Pion radiation for high grade astrocytoma: results of a randomized study

Radiation dose, schedule, and novel systemic targets for radio-immunotherapy combinations

Immunotherapy combinations are being investigated to expand the benefit of immune checkpoint blockade across many cancer types. Radiation combinations, in particular using stereotactic body radiotherapy, are of keen interest because of underlying mechanistic rationale, safety, and availability as a standard of care in certain cancers. In addition to direct tumor cytotoxicity, radiation therapy has immunomodulatory effects such as induction of immunogenic cell death, enhancement of antigen presentation, and expansion of the T-cell receptor repertoire as well as recruitment and increased activity of tumor-specific effector CD8+ cells. Combinations of radiation with cytokines and/or chemokines and anti-programmed death 1 and anticytotoxic T-lymphocyte antigen 4 therapies have demonstrated safety and feasibility, as well as the potential to improve long-term outcomes and possibly induce out of irradiated field or abscopal responses. Novel immunoradiotherapy combinations represent a promising therapeutic approach to overcome radioresistance and further enhance systemic immunotherapy. Potential benefits include reversing CD8+ T-cell exhaustion, inhibiting myeloid-derived suppressor cells, and reversing M2 macrophage polarization as well as decreasing levels of colony-stimulating factor-1 and transforming growth factor-β. Here, we discuss current data and mechanistic rationale for combining novel immunotherapy agents with radiation therapy.

Enhancing radiation therapy for patients with glioblastoma

Radiation therapy has been the foundation of therapy following maximal surgical resection in patients with newly diagnosed glioblastoma for decades and the primary therapy for unresected tumors. Using the standard approach with radiation and temozolomide, however, outcomes are poor, and glioblastoma remains an incurable disease with the majority of recurrences and progression within the radiation treatment field. As such, there is much interest in elucidating the mechanisms of resistance to radiation therapy and in developing novel approaches to overcoming this treatment resistance.

Randomized Phase III controlled trials of therapy in malignant glioma: where are we after 40 years?

The objective of this study was to review the results of randomized Phase III controlled trials (RCTs) that involve initial treatments of malignant glioma and determine changes in median survival times (MST) over the last 40 years. An electronic database search identified RCTs for patients undergoing initial treatment for supratentorial high-grade malignant glioma. MSTs were analysed with respect to the date that patient accrual to the trial started, to identify the time course of changes in MST. Linear regression was used for statistical analysis. The review included 44 clinical trials that recruited patients between 1966 and 2004. Overall, there was a steady significant improvement in MST for the novel treatment cohorts over this period (r(2) = 0.43, p < 0.001), with MST increasing from around 8 to 15 months. There was also consistent improvement in the MST of the control cohorts, from around 7 months to 14 months, that reached statistical significance (r(2) = 0.41, p < 0.001). However, analysis including a quadratic term revealed a trend towards the rate of improvement in MST decreasing in the last two decades in the control, but not novel treatment, groups. The differences, either positive or negative, in MSTs between the control and novel treatment cohorts, and number of trials performed have all decreased with time. Subgroup analysis of the three most recent clinical trials report statistically significant better outcomes in MST after either >90% or 'complete' tumour resection. Despite tremendous advances in both the understanding of the biology of malignant gliomas and treatments in neuro-oncology, the prognosis for patients with malignant gliomas, although improved, remains very poor. The limitations of this type of analysis, including how trial design can bias outcomes and militate against comparison of trials are discussed.

Health-related quality of life in patients with high-grade glioma

Health-related quality of life (HRQOL) has become an increasingly important endpoint in cancer studies; however, the research into the HRQOL of patients with high-grade glioma (HGG) is sparse compared with that for patients with other neoplasms. Owing to the specific location and poor prognosis, it is more important and difficult to study HRQOL in patients with HGG than in those with other tumors; furthermore, the study of HRQOL in patients with HGG differs from that for patients with other tumors. In this review, we identified and compared the most frequently used instruments to assess HRQOL; analyzed specific facets and determinants of HRQOL (such as sex, tumor location and histological classification, depression, and cognitive function), as well as the association between HRQOL and survival; and appraised the effects of new treatments on HRQOL in patients with HGG from randomized controlled trials. Furthermore, we detected broadly existing problems and many contradictory outcomes and gave some proper interpretation and suggestions regarding them.

