy has been shown to shorten the treatment time without detriment in survival when compared to conventional external beam RT and should be considered as an option for treatment of elderly patients with newly diagnosed GBM. QUESTION 14 : In adult patients with newly diagnosed glioblastoma is the addition of Stereotactic Radiosurgery (SRS) boost to conventional standard fractionated RT indicated to improve disease control and survival?

RECOMMENDATION

Level I: Stereotactic Radiosurgery boost to external beam RT has not been shown to be beneficial and is not recommended in patients undergoing routine management of newly diagnosed malignant glioma.

Surgery for Glioblastoma in Elderly Patients

The management of glioblastoma in the elderly population represents a field of growing interest owing a longer life expectancy. In this age group, more than in the young adult, biological age is much more important than chronologic one. The date of birth should not exclude a priori access of treatments. Maximal safe resection is proved to be the first option when performance status and general health is good. Adjuvant therapy and decision about management of recurrence should be choose in a multidisciplinary group according to performance of the patients and O⁶-methylguanine-DNA methyl-transferase methylation.

Short Course Radiotherapy Concomitant with Temozolomide in GBM Patients: A Phase II Study

Purpose

Despite recent advances, the prognosis of glioblastoma (GBM) remains poor. The aim of this study was to assess the efficacy and tolerability of multiple daily fraction radiotherapy performed with multiple temozolomide (TMZ) administrations in newly diagnosed patients with GBM.

Methods

This trial was a prospective, open-label, monocentric, nonrandomized, single arm, phase II study. The primary endpoint was the proportion of progression-free patients at 12 months, and the secondary endpoints were overall survival (OS) and toxicity. Thirty-five patients underwent two radiotherapy courses concomitant with TMZ after surgery. At each course, radiation was delivered 3 times daily, 2 Gy/fraction, for 5 consecutive days, and the total dose was 60 Gy; concurrent TMZ was administered in a total dose of 150-200 mg/m2/day.

Results

The primary endpoint failed to be applied; Macdonald criteria could be used in 16 (46%) patients with local or intracerebral recurrence (group A). In 12 patients, due to suspicion of radiation necrosis vs recurrence, Macdonald criteria were not applied (group B). The OS was 22 months, and OS probabilities at 12, 18, and 24 months were 82%, 59%, and 44%, respectively. Hematologic toxicities generally did not exceed grade 2. The quality of life and cognitive functioning did not significantly change between baseline and the first follow-up. In the multivariate analysis, necrosis and pseudoprogression were significant prognostic factors of OS.

Conclusions

To improve local control and OS, a more aggressive treatment schedule should be explored. The related higher necrosis risk and its implications regarding local control deserve further investigation.

Biopsy versus partial versus gross total resection in older patients with high-grade glioma: a systematic review and meta-analysis

BACKGROUND

Optimal extent of surgical resection (EOR) of high-grade gliomas (HGGs) remains uncertain in the elderly given the unclear benefits and potentially higher rates of mortality and morbidity associated with more extensive degrees of resection.

METHODS

We undertook a meta-analysis according to a predefined protocol and systematically searched literature databases for reports about HGG EOR. Elderly patients (≥60 y) undergoing biopsy, subtotal resection (STR), and gross total resection (GTR) were compared for the outcome measures of overall survival (OS), postoperative karnofsky performance status (KPS), progression-free survival (PFS), mortality, and morbidity. Treatment effects as pooled estimates, mean differences (MDs), or risk ratios (RRs) with corresponding 95% confidence intervals (CIs) were determined using random effects modeling.

RESULTS

A total of 12 607 participants from 34 studies met eligibility criteria, including our current cohort of 211 patients. When comparing overall resection (of any extent) with biopsy, in favor of the resection group were OS (MD 3.88 mo, 95% CI: 2.14-5.62, P < .001), postoperative KPS (MD 10.4, 95% CI: 6.58-14.22, P < .001), PFS (MD 2.44 mo, 95% CI: 1.45-3.43, P < .001), mortality (RR = 0.27, 95% CI: 0.12-0.61, P = .002), and morbidity (RR = 0.82, 95% CI: 0.46-1.46, P = .514) . GTR was significantly superior to STR in terms of OS (MD 3.77 mo, 95% CI: 2.26-5.29, P < .001), postoperative KPS (MD 4.91, 95% CI: 0.91-8.92, P = .016), and PFS (MD 2.21 mo, 95% CI: 1.13-3.3, P < .001) with no difference in mortality (RR = 0.53, 95% CI: 0.05-5.71, P = .600) or morbidity (RR = 0.52, 95% CI: 0.18-1.49, P = .223).

CONCLUSIONS

Our findings suggest an upward improvement in survival time, functional recovery, and tumor recurrence rate associated with increasing extents of safe resection. These benefits did not result in higher rates of mortality or morbidity if considered in conjunction with known established safety measures when managing elderly patients harboring HGGs.

Hippocampal EUD in primarily irradiated glioblastoma patients

BACKGROUND

Radiation delivery for malignant brain tumors is gradually becoming more precise. Particularly the possibilities of sparing adjacent normal structures such as the hippocampus are increasing. To determine its radiation exposure more exactly, the equivalent uniform dose (EUD) of the hippocampus was compared with further treatment parameters. This way sparing options could be found.

METHODS

From the database of the University hospital of Munich 61 glioblastoma patients were selected who received primary radiotherapy in 2011. General data about the etiology, treatment course, survival of the patients and dose parameters were retrieved.

RESULTS

In a linear regression analysis the side of the tumor (left hippocampus: p < 0.001/right hippocampus: p = 0.009) and its temporal location (left hippocampus: p = 0.015/right hippocampus: p = 0.033) were identified as factors with a significant influence on the EUD of the respective hippocampus. Besides this, the size of the planning target volume (PTV) and the EUD of the hippocampus correlated significantly (p = 0.027; Pearson correlation = 0.291). The median PTV size of the tumor in the right hemisphere was 386.1 ml (range 131.2-910.7 ml), and in the left hemisphere 291.3 ml (range 146.0-588.9 ml) (Kruskal-Wallis test: p = 0.048). A dose quartile analysis showed that 31 patients had a high dose exposure of the hippocampus on one side while having a moderate dose exposure in the other side.

CONCLUSIONS

The radiation exposure of the respective hippocampus is dependent on the side where the tumor is located as well as on whether it is temporally located. The exposure of the contralateral hippocampus is further dependent on multiple additional factors - nevertheless a reasonable protection seems to be possible in about half of all cases.