Radiation-induced osteosarcomas of the skull: report of two cases and review of the literature.

Osteosarcoma of the skull as a second neoplasm after radiation therapy is unusual. This neoplasm generally occurs after doses of over 10 Gy. CT, MRI and biopsy are the main diagnostic procedures for this lesion. We report two other cases of osteosarcomas of the skull and review the pertinent literature.

Spontaneous regression of pulmonary involvement after smoking reduction and removal of and radiation therapy for Langerhans cell histiocytosis of the sphenoid bone: which comes first, the chicken or the egg?

Isolated pulmonary Langerhans cell histiocytosis (LCH) in adults is known to regress spontaneously after smoking cessation alone, but little is known about whether this rationale could also apply in cases of multisystem pulmonary LCH. In particular, pediatric patients with multisystem LCH including involvement in "risk organs" such as lungs often benefit from systemic chemotherapy. Here, we present a 37-year-old man with spontaneous regression of pulmonary lesions in multisystem LCH, achieved solely by smoking reduction following local treatment of bone lesions.

Leiomyosarcoma of the uterus with sphenoid bone and orbital metastases.

A 55-year-old woman presented with a 1-week history of vision loss in the right eye associated with proptosis and diplopia. Past medical history was significant for high-grade leiomyosarcoma of the uterus status post total abdominal hysterectomy and bilateral salpingo-oophorectomy and postoperative pelvic radiation 18 months prior to presentation. Staging studies at the time of initial diagnosis of uterine leiomyosarcoma showed no evidence for metastatic disease. At presentation, CT and MRI showed a well-circumscribed 3.0 cm x 3.6 cm x 2.4 cm mass centered in the right greater sphenoid wing, extending into the middle cranial fossa and the superior and lateral orbital wall. Biopsy of the orbital mass revealed a poorly differentiated high-grade leiomyosarcoma, consistent with recurrent metastatic disease from the uterus. The patient subsequently underwent radiation treatment followed by a left orbital exenteration 6 months after the orbital biopsy. A left thoracostomy was performed 8 months after the orbital biopsy for a metastatic nodule in the left lower lobe of the lung. The clinicopathologic findings of this rare metastatic orbital lesion are presented.

Osteoradionecrosis of sphenoid and temporal bones in a patient with maxillary sinus carcinoma: a case report.

A case of radionecrosis of sphenoid and temporal bones is reported. The patient received a combination of surgery, radiotherapy, and chemotherapy for his left maxillary sinus carcinoma. After the combined therapy, necrosis accompanying inflammation developed in the maxillary and temporal regions. Excision of the necrotic tissues was done, and the left ascending ramus of the mandible was resected because of persistent tumor mass at the left infratemporal fossa. Although the excision wound of the maxilla healed by epithelialization, an area of nonvital bone remained exposed in the temporal region, where progressive osteonecrosis with infection led to breakdown of the skin. The necrotic bones of the zygomatic arch and the sphenotemporal sutural region became visible through the skin defect, and computerized tomography scan revealed bone necrosis involving the inferolateral area and the base of the skull. Excision of the necrotic bone and reconstruction with sternocleidomastoid myocutaneous flap were performed.

T classification and clivus margin as risk factors for determining locoregional control by radiotherapy of nasopharyngeal carcinoma.

BACKGROUND: The purpose of this study was to determine risk factors that affect locoregional control of nasopharyngeal carcinoma (NPC) after radiotherapy. Computed tomography (CT) is utilized for radiotherapy planning and for identifying high risk anatomic areas. METHODS: Between April 1990 and December 1993, 40 consecutive patients (1 in Stage I, 3 in Stage II, 5 in Stage III, and 31 in Stage IV) who had locoregional NPC were given definitive radiotherapy at the Koo Foundation Sun Yat-Sen Cancer Center in Taipei, Taiwan. All patients had individualized CT treatment planning. The dimension of each tumor as shown on the treatment planning CT were mapped on conventional simulation films. The extent of each tumor was further affirmed by magnetic resonance imaging (MRI) and the tumor map revised as necessary. The primary radiation fields were designed to include the primary tumor and potential spread areas with appropriate margins. Concurrent chemotherapy was also given to 35 patients (87.5%) who had positive cervical lymph nodes or primary tumors extending beyond the nasopharynx. RESULTS: By the end of December 1995, after a median follow-up of 42 months and minimal follow-up of 24 months, the locoregional control rate at 4 years was 84.8% (95% confidence interval [CI], 72.3-97.3), disease free survival 68.4% (95% CI, 52. 1-84.7), and overall survival 76.7% (95% CI, 63.4-90.0). The radiation field margin near the sphenoid sinus averaged 1.9 cm, the clivus margin 1.1 cm, the pterygoid fossa margin 2.0 cm, and the oral cavity margin 1.7 cm. Risk factor analysis revealed that T classification and the radiation field margin at the clivus were the most important factors for locoregional control of the tumor. The locoregional control rates were 92.6% (25/27) for T1-T3 patients and 76.9% (10/13) for T4 patients (P = 0.03). The locoregional control rates were 71.4% (5/7) for patients with a clivus margin < 1 cm and 90.6% (29/32) for patients with a clivus margin > or = 1 cm (P = 0.08). CONCLUSIONS: The excellent locoregional control observed in this series may be attributed to the concurrent chemotherapy and radiotherapy as well as meticulous treatment planning with CT and MRI. The precise delineation of the involved area with the aid of CT, which is taken while the patient is in the position for irradiation, serves to define the necessary safety margin of the radiation field. T classification and clivus margin are the most important factors in determining locoregional control of radiotherapy of NPC. The statistical trend observed in this study indicated that the clivus margin should be adequate to reduce the failure around the clivus, as all local recurrences were observed in this area.

Reuse of tumorous calvarial bone after gamma irradiation.

Reconstruction of calvarium after tumor resection may present several technical difficulties. The authors reused the resected calvarial bone in four patients after submitting the bone to a lethal dose of gamma radiation. The authors conclude that resected, irradiated, tumorous bone can be reused for the reconstruction of its own defect. This provides a simple method of reconstruction. Partial bone resorption should be anticipated but further reconstruction, if needed, will be facilitated.