Brachytherapy for pediatric soft-tissue sarcoma.

PURPOSE: To review the use of brachytherapy (BRT) to treat soft-tissue sarcoma (STS) in pediatric patients at St. Jude Children's Research Hospital. METHODS AND MATERIALS: Thirty-one patients, median age 11 years (range 1-21 years) with Pediatric Oncology Group (POG) Grade 2-3 soft-tissue sarcoma (excluding rhabdomyosarcoma and Ewing's sarcoma) were treated with BRT initially (n = 27) or at the time of recurrence (n = 4) using I-125 or Ir-192 in a temporary (n = 29) or permanent implant (n = 2). Twelve patients were treated with BRT alone and the remaining 19 were treated with a combination of BRT and external beam irradiation (EBRT). The majority of patients had involved margins of resection (n = 20) and tumors less than 5 cm (n = 17). RESULTS: Twenty-seven patients were treated with BRT at the time of presentation. Among the 10 patients treated with BRT alone, one patient developed metastases (4 months) and died of metastatic disease (12 months after presentation); there were no local or regional failures among the remaining 9 patients. Among the 17 patients treated with a combination of BRT and EBRT, there was one local (17 months), two regional (both at 8 months), and 3 distant failures (12, 15, 66 months). The median survival for the surviving 25 patients was 34 months. Wound dehiscence, fibrosis/telangectasia, pigment changes, and cellulitis were the most common side effects. CONCLUSIONS: BRT is an excellent treatment option for pediatric patients with STS. Disease control may be achieved with a high rate of success when BRT is used alone or in combination with EBRT. BRT should be considered for patients with STS who require radiation therapy with the objective of reducing the dose to normal tissues and shortening the overall treatment time. Limb preservation, functional outcome, and toxicity assessment require careful assessment in a prospective study.

Local tumor control in rhabdomyosarcoma following low-dose irradiation: comparison of group II and select group III patients.

PURPOSE: To determine whether low-dose irradiation (i.e., approximately 40 Gy at 1.5-1.8 Gy/fraction), which is associated with > or = 90% local control in children with initially resected rhabdomyosarcoma and microscopic residual [Intergroup Rhabdomyosarcoma (IRS) group II disease], achieves comparable results in children with locally advanced rhabdomyosarcoma (IRS group III) left with microscopic disease after induction chemotherapy with or without delayed surgery. METHODS AND MATERIALS: Among 103 patients entered on five successive studies between 1968 and 1991, 24 had evidence of microscopic residual disease after initial surgical resection (IRS group II) and received low-dose irradiation. Initial chemotherapy was used in 79 with IRS group III disease. In 28 of these 79 group III patients, chemotherapy alone (n = 16) or in combination with delayed surgery (n = 12) reduced disease to microscopic levels prior to the start of radiotherapy based upon which they received low-dose irradiation. All have a minimum 2-year follow-up and median age of 4 years. Primary tumor sites among the 24 with group II disease included: orbit (5), parameningeal (2), nonparameningeal head and neck (3), genitourinary: nonbladder/prostate (5), extremity (4), and other (5). Irradiation dose ranged from 32-50 Gy, with a median and modal dose of 40 Gy. Primary tumor sites among the 28 with group III disease selectively treated with low-dose irradiation included: orbit (1), parameningeal (6), nonparameningeal head and neck (4), genitourinary: bladder/prostate (12) and nonbladder/prostate (1), extremity (1), and other (3). Irradiation dose ranged from 33-52 Gy, with a median and modal dose of 40 Gy. RESULTS: Local disease control has been maintained in 23 of 24 patients (96%) with group II disease. Local control occurred in eight of nine (89%) group II patients receiving < 40 Gy and in all 15 receiving > or = 40 Gy (p = 0.26). Twenty (83%) are alive and free of disease. Twenty-two of the 28 patients (79%) with group III disease treated with low-dose irradiation have maintained continuous local control of disease which was not statistically different from the group II patients (p = 0.08). Local control occurred in 7 of 11 (64%) group III patients receiving < 40 Gy vs. 15 of 17 (88%) receiving > or = 40 Gy (p < = 0.14). Nineteen (68%) are alive and free of disease. Survival in these group III patients is significantly worse than that of the group II patients, with 19 (68%) alive and free of disease (p = 0.04). CONCLUSION: Children with locally advanced rhabdomyosarcoma (IRS group III) who have only microscopic disease after induction chemotherapy with or without delayed surgery have a high likelihood of achieving local control with low-dose irradiation. For this group, data suggest treatment to a dose level of at least 40 Gy.

Pediatric brachytherapy. The St. Jude Children's Research Hospital experience.

BACKGROUND: The use of interstitial, intracavitary, and permanent placement of radioactive isotopes has become a common practice in adult oncology patients based on numerous reports indicating improved local control and survival when used. These same irradiation techniques and treatments have been infrequently used for children with malignant disease despite known dose localization properties that allow for highly focal irradiation delivery with rapid reduction of the dose in nearby normal tissues. The noted benefit of decreased late complications noted in the adult series is also attractive, especially when considering the treatment of children. METHODS: Between May, 1981 and December 15, 1992, 46 children with non-CNS primary malignancy received 50 brachytherapy applications for primary therapy (n = 11 sites), as a boost in conjunction with external beam irradiation (n = 16 sites), or as treatment of recurrent disease or a second malignant neoplasm in a previously irradiated region that precluded further external irradiation or for metastatic disease (n = 23 sites). The most common tumor histologies were rhabdomyosarcoma (n = 14), soft tissue sarcoma (n = 10) and retinoblastoma (n = 10). Patient age at implantation ranged from 8 weeks to 24 years; follow-up maintained in all patients and has ranged from 2-115 months (median, 39 months). RESULTS: Forty-three of 50 sites receiving brachytherapy have maintained continuous disease free intervals, ranging from 2 to 115 months postimplantation (median, 41 months). The seven local failures occurred 2-20 months postimplant (median, 6 months). Severe complications occurred in 12 patients, two which were life threatening but resolved without further incident. CONCLUSIONS: Based on this ongoing clinical investigation, the authors recommend brachytherapy for selected pediatric malignancies and continue to evaluate the various factors associated with local control, local failures, and complications.