Chained Lightning, Part I

The fundamental principle of radiosurgery is the focusing of energy within a restricted target volume. In examining the history of radiosurgery, various strategies for addressing this issue of energy containment become apparent. This is the first in a series of articles that reviews the evolution of radiosurgery through the development of instruments for beam generation and delivery for improved conformal therapy.

In this first part of the series, we focus specifically on beam generation and the development of particle beams as the initial approach in radiosurgery for focused radiation treatment. We examine the physical characteristics and biological effects of particles and the unique advantage they confer for radiosurgery. We consider clinical studies and treatment of neurological diseases with particles and also assess boron neutron capture therapy as a strategy for selectively targeting neutron beams.

Later in this series, we explore methods of beam delivery with the development of stereotactic radiosurgery. Finally, we introduce new concepts and applications in radiosurgery such as nanotechnology, radiation enhancement, ultrasound, near infrared, and free electron lasers.

The elaboration of these efforts sets the stage for neurosurgeons to further explore new ideas, develop innovative technology, and advance the practice of radiosurgery.

Importance of hypoxia in the biology and treatment of brain tumors

The resistance of gliomas to treatment with radiation and antineoplastic drugs may result in part from the effects of the extensive, severe hypoxia that is present in these tumors. It is clear that brain tumors contain extensive regions in which the tumor cells are subjected to unphysiological levels of hypoxia. Hypoxic cells are resistant to radiation. Hypoxia and the perfusion deficits and metabolic changes that accompany hypoxia in vivo also produce resistance to many commonly used anticancer drugs. The resistance of cells that are hypoxic at the time of therapy may influence the efficacy of the treatment of these tumors with radiation, chemotherapy, and combined modality regimens. Moreover, it is becoming increasingly evident from laboratory studies that exposure of cells to adverse microenvironments produces transient changes in gene expression, induces mutations, and selects for cells with altered genotypes, thus driving the evolution of the cell population toward increasing malignancy and increasingly aggressive phenotypes. Hypoxia may therefore be involved in the evolution of cells in low-grade malignancies to the resistant, aggressive phenotype characteristic of glioblastomas. During the past 50 years, many attempts have been made to circumvent the therapeutic resistance induced by hypoxia, by improving tumor oxygenation, by using oxygen-mimetic radiosensitizers, by adjuvant therapy with drugs that are preferentially toxic to hypoxic cells, by using hyperthermia, or by devising radiation sources and regimens that are less affected by hypoxia. Past clinical trials have provided tantalizing suggestions that the outcome of therapy can be improved by many of these approaches, but none has yet produced a significant, reproducible improvement in the therapeutic ratio, which would be needed for any of these approaches to become the standard therapy for these diseases. Several ongoing clinical trials are addressing other, hopefully better regimens; it will be interesting to see the results of these studies.

Radiotherapy for newly diagnosed malignant glioma in adults: a systematic review

PURPOSE

A systematic review was conducted to develop guidelines for radiotherapy in adult patients with newly diagnosed malignant glioma.

METHODS

MEDLINE, CANCERLIT, the Cochrane Library, and relevant conference proceedings were searched to identify randomized trials and meta-analyses.

RESULTS

Pooling of six randomized trials detected a significant survival benefit favouring post-operative radiotherapy compared with no radiotherapy (risk ratio, 0.81; 95% confidence interval, 0.74 to 0.88, P<0.00001). Two randomized trials demonstrated no significant difference in survival rates for whole brain radiation versus more local fields that encompass the enhancing primary plus a 2 cm margin. A randomized trial detected a small improvement in survival with 60 Gy in 30 fractions over 45 Gy in 20 fractions. Radiation dose intensification and radiation sensitizer approaches have not demonstrated superior survival rates compared with conventionally fractionated doses of 50-60 Gy.

CONCLUSIONS

Post-operative external beam radiotherapy is recommended as standard therapy for patients with malignant glioma. The high-dose volume should incorporate the enhancing tumour plus a limited margin (e.g. 2 cm) for the planning target volume, and the total dose delivered should be in the range of 50-60 Gy in fraction sizes of 1.8-2.0 Gy. Radiation dose intensification and radiation sensitizer approaches are not recommended as standard care. For patients older than age 70, preliminary data suggest that the same survival benefit can be achieved with less morbidity using a shorter course of radiotherapy. Supportive care alone is a reasonable therapeutic option in patients older than age 70 with a poor performance status.

