Value of prophylactic cranial irradiation given at complete remission in small cell lung carcinoma. Controlled clinical trial of prophylactic cranial irradiation for patients with small-cell lung cancer in complete remission. Prophylactic cranial irradiation is indicated following complete response to induction therapy in small cell lung cancer: results of a multicentre randomised trial. United Kingdom Coordinating Committee for Cancer Research (UKCCCR) and the European Organization for Research and Treatment of Cancer (EORTC) Comparative study of prophylactic cranial irradiation in patients with small cell lung cancer achieving a complete response: a long-term follow-up result. Randomized study of initial versus late chest irradiation combined with chemotherapy in limited-stage small-cell lung cancer. Aarhus Lung Cancer Group. Prophylactic cranial irradiation for patients with small-cell lung cancer in complete remission. Prophylactic cranial irradiation for lung cancer patients at high risk for development of cerebral metastasis: results of a prospective randomized trial conducted by the Radiation Therapy Oncology Group. A phase III study of accelerated versus conventional hypofractionated whole brain irradiation in patients of good performance status with brain metastases not suitable for surgical excision. Randomized trial of radiotherapy versus radiotherapy plus metronidazole for the treatment metastatic cancer to brain. A Southwest Oncology Group study.
The optimal use of "prophylactic" cranial irradiation (PCI) in patients with small cell lung cancer remains undetermined. This study reviews the impact of PCI, given at complete remission (CR), on neurologic relapse in 172 consecutive patients with small cell lung cancer treated in three sequential chemotherapy protocols at the University of Maryland Cancer Center. In the first study of 38 patients, none received PCI. In the second study of 109 patients, the first 28 achieving CR were randomized to 3000 rad of PCI in ten fractions (PCI+) or to observation (PCI-). Thereafter, based on interim analysis, all patients achieving CR received PCI. In the third study, to date, 25 patients achieving CR have received PCI. Overall, 169 patients were evaluable for neurologic relapse, and 30 of 90 patients achieving CR received PCI. Among all patients with CR, with adjustment for disease extent, there was a significant delay to any neurologic relapse (P = 0.01) and cerebral metastases (P = 0.02) for PCI+ compared to PCI- patients. Among PCI- patients with CR, cerebral metastases alone occurred in 28% as the sole site and in 33% as the initial site, whereas cerebral relapse occurred prior to systemic relapse in only one PCI+ patient with CR. Patient survival however, was not significantly altered by PCI. PCI at CR confers effective and worthwhile local control in the CNS, especially during periods of systemic response, and a small percentage of patients may benefit. Systemic drug resistance still determines overall survival. We conducted a randomised clinical trial on 211 patients with small-cell lung cancer in complete remission (CR). The aim of this trial was to evaluate the effect of prophylactic cranial irradiation (PCI) on overall survival. Eligible patients were randomly assigned to receive either PCI (100 patients) or no PCI (111 patients). Each centre was allowed to use its own PCI protocol as long as the total dose was within the range of 24-30 Gy and delivered in less than 3 weeks with fractions of 3 Gy or less. The mean follow-up is 5 years. The survival curves do not differ significantly (P = 0.25) between the two groups. The 4-year overall survival rate (95% confidence interval) is 22% [15-32%] in the PCI group versus 16% [10-25%] in the control group. The relative risk of death in the PCI group compared to the control group is 0.84 (95% CI = [0.62-1.13]). The incidence of brain metastasis is lower in the PCI group, but the difference is not statistically significant (P = 0.14). The 4-year cumulative rate of brain metastasis is 44% [32-57%] in the PCI group compared to 51% [38-63%] in the control group. In conclusion, in this study, which had to be closed prematurely, no significant difference was found in terms of the incidence of brain metastases nor in survival. Prophylactic cranial irradiation (PCI) reduces the risk of cranial metastasis in small cell lung cancer (SCLC), but the magnitude and value of this reduction, the risks of radiation morbidity and whether PCI influences survival are unclear. We conducted a randomised trial in patients with limited-stage SCLC who had had a complete response to induction therapy. Initially, patients were randomised equally to (1) PCI 36 Gy in 18 daily fractions, (2) PCI 24 Gy in 12 fractions and (3) no PCI; subsequently, to increase the rate of accrual, randomisation was to clinicians' choice of PCI regimen versus no PCI (at a 3:2 ratio). The endpoints were appearance of brain metastases, survival, cognitive function, and quality of life (QoL). Three hundred and fourteen patients (194 PCI, 120 No PCI) were randomised. In the revised design, the most commonly used PCI regimens were 30 Gy in 10 