Whole-Brain Radiation Therapy With Simultaneous Integrated Boost Versus Whole-Brain Radiation Therapy Plus Stereotactic Radiosurgery for the Treatment of Brain Metastasis From Lung Cancer

Abstract

Radiotherapy is one of the most important treatments for brain metastasis (BM). This study aimed to assess whether whole-brain radiation therapy (WBRT) with simultaneous integrated boost (SIB) provided any therapeutic benefit compared to WBRT followed by stereotactic radiosurgery (SRS). Seventy-two consecutive cases of lung cancer with BM treated from January 2014 to June 2020 were analyzed retrospectively. Thirty-seven patients were treated with WBRT (30 Gy in 10 fractions) and SIB (45 Gy in 10 fractions), and 35 patients were treated with WBRT (30 Gy in ten fractions) followed by SRS (16–24 Gy according to the maximum tumor diameter). The primary endpoint was intracranial progression-free survival (PFS). The secondary endpoints were intracranial objective response (partial and complete responses), pattern of intracranial progression, overall survival (OS), and toxicity. The WBRT + SIB group had a significantly longer median intracranial PFS (9.1 vs. 5.9 months, P = 0.001) than the WBRT + SRS group. The intracranial objective response rate was 67.6% and 62.9% in the WBRT + SIB and in WBRT + SRS groups, respectively (P = 0.675). The incidence of progression outside the P-GTV in the WBRT + SIB group was significantly lower than that in the WBRT + SRS group (39.4% vs. 75.0%, P = 0.004). The median OS was 24.3 and 20.3 months in the WBRT + SIB and WBRT + SRS groups, respectively (P = 0.205). There was no significant difference in the incidence of grade 3 or worse adverse reactions between the two groups. Compared to treatment with WBRT + SRS, that with WBRT + SIB for BM appeared to contribute to local control.

The First Survival Score for Patients Treated with Whole-Brain Radiotherapy Plus Simultaneous Integrated Boost for Brain Metastases

“…In addition to demonstrating the feasibility of WBRT+SIB, several studies have shown that this approach leads to local and intra-cerebral control rates at least comparable to other radiation approaches, namely WBRT alone, stereotactic radiotherapy alone, or WBRT plus stereotactic radiotherapy [ 6 , 16 , 17 , 18 , 19 ]. Some data suggests that WBRT+SIB may be superior to WBRT with or without stereotactic radiosurgery [ 7 , 20 , 21 , 22 ]. For example, in the most recent study, WBRT+SIB resulted in longer median intra-cerebral progression-free survival than WBRT, followed by stereotactic radiosurgery (91 vs. 5.0 months, p = 0.001) [ 22 ].…”

“…Some data suggests that WBRT+SIB may be superior to WBRT with or without stereotactic radiosurgery [ 7 , 20 , 21 , 22 ]. For example, in the most recent study, WBRT+SIB resulted in longer median intra-cerebral progression-free survival than WBRT, followed by stereotactic radiosurgery (91 vs. 5.0 months, p = 0.001) [ 22 ]. However, despite increasing interest in using WBRT+SIB, particularly with hippocampus-sparing techniques, not all patients may benefit from this approach.…”

“…Moreover, in several studies, WBRT+SIB was similarly effective as stereotactic radiotherapy, WBRT, or a combination of both with respect to local control or intra-cerebral control [ 6 , 16 , 17 , 18 , 19 ]. Some studies even suggested that WBRT+SIB resulted in improved outcomes compared to WBRT with or without stereotactic radiosurgery [ 7 , 20 , 21 , 22 ]. Based on these results, interest has increased in using WBRT+SIB, including the combination with hippocampus-sparing techniques to reduce the risk of neurocognitive decline [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

“…Some studies even suggested that WBRT+SIB resulted in improved outcomes compared to WBRT with or without stereotactic radiosurgery [ 7 , 20 , 21 , 22 ]. Based on these results, interest has increased in using WBRT+SIB, including the combination with hippocampus-sparing techniques to reduce the risk of neurocognitive decline [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. However, not all patients considered candidates for WBRT may benefit from the addition of a SIB, especially patients with poor prognoses.…”

Modern Radiation Therapy for the Management of Brain Metastases From Non-Small Cell Lung Cancer: Current Approaches and Future Directions

“…WBRT+SIB on large lesions appears to be safe and effective even for patients with 4-10 BMs, without significant cognitive decline ( 113 ); therefore, SIB is frequently employed for the treatment of poly-metastatic disease. Recently it has also been shown to provide a significantly longer median intracranial PFS (9.1 vs 5.9 months, p=0.001) and median OS (14 vs 11 months, p=0.037) compared to WBRT + sequential boost ( 114 , 115 ). There is no consensus on the most appropriate hypofractionation schedule and each institute bases the choice on clinical judgment and experience.…”