Stereotactic radiosurgery, a potential alternative treatment for pulmonary metastases from osteosarcoma

Abstract

Stereotactic radiosurgery (SRS), such as body gamma knife, was reported to achieve excellent rates of local disease control with limited toxicity in many cases of primary or secondary pulmonary tumor, except osteosarcoma. To confirm the value of SRS in pulmonary metastases from osteosarcoma, we reviewed the experience from our institution (Department of Oncology, Affiliated Sixth People's Hospital, Shanghai) and compared the efficiency of SRS with that of surgical resection. From January 2005 to December 2012, we carried out a retrospective investigation of 58 patients (age, 8-59 years; mean, 25.2 years) who were diagnosed with non-metastatic osteosarcoma of the extremity and later developed pulmonary metastasis during the period of adjuvant chemotherapy or follow-up. Among them, 27 patients were treated by SRS using the body gamma-knife system. A total dose of 50 Gy was delivered at 5 Gy/fraction to the 50% isodose line covering the planning target volume, whereas a total dose of 70 Gy was delivered at 7 Gy/fraction to the gross target volume. The other 31 patients were treated by surgical resection. Two-year progression-free survival rate, two-year survival rate, median time of PRPFS (post-relapse progress-free survival) and PROS (post-relapse overall survival) in SRS group were parallel to that in surgical group. All 27 patients tolerated gamma knife radiosurgery well while only 9 patients had grades 1-2 pneumonitis. We believe SRS, compared with surgical resection, is effective and safe in treating pulmonary metastasis from osteosarcoma, especially for those patients who were medically unfit for a resection or who refused surgery.

Figure 1.

Kaplan-Meier plots of post-relapse progress-free survival (A) and post-relapse overall survival (B) for all patients.

Figure 2.

Kaplan-Meier plots of post-relapse progress-free survival (A) and post-relapse overall survival (B) for the surgical and SRS group. The median time of PRPFS and PROS in SRS group was parallel to that in the surgical group.

Figure 3.

Radiation pneumonitis occurs 2 months after SRS treatment. Before SRS treatment (A). Two months after SRS treatment (B), CT scan showed radiation pneumonitis (black arrow) without any complaint from the patient. (C) Without medical intervention, radiation pneumonitis resolved two months later.

Figure 4.

Complications after surgical resection treatment. (A) Pneumonitis. (B) Persistent pneumothorax. (C) Intrapulmonary hematomas accompanied with blood pleural effusion.

Figure 5.

Incidence of complications which were resolved by medical intervention in SRS and resection groups. There were more patients with complications needing medical intervention (10 out of 31) in the surgical group than (2 out of 27) in the SRS group.