Dose-response relationship for prophylactic cranial irradiation in small cell lung cancer

Radiotherapy for brain metastases from small-cell lung cancer in distinct clinical indications and scenarios

Management of brain metastases (BM) from small-cell lung cancer (SCLC) is complex and not supported by a strong evidence from prospective clinical trials. Owing to the different clinical and pathological characteristics of SCLC, patients with this histology were not included in the prospective studies on the value of whole-brain radiotherapy (WBRT) and local surgical or ablative radiation treatment like stereotactic radiosurgery (SRS). Chemotherapy also represents a major part of the armamentarium against BM from SCLC due to the well-recognized chemoresponsiveness of this cancer and the frequent presentation of BM with extracranial progression. WBRT in combination with chemotherapy has long been a standard approach in this setting. However, data on the neurocognitive toxicity and the lack of documented impact on overall survival of WBRT in the management of BM from other solid tumors, as well as the increasing availability of the stereotactic radiotherapy technologies, has led to the increasing use of SRS with omission of WBRT also in SCLC. In the current review the use of different modalities of radiotherapy and ways of combining radiotherapy with chemotherapy for BM from SCLC will be presented for distinct clinical situations: presentation of BM synchronous with primary, metachronous presentation of BM-without previous prophylactic cranial irradiation (PCI) vs. after PCI, and asymptomatic BM found at the staging before PCI.

Prophylactic cranial irradiation in SCLC

Prophylactic cranial irradiation (PCI) has well established place in therapy for patients with limited-disease small cell lung cancer who responded to treatment. The data from randomized trials document that PCI reduces brain metastases rate from approximately 60% to 30%, and increases 3-year overall survival by approximately 5%. Currently, the dose of 25 Gy in 10 fractions is considered as standard. In attempt to reduce neuropsychological sequelae attributable to PCI hippocampal sparing techniques are employed. The existing studies suggest the benefit of hippocampal sparing in limiting memory and higher neurocognitive function losses, but with a risk of failures in the spared region. Ongoing studies will further validate the role of hippocampal sparing, both in terms of toxicity reduction and metastases prevention. PCI for patients who have undergone resection for stage I small cell lung cancer (SCLC) is not recommended, PCI may be, however, associated with a favourable outcome in SCLC patients who have undergone complete surgery in stages II−III. The role of PCI in extensive-disease (ED) SCLC has been evolving. Most recent evidence indicate that PCI is controversial in ED patients with response to initial chemotherapy and absence of brain metastases confirmed by contrast-enhanced MRI. The patients who do not receive PCI, must, however, receive periodic MRI examination during follow-up, i.e., remain under active surveillance with access to radiotherapy at brain relapse. The assessment of safety and effectiveness of hippocampal-sparing PCI, with or without drug neuroprotection in consideration of diverse combinations of radiotherapy, chemotherapy and immunotherapy create a background for future directions of research.

Prophylactic cranial irradiation reduces the incidence of brain metastasis in a mouse model of metastatic, HER2-positive breast cancer

Prophylactic cranial irradiation (PCI) can reduce the incidence of brain metastasis and improve overall survival in some patients with acute lymphoblastic leukemia or small-cell lung cancer. We examined the potential effects of PCI in a mouse model of breast cancer brain metastasis. The HER2+ inflammatory breast cancer cell line MDA-IBC3 was labeled with green fluorescent protein and injected via tail-vein into female SCID/Beige mice. Mice were then given 0 Gy or 4 Gy of whole-brain irradiation 2 days before tumor-cell injection or 5 days, 3 weeks, or 6 weeks after tumor-cell injection. Mice were sacrificed 4-weeks or 8-weeks after injection and brain tissues were examined for metastasis by fluorescent stereomicroscopy. In the unirradiated control group, brain metastases were present in 77% of mice at 4 weeks and in 90% of mice at 8 weeks; by comparison, rates for the group given PCI at 5 days after tumor-cell injection were 20% at 4 weeks (p=0.01) and 30% at 8 weeks (p=0.02). The PCI group also had fewer brain metastases per mouse at 4 weeks (p=0.03) and 8 weeks (p=0.006) versus the unirradiated control as well as a lower metastatic burden (p=0.01). Irradiation given either before tumor-cell injection or 3-6 weeks afterward had no significant effect on brain metastases compared to the unirradiated control. These results underscore the importance of timing for irradiating subclinical disease. Clinical whole brain strategies to target subclinical brain disease as safely as possible may warrant further study.

In regards to Chu et al.: Patterns of brain metastasis immediately before prophylactic cranial irradiation (PCI): implications for PCI optimization in limited-stage small cell lung cancer

We read the article entitled “Patterns of brain metastasis immediately before prophylactic cranial irradiation (PCI): implications for PCI optimization in limited-stage small cell lung cancer” with great interest. In that study, the author reported about the importance of PCI timing in limited stage small cell lung cancer (LS-SCLC) in the era of MRI surveillance. In addition, the authors raise the issue of neurotoxicity of PCI. In this letter, we aimed to clarify the value of PCI in LS-SCLC and present ongoing trials regarding PCI and MRI surveillance in SCLC. As a result, we see the need for the development of a prediction tool to estimate the risk of intracranial relapse in LS-SCLC after chemoradiotherapy in order to support shared decision making through improved guidance.

Should Stereotactic Radiosurgery Be Considered for Salvage of Intracranial Recurrence after Prophylactic Cranial Irradiation or Whole Brain Radiotherapy in Small Cell Lung Cancer? A Population-Based Analysis and Literature Review

BACKGROUND

Prophylactic cranial irradiation (PCI) improves survival and prevents intracranial recurrence (IR) in limited stage (LS) and extensive stage (ES) small cell lung cancer (SCLC). However, despite PCI, IR affects 12%-45%, and limited data exist regarding salvage brain reirradiation (ReRT). We performed a population-based review of IR in SCLC.

METHODS

Demographic, treatment, and outcome data of consecutive patients (N = 371) with SCLC assessed at a tertiary cancer centre (01/2013-12/2015) were abstracted, and summary statistics calculated. Kaplan-Meier estimates and univariate and multivariate analysis (MVA) via the Cox proportional hazard model were performed.