Health related quality of life assessment methodology and reported outcomes in randomised controlled trials of primary brain cancer patients

Over the last 20 years, the assessment of quality of life (QOL) has become an important endpoint in cancer clinical trials, helping us to understand patient survival and QOL experiences and aiding clinicians in providing the best possible treatment and care, with the least toxicity and ill-effects. In primary brain cancer, these are critical issues. Survival is often limited and treatment difficult to tolerate. In recent years, some authors have questioned the methodological quality of the investigations and the reporting of QOL assessments from randomised controlled trials (RCTs), of cancer patients yet this assessment has never specifically focused on brain cancer. This paper therefore reports a systematic review of the research methodology and QOL assessment reporting in brain cancer patients in RCTs. The search was mainly performed on the following databases: Medline, Cancerlit and the Cochrane Controlled Trials Register. We identified only five RCTs, enrolling a total of 1026 patients. In many of these studies, we had identified methodological limitations which would hinder the interpretation of the results. These included a lack of detailed reporting regarding missing data, use of poorly validated tools, and general limitations regarding the presentation and interpretation of the results. Based on the results of our review, we make recommendations for future investigations to avoid these shortcomings.

Quality of life in patients with glioblastoma multiforme participating in a randomized study of brachytherapy as a boost treatment

OBJECT

Until recently the assessment of outcome in patients treated for glioma has emphasized length of survival with the evaluation of quality of life (QOL) limited to unidimensional, mostly physical, measures. The authors report the multidimensional assessment of QOL as part of a randomized clinical trial of brachytherapy as a boost in the initial treatment of patients with glioblastoma multiforme.

METHODS

A questionnaire previously developed by the senior authors and psychometrically validated was completed by patients on randomized entry into the study and at follow-up review every 3 months thereafter. The questionnaire was presented in a linear-analog self-assessment format. Karnofsky Performance Scale (KPS) scores were also recorded on each occasion. No differences were found between patients in either arm of the study (conventional radiation therapy consisting of 50 Gy in 25 fractions or conventional radiation plus a brachytherapy boost of a minimum peripheral tumor dose of 60 Gy) in KPS and QOL scores during the 1st year of follow-up review. However, there was a statistically significant deterioration in patients' overall KPS scores during the 1st year of follow up compared with baseline scores. Of QOL items evaluated, statistically significant deteriorations were found in self care, speech, and concentration, and on subscale analyses, cognitive functioning and physical experience (symptoms) deteriorated significantly during the 1st year of follow up, compared with baseline values. The correlation between QOL and KPS scores was low.

CONCLUSIONS

Future studies in patients harboring malignant gliomas must incorporate measures assessing QOL because traditional measures focusing on physical or neurological functioning give an incomplete assessment of the patient's experience.

The standard of reporting of health-related quality of life in clinical cancer trials

The standard of reporting of randomized controlled trials (RCTs) is important to the interpretation of outcomes such as health-related quality of life (HRQL). HRQL is used increasingly as an outcome in clinical cancer trials.

DESIGN

All 1997 issues of 36 selected journals were hand searched to identify original articles that included the term "quality of life" in the title, abstract, keywords or methods. Studies were included if they were RCTs and addressed cancer-related topics. A checklist to assess the adequacy of reporting of HRQL was developed based on a guideline previously published by an expert panel. Two unblinded reviewers applied the quality of life reporting (QLR) and CONSORT checklists, along with an instrument to assess the likelihood of bias to each selected RCT.

RESULTS

72 articles were identified of which 20 were RCTs and cancer-related. For these 20 reports the median number of items in the QLR checklist that were adequately reported is 42% (range 15% to 85%). The median number of items in the CONSORT checklist that were adequately reported is 70% (range 47% to 95%). The mean score for the instrument to assess the likelihood for bias is 2.6 (95% CI 2. 08-3.12).

