Primary lung sarcoma treated with stereotactic ablative radiotherapy: a case report

Abstract

Primary lung sarcoma (PLS) is an extremely rare, very aggressive malignancy. Surgical removal is considered the treatment of choice, and patients who have been given conventional radiotherapy have had inferior outcomes. This study is the first describing a case of PLS treated with stereotactic ablative radiotherapy (SABR), which precisely targets a small tumor with a markedly higher biologically effective dose than conventional radiotherapy. The patient was an 82-year-old man who was diagnosed with primary lung leiomyosarcoma based on radiology, pathology, and immunohistochemical examinations. The PLS was located in the right lower lobe and measured 2.5 cm. No regional nodal or distant organ metastasis was observed. He was inoperable medically. The SABR was performed using volumetric modulated arc therapy and a dose of 56 Gy in four fractions. Follow-up computed tomography 2 months after SABR revealed a complete tumor response. The toxicity was limited to mild respiratory symptoms. The patient is alive and has had no evidence of disease for 2 years. This study suggests that SABR can be a safe and effective treatment option for PLS.

SEER-Based Survival Nomogram (1998-2015) Based on ‘Stage, Lymph Node Dissection, Tumor Size and Degree of Differentiation, and Therapies’ for Prognosis of Primary Pulmonary Sarcoma

“… 32 , 33 In a large retrospective analysis based on the SEER database, Spraker et al 16 described that the 5-year survival rates of PPS patients receiving surgery alone, radiotherapy alone, surgery and radiotherapy were 41%, 7%, and 25%, respectively. Yeo et al 12 reported the effect of ‘stereotactic ablation radiotherapy’ (SABR) for treating PPS. The results showed that SABR achieved excellent local control with minimal toxicity in both extrapulmonary metastatic sarcoma and PPS.…”

“…Five-year OS rate pertinent to PPS is influenced by several factors including patient age, tumor size, surgery, metastasis, degree of histological malignancy, and therapeutic modalities. 2 , 11 , 12 Tumor prognosis can be accurately predicted using nomograms. Data pertinent to PPS patients procured from the registry of ‘Surveillance, Epidemiology, and End Results (SEER) program database’.…”

“…10 Very limited patients cases with PPS have been reported in the literature so far due to the low, and sporadic incidence rate. 11,12 Generally, the prediction of survival rate of patients with PPS is based on the personal experience of doctors. 2 Till now, there is no standard predictive model for the risk and prognosis of PPS patients.…”

An uncommon histopathological diagnosis

“…In case of incomplete resection or prior inoperability, adjuvant or palliative radio- and chemotherapy are recommended, although survival benefit has not been established for these treatment modalities [ 1 – 3 ]. Recently, stereotactic ablative radiotherapy has been suggested to be a valuable alternative for surgery for small lesions in medically inoperable patients, although robust evidence is still lacking [ 15 ]. Results of conventional radiotherapy appear to be inferior.…”