<p>Efficacy and tolerability of stereotactic body radiotherapy for lung metastases in three patients with pediatric malignancies</p>

Abstract

Purpose: To report a case series of 3 pediatric patients treated with Stereotactic Body Radiation Therapy (SBRT) for lung metastases. Patients and methods: Three patients (ages 9, 11, and 21) received SBRT for rhabdoid tumor, Ewing sarcoma, and Wilms tumor histologies, respectively. SBRT doses were 37.5–50 Gy in 3–5 fractions treating twelve lesions. Results: Three patients (ages 9, 11, and 21) received photon SBRT for pulmonary metastases. The patients were as follows: 1) 21-year-old male with favorable histology Wilms tumor and 1 lesion treated, 2) 11-year-old female with Ewing sarcoma and 1 lesion treated for relapse after previous whole lung radiation (15 Gy), and 3) 9-year-old female with rhabdoid tumor of the left thigh with 10 lesions treated over a two-year period. Median dose delivered was 40 Gy (range, 37.5–50 Gy), delivered in a median of 4 fractions (range, 4–5) of a median of 10 Gy per fraction (range, 9.4–10 Gy). Within a minimum follow-up of 1.9 years (range 1.9–4 years), local control for all 13 treated metastases is 100% without any observed acute toxicities. One possible late toxicity (grade 2 rib fracture) developed 1.3 years following SBRT for treatment of a peripheral lesion (rhabdoid tumor) in an area of disease progression and was managed conservatively. Two patients are surviving 2.9 years (Wilms tumor) and 1.9 years (Ewing sarcoma) after SBRT, and one (rhabdoid tumor) expired 2 years after her final course (4 years after initial SBRT). Two patients (rhabdoid tumor and Ewing sarcoma) suffered disease progression outside of the treated lesions and one patient (Wilms tumor) is without evidence of disease and has not required whole lung irradiation or further systemic therapy. Conclusion: SBRT appears effective and well tolerated for pediatric lung metastases, however further studies are warranted.

A multi‐institutional phase 2 trial of stereotactic body radiotherapy in the treatment of bone metastases in pediatric and young adult patients with sarcoma

“…As an alternative, stereotactic body RT (SBRT) allows for the delivery of ablative doses to small volumes with a steep dose gradient to spare surrounding normal structures. Although SBRT is increasingly used in adult patients for the treatment of oligometastatic disease, 36‐44 to our knowledge there are limited data regarding its safety and efficacy in a pediatric population 45,46 . There is a particularly strong rationale for SBRT in this population as a strategy to reduce dose to nontarget tissues and potentially reduce the late effects of RT.…”

Phase I/II Study of Stereotactic Body Radiation Therapy for Pulmonary Metastases in Pediatric Patients

“…Previous retrospective reports reported a rib fracture and radiation pneumonitis in pediatric patients after lung SBRT. 9 , 11 One patient who received concurrent nivolumab developed grade 2 pneumonitis, requiring prolonged steroid taper. In adult patients, trials investigating concurrent checkpoint inhibitors and SBRT have noted pneumonitis 21 , 22 ; however, the rate of grade ≥3 pulmonary events appeared comparable to that of Radiation Therapy Oncology Group 0236, a phase II trial investigating SBRT alone for inoperable nonsmall cell lung cancer.…”

“… 7 , 8 Within the pediatric population, few retrospective case reports and series have described SBRT for pulmonary metastases. 9 , 10 , 11 , 12 We aimed to prospectively investigate the lowest dose of SBRT with an acceptable safety profile and efficacy in pediatric patients with metastatic pulmonary lesions.…”

Treatment paradigms for oligometastatic pediatric cancers: a narrative review with a focus on radiotherapy approaches

“…While mostly limited to single-institution retrospective series, there are some compelling data reporting outcomes with the use of SBRT in pediatric patients which can apply to oligometastatic patients (27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38).…”

“…With regard to efficacy and safety of SBRT for lung metastases in pediatric malignancies, a case series from SUNY Upstate Medical University reported favorable outcomes. Three patients were treated with SBRT for 12 pulmonary lesions consisting of rhabdoid tumor, Ewing sarcoma and Wilms tumor histologies (33). Two of the three patients underwent SBRT for a single lung lesion, while one patient with metastatic rhabdoid tumor underwent SBRT to 10 lung lesions over a 2-year period.…”