RESULTS

Median age was 66.1 years, and 59.8% were Eastern Cooperative Oncology Group (ECOG) performance status 0-2. Median survival was 24 months (95% CI 18.3-29.7 months) for LS (N = 103) and 7 months (95% CI 6.1-7.9 months) for ES (N = 268). 72 of 103 patients with LS and 97 of 214 of those with ES received PCI. 54 of 268 ES presented with brain metastases (BM) of whom 46 of 54 received whole brain RT (WBRT). 18.9% (32/169) recurred post-PCI (13 LS; 19 ES) and 30.4% (14/46) recurred after WBRT. Of those who recurred/progressed after cranial RT, 56.5% (26/46) had <5 BM, 39.1% had no extracranial disease, and 50% were ECOG 0-2. In retrospect, 17 of 46 would have been candidates for salvage stereotactic radiosurgery: 13 post-PCI and 4 post-WBRT.

CONCLUSIONS

This cohort challenges commonly held beliefs that IR is always diffuse, associated with clinical deterioration, and synchronous with systemic failure. Approximately 1 in 3 SCLC patients with IR after PCI or WBRT appear clinically appropriate for salvage stereotactic radiosurgery.

The role of prophylactic cranial irradiation for patients with small-cell lung cancer

Small-cell lung cancer (SCLC) has a particular propensity to metastasize to the brain, affecting ~10% of SCLC patients at diagnosis, but may occur in more than 50% of 2-year survivors. Most cytotoxic drugs have limited ability to cross the blood-brain barrier, and the effectiveness of chemotherapy for brain metastasis is limited. Therefore, prophylactic cranial irradiation (PCI) has been proposed to treat SCLC. A meta-analysis revealed that PCI significantly decreased the risk of brain metastasis and increased the 3-year survival rate; it has been established as a standard therapy for limited-disease SCLC. However, certain aspects of PCI remain unclarified, including the roles in resected SCLC and extensive-disease SCLC, and its neurotoxicities. In addition, information on PCI has been obtained from old clinical trials without the use of new imaging devices, such as magnetic resonance imaging. Evidence from advanced imaging techniques is needed in this era.

WITHDRAWN: Cranial irradiation for preventing brain metastases of small cell lung cancer in patients in complete remission

BACKGROUND

Prophylactic cranial irradiation halves the rate of brain metastases in patients with small cell lung cancer. Individual randomized trials conducted on patients in complete remission were unable to clarify whether this treatment improves survival.

OBJECTIVES

This study aims to test whether prophylactic cranial irradiation prolongs survival of patients with small cell lung cancer in complete remission.

SEARCH METHODS

Published and unpublished trials were eligible. Electronic databases (Medline, Cancerlit, Excerpta Medica, Biosis from 1965 to 1998), reference lists of trial publications, review articles and relevant books were used to identify potentially eligible trials. The search was also guided by discussions with investigators and experts, and the examination of meeting proceedings and of the Physician Data Query clinical trial registry.

SELECTION CRITERIA

Randomized trials comparing prophylactic cranial irradiation with no prophylactic cranial irradiation in patients with small cell lung cancer in complete remission.

DATA COLLECTION AND ANALYSIS

Meta-analysis based on updated individual data. The main endpoint was survival.

MAIN RESULTS

Seven trials with a total of 987 participants were included. The relative risk of death in the treatment group compared to the control group was 0.84 (95% confidence interval=0.73 to 0.97, P=0.01), corresponding to a 5.4 percent increase in the 3-year survival rate (from 15.3 percent in the control group to 20.7 percent in the treatment group). Prophylactic cranial irradiation also increased disease-free survival (relative risk=0.75, 95% confidence interval=0.65 to 0.86, P<0.001) and decreased the risk of brain metastases (relative risk=0.46, 95% confidence interval=0.38 to 0.57, P<0.001). Increasing doses of irradiation decreased the risk of brain metastases when four groups (8 Gy, 24-25 Gy, 30 Gy, 36-40 Gy) were analyzed [trend test, P=0.02], but the effect on survival did not differ significantly according to the dose. We found a trend (P=0.01) for a decrease in the brain metastasis risk in favour of earlier administration of cranial irradiation after the initiation of induction treatment.

AUTHORS' CONCLUSIONS

Prophylactic cranial irradiation significantly improves survival and disease-free survival for patients with small cell lung cancer in complete remission. Further clinical trials are needed to confirm the potential greater benefit on brain metastasis rate suggested when cranial irradiation is given earlier or at higher doses.

Prophylactic cranial irradiation for patients with lung cancer

The incidence of brain metastases in patients with lung cancer has increased as a result of improved local and systemic control and better diagnosis from advances in brain imaging. Because brain metastases are responsible for life-threatening symptoms and serious impairment of quality of life, resulting in shortened survival, prophylactic cranial irradiation has been proposed in both small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) to try to improve incidence of brain metastasis, survival, and eventually quality of life. Findings from randomised controlled trials and a meta-analysis have shown that prophylactic cranial irradiation not only reduces the incidence of brain metastases in patients with SCLC and with non-metastatic NSCLC, but also improves overall survival in patients with SCLC who respond to first-line treatment. Although prophylactic cranial irradiation is potentially associated with neurocognitive decline, this risk needs to be balanced against the potential benefit in terms of brain metastases incidence and survival. Several strategies to reduce neurotoxicity are being investigated.

Nine-year Experience: Prophylactic Cranial Irradiation in Extensive Disease Small-cell Lung Cancer

BACKGROUND

In 2007, the European Organization for Research and Treatment of Cancer (EORTC) study (ClinicalTrials.gov identifier, NCT00016211) demonstrated a beneficial effect on overall survival (OS) with the use of prophylactic cranial irradiation (PCI) for extensive disease (ED) small-cell lung cancer (SCLC). Nevertheless, debate is ongoing regarding the role of PCI, because the patients in that trial did not undergo magnetic resonance imaging (MRI) of the brain before treatment. Also, a recent Japanese randomized trial showed a detrimental effect of PCI on OS in patients with negative pretreatment brain MRI findings.

MATERIALS AND METHODS

We examined the medical records of 136 patients with ED SCLC who had initially responded to chemotherapy and undergone PCI from 2007 to 2015. The outcomes, radiation toxicity, neurologic progression-free survival, and OS after PCI were analyzed. Survival and correlations were calculated using log-rank and univariate Cox proportional hazard ratio analyses.

RESULTS

The median OS and the median neurologic progression-free survival after PCI was 12 and 19 months, respectively. No significant survival difference was seen for patients who had undergone MRI before PCI compared with patients who had undergone contrast-enhanced computed tomography (P = .20). Univariate analysis for OS did not show a statistically significant effect for known cofactors.

