Different fractionation schedules in radiation treatment of cerebral metastases

Whole brain radiotherapy with a conformational external beam radiation boost for lung cancer patients with 1-3 brain metastasis: a multi institutional study

Background

To determine the outcome of patients with brain metastasis (BM) from lung cancer treated with an external beam radiotherapy boost (RTB) after whole brain radiotherapy (WBRT).

Methods

A total of 53 BM patients with lung cancer were treated sequentially with WBRT and RTB between 1996 and 2008 according to our institutional protocol. Mean age was 58.8 years. The median KPS was 90. Median recursive partitioning analysis (RPA) and graded prognostic assessment (GPA) grouping were 2 and 2.5, respectively. Surgery was performed on 38 (71%) patients. The median number of BM was 1 (range, 1-3). Median WBRT and RTB combined dose was 39 Gy (range, 37.5 - 54). Median follow-up was 12.0 months.

Results

During the period of follow-up, 37 (70%) patients died. The median overall survival (OS) was 14.5 months. Only 13 patients failed in the brain. The majority of patients (n = 29) failed distantly. The 1-year OS, -local control, extracranial failure rates were 61.2%, 75.2% and 60.8%, respectively. On univariate analysis, improved OS was found to be significantly associated with total dose (≤ 39 Gy vs. > 39 Gy; p < 0.01), age < 65 (p < 0.01), absence of extracranial metastasis (p < 0.01), GPA ≥ 2.5 (p = 0.01), KPS ≥ 90 (p = 0.01), and RPA < 2 (p = 0.04). On multivariate analysis, total dose (p < 0.01) and the absence of extracranial metastasis (p = 0.03) retained statistical significance.

Conclusions

The majority of lung cancer patients treated with WBRT and RTB progressed extracranially. There might be a subgroup of younger patients with good performance status and no extracranial disease who may benefit from dose escalation after WBRT to the metastatic site.

Palliative radiation therapy in oncology

Palliative radiation therapy is considered when the incurable cancer patient has symptoms specifically related to a malignancy that may be relieved by localized treatment of the primary tumor or metastatic lesions. Developing a treatment plan with radiation in the palliative setting may be more difficult than the curative setting, where there are clear guidelines for many situations. Radiation therapy has been used successfully in the management of a variety of pain syndromes. Radiation also has proven effective in the management of other tumor-related symptoms, including bleeding, neurologic compromise, dysphagia, and airway obstruction. Palliative radiation can be delivered using a variety of techniques: external beam radiation therapy, intraluminal brachytherapy (radioactive seed delivery), and systemic radionucleotides.

Effectiveness of whole brain radiotherapy in the treatment of brain metastases: a systematic review

BACKGROUND

Brain metastases are the most common intracranial tumour in adults, estimated to occur in up to 40% of patients with cancer. Despite being used in clinical practice for 50 years, the effectiveness of whole brain radiotherapy for the treatment of brain metastases remains uncertain.

OBJECTIVES

To assess the effectiveness of whole brain radiotherapy (WBRT) on survival and quality of life. To identify whether patient performance status, number of brain metastases, extent of extracranial disease and primary site of cancer are important effect modifiers.

DESIGN

Systematic literature review.

METHODS

Electronic searches of four databases, augmented by hand searches of the most frequently encountered journal and assessment of the reference lists of consensus statements and all retrieved papers. Included papers underwent structured data extraction, assessment and qualitative synthesis.

RESULTS

Thirty-two primary studies were included, with a range of study designs, methodological quality, pre-treatment variables, interventions and outcome measures. From the limited evidence available, survival appeared to increase when patients were selected by performance status (survival increasing from approximately three to seven months in high performance status groups, as defined by Karnofsky performance status or Recursive Partitioning Analysis classification). The evidence suggests no survival benefit when patients with poor performance status were treated with whole brain radiotherapy. No studies undertook direct measurement of patients' quality of life. Surrogate measures of patients' quality of life, such as improvement in neurological function or improvement/maintenance of KPS > or =70, produced response rates ranging from 7 to 90%.

CONCLUSION

The heterogeneity of study designs, quality and outcomes necessitates caution in interpreting the review findings. WBRT appears to be of benefit in higher performance status patients but not in low performance status patients. This suggests a basis for current practice, however further robust trial evidence is required.

