Electron beam intraoperative radiation therapy for pediatric neoplasms

Abstract

Background. Intraoperative radiation therapy (IORT) has potential advantages over conventional external beam radiation in that a single large dose is delivered to the tumor and its regional bed at the time of surgical exploration. The therapeutic ratio is enhanced by direct tumor visualization, precise treatment volume, and exclusion of normal organs. In childhood, local tumor control is critical for lesions that cannot be totally excised or residual disease not ablated by systemic therapy. Methods. During the past decade, the authors evaluated IORT in pediatric patients with unresectable or recurrent tumors. Fifty-nine patients were treated, 48 for advanced malignant disease and 11 for histologically benign but locally aggressive tumors. Sixty-four operations were performed, during which 84 separate radiation fields were used. High energy electrons at 5-11 MeV were delivered at a dose of 1000-1700 cGy to a tissue depth of 0.5-3 em. Results. Of 25 children with advanced neuroblastoma, 15 were alive 14-104 months (mean, 51 months) after treatment. The survival of all patients with solid malignancies was 63%. Local tumor control was achieved in 75% of children with cancer and 91% of those with benign tumors. Complications of IORT at the doses used were trivial. Conclusions. Electron beam therapy can be safely and efficiently delivered to young patients during operations intended to treat the primary tumor. The outcome achieved for overall survival and local control of the primary tumor is encouraging, and an acceptable complication rate during intermediate to long-term follow-up has been noted. Cancer 1994; 73:740-7.

Intraoperative radiation therapy for advanced neuroblastoma: the problem of securing the IORT field

“…Recently IORT has been described in a cohort of pediatric patients with varying benign conditions and malignancy [5]. EBRT also has been described that it was effective in advanced neuroblastoma [19][20][21].…”

“…In intraoperative radiation therapy (IORT) a high single radiation dose is delivered to the tumor site with protection of normal uninvolved organs and tissues [1][2][3][4][5][6]. Neuroblastoma is the most common solid tumor in childhood [7].…”

Intraoperative phosphorus-32 brachytherapy plaque for multiply recurrent high-risk epidural neuroblastoma

“…High doses can be delivered in a single fraction, potentially resulting in a significantly increased radiobiological treatment effect. 2,6 Specifically in the setting of neuroblastoma, most institutions have used intraoperative electron beam radiation therapy; 8,10,16,19,20 the use of intraoperative brachytherapy has been reported at a smaller number of institutions. 7,18 While intraoperative brachytherapy with flexible applicators is highly versatile, allowing ease of access to and conformal placement in anatomical locations that a bulky electron cone applicator may not be able to reach, the dose falloff with 192 Ir, while rapid, may not allow sparing of sensitive structures such as the spinal cord when the dura (only 3-4 mm away) must be effectively treated.…”

“…Intraoperative electron beam therapy 8,10,16,19,20 or brachytherapy 7,[13][14][15]17,21 for pediatric solid tumors has been used in many institutions to increase the likelihood of durable local control. Rich et al 18 recently described the outcomes for 44 patients with recurrent or persistent primary high-risk neuroblastoma treated with resection and intraoperative radiation therapy with iridium-192 ( 192 Ir) high-dose-rate afterloader brachytherapy using the Harrison-Anderson-Mick (HAM) radiation applicator.…”

Dosimetry of leakage doses from a mobile accelerator for IORT and legal issues for its clinical use in Japan

“…This method has been developed in Japan 1,2 and its usefulness in the treatment of almost all malignant cancers has been recognized; treated cancers include bladder cancer, 3 lung cancer, 4 rectum cancer, 5,6 malignant brain cancer, 7 gallbladder cancer, 8 pancreas cancer, 9 stomach cancer, 10,11 malignant sarcoma, 12 uterine cancer, 13 and pediatric cancer. 14 For this method, the following processes are required: surgical manipulation in the operating room; transport of patients to the accelerator room, which may be located close to or far from the operating room; irradiation and closing of the wound in the accelerator room, or irradiation in the accelerator room and closing of the wound after transport to the operating room. This procedure reduces the advantages of the method, requires large numbers of staff, and hinders the propagation of the method.…”