Detection of brain metastases from small cell lung cancer: consequences of changing imaging techniques (CT versus MRI)

Prophylactic cranial irradiation for small-cell lung cancer: how, when and for whom?

Prophylactic cranial irradiation (PCI) reduces the incidence of brain metastases and improves overall survival in both limited disease (LD) and extensive disease (ED) small-cell lung cancer (SCLC), in complete and good responders to initial chemo(radio)therapy. In LD-SCLC, a standard dose of 25 Gy given in ten fractions is recommended, whereas in ED-SCLC a shorter schedule of 20 Gy in five fractions could be used. The issues of acute neurotoxicity (NT) and the potential impact of PCI on quality of life are of particular concern in ED-SCLC patients, as their expected survival is short. In LD-SCLC late neurologic sequelae may worsen quality-adjusted life expectancy for long-term survivors, as the pronounced effect of NT becomes apparent after several years. Some novel potential approaches to reduce the PCI-related late NT have recently been investigated. Despite the growing incidence of lung cancer in elderly people, there are no established standards of treatment for this subset of the population.

Intraventricular metastases from small cell carcinoma of the lung

Small cell lung carcinoma (SCLC) represents 15-20% of all lung cancers. It is characterised by rapid growth and early metastatic dissemination. Generally, the prognosis of these patients is poor. When brain metastases develop, the prognosis is even poorer. Most of these cases present parenchymal metastases; however, intraventricular dissemination may also occur although it is very uncommon. To our knowledge the case reported here is the first showing multiple synchronic intraventricular dissemination from SCLC.

The role of whole brain radiation therapy for the management of brain metastases in the era of stereotactic radiosurgery

The goals of treatment for brain metastases (BMs) include preservation of function and improvement of survival. Although whole brain radiotherapy (WBRT) has been a mainstay in the treatment of BMs, stereotactic radiosurgery (SRS) monotherapy has been increasingly used because of concern about the deterioration of neurocognitive function as a late adverse effect of WBRT. The results of four randomized controlled trials comparing focal treatment alone versus focal treatment combined with WBRT have shown, however, that SRS monotherapy significantly increases the risk of brain tumor recurrence (BTR) and that this increased risk of BTR may cause deterioration of neurocognitive function. We suggest identifying patients according to their risk of BTR when selecting treatment. Patients who have solitary BM with the absence of extracranial metastases may be indicated for SRS monotherapy given the lower risk of BTR compared with those having multiple BMs or extracranial metastases.

Contribution of CSF cytology in the diagnostic work-up of breast cancer patients with neurological symptoms: a retrospective analysis over two decades

The aim of this study was to evaluate the contribution of cytological analysis of cerebrospinal fluid (CSF) in the diagnostic work-up of breast cancer patients who present with neurological symptoms suspected for central nervous system (CNS) metastases. In the period 1989-2009, a total of 81 patients with breast cancer underwent CSF cytological examination. Relevant tumour characteristics, clinical presentation and radiological findings were scored. The CSF cytological diagnosis was classified according to the 1996 NCI-sponsored conference approach as malignant, suspicious for malignancy, atypical, benign or inadequate. During the course of 20 years, 145 CSF cytological examinations were performed. Relatively common neurological symptoms resulting in cytological CSF examination were headache (n = 25), nausea and vomiting (n = 19), sensory disturbances (n = 16), and cranial nerve dysfunction (n = 16). Of these, headache and nausea/vomiting were most often associated with malignant cells in the CSF (CSF(+)) (in 48 and 53% of the cases, respectively). The 4 patients with both headache and confusion/altered mental status all had CSF(+). In 10 patients, CSF(+) was found despite the absence of radiological evidence for metastasis in/around the CNS. In our series, repeated CSF analysis appeared to have limited additional value, and CSF(+) was strongly correlated with shorter survival. A substantial number of patients with neurological symptoms but without radiological abnormalities can have CSF(+). In our series, the additional value of repeated cytological examination of CSF was limited. Our study underscores the value of CSF cytology as a tool for the unequivocal diagnosis of metastatic spread of breast cancer to the CNS, and confirms that CSF(+) is a strong predictor of poor survival.