CONCLUSIONS

The current standard of reporting of HRQL needs to be improved. Major deficiencies that should be addressed are failure to provide a rationale for HRQL assessment and inadequate description of methodology. Development and application of structured formats for presentation of HRQL may help to improve the standard of reporting of HRQL in the literature.

Report on the quality of life analysis from the phase III trial of pion versus photon radiotherapy in locally advanced prostate cancer

This report examines the quality of life (QOL) of 215 patients entered into a randomised trial between pion and photon radiotherapy for prostate cancer at a single institution. The survival and local control results of the trial were equivalent in both arms. A modification of the Rotterdam Symptom Checklist (RSCL) was used to assess QOL. Global QOL, toxicity and physical scores were found to be worse in pion-treated patients at the end of treatment (P<0.001, P<0.001, and P=0.02 respectively). There are no long-term differences in the QOL of pion- versus photon-treated patients. Sexual function was a concern for patients even at baseline. There was a progressive loss of sexual interest and erectile function. There was a significant impact from hormonal therapy at relapse. Hormonal treatment produced a stepwise significant worsening in global QOL, particularly for physical and psychological domains.

Accelerated fractionated proton/photon irradiation to 90 cobalt gray equivalent for glioblastoma multiforme: results of a phase II prospective trial

OBJECT

After conventional doses of 55 to 65 Gy of fractionated irradiation, glioblastoma multiforme (GBM) usually recurs at its original location. This institutional phase II study was designed to assess whether dose escalation to 90 cobalt gray equivalent (CGE) with conformal protons and photons in accelerated fractionation would improve local tumor control and patient survival.

METHODS

Twenty-three patients were enrolled in this study. Eligibility criteria included age between 18 and 70 years, Karnofsky Performance Scale score of greater than or equal to 70, residual tumor volume of less than 60 ml, and a supratentorial, unilateral tumor. Actuarial survival rates at 2 and 3 years were 34% and 18%, respectively. The median survival time was 20 months, with four patients alive 22 to 60 months postdiagnosis. Analysis by Radiation Therapy Oncology Group prognostic criteria or Medical Research Council indices showed a 5- to 11-month increase in median survival time over those of comparable conventionally treated patients. All patients developed new areas of gadolinium enhancement during the follow-up period. Histological examination of tissues obtained at biopsy, resection, or autopsy was conducted in 15 of 23 patients. Radiation necrosis only was demonstrated in seven patients, and their survival was significantly longer than that of patients with recurrent tumor (p = 0.01). Tumor regrowth occurred most commonly in areas that received doses of 60 to 70 CGE or less; recurrent tumor was found in only one case in the 90-CGE volume.

CONCLUSIONS

A dose of 90 CGE in accelerated fractionation prevented central recurrence in almost all cases. The median survival time was extended to 20 months, likely as a result of central control. Tumors will usually recur in areas immediately peripheral to this 90-CGE volume, but attempts to extend local control by enlarging the central volume are likely to be limited by difficulties with radiation necrosis.

Pion conformal radiation of prostate cancer: results of a randomized study

PURPOSE

To compare the efficacy of pion radiation therapy with conventional external beam photon therapy, for the treatment of locally advanced stage T3/4, N0, M0 adenocarcinoma of the prostate.

METHODS AND MATERIALS

Two hundred seventeen eligible patients were randomly allocated to either photon or pion therapy. No adjuvant hormone therapy was used.

RESULTS

Median follow-up was 42 months (range 2-90). Acute bladder toxicity was worse in the pion arm, p = 0.2, but other acute toxicity did not differ. Late grade 2 toxicity was significantly less in the pion arm (29% at 5 years versus 48%, p = 0.002), but late grade 3 or 4 toxicity did not differ. Clinical local control was not significantly different between treatment arms (64% after 5 years with photons, 56% with pions, p = 0.6). Cause-specific and overall survival also did not differ (p = 0.7). There was a significant delay in time to first failure in the photon arm, largely as a result of decreased biochemical relapse, p = 0.01. A multivariate analysis is presented.

CONCLUSION

Pion therapy was well tolerated, with increased acute toxicity and significantly decreased late tissue injury. This contrasts with the late toxicity observed with higher LET particle therapy such as neutron therapy. No improvement in local control with pion therapy was observed.