CONCLUSION

In the present cohort, PCI was associated with improved survival compared with the PCI arm of the EORTC trial, with a nearly doubled median OS period. Also, the median OS was prolonged by 2 months compared with the irradiation arm of the Japanese trial.

Prophylactic cranial irradiation in small cell lung cancer: A single institution experience

AIM

To compare patient demographics, prophylactic cranial irradiation (PCI) utilization and overall survival (OS) of patients with small cell lung cancer (SCLC) referred to a large tertiary center with those reported in large clinical trials.

PATIENTS AND METHODS

A retrospective review was conducted of consecutive patients with limited stage (LS) and extensive stage (ES) SCLC diagnosed at the Princess Alexandra Hospital between January 2008 and December 2013.

RESULTS

Two hundred and three patients with a mean age of 65.4 (±10.7) years were followed for a median duration of 7.6 months (range 0.5-76.5). At diagnosis, 129 (64%) patients had ES-SCLC, including 39 (19.2%) with cerebral metastases. Median OS in LS-SCLC patients receiving PCI was 18.8 months (0.9-69.4), compared with 8.2 months (0.1-34.4) in patients who did not receive PCI (P < 0.001). Median OS in the ES-SCLC cohort receiving PCI was 13.6 months (5.2-37.5) compared to 5.6 months (0.1-73.6) in patients who did not receive the therapy (P < 0.001). There was a significant improvement in intracranial disease-free survival of 7.1 months in patients with ES-SCLC who received PCI. Forty-two LS-SCLC patients (57%) did not receive PCI due to patient suitability.

CONCLUSIONS

In our SCLC cohort, median OS following PCI in LS-SCLC and ES-SCLC is comparable to published data. PCI use at our institution was lower than utilization rates in large meta-analyses, predominately due to poor chemotherapy tolerance and patient suitability. This may be more representative of patients treated in clinical practice rather than those recruited into large phase III trials.

Computational Modeling of Micrometastatic Breast Cancer Radiation Dose Response

PURPOSE

Prophylactic cranial irradiation (PCI) involves giving radiation to the entire brain with the goals of reducing the incidence of brain metastasis and improving overall survival. Experimentally, we have demonstrated that PCI prevents brain metastases in a breast cancer mouse model. We developed a computational model to expand on and aid in the interpretation of our experimental results.

METHODS AND MATERIALS

MATLAB was used to develop a computational model of brain metastasis and PCI in mice. Model input parameters were optimized such that the model output would match the experimental number of metastases per mouse from the unirradiated group. An independent in vivo-limiting dilution experiment was performed to validate the model. The effect of whole brain irradiation at different measurement points after tumor cells were injected was evaluated in terms of the incidence, number of metastases, and tumor burden and was then compared with the corresponding experimental data.

RESULTS

In the optimized model, the correlation between the number of metastases per mouse and the experimental fits was >95. Our attempt to validate the model with a limiting dilution assay produced 99.9% correlation with respect to the incidence of metastases. The model accurately predicted the effect of whole-brain irradiation given 3 weeks after cell injection but substantially underestimated its effect when delivered 5 days after cell injection. The model further demonstrated that delaying whole-brain irradiation until the development of gross disease introduces a dose threshold that must be reached before a reduction in incidence can be realized.

CONCLUSIONS

Our computational model of mouse brain metastasis and PCI correlated strongly with our experiments with unirradiated mice. The results further suggest that early treatment of subclinical disease is more effective than irradiating established disease.

The Role of Radiotherapy in the Treatment of Small-Cell Lung Cancer

OPINION STATEMENT

The standard therapy for limited disease small cell lung cancer (LD-SCLC) is concurrent chemoradiotherapy and prophylactic cranial irradiation (PCI) for those who achieve complete remission (CR) or good partial response (PR) with initial therapy. On the other hand, the standard therapy for extensive disease (ED-SCLC) is chemotherapy only. After the two phase III study conducted by Slotman et al., PCI with/without thoracic radiotherapy (TRT) is also recommended in the treatment of ED-SCLC. However, a Japanese phase III study failed to confirm the benefit of PCI for patients with ED-SCLC. All studies have demonstrated the effectiveness of PCI for preventing brain metastasis, but PCI seems to have a limited influence on OS. In the 2014 edition of the Guidelines for the Treatment of Lung Cancer from the Japan Lung Cancer Society (JLCS), use of PCI for patients with ED-SCLC has been changed from "recommended" to "not recommended". Appropriate selection of patients for PCI with/without TRT is very important. It is hoped that the characteristics of patients for whom PCI with/without TRT should be considered or avoided will be better defined in the future.

Potential toxicities of prophylactic cranial irradiation

Prophylactic cranial irradiation (PCI) with total doses of 20-30 Gy reduces the incidence of brain metastasis (BM) and increases survival of patients with limited and extensive-disease small-cell lung cancer (SCLC) that showed any response to chemotherapy. PCI is currently not applied in non-small-cell lung cancer (NSCLC) since it has not proven to significantly improve OS rates in stage IIIA/B, although novel data suggest that subgroups that could benefit may exist. Here we briefly review potential toxicities of PCI which have to be considered before prescribing PCI. They are mostly difficult to delineate from pre-existing risk factors which include preceding chemotherapy, patient age, paraneoplasia, as well as smoking or atherosclerosis. On the long run, this will force radiation oncologists to evaluate each patient separately and to estimate the individual risk. Where PCI is then considered to be of benefit, novel concepts, such as intensity-modulated radiotherapy and/or neuroprotective drugs with potential to lower the rates of side effects will eventually be superior to conventional therapy. This in turn will lead to a re-evaluation whether benefits might then outweigh the (lowered) risks.

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.

Selecting patients with extensive-stage small cell lung cancer for prophylactic cranial irradiation by predicting brain metastases

INTRODUCTION

Prophylactic cranial irradiation has recently been reported to improve overall survival and quality of life in patients with extensive-stage small cell lung cancer. The generalizability of this treatment to an unselected population with extensive-stage small cell lung cancer is not clear, as the incidence of brain metastases is variably reported in the literature, ranging from 25 to 60%.

METHODS

We completed a retrospective review of 130 consecutive patients with extensive-stage small cell lung cancer seen in consultation between January 1, 2004, and December 31, 2006. Our primary objective was to determine the incidence of brain metastases and to establish significant factors that were predictive of developing brain metastases, using both univariate and multivariate regression analysis.

