Late Toxicity and Outcomes Following Radiation Therapy for Chest Wall Sarcomas in Pediatric Patients

Publication date: Available online 26 April 2017
Source:Practical Radiation Oncology
Author(s): John T. Lucas, Israel Fernandez-Pineda, Christopher L. Tinkle, Michael W. Bishop, Sue C. Kaste, Rajiv Heda, Andrew M. Davidoff, Matthew J. Krasin
PurposeTo investigate the contribution of radiotherapy to acute and late toxicity in pediatric chest wall sarcoma patients and evaluate dosimetric correlates of higher incidence toxicities such as scoliosis, and pneumonitis.Methods/MaterialsThe data from 23 consecutively treated pediatric patients with chest wall sarcomas of various histologies (desmoid, Ewing, rhabdomyosarcoma, non-rhabdomyosarcoma-soft tissue sarcomas (NRSTS) were reviewed to evaluate the relationship between end-organ radiation dose, clinical factors, and the risk of subsequent late effects (scoliosis, pneumonitis). Cobb angles were used to quantify the extent of scoliosis. Doses to the spine and lung were calculated from the radiation treatment plan.ResultsThe range of scoliosis identified on follow-up imaging ranged from −47.6 to 64 degrees (median 2.95°). No relationship was identified between either radiation dose to the ipsilateral or contralateral vertebral body or tumor size and the degree or direction of scoliosis. The extent of surgical resection and number and location of resected ribs affected the extent of scoliosis. The dominant predictor of extent of scoliosis at long-term follow-up was the extent of scoliosis following surgical resection. Radiation pneumonitis was uncommon and was not correlated with mean dose or volume of lung receiving 24Gy. However, one of three surviving patients who received whole pleural surface radiotherapy developed significant restrictive lung disease.ConclusionsAcute and late radiotherapy associated toxicities in pediatric chest wall sarcoma patients are modest. The degree of scoliosis following resection is a function of the extent of resection and of the number and location of ribs resected, and the degree of scoliosis at the last follow-up visit is a function of the extent of scoliosis following surgery. Differential radiotherapy dose across the vertebral body does not increase the degree of scoliosis. Severe restrictive pulmonary disease is a late complication of survivors after whole pleural surface radiotherapy.SummaryWe evaluated 23 pediatric patients with chest wall sarcoma on a prospective trial for acute and late toxicities related to multimodality care, with particular emphasis on restrictive pulmonary disease and scoliosis. Disease control was comparable to that in prior series, with distant failure being the most common progression event. Restrictive pulmonary disease was uncommon but seemed to be compounded by multimodality therapy. We observed a substantial effect of the extent of surgical resection and the number and location of ribs resected on the risk of postoperative scoliosis. The greatest predictor of continued scoliosis was the extent of scoliosis prior to radiotherapy.



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