Stereotactic Radiosurgery May Offer Control in SCLC With >5 Brain Metastases

"We found that SRS for [brain metastases] from SCLC is potentially effective in patients with 5 or fewer brain metastases," according to the authors of a retrospective review published in Advances in Radiation Oncology.

Stereotactic radiosurgery (SRS) may be a more effective and tolerable alternative to whole brain radiation therapy (WBRT) as a treatment for patients with 5 or fewer brain metastases from small cell lung cancer (SCLC), according to findings from a retrospective review published in Advances in Radiation Oncology.

The median number of treated brain metastases among 25 patients without prior WBRT was 3 (range, 1-13 BM); the corresponding figure was 4 (range, 1-29) among 45 who had received such therapy. Moreover, among those without prior WBRT, there were no instances of local failure and 8 instances of distant brain failure. The median time to failure was 4.1 months, and the 1-year rate of distant brain recurrence-free survival was 52%.

The corresponding figure was 22% among patients who’d undergone WBRT, with 23 patients within the group experiencing subsequent distant brain failure.

Notably, treatment with SRS alone did not yield a survival advantage over SRS plus prior WBRT, but patients treated with SRS alone had reduced rates of distant brain failure compared with patients who had previous WBRT (P <.040).

Additionally, patients with fewer treated brain metastases experienced longer overall survival (OS; P <.021). The median OS was 9.5 months among those with 1 or 2 metastases, 4.2 months among those with 3 to 5, and 3.3 months among those with more than 5. The median survival across the entire population was 4.9 months (range, 0.70-23.9).

The central nervous system (CNS) control rates at 1 year were 39.2% among those with 1 or 2 metastases, 27.6% among those with 3 to 5, and 0% among those with more than 5.

“Because of the high [brain metastases] rates, it was standard for patients without [brain metastases] to be offered prophylactic cranial irradiation [PCI] and patients with [brain metastases] to have treatment with WBRT. However, more recent data have called into question the value of PCI for patients without [brain metastases], and for patients who have [such metastases], the treatment options have begun to include SRS,” the investigators wrote. “We found that SRS for [brain metastases] from SCLC is potentially effective in patients with 5 or fewer brain metastases.”

Investigators collected data for this review from an SRS database from April 2008 to April 2019. In sum, 70 patients with 337 treated brain metastases underwent examination and analysis. The 45 patients with prior WBRT underwent their therapy for a median of 8.7 months before SRS, 17 of whom received prophylactic treatment.

The median age in the study population was 62 years old (range, 49-80). More patients were male (n = 40) than female (n = 30), and most (n = 36) did not have CNS metastases at their initial diagnosis. Most (n = 47) had received prior chemotherapy. The most common CNS recursive portioning analysis (RPA) class was 2 (n = 47).

The median follow-up time was 3.8 months (range, 0.70-23.9) in the overall population and 5.5 months (range, 2.7-23.9) among those without previous WBRT.

Among the other findings, survival differed according to recursive portioning analysis class. The median survival time was 7.6 months for class 1, 4.9 months for class 2, and 3.6 months for class 3.

Investigators noted that the lack of randomization is a potential limitation to these findings. Additionally, variables such as patient frailty, social support, brain metastasis volume, and receipt of immunotherapy were not controlled for.

“Our results contribute to the growing information regarding SRS for SCLC [brain metastasis] as being a potential treatment option,” the investigators concluded. “Treating SCLC brain metastases with SRS rather than WBRT would reduce treatment toxicity and is logistically easier for patients and caregivers.”

Reference

Wang VH, Juneja B, Goldman HW, et al. Stereotactic radiosurgery for brain metastases in patients with small cell lung cancer. Adv Radiat Oncol. 2023;8(5):101237. doi:10.1016/j.adro.2023.101237