fractions and 8 Gy in a single dose. With PCI, there was a large and highly significant reduction in brain metastases (HR = 0.44, 95% CI 0.29-0.67), a significant advantage in brain-metastasis-free survival (HR = 0.75, 95% CI 0.58-0.96) and a non-significant overall survival advantage (HR = 0.86, 95% CI 0.66-1.12). In both groups, there was impairment of cognitive function and QoL before PCI and additional impairment at 6 months and 1 year, but no consistent difference between the two groups and thus no evidence over 1 year of major impairment attributable to PCI. PCI can safely reduce the risk of brain metastases. Further research is needed to define optimal dose and fractionation and to clarify the effect on survival. Patients with SCLC achieving a complete response to induction therapy should be offered PCI. Between 1981 and 1986, a total of 46 patients with small cell lung cancer (SCLC) achieving a complete response by chemotherapy with or without chest irradiation were randomized either to receive prophylactic cranial irradiation (PCI) or not. With a median follow-up time of 8.5 years for both groups, only five of 23 patients (22%) in the PCI group developed brain relapse, while 12 out of 23 (52%) in the no PCI group did so (P < 0.05). The frequency of patients developing a sole brain relapse during their whole clinical course was 4% for the PCI group and 17% for the no PCI group, however, the difference was not statistically significant. Patient survival was better for the PCI group (median survival time of 21 months, and 5-year survival rate of 22%) as compared with the no PCI group (median survival time of 15 months, and 5-year survival rate of 13%), showing a marginal significance (P = 0.097). Late neurologic toxicity was infrequent; only one developed a mild deterioration among seven long-term disease-free survivors in the PCI group. These results appear to warrant further clinical trials to clarify the utility of PCI in patients with SCLC achieving a complete response. To evaluate if the timing of chest irradiation with respect to chemotherapy would influence survival and local and distant control in patients with limited-stage small-cell lung cancer (LSCLC).
                From 1981 to 1989, 199 consecutive patients with LSCLC were randomly allocated to receive initial chest irradiation (ICI; n = 99) or late chest irradiation (LCI; n = 100) given 18 weeks delayed. Both groups received the same nine cycles of combination chemotherapy: three cycles of cisplatin and etoposide and six cycles of cyclophosphamide, doxorubicin, and vincristine. In the first part of the study, prophylactic cranial irradiation (PCI) was only given to patients randomized to ICI, but after inclusion of 42 patients in the LCI arm, the protocol was changed, so that all patients received PCI independent of the timing of the chest irradiation (CI). A total of 157 patients received PCI with a radiation dose of 25 Gy in 11 fractions.
                The timing of radiotherapy had no significant effect on the 2-year overall survival rate (20% after ICI v 19% after LCI, P = .4) or the 2-year in-field recurrence rate (72% after ICI v 68% after LCI, P = .2). Median survival durations were 10.5 (ICI) and 12.0 (LCI) months. Similarly, no difference in the 2-year incidence of CNS recurrences was found between the 2 arms in patients who received PCI (19% after ICI v 13% after LCI, P = .24). Bone marrow toxicity was acceptable, as 15% developed World Health Organization (WHO) grade 4 leukocytopenia and 4% grade 4 thrombocytopenia. Grade 4 leukocytopenia was more pronounced in the ICI group. There was no difference in the frequency and severity of other toxicities between the 2 groups.
                Timing of CI did not significantly influence the incidence of in-field recurrences, CNS recurrences, or overall survival. Prophylactic cranial irradiation in patients with small-cell lung cancer decreases the overall rate of brain metastases without an effect on overall survival. It has been suggested that this treatment may increase neuropsychological syndromes and brain abnormalities indicated by computed tomography scans. However, other retrospective data suggested a beneficial effect on overall survival for patients in complete remission.
                Our purpose was to evaluate the effects of prophylactic cranial irradiation on brain metastasis, overall survival, and late-occurring toxic effects in patients with small-cell lung cancer in complete remission.
                We conducted a prospective study of 300 patients who had small-cell lung cancer that was in complete remission. The patients were randomly assigned to receive either prophylactic cranial irradiation delivering 24 Gy in eight fractions during 12 days (treatment group) or no prophylactic cranial irradiation (control group). A neuropsychological examination and a computed tomography scan of the brain were performed at the time of random assignment and repeatedly assessed at 6, 18, 30, and 48 months. Patterns of failure were analyzed according to total event rates and also according to an isolated first site of relapse, using a competing-risk approach.
