Retroperitoneal sarcomas are a special issue since radiosensitivity of the bowel to injury makes postoperative radiation therapy less desirable. Reasons for this include the postoperative adhesions and bowel immobility that increase the risk of damage from any given radiation dose. This is in contrast to the preoperative approach in which the tumor often displaces bowel outside of the radiation field, and any exposed bowel is more mobile, which decreases exposure to specific bowel segments.
Radiation volume and dose depend on all patient, tumor, and surgical variables as noted above. Considerations include patient age and growth potential, the ability to avoid critical organs, epiphyseal plates, and lymphatics (but not the neurovascular bundles that are relatively radiation tolerant), and the functional/cosmetic outcome. Radiation margins are typically 2 cm to 4 cm longitudinally, and encompassing fascial planes axially. Radiation doses are typically 45 Gy to 50 Gy preoperatively, with consideration for postoperative boost of 10 Gy to 20 Gy if resection margins are microscopically or grossly positive, or planned brachytherapy if the resection is predicted to be subtotal. However, data documenting the efficacy of a postoperative boost are lacking. The postoperative radiation dose is 55 Gy to 60 Gy, or rarely, higher in the situation where unresectable gross residual disease exists.
The role of adjuvant (postoperative) chemotherapy remains controversial. A meta-analysis of updated data from adult STS patients from all available randomized trials concluded that recurrence-free survival was better with adjuvant chemotherapy for patients with high-grade tumors larger than 5 cm. The largest prospective pediatric trial failed to demonstrate any benefit with adjuvant vincristine, dactinomycin, cyclophosphamide, and doxorubicin.
Special Treatment Considerations for Children With STS
Many therapeutic strategies for children and adolescents with soft tissue tumors are similar to those for adult patients, although there are important differences. For example, the biology of the neoplasm in pediatric patients may differ dramatically from that of the adult lesion. Additionally, limb-sparing procedures are more difficult to perform in pediatric patients. The morbidity associated with radiation therapy, particularly in infants and young children, may be much greater than that observed in adults.
Improved outcomes with multimodality therapy in adults and children with STSs over the past 20 years has caused increasing concern about the potential long-term side effects of this therapy in children, especially when considering the expected longer life span of children versus adults. Therefore, to maximize tumor control and minimize long-term morbidity, treatment must be individualized for children and adolescents with nonrhabdomyosarcomatous STS. These patients should be enrolled in prospective studies that accurately assess any potential complications.
- Okcu MF, Despa S, Choroszy M, et al.: Synovial sarcoma in children and adolescents: thirty three years of experience with multimodal therapy. Med Pediatr Oncol 37 (2): 90-6, 2001.
- Sugiura H, Takahashi M, Katagiri H, et al.: Additional wide resection of malignant soft tissue tumors. Clin Orthop (394): 201-10, 2002.
- Cecchetto G, Guglielmi M, Inserra A, et al.: Primary re-excision: the Italian experience in patients with localized soft-tissue sarcomas. Pediatr Surg Int 17 (7): 532-4, 2001.
- Chui CH, Spunt SL, Liu T, et al.: Is reexcision in pediatric nonrhabdomyosarcoma soft tissue sarcoma necessary after an initial unplanned resection? J Pediatr Surg 37 (10): 1424-9, 2002.
- Paulino AC, Ritchie J, Wen BC: The value of postoperative radiotherapy in childhood nonrhabdomyosarcoma soft tissue sarcoma. Pediatr Blood Cancer 43 (5): 587-93, 2004.
- Kaste SC, Hill A, Conley L, et al.: Magnetic resonance imaging after incomplete resection of soft tissue sarcoma. Clin Orthop (397): 204-11, 2002.
- Chandrasekar CR, Wafa H, Grimer RJ, et al.: The effect of an unplanned excision of a soft-tissue sarcoma on prognosis. J Bone Joint Surg Br 90 (2): 203-8, 2008.
- Daigeler A, Kuhnen C, Moritz R, et al.: Lymph node metastases in soft tissue sarcomas: a single center analysis of 1,597 patients. Langenbecks Arch Surg 394 (2): 321-9, 2009.
- Neville HL, Andrassy RJ, Lally KP, et al.: Lymphatic mapping with sentinel node biopsy in pediatric patients. J Pediatr Surg 35 (6): 961-4, 2000.
- Neville HL, Raney RB, Andrassy RJ, et al.: Multidisciplinary management of pediatric soft-tissue sarcoma. Oncology (Huntingt) 14 (10): 1471-81; discussion 1482-6, 1489-90, 2000.