RESULTS

The median patient age was 68.0 years, and the median survival time was 25.6 weeks. The majority of patients (84.9%) received systemic therapy. Twenty-nine patients (22.3%) presented with brain metastases while an additional 21 patients (20.8%) developed brain metastases over their lifetime. Response to chemotherapy was a predictor of brain metastases using univariate (odds ratio [OR] 5.28, p = 0.03) and multivariate analysis (OR 5.49, p = 0.04). Weight loss more than 5 kg predicted for freedom from the development of brain metastases using univariate (OR 0.20, p = 0.01) and multivariate analysis (OR 0.69, p = 0.03).

CONCLUSIONS

20.8% of patients developed brain metastases after their initial presentation. This incidence is lower than that previously reported and may suggest that prophylactic cranial irradiation should be targeted to patients at highest risk. Response to chemotherapy and less than 5 kg baseline weight loss were independent predictors of future brain metastases.

Empirically-based estimates for the burden of subclinical metastases

PURPOSE

To describe the frequency distribution for the number of residual subclinical metastatic tumor cells after removal of the primary cancer.

MATERIALS AND METHODS

Previously obtained autopsy, surgical pathological and laboratory data were used to characterize the size and number distributions for hematogenous and lymphatic metastases. Monte Carlo simulations were used to estimate the numbers of residual tumor cells based upon the assumption of a lognormal distribution for the sizes of metastases and Poisson, Poisson negative binomial, or negative binomial distributed numbers of metastases (corresponding to lymphatic metastases within individuals, hematogenous metastases within individuals, and lymphatic metastases within populations, respectively).

RESULTS

In each of the scenarios the resultant distribution for the numbers of subclinical tumor cells was unimodal and positively skewed, with a tail extending to the higher numbers of metastases. When plotted with equal sized counting bins and according the logarithm of the number of tumor cells, the distributions showed deviations from the normal form no greater than several percentage points--a result considered acceptable given the variabilities inherent to metastasis data.

CONCLUSIONS

The distribution for the number of residual subclinical metastases may be extrapolated from data and models derived from the size and number distributions for metastases. In the absence of a closed form description for this distribution, the lognormal distribution could provide a crude, but practical, approximation for cases limited to occult microscopic residual disease. These analyses will facilitate the definition of the dose-response for the adjuvant therapy of subclinical metastases.

Time factor and treatment strategies in subclinical disease

Rational biological development of treatment strategies for subclinical metastases has lagged behind such efforts with primary cancers: most adjuvant therapies for subclinical disease have been developed empirically, based on clinical observation. This paper reviews recent studies that point to rapid growth of subclinical disease. The effect of rapid growth of occult metastases and undetectable extensions of primary cancer is to increase the radiation dose necessary for their elimination if treatment duration is extended. This increase may be evident even when changes are made to short courses of treatment, consistent with no lag time between the start of treatment and rapid growth or regrowth of subclinical tumour deposits. This provides a strong rationale for avoiding gaps or delays in adjuvant treatments and suggest that accelerated regimens of radiation or chemoradiation may be advantageous in the treatment of subclinical disease provided that the total dose can be maintained or not greatly reduced from those used conventionally. Conversely, an escalation of total dose with a concomitant increase in overall treatment duration may not result in improved control rates because the rapid growth of small clonogen deposits might counterbalance the effect of the higher dose.

Time Factor in Radiotherapy and Chemotherapy for Limited Disease Small-Cell Lung Cancer

The prognostic significance of planned and unplanned gaps in radiotherapy and chemotherapy for limited-disease small-cell lung cancer (LD-SCLC) has been retrospectively evaluated in a series of 245 patients. All of them had cisplatine-based chemotherapy and fractionated radiotherapy. There was substantial heterogeneity in overall radiation treatment time and dose-intensity of chemotherapy attributable mostly to planned and unplanned gaps in therapy. Several variables that potentially may influence survival of the patients after treatment, including duration of treatment gaps, and dose-intensity of chemotherapy and radiotherapy were analyzed using univariate and multivariate Cox regression model. The following variables had significant and independent negative influence on survival in a multivariate model: performance status ZUBROD > 0 (p < 0.0001), metastases to supraclavicular nodes (p = 0.001), dyspnoea according to Borg scale > 2 (p = 0.004) and the average dose intensity of radiotherapy < 80 percent (p = 0.02). An independent association between total dose and survival also has been found. The dose-intensity of chemotherapy did not appear to significantly influence survival. While due to the retrospective character of the present research, this conclusion must be regarded as hypothesis-generating only, we assume that within the range of doses and dose-intensitites used in the present group the preventable gaps in radiotherapy and undue reduction of total radiation dose should be promptly avoided, while gaps in chemotherapy can be deemed acceptable if crucially demanded by the tolerance of treatment.

Standard-dose versus higher-dose prophylactic cranial irradiation (PCI) in patients with limited-stage small-cell lung cancer in complete remission after chemotherapy and thoracic radiotherapy (PCI 99-01, EORTC 22003-08004, RTOG 0212, and IFCT 99-01): a randomised clinical trial

BACKGROUND

The optimum dose of prophylactic cranial irradiation (PCI) for limited-stage small-cell lung cancer (SCLC) is unknown. A meta-analysis suggested that the incidence of brain metastases might be reduced with higher PCI doses. This randomised clinical trial compared the effect of standard versus higher PCI doses on the incidence of brain metastases.

METHODS

Between September, 1999, and December, 2005, 720 patients with limited-stage SCLC in complete remission after chemotherapy and thoracic radiotherapy from 157 centres in 22 countries were randomly assigned to a standard (n=360, 25 Gy in 10 daily fractions of 2.5 Gy) or higher PCI total dose (n=360, 36 Gy) delivered using either conventional (18 daily fractions of 2 Gy) or accelerated hyperfractionated (24 fractions in 16 days with two daily sessions of 1.5 Gy separated by a minimum interval of 6 h) radiotherapy. All of the treatment schedules excluded weekends. Randomisation was stratified according to medical centre, age (</=60 and >60 years), and interval between the start of induction treatment and the date of randomisation (</=90, 91-180, and >180 days). Eligible patients were randomised blindly by the data centre of the Institut Gustave Roussy (PCI99-01 and IFCT) using minimisation, and by the data centres of EORTC (EORTC ROG and LG) and RTOG (for CALGB, ECOG, RTOG, and SWOG), both using block stratification. The primary endpoint was the incidence of brain metastases at 2 years. Analysis was by intention-to-treat. This study is registered with ClinicalTrials.gov number NCT00005062.

