1/7. Potential reduction of the incidence of radiation-induced second cancers by using proton beams in the treatment of pediatric tumors.PURPOSE: To assess the potential influence of improved dose distribution with proton beams compared to conventional or intensity-modulated (IM) X-ray beams on the incidence of treatment-induced secondary cancers in pediatric oncology. methods AND MATERIALS: Two children, one with a parameningeal rhabdomyosarcoma (RMS) and a second with a medulloblastoma, were used as models for the purpose of this study. After defining the target and critical structures, treatment plans were calculated and optimized, four for the RMS case (conventional X-ray, IM x-rays, protons, and IM protons) and three for the irradiation of the spinal axis in medulloblastoma (conventional X-ray, IM x-rays, protons). Secondary cancer incidence was estimated using a model based on Publication No. 60 of the International Commission on Radiologic Protection. This model allowed estimation of absolute risks of secondary cancer for each treatment plan based on dose-volume distributions for the nontarget organs. RESULTS: Proton beams reduced the expected incidence of radiation-induced secondary cancers for the RMS patient by a factor of >or=2 and for the medulloblastoma case by a factor of 8 to 15 when compared with either IM or conventional X-ray plans. CONCLUSIONS: The potential for a significant reduction in secondary cancers with pediatric cancers after using proton beams (forward planned or IM) in the treatment of RMS and MBD in children and adolescents represents an additional argument supporting the development of proton therapy for most radiotherapy indications in pediatric oncology.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
2/7. The role of surgery in rhabdomyosarcoma of the head and neck in children.The role of surgery in the treatment of rhabdomyosarcoma of the head and neck has diminished during the past 25 years. Treatment of this tumor in the pediatric population has involved radical radiation therapy and chemotherapy with little or no role for surgery. However, the potential effect of irradiation on facial growth and the appearance of secondary irradiation-induced tumors has raised the question as to whether surgery may once again play a role in the treatment of these patients. Advances in skull base and reconstructive surgery and microsurgical techniques have permitted a reconsideration of initial ablative surgery. The head and neck surgical team must be prepared to respond in those patients in whom craniofacial development is at risk or recurrence has occurred after radical chemotherapy and/or radiation therapy.- - - - - - - - - - ranking = 0.2keywords = radiation-induced (Clic here for more details about this article) |
3/7. Post-irradiation osteosarcoma of the iliac bone: a case report.A case of osteosarcoma of the iliac bone developing 12 years after the successful management of childhood rhabdomyosarcoma is presented. The frequency of secondary tumors, mainly bone malignancies, following therapeutic irradiation in the pediatric age-group, and the criteria for the diagnosis of radiation-induced bone sarcoma are discussed.- - - - - - - - - - ranking = 0.2keywords = radiation-induced (Clic here for more details about this article) |
4/7. Conjunctival flap-cosmetic shell-ptosis procedure. Treatment of blepharoptosis in severe keratopathy.The correction of marked blepharoptosis in patients with severe or potential keratopathy will worsen the keratopathy and possibly lead to the complications of corneal ulceration and endophthalmitis. The conjunctival flap--cosmetic shell--ptosis procedure is well suited to this difficult management problem. patients are initially treated with a conjunctival flap to protect their cornea. Subsequently they are fit with a cosmetic shell, and finally they undergo surgery to correct their ptosis. This three-stage procedure has produced excellent cosmetic and functional results in two patients, one of whom had ptosis and severe radiation-induced keratopathy following the treatment of a rhabdomyosarcoma; the other patient had severe ptosis associated with lack of corneal sensation and orbicularis function following removal of a cerebral meningioma.- - - - - - - - - - ranking = 0.2keywords = radiation-induced (Clic here for more details about this article) |
5/7. X-radiation-induced differentiation of xenotransplanted human undifferentiated rhabdomyosarcoma.A serially xenotransplantable strain of undifferentiated embryonal rhabdomyosarcoma originating from the nasal cavity of a 42-year-old woman has been established in our laboratory. After radiotherapy for the tumor donor, distinct rhabdomyoblastic differentiation of the undifferentiated sarcoma cells appeared in the primary lesion, and it is a reasonable assumption that X-irradiation has a certain potentiality to induce morphologic differentiation of tumor cells. To study this possibility, tissue fragments of undifferentiated embryonal rhabdomyosarcoma that had grown to more than 10 mm after being transplanted to nude mice were selectively irradiated in situ. The degree of rhabdomyoblastic differentiation according to radiation dose was evaluated by light and electron microscopy and by immunostainability for myoglobin, creatine phosphokinase-MM, and desmin. Distinct morphologic differentiation of undifferentiated sarcoma cells could be induced by repeated X-irradiations at several-week intervals.- - - - - - - - - - ranking = 0.8keywords = radiation-induced (Clic here for more details about this article) |
6/7. Slipped capital femoral epiphysis (SCFE) following pelvic irradiation for rhabdomyosarcoma.A 7-year-old child developed slipped capital femoral epiphysis (SCFE) 3 years following pelvic irradiation for rhabdomyosarcoma. The reasons for this occurrence are discussed. This is the second report of radiation-induced SCFE and it is anticipated that more such cases are likely to occur.- - - - - - - - - - ranking = 0.2keywords = radiation-induced (Clic here for more details about this article) |
7/7. Modified technique for radical transmediastinal forequarter amputation and chest wall resection.Forequarter or interscapulothoracic amputation is a major surgical procedure indicated primarily in the treatment of malignant lesions involving the bony and soft tissue parieties of the upper part of the arm, shoulder, and scapula. It is also indicated in extensive trauma with irreparable damage to the shoulder area and as a palliative measure in intractable pain caused by incurable tumors of the shoulder girdle. Several operative techniques have been described: the classical Berger approach, an anterior pectoral approach, and posterior retroscapular approaches. A radical transthoracic approach has been described in cases in which the tumor had spread through the chest wall. The two main goals of these approaches have been early ligation of the subclavian vessels and immediate exploration for operability. This report details our experience with a modified technique for radical forequarter amputation and chest wall resection in which a transmediastinal approach is employed. This approach was used in two patients: One had a radiation-induced fibrosarcoma of the left axilla and adjacent chest wall following a radical mastectomy 19 years earlier, and the other patient had a recurrent rhabdomyosarcoma of the right axilla with invasion of the chest wall. This technique avoids time-consuming and individual excision of ribs and minimizes the amount of blood loss by early ligation of the internal mammary vessels. Safe and excellent exposure and division of the subclavian vessels and early exploration for mediastinal and intrathoracic involvement are made possible. Details of the procedure with illustrations are described.- - - - - - - - - - ranking = 0.2keywords = radiation-induced (Clic here for more details about this article) |