Gamma knife stereotactic radiosurgery for the management of incidentally-identified brain metastasis from non-small cell lung cancer

Abstract

Initial staging workup of non-small cell lung cancer (NSCLC) patients has led to increased identification of incidental brain metastases in patients who otherwise have minimal or no neurologic symptoms. We present our experience treating these metastases with stereotactic radiosurgery (SRS) alone and compare outcomes to those of patients with brain metastases treated with other strategies. We queried our neuro-oncology and radiation oncology databases for patients with incidentally-identified NSCLC brain metastases treated with upfront SRS alone between 1997 and 2006. We performed a retrospective analysis to evaluate outcomes in these patients. We found 26 patients with incidentally-identified NSCLC brain metastases (KPS 90-100) treated with SRS alone within 60 days of diagnosis of the metastases. These patients underwent SRS at a median 15 days from diagnosis to an average of 1.6 lesions (range: 1-7), with a mean lesion volume of 1.86 cm(3). The median prescription was 24 Gy delivered to the median 53% isodose line. The median survival for these patients was 8.2 months (mean 12.3 months) from diagnosis of brain metastases. Local CNS progression occurred in 2 patients (7.7%, mean 229.7 days). Survival was not statistically different from similar patients treated with whole brain radiotherapy (WBRT) (P = 0.98), WBRT + Surgery (P = 0.07) or WBRT + SRS (P = 0.62). Patients with incidentally-identified NSCLC brain metastases treated with SRS alone may achieve a survival rate comparable to patients managed with other standard therapeutic modalities. Our findings suggest that SRS alone may be a viable therapeutic option for patients with incidentally-discovered NSCLC brain metastases.

CT-guided Stereotactic Microsurgical Resection of Cerebral Mass Lesions

“…Meanwhile, Leksell established the basis of a novel system combining the cartesian system with other systems, which consisted of an apparatus fixed to Guiot et al 6,7 and Riechert and Mundinger 8 were the first investigators to introduce open stereotactic craniotomy, which was then enjoyed broader applications and further refinements owing to the advances in the field of medical imaging such as computerized tomography 9 and magnetic resonance imaging 10 . Current image-guided stereotactic procedures include biopsy [11][12][13][14][15] , cyst aspiration 16,17 , focal irradiation 18,19 , and hematoma evacuation [20][21][22] , neuroaugmentation 22,23 , stereotactic robotic microsurgery [24][25][26] and neural transplantation 27,28 . These techniques facilitate precise localization and resection of lesions in eloquent regions of brain and help minimize operative injury to the surrounding tissues.…”

Methods and results of locoregional treatment of brain metastases in patients with non-small cell lung cancer

“…In patients with non-small cell lung cancer (NSCLC), accounting for 80–85% of all lung cancers, the risk of development of brain metastases (BMF-NSCLC) throughout the course of the disease is 30–50%; brain metastases are found in 7–10% of patients with NSCLC at diagnosis [7–18]. The risk of BMF-NSCLC development is significantly higher in patients with advanced NSCLC (stage III and IV) and in patients with adenocarcinoma and large-cell carcinoma, as compared to squamous-cell carcinoma histology [12–14, 19, 20].…”

“…Occurrence of BMF-NSCLC is associated with a very poor prognosis: median survival of untreated patients is about 1 month [1, 6, 8, 10, 11, 15, 17, 18, 21, 22] and of those receiving palliative corticosteroid treatment slightly over 2 months [17, 18]. Palliative whole brain radiotherapy (WBRT) prolongs median survival to 3–6 months [8, 10, 17].…”

“…However, in recent years a positive change has been observed [15, 22]. In patients qualified for definitive surgery or stereotactic radiosurgery (SRS), with or without WBRT, median survival reaches even more than 10 months; however, this is true only for selected patients: with good performance status, complete or very good extracranial disease control and 1–3 BMF-NSCLC [8, 15, 18, 23–27]. …”

“…In general, local (surgery, SRS) [1, 4, 6, 8, 17, 18, 28–30, 35] or regional (WBRT) [1, 4, 19, 28–30, 33–35] treatment is preferred, including combination of surgery and radiotherapy. There is a growing importance of systemic treatment, in particular of immunotherapy [1, 2, 4, 11, 12, 30–32].…”