FINDINGS

Five patients in the standard-dose group and four in the higher-dose group did not receive PCI; nonetheless, all randomised patients were included in the effectiveness anlysis. After a median follow-up of 39 months (range 0-89 months), 145 patients had brain metastases; 82 in the standard-dose group and 63 in the higher-dose group. There was no significant difference in the 2-year incidence of brain metastases between the standard PCI dose group and the higher-dose group, at 29% (95% CI 24-35) and 23% (18-29), respectively (hazard ratio [HR] 0.80 [95% CI 0.57-1.11], p=0.18). 226 patients in the standard-dose group and 252 in the higher-dose group died; 2-year overall survival was 42% (95% CI 37-48) in the standard-dose group and 37% (32-42) in the higher-dose group (HR 1.20 [1.00-1.44]; p=0.05). The lower overall survival in the higher-dose group is probably due to increased cancer-related mortality: 189 patients in the standard group versus 218 in the higher-dose group died of progressive disease. Five serious adverse events occurred in the standard-dose group versus zero in the higher-dose group. The most common acute toxic events were fatigue (106 [30%] patients in the standard-dose group vs 121 [34%] in the higher-dose group), headache (85 [24%] vs 99 [28%]), and nausea or vomiting (80 [23%] vs 101 [28%]).

INTERPRETATION

No significant reduction in the total incidence of brain metastases was observed after higher-dose PCI, but there was a significant increase in mortality. PCI at 25 Gy should remain the standard of care in limited-stage SCLC.

FUNDING

Institut Gustave-Roussy, Association pour la Recherche sur le Cancer (2001), Programme Hospitalier de Recherche Clinique (2007). The European Organisation for Research and Treatment of Cancer (EORTC) contribution to this trial was supported by grants 5U10 CA11488-30 through 5U10 CA011488-38 from the US National Cancer Institute.

Evaluation of the use of prophylactic cranial irradiation in small cell lung cancer

BACKGROUND

Prophylactic cranial irradiation has been used in patients with small cell lung cancer to reduce the incidence of brain metastasis after primary therapy. The purpose of this study was to evaluate the effects of prophylactic cranial irradiation (PCI) on overall survival and cause-specific survival.

METHODS

A total of 7995 patients with limited stage small cell lung cancer diagnosed between 1988 and 1997 were retrospectively identified from centers participating in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. Of them, 670 were identified as having received PCI as a component of their first course of therapy. Overall survival and cause-specific survival were estimated by the Kaplan-Meier method, comparing patients treated with or without prophylactic whole-brain radiotherapy. The Cox proportional hazards model was used in the multivariate analysis to evaluate potential prognostic factors.

RESULTS

The median follow-up time was 13 months (range, 1 month to 180 months). Overall survival at 2 years, 5 years, and 10 years was 23%, 11%, and 6%, respectively, in patients who did not receive PCI. In patients who received PCI, the 2-year, 5-year, and 10-year overall survival rates were 42%, 19%, and 9%, respectively (P =or <.001). The cause-specific survival rate at 2 years, 5 years, and 10 years was 28%, 15%, 11%, respectively, in patients who did not receive PCI and 45%, 24%, 17%, respectively, in patients who did receive PCI (P =or <.001). On multivariate analysis of cause-specific and overall survival, age at diagnosis, sex, grade, extent of primary disease, size of disease, extent of lymph node involvement, and PCI were found to be significant (P = or<.001). The hazards ratios for disease-specific and all cause mortality were 1.13 and 1.11, respectively, for those not receiving PCI.

CONCLUSIONS

Significantly improved overall and cause-specific survival was observed in patients treated with prophylactic cranial irradiation on unadjusted and adjusted analyses. This study concurs with the previously published European experience. Prophylactic cranial irradiation should be considered for patients with limited stage small cell lung cancer.

Prevalence of brain metastases immediately before prophylactic cranial irradiation in limited disease small cell lung cancer patients with complete remission to chemoradiotherapy: a single institution experience

This single-center study investigated the prevalence of brain metastases immediately before prophylactic cranial irradiation in 40 consecutive limited disease small cell lung cancer complete responders to chemoradiotherapy and revealed that 13/40 (32.5%; 95% confidence interval: 18-47%) patients suffer relapse with brain metastases and show a significantly worse prognosis than those without detected brain metastases.

Prophylactic cranial irradiation in extensive small-cell lung cancer

BACKGROUND

We conducted a randomized trial of prophylactic cranial irradiation in patients with extensive small-cell lung cancer who had had a response to chemotherapy.

METHODS

Patients between the ages of 18 and 75 years with extensive small-cell lung cancer were randomly assigned to undergo prophylactic cranial irradiation (irradiation group) or receive no further therapy (control group). The primary end point was the time to symptomatic brain metastases. Computed tomography or magnetic resonance imaging of the brain was performed when any predefined key symptom suggestive of brain metastases was present.

RESULTS

The two groups (each with 143 patients) were well balanced regarding baseline characteristics. Patients in the irradiation group had a lower risk of symptomatic brain metastases (hazard ratio, 0.27; 95% confidence interval [CI], 0.16 to 0.44; P<0.001). The cumulative risk of brain metastases within 1 year was 14.6% in the irradiation group (95% CI, 8.3 to 20.9) and 40.4% in the control group (95% CI, 32.1 to 48.6). Irradiation was associated with an increase in median disease-free survival from 12.0 weeks to 14.7 weeks and in median overall survival from 5.4 months to 6.7 months after randomization. The 1-year survival rate was 27.1% (95% CI, 19.4 to 35.5) in the irradiation group and 13.3% (95% CI, 8.1 to 19.9) in the control group. Irradiation had side effects but did not have a clinically significant effect on global health status.

CONCLUSIONS

Prophylactic cranial irradiation reduces the incidence of symptomatic brain metastases and prolongs disease-free and overall survival. (ClinicalTrials.gov number, NCT00016211 [ClinicalTrials.gov].).

Tolerability of accelerated chest irradiation and impact on survival of prophylactic cranial irradiation in patients with limited-stage small cell lung cancer: review of a single institution's experience

INTRODUCTION

Evidence that has been published in the last decade indicates that in patients with limited-stage small-cell lung cancer (SCLC), hyperfractionated accelerated thoracic radiotherapy (RT) given twice daily and prophylactic cranial irradiation (PCI) have each separately improved survival. Concerns about the toxicities associated with these treatments and uncertainty about their impact on survival outside the trial setting may have restricted the extent to which they have been incorporated into standard treatment protocols. We have reviewed the experience at Peter MacCallum Cancer Centre to determine the tolerability of these treatments in routine practice and to determine their effects on survival.

