This prospective study generated a large QoL data set related to the radiotherapy of brain metastases with a validated brain-specific QoL questionnaire. Only one study group reported on a bigger patient group of 170, but used a general QoL tool (ESAS – Edmonton Symptom Assessment Scale) without a brain-specific module [5
Three smaller trials used the Functional Assessment of Cancer therapy – General scale (FACT-G) with a brain module (FACT-BR) [19
]. The results are not comparable to our study because of the addition of temozolomide to WBRT [19
] or different evaluation points of time. The brain module BN20 has been validated by the EORTC in an international study incorporating 891 patients with primary brain tumours [22
] and has been applied in some smaller QoL studies of patients with brain metastases [4
]. Because of short assessment periods [4
] after radiotherapy or analysis only of special radiation techniques like radiosurgery these studies are not directly acceptable to the routine palliative radiotherapy setting with predominant whole-brain radiotherapy and short survival times.
The BN20 questionnaire was used in this study with the shortened questionnaire variant EORTC QLQ-C15-PAL to reduce the burden of repeated questionnaire completion for the incurable patients. It should be noted that the short version QLQ-C15-PAL lacks the two questions regarding cognitive function from QLQ-C30 [15
], and therefore some potentially interesting information was lost by the decision for the shorter version.
QoL was evaluated at only two points in time. The second point of time after 3
months was chosen to reduce the effects of rapid deterioration by very early tumour progression, while maintaining a reasonable number of patients available for assessment. It must be acknowledged that the addition of both earlier and later points of time would have been informative. However, a distinction between brain-metastasis-related, extracranial-tumour-related and treatment-related impairment would probably have been similarly problematic at other points of time. The choice of the 3-month-point was a compromise for pragmatic reasons. Given all the problems associated with the highly palliative situation of the patients studied, a response rate of 70
% of survivors at this point of time appears adequate.
The overall survival in the patient group (38
% dead at three months) is comparable to other reports [3
]. Previously, improved survival in patients with brain metastases has been linked to lower RPA class [10
], higher GPA scores [25
], with stable extracranial tumour situation, limited (1–3) intracranial metastases and therefore possible radiosurgery [27
] and low steroid dose [29
One of the most important results of this study was the deterioration of different domains and symptom scales of QoL in patients after three months. This was acceptable in potentially treatment-related symptom scales such as hair loss (only a trend in this study) and fatigue. In our study 42
% and 54.2
% of patients showed an increase of hair loss and fatigue scores, respectively, over 20 points. This can be considered clinically relevant. The study of Slotman et al. [17
] examined QoL of patients with or without prophylactic cranial irradiation (PCI) for small-cell lung cancer with the same questionnaires. Slotman et al. [17
] found a worsening hair loss (≥ 20 points) in 22.4
% of patients with PCI and 12.2
% of controls and a worsening of fatigue on this order of magnitude in 49
% of patients with PCI and 26.7
% of controls. Hair loss and fatigue are both also potential chemotherapy-associated symptoms. In our study subsequent chemotherapies after irradiation were not evaluated. Our findings are comparable with the results of Wong et al. who reported more severe fatigue symptoms in 57
% of patients over time [3
]. The testing of influencing factors in our study showed a significant association of WBRT as treatment strategy and the fatigue score after three months.
The score for headache was slightly better after 3
months in the pilot phase of this study and remained unchanged in the now reported main phase with a larger cohort of patients. Additionally, the steroid use after 3
months was significantly lower. Therefore, these results show one important benefit of the radiotherapy.
The deterioration of global health status, physical function and of symptom scales like motor dysfunction, communication deficit or weakness of legs after three months were not necessarily expected. The most important aim of brain irradiation in patients with brain metastases should be the improvement or stabilization of the performance status and of QoL.
