Prophylactic cranial irradiation in small cell lung cancer (SCLC) makes a comeback

Prophylactic cranial irradiation for patients with limited-stage small-cell lung cancer with response to chemoradiation

BACKGROUND

Previous clinical studies have generally reported that prophylactic cranial irradiation (PCI) was given to patients with a complete response (CR) to chemotherapy and chest radiotherapy in limited-stage small-cell lung cancer (SCLC). It is not clear if those with incomplete response (IR) would benefit from PCI.

PATIENTS AND METHODS

The Saskatchewan experience from 1981 through 2007 was reviewed. Patients were treated with chest radiotherapy and chemotherapy with or without PCI (typical doses: 2500 cGy in 10 fractions over 2 weeks, 3000 cGy in 15 fractions over 3 weeks, or 3000 cGy in 10 fractions over 2 weeks).

RESULTS

There were 289 patients treated for curative intent, 177/289 (61.2%) of whom received PCI. For the whole group of 289 patients, PCI resulted in significant overall survival (OS) and cause-specific survival (CSS) benefit (P = .0011 and 0.0005, respectively). The time to symptoms of first recurrence at any site with or without PCI was significantly different: 16.9 vs. 13.2 months (P = .0006). PCI significantly delayed the time to symptoms of first recurrence in the brain: 20.7 vs. 10.6 months (P < .0001). The first site of metastasis was the brain for 12.5% and 45.5% patients with CR with and without PCI, respectively (P = .02) and in 6.1% and 27.6% of patients with IR with and without PCI, respectively (P = .05). For the 93 patients with IR, PCI did not confer OS or CSS benefit (P = .32 and 0.39, respectively).

CONCLUSIONS

Patients with IR benefited from PCI, with a reduced rate of and a delayed time for the development of brain metastases, although without significant OS or CSS benefit. PCI could be considered for all patients with limited-stage SCLC responding to chemoradiation.

Prophylactic cranial irradiation revisited: cost-effectiveness and quality of life in small-cell lung cancer

PURPOSE

To investigate the therapeutic usefulness and cost-effectiveness of prophylactic cranial irradiation (PCI) in patients with limited-stage small-cell lung cancer (SCLC) who had achieved a complete remission.

METHODS

A retrospective chart review was undertaken of all patients diagnosed in Saskatchewan with SCLC between 1987 and 1998 inclusive. Patients who achieved a complete remission were divided into two groups, depending on whether they underwent PCI (PCI+ and PCI-, respectively). The quality-of-life-adjusted survival was estimated by the Q-TWiST method (quality time without symptoms and toxicity). The mean incremental costs per month of incremental OS were calculated in a cost-effectiveness analysis.

RESULTS

Among the 98 complete remission patients, the median OS for PCI+ and PCI- patients was 20.0 and 19.0 months, respectively (p > 0.05, nonsignificant). The median disease-free survival was 14.7 and 10.0 months, respectively (p < 0.05). The difference in the mean Q-TWiST survival was significant (p < 0.01). The mean marginal cost was $18,834/PCI+ patient and $17,885/PCI- patient (p > 0.05, nonsignificant). The cost-effectiveness ratio was $70/mo of incremental OS if u(tox) and u(rel) (the utility coefficients to reflect the value of time in health states of toxicity and relapse) were assumed to be 1.0.

CONCLUSION

PCI is a cost-effective treatment that improves the quality-of-life-adjusted survival for patients with a complete remission of SCLC.

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.