METHODS

A retrospective review of patients with limited-stage SCLC receiving a radical course of thoracic RT between June 1998 and May 2002, including either conventional fractionation at 50 Gy for 5 weeks, or hyperfractionated accelerated RT at 45 Gy for 3 weeks. Patients achieving a complete response were offered PCI at 36 Gy in 18 fractions. The main outcomes recorded were RT toxicity (graded using CTCAE v. 3.0 and RTOG/EORTC late scoring criteria), response, relapse-free survival, and overall survival.

RESULTS

Ninety patients were identified as having undergone radical-intent thoracic RT, with a median potential follow-up of 4.2 years. Fifty-seven patients (63%) were treated with hyperfractionated accelerated RT, and 33 (37%) were treated with conventional fractionation. Forty-six patients (51%) received PCI. Patients receiving hyperfractionated accelerated RT compared with conventional fractionation had higher rates of grade 3 and 4 esophagitis (14% versus 6%; p = 0.312), a higher rate of treatment interruptions (12% versus 3%; p = 0.250), and a higher hospital admission rate (39% versus 15%; p = 0.031). The majority of patients were able to complete the planned treatment, and there were no treatment-related deaths. Median survival for all patients from commencement of RT was 14.2 months (95% confidence interval [CI]: 11.9-18.1 months), and survival at 2 years was 24.8% (95% CI: 16.9-35.0%). On multifactor analysis, the only factor associated with longer survival was PCI (hazard ratio = 0.40; p < 0.001).

CONCLUSIONS

Hyperfractionated accelerated RT was more toxic than conventional fractionation, but it was possible to deliver treatment as planned in the majority of patients. PCI was associated with improved survival. Both treatments can be incorporated into routine practice.

Prolonged survival after resection and radiotherapy for solitary brain metastases from non-small-cell lung cancer

Selected patients with brain metastases from non-small-cell lung cancer benefit from aggressive treatment. This report describes three patients who developed solitary brain metastases after previous resection of primary adenocarcinoma of the lung. Each underwent surgical resection of their brain metastasis followed by cranial irradiation and remain disease free 10 or more years later. Two patients developed cognitive impairment approximately 8 years after treatment of their brain metastasis, which was felt to be due to their previous brain irradiation. Here we discuss the treatment of solitary brain metastasis, particularly the value of combined method approaches in selected patients and dose-volume considerations.

Prophylactic Cranial Irradiation for Patients with Lung Cancer

The central nervous system is a common site of metastasis in patients with small cell lung cancer (SCLC) and non-small-cell lung cancer. Despite advances in combined modality therapy, intracranial relapse continues to be a common site of recurrence and a major cause of morbidity for patients with lung cancer. Prophylactic cranial irradiation (PCI) has proven to be effective in reducing the incidence of brain metastases in patients with lung cancer. Based upon results of a metaanalysis demonstrating a small improvement in overall survival, PCI is now routinely offered to patients with limited-stage SCLC after a complete or near-complete response to initial treatment. However, many questions remain unanswered regarding the optimal dose, fractionation, and toxicity of PCI in patients with limited-stage SCLC. Additionally, the role of PCI in patients with extensive-stage SCLC and locally advanced non-small-cell lung cancer is unclear. Several important collaborative group trials are under way in an attempt to further define the role of PCI in patients with lung cancer.

Low-dose prophylactic cranial irradiation in patients with poor prognosis small-cell lung cancer

AIMS

In small-cell lung cancer (SCLC), prophylactic cranial irradiation (PCI) provides a survival advantage in good performance status patients with limited disease. Its role in those with poor performance status limited disease or extensive disease is unclear. A low-dose PCI schedule has been used in these groups, and outcomes have been analysed.

MATERIALS AND METHODS

Retrospective analyses of brain metastasis-free survival and overall survival of patients receiving low-dose PCI over a 2-year period.

RESULTS

Fifty-six patients were treated, with 55 evaluable due to missing notes for one. No major treatment-related toxicity was observed. Median brain metastasis-free survival and overall survival for the group were 44 and 46 weeks, respectively. The median brain metastasis-free survival were 32 and 50 weeks, and median overall survival were 39 and 57 weeks, in those with extensive and limited disease, respectively. A total of 10 patients developed clinical or radiological evidence of brain metastases, four (16%) with limited disease and six (21%) with extensive disease. Thirteen (52%) with limited disease and 10 (36%) with extensive disease survived 1 year.

CONCLUSIONS

Symptomatic brain metastases occurred less frequently than would be expected, with most patients developing widespread metastatic disease. Low-dose PCI may benefit these groups, and the results of an ongoing EORTC randomised-controlled trial in extensive disease should provide more information.

Prophylactic cranial irradiation in lung cancer

Patients with locally advanced lung cancer (non-small cell lung cancer or small cell lung cancer ) are threatened by concurrent risks of local, regional, and distant failure. By improving locoregional and systemic control within multimodality protocols, the brain emerges as one of the major relapse sites; therefore, prevention of brain relapse has become a primary focus of attention. Prophylactic cranial irradiation (PCI) has a high potential to reduce the risk of brain metastases. Clear evidence exists from meta-analysis that PCI improves overall and disease-free survival rates for patients with SCLC in complete remission. Long-term toxicities, predominantly neurocognitive impairments, represent potential risks, but within large prospective trials, including adequate control groups, late complications of clinical significance rarely have been observed. PCI is the recommended standard of care for the patients with limited disease SCLC in complete remission. As long as the optimal dose and fractionation remain to be defined in this setting, conventional fractionation with moderate total doses of approximately 30 Gy is preferred. In patients with locally advanced stage III non-small cell lung cancer treated within multimodality protocols, comparable relative risks for cumulative brain relapse have been demonstrated in long-term survivors. Although not the standard of care in this situation, the scientific community should be encouraged to further investigate PCI in these patient subgroups within carefully designed clinical trials, including untreated control arms.

Modeling killing and repopulation kinetics of subclinical cancer: direct calculations from clinical data

PURPOSE

Models for cell killing and repopulation can provide insight into the efficacy of therapies. Using clinical data on breast cancer recurrence after lumpectomy with or without radiotherapy (L+/-RT) and brain metastases after chemotherapy with or without prophylactic cranial irradiation (C+/-PCI) for small-cell lung cancer, estimates of cell killing and subclinical repopulation were tested against the results from simple radiobiologic models.