Small-cell lung cancer

The incidence and mortality of small-cell lung cancer worldwide make this disease a notable health-care issue. Diagnosis relies on histology, with the use of immunohistochemical studies to confirm difficult cases. Typical patients are men older than 70 years who are current or past heavy smokers and who have pulmonary and cardiovascular comorbidities. Patients often present with rapid-onset symptoms due to local intrathoracic tumour growth, extrapulmonary distant spread, paraneoplastic syndromes, or a combination of these features. Staging aims ultimately to define disease as metastatic or non-metastatic. Combination chemotherapy, generally platinum-based plus etoposide or irinotecan, is the mainstay first-line treatment for metastatic small-cell lung cancer. For non-metastatic disease, evidence supports early concurrent thoracic radiotherapy. Prophylactic cranial irradiation should be considered for patients with or without metastases whose disease does not progress after induction chemotherapy and radiotherapy. Despite high initial response rates, most patients eventually relapse. Except for topotecan, few treatment options then remain. Signalling pathways have been identified that might yield new drug targets.

[Analysis of prognostic factors in NSCLC patients with brain metastases diagnosed by constrast-enhanced MRI after whole brain radiotherapy]

背景与目的

肺癌脑转移约占脑转移瘤的20%-40%。本研究旨在探讨基于增强MRI诊断并行全脑放疗的非小细胞肺癌（non-small cell lung cancer, NSCLC）脑转移的预后因素。

方法

回顾性分析2007年4月-2008年10月241例NSCLC脑转移并接受全脑放疗的病例资料，采用Kaplan-Meier法计算生存率，Log-rank法进行单因素分析，Cox回归分析进行多因素分析。

结果

中位随访时间为19.1个月，全组中位生存时间为8.7个月。影响NSCLC脑转移生存的单因素包括女性、KPS（karnofsky performance score） > 70分、脑转移无症状、胸内病变控制、化疗3周期以上及合并靶向治疗。多因素分析显示性别、随访截止时胸内病变控制状态、靶向治疗是影响NSCLC脑转移生存的独立预后因素。

结论

对于基于增强MRI诊断并行全脑放疗的NSCLC脑转移患者，性别、胸内病变控制、靶向治疗是影响生存的独立预后因素。

Clinical neurological outcome and quality of life among patients with limited small-cell cancer treated with two different doses of prophylactic cranial irradiation in the intergroup phase III trial (PCI99-01, EORTC 22003-08004, RTOG 0212 and IFCT 99-01)

BACKGROUND

We recently published the results of the PCI99 randomised trial comparing the effect of a prophylactic cranial irradiation (PCI) at 25 or 36 Gy on the incidence of brain metastases (BM) in 720 patients with limited small-cell lung cancer (SCLC). As concerns about neurotoxicity were a major issue surrounding PCI, we report here midterm and long-term repeated evaluation of neurocognitive functions and quality of life (QoL).

PATIENTS AND METHODS

At predetermined intervals, the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 and brain module were used for self-reported patient data, whereas the EORTC-Radiation Therapy Oncology Group Late Effects Normal Tissue-Subjective, Objective, Management, Analytic scale was used for clinicians' assessment. For each scale, the unfavourable status was analysed with a logistic model including age, grade at baseline, time and PCI dose.

RESULTS

Over the 3 years studied, there was no significant difference between the two groups in any of the 17 selected items assessing QoL and neurological and cognitive functions. We observed in both groups a mild deterioration across time of communication deficit, weakness of legs, intellectual deficit and memory (all P < 0.005).

CONCLUSION

Patients should be informed of these potential adverse effects, as well as the benefit of PCI on survival and BM. PCI with a total dose of 25 Gy remains the standard of care in limited-stage SCLC.

Increases in the number of brain metastases detected at frame-fixed, thin-slice MRI for gamma knife surgery planning

For gamma knife planning, 2.4-mm-slice MRIs are taken under rigid frame fixation, so tiny tumors become visible. This study evaluated differences in the numbers of brain metastases between conventional contrast-enhanced MRI (6 ± 1 mm slice thickness) taken before patient referral and contrast-enhanced MRI for gamma knife planning. The numbers of metastases on the 2 images were counted by at least 2 oncologists. For gamma knife planning, spoiled gradient-recalled echo images were obtained after 0.1 mmol/kg gadolinium administration using a 1.5-T system. Images from 1045 patients with an interval between the 2 MRI studies of 6 weeks or less were analyzed. Increases in the number of metastases were found in 33.7% of the 1045 patients, whereas the number was identical in 62.3%. In 4.0%, the number decreased, indicating overdiagnosis at conventional MRI. These proportions did not differ significantly by the interval before gamma knife. An increase from single to multiple metastases was found in 16.0%. Meningeal dissemination was newly diagnosed in 2.3%. On planning images, the proportions of patients with 1, 2, 3, and 4 or more lesions were 37.6%, 19.3%, 9.3%, and 33.8%, respectively. In cases of colorectal cancer and hepatoma, the proportions of patients with a single metastasis (32 of 61 [52%] and 5 of 6 [83%], respectively) were higher than that of patients with other malignancies. In about one-third of the patients, an increased number of metastases were found on the thin-slice images. This should be kept in mind when deciding the treatment strategy for brain metastases.