                Two hundred ninety-four patients who did not have brain metastases at the time of random assignment were analyzed. The 2-year cumulative rate of brain metastasis as an isolated first site of relapse was 45% in the control group and 19% in the treatment group (P < 10(-6)). The total 2-year rate of brain metastasis was 67% and 40%, respectively (relative risk = 0.35; P < 10(-13)). The 2-year overall survival rate was 21.5% in the control group and 29% in the treatment group (relative risk = 0.83; P = .14). There were no significant differences between the two groups in terms of neuropsychological function or abnormalities indicated by computed tomography brain scans.
                Prophylactic cranial irradiation given to patients with small-cell lung cancer in complete remission decreases the risk of brain metastasis threefold without a significant increase in complications. A possible beneficial effect on overall survival should be tested with a higher statistical power.
                The results of the trial favor, at present, the indication of prophylactic cranial irradiation for patients who are in complete remission. A longer follow-up and confirmatory trials are needed to fully assess late-occurring toxic effects. The possible effect on overall survival needs to be evaluated with a larger number of patients in complete remission, and a meta-analysis of similar trials is recommended. Beginning in February 1984, 187 evaluable patients with adenocarcinoma or large cell carcinoma of the lung clinically confined to the chest were randomized to receive either conventionally fractionated thoracic irradiation alone or thoracic irradiation with concurrent, prophylactic cranial irradiation. The study population included 161 patients treated for medically or surgically inoperable primary cancers, and 26 patients undergoing adjuvant postoperative mediastinal irradiation following attempted curative resection of primary cancers found to have metastasized to hilar or mediastinal lymph nodes. Elective brain irradiation was not effective in preventing the clinical appearance of brain metastases, although the time to develop brain metastases appears to have been delayed. Eighteen of 94 patients (19%) randomized to chest irradiation alone have developed brain metastases as opposed to 8/93 patients (9%) randomized to receive prophylactic cranial irradiation (p = .10). No survival difference was observed between the treatment arms. Among the 26 patients undergoing prior resection of all gross intrathoracic disease, brain metastases were observed in 3/12 patients (25%) receiving adjuvant chest irradiation alone, compared to none of 14 receiving prophylactic cranial irradiation (p = .06). In the absence of fully reliable therapy for the primary disease, and without effective systemic therapy preventing dissemination to other, extrathoracic sites, prophylactic cranial irradiation for inoperable non-small cell lung cancer cannot be justified in routine clinical practice. Further investigation in the adjuvant, postoperative setting may be warranted. An accelerated prescription for whole brain irradiation (WBI) in the treatment of brain metastases has been reported to provide favourable survival in good performance status patients. Because it was not known whether this outcome represented patient selection or a radiobiologically advantageous regimen, a phase III study to compare overall survival following accelerated and conventional hypofractionated daily WBI was proposed.
                Ninety patients were randomized between 1996 and 2003 at two centres. The investigational arm received 40 Gy in 20 fractions of 2 Gy twice daily. The control arm received 20 Gy in 5 daily fractions. The study was designed to detect an increase in median survival of 1.75x. Outcome measures included acute side effects (WHO epilation score), neurological function (modified Barthel Index) and late toxicity (LENT/SOMA score for the CNS).
                Both arms of the study were balanced by RPA class. The median survival was 19 weeks in both arms. Subset analysis showed time to retreatment for intracranial relapse was 14 weeks in the control arm and 32 weeks in the accelerated arm (p=0.03). Trends for more severe epilation and improved neurological function in the accelerated arm did not reach statistical significance. Overall survival was associated with RPA class and colorectal pathology.
                Although accelerated WBI may improve local control this did not translate into improved overall survival in the patients studied. One hundred sixteen eligible patients with metastatic cancer to the brain were randomized to receive either radiotherapy 3000 rad/10 fractions (treatment 1) or the same radiotherapy plus metronidazole 6 gm/m2 (treatment 2). One hundred eleven patients were either fully or partially evaluable. The response rates (CR + PR) and survival showed no significant differences between treatments. Treatment 1: CR + PR 24%, median survival 14 weeks, Treatment 2: CR + PR 27%, median survival 12 weeks. There were no differences observed in response rates based on primary tumor site, neurologic performance status, or extent of metastatic disease. Metronidazole therapy was associated with substantial nausea and vomiting but no neurotoxicity was observed. Oral metronidazole given every other day during radiation therapy provided no clinical benefit for patients with brain metastases compared to radiotherapy alone.
This update of the review published in 2005 does not contain any new trials published in full. One new trial that has only been published as an abstract, does not show any benefit in overall survival in patients receiving prophylactic cranial irradiation. There is insufficient evidence to support the use of PCI in clinical practice. Where possible, patients should be offered entry into a clinical trial.