METHODS AND MATERIALS

The rates of local breast cancer recurrence after L+/-RT and of brain metastases after C+/-PCI were extracted from published randomized trials. In Method 1, assuming simple exponential growth, the cell number distributions after L+/-RT and C+/-PCI were calculated from the clinical data, and the impact of RT on these distributions was determined. In Method 2, "classic" radiobiology dictates that a typical course of breast RT and PCI results in approximately =7 and approximately =4.5 log of cell kill, respectively. Using an assumption of uniform log-kill, the clinical doubling times (CDTs) can be calculated directly from the clinical data.

RESULTS

Using Method 1, for breast cancer and assuming a CDT of 110 days and a clinically detectable cell number of 10(9), the calculated cell number distribution would be approximately uniformly distributed from 1 to 10(8) cells, with RT reducing the frequency at all points by approximately =75%. From the brain metastasis data, assuming a CDT of 55 days, a cell number distribution of 10(3) to 10(8) cells would be calculated. PCI reduces the frequency of metastases by roughly 40%. For both the breast and the brain data, the effects of RT on the cell number distribution are not consistent with uniform radiosensitivity. Using Method 2, assuming a cell number of 10 after L+/-RT, the calculated CDTs range from 14 to 124 days. For the brain metastasis case, assuming a starting cell number of 3.16 x 10(3), the CDTs would primarily be in the 10-30-day range.

CONCLUSION

The distribution of clinical responses to adjuvant RT suggests a broad range of radiosensitivity, rather than uniform log cell kill. The subpopulation of tumors with minimal cell kill appears to be significant. This heterogeneity may be due to radioresistant subpopulations, failure to irradiate tumor cells, and/or new tumor formation. Similarly, the computed CDTs consistent with the clinical data are shorter than those reported in the literature. Simple radiobiologic models that fail to incorporate heterogeneity of radiosensitivity and/or tumor cell repopulation do not adequately describe clinical outcomes.

Prophylactic cranial irradiation as a component of intensified initial treatment of locally advanced non-small cell lung cancer

Patients with locally advanced non-small cell lung cancer are threatened by the concurrent risks of local, regional and distant failure. By improving local and regional control with multimodality protocols, the brain becomes one of the major sites of relapse. PCI has a high potential to reduce the risk of brain metastases. Long-term toxicity is presently poorly defined and represents an important potential risk. The value of PCI as an adduct to present aggressive multimodality protocols and the optimal total dose with conventional fractionation will be investigated within clinical studies by two study groups in the future. As the best dose and fractionation still remains undefined, the integration of PCI into multimodality protocols.

Small cell undifferentiated (neuroendocrine) carcinoma of the uterine cervix

BACKGROUND

Small cell undifferentiated (neuroendocrine) carcinoma of the cervix is a rare and agressive tumor. Most medical centers have little experience with this tumor. The purposes of our study were to evaluate our experience and compare our findings with those reported in current literature.

STUDY DESIGN

Fifteen patients with small cell undifferentiated carcinoma of the cervix were treated between 1977 and 1997. Clinical data including age, pregnancy history, tumor stage, recurrence, type of therapy, presenting symptoms, location of metastasis, and survival were studied.

RESULTS

The ages of patients ranged from 20 to 83 years, with a mean of 47 years. Two patients were nulliparous, 2 primiparous, and 11 multiparous. Five patients (33%) were stage I, three (20%) stage II, one (7%) stage III, and six (40%) stage IV at diagnosis. Five patients (33%) progressed without response to treatment, and seven (47%) experienced a recurrence of their cancer, on average after 15 months. Treatments included surgery, radiation, chemotherapy, or a combination of them. Extrapelvic metastases developed in five patients with stage I or stage II disease. Three patients (20%) developed brain metastasis. Tumor lysis syndrome was encountered in one patient. Thirteen patients died of their disease, one remained alive 80 months after diagnosis, and one was lost to followup.

CONCLUSIONS

Our experience with this rare and aggressive tumor raises the question of increased incidence of central nervous system metastases with small cell undifferentiated carcinoma. Present therapy has not significantly improved outcomes. Tumor lysis syndrome is a possible risk when treating these patients.

Lung cancer 5: state of the art radiotherapy for lung cancer

Radiotherapy has a key role in curative and palliative treatments of patients with lung cancer. Important advances are described in the technique of treatment delivery and its integration with chemotherapy.

Prophylactic cranial irradiation in small cell lung cancer

Prophylatic cranial irradiation (PCI) in patients with small cell lung cancer (SCLC) is a treatment under evaluation for about 30 years. Since the first randomized trials, it was clear that its use significantly decreased the brain metastasis rate. However, its effect on overall survival was not demonstrated. Retrospective reviews suggested that PCI could induce late neurologic damage. In recent years, two large randomized trials did not confirm this deleterious effect and even suggested a beneficial effect on survival. A recent meta-analysis including almost 1,000 randomized patients confirmed an improvement in overall survival. We discuss here the different aspects of this preventive treatment in a potentially curable disease.

The role of prophylactic cranial irradiation in the treatment of lung cancer

Patients with lung cancer face concurrent risks of their disease by local, regional as well as distant failure. The brain is one of the major sites of distant relapse and the prevention of cerebral metastasis has therefore gained rising interest. A recent meta-analysis has confirmed the benefit of prophylactic cranial irradiation in patients with limited disease small-cell lung cancer in complete remission following induction therapy. In non-small-cell lung cancer, aggressive multimodality therapy regimens including surgery have achieved locoregional control rates of 50% and higher. In these patient groups the relatively high incidence of brain relapses as a site of first failure causes substantial morbidity and worsens the prognosis. Given the proven efficacy of prophylactic cranial irradiation (PCI) to prevent metastases to the brain, the introduction of PCI into the treatment of non-small cell lung cancer in the curative setting seems promising.

Practice guideline on prophylactic cranial irradiation in small-cell lung cancer

PURPOSE

To develop an evidence-based clinical practice guideline that would address the following questions: (a) What is the role of prophylactic cranial irradiation (PCI) in patients with limited or extensive stage small-cell lung cancer (SCLC) who have achieved complete remission in response to induction therapy (chemotherapy or chemoradiotherapy)? (b) What dose and fractionation schedules of PCI are optimal? (c) Does the use of PCI in patients with SCLC in complete remission affect quality of life? Survival, disease-free survival, quality of life, and adverse effects were the outcomes of interest.