Intracranial and extracranial progression or adverse treatment effects are potential explanations for the deterioration of QoL within three months after start of radiotherapy. Further published QoL studies did not analyze intra- or extracranial progression over time. This study provided some limited information on progression of the primary, additional extracranial and intracranial metastases or increase in the size of brain metastases. Due to the poor condition of most patients, it was felt to be unethical to require specific imaging studies to be performed at defined points of time. Imaging data after radiotherapy was available for 53
% of patients and showed intracranial progression in 20
% and extracranial progression in 53
% of patients among these patients. For specific preselected QoL domains, predominant factors influencing the scores at the 3-month-point were identified. For instance, brain metastases from breast cancer were associated with better physical function at 3
months. This may be related to the known slightly better prognosis after radiotherapy for patients with brain metastases from breast cancer compared to other primaries [30
] but also to the more recently documented improved outcome of subgroups e. g. with positive Her-2 status [31
A known prognostic factor in brain metastases patients, KPS, was associated with motor dysfunction after three months. The therapeutic strategy (WBRT vs. stereotactic radiotherapy) was significantly associated with the physical function score during the same period. Although the limited information on imaging response of brain metastasis precludes definitive conclusions, factors related to the initial selection of patients for specific strategies (e. g. stereotactic radiotherapy for fitter patients with limited number of metastases) are likely to explain part of the variation in post-radiotherapy QoL. Data from the literature suggests that achieving local control of brain metastases is a prerequisite for maintaining neurologic function[32
]. Therefore, patients treated with palliative whole-brain radiotherapy alone may deteriorate not because of, but despite of radiotherapy, not considering the frequent rapid extracranial progression of metastases.
A second main result of this study was the difference of baseline QoL of 3-month survivors vs. non-survivors. Baseline pre-treatment QoL scores of physical function, fatigue, pain, appetite loss, motor dysfunction, weakness of legs were significantly better in survivors suggesting that these scores might contain prognostic information.
Similar results were presented by Movsas et al. who analyzed the QoL of 239 patients with locoregionally advanced non-small-cell lung cancer treated with amifostine and chemotherapy using the EORTC QLQ-C30 and LC-13 (RTOG 9801) [33
]. Patients with a global QoL score less than 66.7 had an approximately 70
% higher rate of death than patients with scores of ≥66.7 (p
0.012). Other QoL predictors for OS were physical functioning and dyspnoea. In their study, these QoL scales seemed to be more relevant and powerful as prognostic factors than standard measures like KPS, so the authors suggested patient-reported QoL as a good stratification factor in future.
Other prior studies with lung cancer patients, who were also a predominant subgroup in the present cohort, have shown similiar results. Montezari et al. reported the initial global QoL as the most significant predictor of survival at 3
]. In the literature, global QoL, appetite loss, fatigue and pain were the most important indicators for predicting survival times in cancer patients after adjusting known clinical prognostic factors [35
]. It is argued that measures such as global QoL are patient-rated and thus have the potential to reflect the patient's well-being better than physician's observed indicators. Patient-reported outcomes detect prognostically relevant lowered patient well-being earlier than other measures. Higher scores correlate with more positive behaviour and reflect individual characteristics that affect survival [36
]. Data for high-grade glioma patients defined fatigue as a prognostic factor [37
] but no other trial has so far shown a specific QoL score of patients with brain metastases as predictive.
In the present study, using a multiple logistic stepwise regression model, only pain as one of six predetermined QoL domains, when tested together with clinical variables, remained prognostically significant. KPS and age were also significant predictors of survival. One possible explanation is that the KPS, as a global performance measure, contains information overlapping with that of the selected QoL domains. It could be argued that KPS alone integrates some of the prognostically relevant information obtainable from the QoL questionnaires. The prognostic role of pain, as assessed by EORTC QLQ-C15-PAL, for survival may be that on an indicator of uncontrolled extracranial disease. Sundaresan et al. developed a prognostic index for patients with WBRT for brain metastases of lung cancer and scored the factors age, ECOG performance status, histology, weight loss, primary and systemic disease status [38
]. The new scoring system suggested by Rades et al. predicted the survival of all patients with brain metastases treated with WBRT [11
]. Actuarial 6-month survival varied from 6
% of patients in the worst prognostic group, via 15
% and 43
% to 76
% of patients with better status. No QoL scores were used because of the retrospective nature of these studies. Sperduto et al. defined a disease-specific GPA, because patients with brain metastases are a heterogeneous population and different primaries are not comparable [26
Potentially, the inclusion of self-reported QoL scores in prognostic scoring systems for patients with brain metastases may be more relevant within more specifically defined patients subgroups, e. g. only lung cancer or breast cancer patients. Given the generally unsatisfactory QoL outcomes after palliative radiotherapy for brain metastases, novel strategies to improve intracranial tumour control are needed. Further QoL studies are necessary to better identify patients groups who may benefit from specific modes of radiotherapy, e. g. shorter or longer-course WBRT, local (stereotactic) treatment alone or combinations. At the same time, a patient subgroup with very poor baseline characteristics (including clinical and QoL parameters) may be defined, in whom radiotherapy can be withheld.