size, number of lung metastases, BED, tracking method, central vs. peripheral ... isodose line with 66-69 beams utilizing isocentric technique. The tumors.
Review of Cyberknife-Delivered Stereotactic Body Radiation Therapy for Lung Metastases William R Rate IV5, Abhishek Mishra3, R. M. Lanciano1,2,3, A. Hanlon4, J. Lamond1,2,3, S. Arrigo1,2,3, J. Yang1,2,3, M. Good1, L. Brady1,3 1 Philadelphia
Cyberknife, 2 Delaware County Memorial Hospital / Crozer Keystone Healthcare System, 3Drexel University College of Medicine, Philadelphia, PA, 4University of Pennsylvania, Philadelphia, PA, 5Washington College, Chestertown, MD
INTRODUCTION Stereotactic body radiation therapy (SBRT) is the standard non-surgical treatment modality for early-stage non-small cell lung cancer. Limited retrospective data exists however with SBRT for non-surgical treatment of metastatic lung disease. We report our institutional experience with lung metastases from all primary sites excluding primary lung cancer with special emphasis on treatment factors particularly dose.
METHODS From January 2008 to April 2014, 51 patients (median age of 64) with 67 metastatic lung lesions received CyberKnife high-dose SBRT (45-60 Gy in 3-5 fractions). All patients had at least 2 months follow up and CT of the Chest or PET/CT to assess local control. The 67 metastases arose from various primaries including; colorectal (n=24), renal (n=12), breast (n=8), head and neck (n=6), melanoma (n=6), urogenital (n=6), GI (n=2), liver (n=2), and pancreas (n=1). Biologically effective dose (BED) calculations were performed for each tumor utilizing an alpha/beta ratio of 10Gy. Variables assessed for outcome included age at SBRT, primary site, stage at initial diagnosis, time from initial diagnosis to SBRT, CTV size, number of lung metastases, BED, tracking method, central vs. peripheral presentation and dose calculation method. Toxicity assessment utilized RTOG Late Radiation Morbidity Scoring Schema. Kaplan Meier survival and local control curves were generated with GraphPad Prism and comparison of curves utilized log rank testing.
RESULTS Median age of the entire cohort was 64 years (range of 31 to 87). Actuarial overall survival (OS) and disease free survival (DFS) rates at 2 years for all patients were 59.6% and 52.3% and at 3 years 44.9% and 28.8% respectively. The median OS was 28.7 months and the median DFS was 26.1 months. Actuarial local control (LC) at both 2 and 3 years was 82.2% respectively, with 11 treated lesions failing locally. Tumors receiving BED above 100 Gy10 (n=59) had higher rates of local control at 2 and 3 years than tumors receiving 100 Gy10 or less (n=8, 3 year LC rate of 86.7% vs 44.4%, p=0.0017). No other factors analyzed were significant for local control in univariate analysis. No cases of grade ≥3 toxicity were observed.
Case report of a durable complete response to SBRT assessed by PET/CT RG is a 71 year old WM with a clinical stage T3N1 poorly differentiated adenocarcinoma of the rectum treated with preopertive chemotherapy and radiation followed by low anterior resection 3/2009. PET/CT 6/2010 revealed a 1.4 cm nodule with maximum SUV of 3.5 in the RLL, and a 2.2 cm nodule with maximum SUV of 5.4 in the LUL. Biopsy revealed adenocarcinoma consistent with his rectal primary. Fiducials were placed in each nodule before treatment. He received SBRT 60 Gy in 3 fractions 8/2010 to the LUL mass and 3/2011 to the RLL mass (5mm margin for each tumor) prescribed to the 64-75% isodose line with 66-69 beams utilizing isocentric technique. The tumors were tracked with real time tracking using Synchrony technology/fiducial. Figure 1 represents Pre and Post PET scans for each lesion.
June 2010 Pretreatment
October 2014 NED lung 50 months post CK
January 2011 Pretreatment
October 2014 NED lung 43 months post CK
Figure 2 represents treatment planning for each lesion.
Author
Patient Description
# of Patients/ Lesions
Lesion Location
Fractionation
Local Control at Primary tumor site
Rusthoven et al. (2009)
Phase I/II multicenter/ 1-3 Lung metastases
38/63
Central and Peripheral
60Gy/3 fractions 96% (2yr) Prescribed to PTV
Zhang et al. (2011)
Single Institution
71/172
Central and Peripheral
30-60Gy/ 2-12 fractions
75% (3yr); 75% (5yr)
Baschnagel 1-3 Lung metastases et al. (2013)
32/47
Central and Peripheral
48-65Gy/ 4-10 fractions Prescribed to PTV
92% (2yr); 85% (3yr)
Milano et al. Single Institution/ 1-5 Lung (2014) metastases. KPS > 70, tumor diameter
