Purpose/Objective(s):To evaluate the treatment outcomes and the feasibility of proton beam therapy for metastatic lung tumors.Materials/Methods:Thirty-one patients with 44 metastatic lung tumors who had no active disease except the lung and treated with proton beam therapy between March 2002 and December 2012 were reviewed. Sixteen patients were men, and the median age was 64 years. The primary sites were the rectum in 10 patients, the lung in 5, the liver in 4, and the other in 12. The clinical target volume ranged from 1.2 to 91.2 cc (median, 12.8 cc). The total dose of 66.0 GyE in 10 fractions or 72.6 GyE in 22 fractions was prescribed to 33 of 44 targets. Clinical outcomes and major toxicities were analyzed based on medical records and clinical follow-up.Results:Median follow-up time was 18 months for all patients. Over the entire follow-up, local recurrence was observed in 11 lesions (25%). The 2-year local control rate was 70%. On the univariate analysis, the clinical target volume was significantly associated with local control. The 2-year local control rate for targets < 10 cc was 77% compared with 70% for targets ≥ 10 cc (log-rank, p = 0.04). The primary site was not associated with local control. Twenty-one (68%) of 31 patients developed new metastasis after proton beam therapy. The median time from proton beam therapy to the new metastasis was 6 months. The 2-year disease-free and overall survival rates were 34% and 83%, respectively. No Grade 3 or higher acute and late toxicities were observed.Conclusions:Proton beam therapy is considered to be effective and safe treatment option for metastatic lung tumors. However, most of the patients developed new metastasis after proton beam therapy. Further investigation is needed to clarify the better indication for proton beam therapy.
Ohnishi, K,
Clinical Outcomes of Proton Beam Therapy for Metastatic Lung Tumors. Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL.
http://archive.rsna.org/2014/14045822.html