- Kayton ML, Delgado R, Busam K, et al.: Experience with 31 sentinel lymph node biopsies for sarcomas and carcinomas in pediatric patients. Cancer 112 (9): 2052-9, 2008.
- Marcus KC, Grier HE, Shamberger RC, et al.: Childhood soft tissue sarcoma: a 20-year experience. J Pediatr 131 (4): 603-7, 1997.
- Delaney TF, Kepka L, Goldberg SI, et al.: Radiation therapy for control of soft-tissue sarcomas resected with positive margins. Int J Radiat Oncol Biol Phys 67 (5): 1460-9, 2007.
- Blakely ML, Spurbeck WW, Pappo AS, et al.: The impact of margin of resection on outcome in pediatric nonrhabdomyosarcoma soft tissue sarcoma. J Pediatr Surg 34 (5): 672-5, 1999.
- Skytting B: Synovial sarcoma. A Scandinavian Sarcoma Group project. Acta Orthop Scand Suppl 291: 1-28, 2000.
- Hua C, Gray JM, Merchant TE, et al.: Treatment planning and delivery of external beam radiotherapy for pediatric sarcoma: the St. Jude Children's Research Hospital experience. Int J Radiat Oncol Biol Phys 70 (5): 1598-606, 2008.
- Pratt CB, Pappo AS, Gieser P, et al.: Role of adjuvant chemotherapy in the treatment of surgically resected pediatric nonrhabdomyosarcomatous soft tissue sarcomas: A Pediatric Oncology Group Study. J Clin Oncol 17 (4): 1219, 1999.
- Merchant TE, Parsh N, del Valle PL, et al.: Brachytherapy for pediatric soft-tissue sarcoma. Int J Radiat Oncol Biol Phys 46 (2): 427-32, 2000.
- Sadoski C, Suit HD, Rosenberg A, et al.: Preoperative radiation, surgical margins, and local control of extremity sarcomas of soft tissues. J Surg Oncol 52 (4): 223-30, 1993.
- Virkus WW, Mollabashy A, Reith JD, et al.: Preoperative radiotherapy in the treatment of soft tissue sarcomas. Clin Orthop (397): 177-89, 2002.
- Zagars GK, Ballo MT, Pisters PW, et al.: Preoperative vs. postoperative radiation therapy for soft tissue sarcoma: a retrospective comparative evaluation of disease outcome. Int J Radiat Oncol Biol Phys 56 (2): 482-8, 2003.
- O'Sullivan B, Davis AM, Turcotte R, et al.: Preoperative versus postoperative radiotherapy in soft-tissue sarcoma of the limbs: a randomised trial. Lancet 359 (9325): 2235-41, 2002.
- Davis AM, O'Sullivan B, Turcotte R, et al.: Late radiation morbidity following randomization to preoperative versus postoperative radiotherapy in extremity soft tissue sarcoma. Radiother Oncol 75 (1): 48-53, 2005.
- Schomberg PJ, Gunderson LL, Moir CR, et al.: Intraoperative electron irradiation in the management of pediatric malignancies. Cancer 79 (11): 2251-6, 1997.
- Nag S, Shasha D, Janjan N, et al.: The American Brachytherapy Society recommendations for brachytherapy of soft tissue sarcomas. Int J Radiat Oncol Biol Phys 49 (4): 1033-43, 2001.
- Viani GA, Novaes PE, Jacinto AA, et al.: High-dose-rate brachytherapy for soft tissue sarcoma in children: a single institution experience. Radiat Oncol 3: 9, 2008.
- Al Yami A, Griffin AM, Ferguson PC, et al.: Positive surgical margins in soft tissue sarcoma treated with preoperative radiation: is a postoperative boost necessary? Int J Radiat Oncol Biol Phys 77 (4): 1191-7, 2010.
- Ferrari A: Role of chemotherapy in pediatric nonrhabdomyosarcoma soft-tissue sarcomas. Expert Rev Anticancer Ther 8 (6): 929-38, 2008.
- Adjuvant chemotherapy for localised resectable soft-tissue sarcoma of adults: meta-analysis of individual data. Sarcoma Meta-analysis Collaboration. Lancet 350 (9092): 1647-54, 1997.
- Suit H, Spiro I: Radiation as a therapeutic modality in sarcomas of the soft tissue. Hematol Oncol Clin North Am 9 (4): 733-46, 1995.
- Okcu MF, Pappo AS, Hicks J, et al.: The nonrhabdomyosarcoma soft tissue sarcomas. In: Pizzo PA, Poplack DG, eds.: Principles and Practice of Pediatric Oncology. 6th ed. Philadelphia, Pa: Lippincott Williams and Wilkins, 2011, pp 954-86.