Radiotherapy for brain metastases: defining palliative response

BACKGROUND AND PURPOSE

Most patients with brain metastases are treated with palliative whole brain radiotherapy (WBRT). There is no established definition of palliative response. The aim of this study was to develop and test clinically useful criteria for response following palliative WBRT.

MATERIALS AND METHODS

A prospective study was conducted of patients with symptomatic brain metastases treated with WBRT (20 Gy/5 fractions) and standardised steroid tapering. Assessments included observer rating of neurological symptoms, patient-completed symptom checklist and performance status (PS). Response criteria were operationally defined based on a combination of neurological symptoms, PS and steroid dose.

RESULTS

Seventy-five patients were accrued. At 1 month, presenting neurological symptoms were improved in 14 patients, stable in 17, and worse in 21; 23 patients were not assessed, mainly due to death or frailty. Using response criteria defined a priori, 15% (95% CI 7-23%) of patients were classified as having a response to RT, 25% no response, and 29% progression; 27% were deceased at or soon after 1 month. A revised set of criteria was tested, with less emphasis on complete tapering of steroids: they increased the proportion of patients responding to 39% (95% CI 27-50%) but didn't change the large proportion who did not benefit (44%).

CONCLUSIONS

Clinical response to RT of patients with brain metastases is multifactorial, comprising symptoms, PS and other factors. Assessment of degree of palliation depend on the exact definition used. More research is needed in this important area, to help validate criteria for assessing palliation after WBRT.

A randomized phase III study of accelerated hyperfractionation versus standard in patients with unresected brain metastases: a report of the Radiation Therapy Oncology Group (RTOG) 9104

PURPOSE

To compare 1-year survival and acute toxicity rates between an accelerated hyperfractionated (AH) radiotherapy (1.6 Gy b.i.d.) to a total dose of 54.4 Gy vs. an accelerated fractionation (AF) of 30 Gy in 10 daily fractions in patients with unresected brain metastasis.

METHODS AND MATERIALS

The Radiation Therapy Oncology Group (RTOG) accrued 445 patients to a Phase III comparison of accelerated hyperfractionation vs. standard fractionation from 1991 through 1995. All patients had histologic proof of malignancy at the primary site. Brain metastasis were measurable by CT or MRI scan and all patients had a Karnofsky performance score (KPS) of at least 70 and a neurologic function classification of 1 or 2. For AH, 32 Gy in 20 fractions over 10 treatment days (1.6 Gy twice daily) was delivered to the whole brain. A boost of 22.4 Gy in 14 fractions was delivered to each lesion with a 2-cm margin.

RESULTS

The average age in both groups was 60 years; nearly two-thirds of all patients had lung primaries. Of the 429 eligible and analyzable patients, the median survival time was 4.5 months in both arms. The 1-year survival rate was 19% in the AF arm vs. 16% in the AH arm. No difference in median or 1-year survival was observed among patients with solitary metastasis between treatment arms. Recursive partitioning analysis (RPA) classes have previously been identified and patients with a KPS of 70 or more, a controlled primary tumor, less than 65 years of age, and brain metastases only (RPA class I), had a 1-year survival of 35% in the AF arm vs. 25% in the AH arm (p = 0.95). In a multivariate model, only age, KPS, extent of metastatic disease (intracranial metastases only vs. intra- and extracranial metastases), and status of primary (controlled vs. uncontrolled) were statistically significant (at p < 0.05). Treatment assignment was not statistically significant. Overall Grade III or IV toxicity was equivalent in both arms, and one fatal toxicity at 44 days secondary to cerebral edema was seen in the AH arm.

CONCLUSION

Although a previous RTOG Phase I/II report had suggested a potential benefit in patients with limited metastatic disease, a good Karnofsky performance status, or neurologic function when treated with an AH regimen, this randomized comparison could not demonstrate any improvement in survival when compared to a conventional regimen of 30 Gy in 10 fractions. Therefore, this accelerated hyperfractionated regimen to 54.4 Gy cannot be recommended for patients with intracranial metastatic disease.