Radiation therapy for brain metastases in breast cancer patients

Most randomized comparison trials (RCTs) investigating treatments for brain metastases (BM) have included BM from any origin; as a result, more than half (52.4-77.0%) of the BM in these trials originated from the lungs (mostly non-small-cell lung cancer, NSCLC), with the breasts being the origin in only 6.8-19.0% of cases. In addition, patients with poor systemic status (KPS < 70) were not included in these trials. Hence, before we can apply RCT-based information to the daily clinical treatment of BM from breast cancers, it will be crucial to differentiate the characteristics of BM originating from NSCLC and BM originating from breast cancer. Although stereotactic radiosurgery (SRS) is widely used in Japan, level-1 evidence suggests that the benefit of using SRS in addition to whole-brain radiation therapy (WBRT) has been proven only for patients with a single BM. Treatment with SRS alone, which is widely used in Japan, seems attractive because it could avoid the risk of long-term adverse effects of WBRT. However, level-1 evidence suggests that the omission of WBRT results in a high frequency of brain tumor recurrence (BTR). In an RCT between SRS-alone and SRS + WBRT conducted in Japan, we found that patients who had a single BM and no extracranial metastases had a low risk of developing BTR after initial brain management (low-risk group) compared with those who had 2 or more BM and extracranial metastases (high-risk group). In order to meet the criteria of "low-risk" BTR, patients also should have good systemic status (KPS ≧ 70). Epidemiologic data suggest that the prognosis is twice as likely to be poor in patients with BM from breast cancer (RPA III = KPS < 70) than in patients with BM from NSCLC (40 vs. 20%); in addition, the probability of brain-only metastases in patients with breast cancer is less than half that in patients with NSCLC (20-25 vs. 60-75%). Considering these findings, we should be aware that most patients with BM from breast cancer are not good candidates for SRS alone, and, therefore, the role of WBRT is still important in the era of modern radiation techniques.

CT and MR imaging features of primary central nervous system lymphoma in Norway, 1989-2003

BACKGROUND AND PURPOSE

Studying imaging findings of non-acquired immunodeficiency syndrome (AIDS) primary central nervous system lymphoma (PCNSL), we hypothesized that the imaging presentation has changed with the increasing incidence of PCNSL and is related to clinical factors (eg, time to diagnosis and the patient's being diagnosed alive or at postmortem examination).

MATERIALS AND METHODS

Chart and histologic reviews of patients recorded as having PCNSL during 1989-2003 in the Norwegian Cancer Registry identified 98 patients with non-AIDS PCNSL; 75 had available imaging. CT and MR images from the first diagnostic work-up after onset of symptoms but before histologic diagnosis were reviewed.

RESULTS

CT and/or MR imaging in the 75 patients revealed no lesion in 10 (13%), a single focal lesion in 34 (45%), multiple focal lesions in 26 (35%), and disseminated lesions in 5 (7%) patients. All together, we identified 103 focal lesions (single/multiple): 63% in white matter, 56% abutting the ventricular surface, and 43% in the frontal lobes); 100% (102/102 lesions evaluated with contrast) showed contrast enhancement. The median time from imaging to diagnosis for patients with no, single, multiple, or disseminated lesions was 32, 3, 5, and 3 weeks, respectively (P = .01). Patients with no or disseminated lesions were more often diagnosed at postmortem examination (P = .06). Imaging findings were practically unchanged during the consecutive 5-year periods.

CONCLUSIONS

White matter periventricular contrast-enhancing single or multiple focal lesions were typical of non-AIDS PCNSL. No or disseminated lesions heightened the risk of delayed or postmortem diagnosis. Although the incidence of non-AIDS PCNSL has increased, its presentation at imaging remains unchanged.