METHODS AND MATERIALS

A systematic review of the published literature was undertaken to provide the data for an evidence-based practice guideline.

RESULTS

Six randomized controlled trials and one fully published individual patient data meta-analysis were included in the systematic review of the evidence. For patients who have achieved complete response after induction therapy, there is evidence of a disease-free survival benefit (4 of 6 trials) and an overall survival benefit (meta-analysis). There is insufficient evidence to make a definitive recommendation with respect to dose. There is some indication that 30-36 Gy in 2-3 Gy per fraction, or a biologically equivalent dose, may produce a better outcome than a lower dose or less aggressive fractionation regimen. The schedule commonly used in Canada is 25 Gy in 10 fractions over 2 weeks. Data from further research, including a trial currently ongoing that compares 25 Gy in 10 fractions with 36 Gy in 18 fractions, will be required to determine optimal dose of PCI. There is insufficient evidence to make recommendations concerning the optimal timing of PCI in relation to the administration of chemotherapy. Lung DSG members generally felt that it should be given as soon as possible after completion of chemotherapy. There is evidence from trials with data for up to 2 years of follow-up that prophylactic cranial irradiation does not produce significant late neurotoxicity. There is evidence from one trial that prophylactic cranial irradiation does not have a detrimental effect on quality of life in the first 12 months following the completion of therapy. There is insufficient evidence to comment on the long-term effects of prophylactic cranial irradiation on quality of life.

CONCLUSION

For adult patients with limited or extensive SCLC who achieve a complete remission with induction therapy, PCI is recommended.

Prophylactic cranial irradiation in small-cell lung cancer

Prophylactic cranial irradiation is now known to improve survival to a significant degree in small-cell lung cancer (SCLC) patients; this is in addition to its established role in preventing the disabling symptoms of brain metastases. New information indicates that it confers a survival benefit for limited or extensive stage SCLC patients gaining a complete response in the chest. A review of causes of cerebral dysfunction as a complication indicates that such problems can be due to suboptimal radiation fractionation, chemotherapy, or an inappropriate combination of prophylactic brain irradiation with chemotherapy. Optimum treatment with prophylactic brain irradiation has been shown not to cause adverse effects with detailed psychometric testing. Several additional sources of information can be drawn together to suggest a dose-response pattern for prophylactic brain irradiation, leading to the recommendation that a dose of 25-36 Gy is optimal, delivered in 2-3 Gy daily fractions after the completion of chest irradiation and chemotherapy. This will be better defined in future clinical trials.

Cranial irradiation for preventing brain metastases of small cell lung cancer in patients in complete remission

BACKGROUND

Prophylactic cranial irradiation halves the rate of brain metastases in patients with small cell lung cancer. Individual randomized trials conducted on patients in complete remission were unable to clarify whether this treatment improves survival.

OBJECTIVES

This study aims to test whether prophylactic cranial irradiation prolongs survival of patients with small cell lung cancer in complete remission.

SEARCH STRATEGY

Published and unpublished trials were eligible. Electronic databases, reference lists of trial publications, review articles and relevant books were used to identify potentially eligible trials. The search was also guided by discussions with investigators and experts, and the examination of meeting proceedings and of the Physician Data Query clinical trial registry.

SELECTION CRITERIA

Randomized trials comparing prophylactic cranial irradiation with no prophylactic cranial irradiation in patients with small cell lung cancer in complete remission.

DATA COLLECTION AND ANALYSIS

Meta-analysis based on updated individual data. The main endpoint was survival.

MAIN RESULTS

The relative risk of death in the treatment group compared to the control group was 0.84 (95% confidence interval=0.73 to 0.97, P=0.01), corresponding to a 5.4 percent increase in the 3-year survival rate (from 15.3 percent in the control group to 20.7 percent in the treatment group). Prophylactic cranial irradiation also increased disease-free survival (relative risk=0.75, 95% confidence interval=0.65 to 0.86, P<0.001) and decreased the risk of brain metastases (relative risk=0.46, 95% confidence interval=0.38 to 0.57, P<0.001). Increasing doses of irradiation decreased the risk of brain metastases when four groups (8 Gy, 24-25 Gy, 30 Gy, 36-40 Gy) were analyzed [trend test, P=0.02], but the effect on survival did not differ significantly according to the dose. We found a trend (P=0.01) for a decrease in the brain metastasis risk in favour of earlier administration of cranial irradiation after the initiation of induction treatment.

REVIEWER'S CONCLUSIONS

Prophylactic cranial irradiation significantly improves survival and disease-free survival for patients with small cell lung cancer in complete remission. Further clinical trials are needed to confirm the potential greater benefit on brain metastasis rate suggested when cranial irradiation is given earlier or at higher doses.

Prophylactic cranial irradiation in locally advanced non-small-cell lung cancer after multimodality treatment: long-term follow-up and investigations of late neuropsychologic effects

PURPOSE

Relapse pattern and late toxicities in long-term survivors were analyzed after the introduction of prophylactic cranial irradiation (PCI) into a phase II trial on trimodality treatment of locally advanced (LAD) non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Seventy-five patients with stage IIIA(N2)/IIIB NSCLC were treated with induction chemotherapy, preoperative radiochemotherapy, and surgery. PCI was routinely offered during the second period of study accrual. Patients were given a total radiation dose of 30 Gy (2 Gy per daily fraction) over a 3-week period starting 1 day after the last chemotherapy cycle.

RESULTS

Introduction of PCI reduced the rate of brain metastases as first site of relapse from 30% to 8% at 4 years (P =.005) and that of overall brain relapse from 54% to 13% (P <.0001). The effect of PCI was also observed in the good-prognosis subgroup of 47 patients who had a partial response or complete response to induction chemotherapy, with a reduction of brain relapse as first failure from 23% to 0% at 4 years (P =.01). Neuropsychologic testing revealed impairments in attention and visual memory in long-term survivors who received PCI as well as in those who did not receive PCI. T2-weighted magnetic resonance imaging revealed white matter abnormalities of higher grades in patients who received PCI than in those who did not.

CONCLUSION

PCI at a moderate dose reduced brain metastases in LAD-NSCLC to a clinically significant extent, comparable to that in limited-disease small-cell lung cancer. Late toxicity to normal brain was acceptable. This study supports the use of PCI within intense protocols for LAD-NSCLC, particularly in patients with favorable prognostic factors.