Final results of the Royal College of Radiologists' trial comparing two different radiotherapy schedules in the treatment of cerebral metastases

Between February 1990 and February 1993, 25 centres in the UK recruited 544 patients into a prospective randomized trial comparing two whole-brain radiotherapy regimens (30 Gy in ten fractions over 2 weeks versus 12 Gy in two fractions on consecutive days) for the treatment of patients with symptomatic cerebral metastases. Of these patients 533 were eligible for analysis: 270 assigned to the two-fraction arm and 263 to the ten-fraction arm. The two groups were well balanced with respect to patient characteristics. Median survival was 77 days with two fractions (95% CI 68-89) and 84 days for the longer schedule (95% CI 67-102). Analysis of the survival curves showed a marginal advantage for ten fractions (P = 0.04). Performance status (P = 0.0001), site of primary tumour (P = 0.006), dose of dexamethasone (P = 0.004), age (P = 0.04) and randomization treatment (P = 0.03) were independant factors associated with survival. The classification of patients into good or poor risk groups based on these factors, excluding treatment, showed highly significant differences in survival (P < 0.0001). Predictive models suggested that any benefit attributable to the longer radiotherapy schedule was confined to those in a good prognostic group (these patients formed 22% of the study population). Radiation related side effects, other than alopecia, were seen in 12% of patients receiving two fractions and 8% of those given ten fractions. The short survival of many patients hampered the assessment of response, but overall responses were seen in 39% of those given two fractions and 44% of patients receiving ten fractions. These results suggest that any increase in survival due to longer radiotherapy treatment is confined to good prognosis patients, but, for the majority, there is no advantage and the value of radiotherapy for these patients relates purely to the possibility of control or relief of distressing symptoms.

A randomized phase III protocol for the evaluation of misonidazole combined with radiation in the treatment of patients with brain metastases (RTOG-7916)

From 1979 through July 1983, 859 patients were enrolled in a Phase III RTOG Protocol (7916) evaluating the role of Misonidazole combined with radiation in the treatment of brain metastasis. Patients were randomized to one of four treatment arms (3.0 Gy x 10 fractions with or without 1 g/m2 of Misonidazole [total 10 g/m2] versus 5.0 Gy x 6 fractions with or without 2 g/m2 of Misonidazole) [total 12 g/m2]. Among the 779 analyzable cases, 63% had a lung primary and 12% had breast. Of the histologic types, 43% were adenocarcinoma and 24% were squamous cell. Seventy-eight percent had a Karnofsky of greater than 70. Of the 779 cases, 773 are dead (99%). Median survival is 3.9 months, with 60% alive at 3 months, 35% at 6 months, and 15% at 1 year. Survival was evaluated by treatment arm, Misonidazole status, and fractionation scheme; none showed any statistical significance. Favorable prognostic factors were assessed (age less than 60, Karnofsky of 70-100, controlled primary and brain metastasis only) in each treatment arm and no difference was found. Brain metastasis was cause of death in 1/3, and 19-33% of patients were retreated. Because up to 1/3 of the patients in this study died secondary to uncontrolled brain metastasis, improvement in local control remains an important goal. Until proven otherwise, the treatment of choice for the majority of patients still remains a conventional palliative course of 3.0 Gy x 10 fractions.

The influence of extent and local management on the outcome of radiotherapy for brain metastases

The results of cranial irradiation for brain metastases in 164 consecutive patients have been reviewed to evaluate a policy of localized high dose irradiation for solitary metastases. Fifty of the 164 patients receiving whole brain irradiation (35 Gy in 15 daily fractions) were selected for boosts delivering 15 Gy in 8 daily fractions to the site of solitary deposits. No difference in overall survival or the incidence of death from progressive brain metastases was seen between the patients receiving a boost and those who did not. Overall median survival was 112 days with 62% of patients dying from metastatic disease outside the brain. Factors associated with increased survival were early response to radiotherapy and, in breast cancer patients, a disease-free interval of 2 years. Palliation of presenting symptoms was achieved in 86% of patients at 3 weeks from starting radiotherapy. It is concluded that whereas whole brain irradiation results in useful symptom control, there is no advantage for high dose treatment in the majority of patients with solitary metastases even in the absence of metastatic disease elsewhere.