Assessment of local blood flow with laser Doppler flowmetry in irradiated mandibular and frontal bone, an experiment in Göttingen minipigs.

PURPOSE: The aim of this study was to investigate local blood flow changes in the mandibular bone compared to the os frontale after irradiation in various doses. MATERIALS AND METHODS: This study used an animal experiment with 16 female Göttingen minipigs. Three groups of four animals were irradiated with equivalent doses of 25, 50 or 70 Gray on the mandible and os frontale and four animals served as control. Three months after irradiation laser Doppler flowmetry (LDF) was used to record local blood flow on the left mandible and in the irradiated area on the os frontale. At 6 months measurements were repeated. Descriptive and univariate analyses were conducted and p-values lower than 0.05 were considered statistically significant. RESULTS: Local blood flow measurements in the mandible were significantly higher compared to the os frontale. In the os frontale and mandible there was no significant change in the measurements with increasing irradiation dose. CONCLUSION: We found a non-significant decrease in LDF values with an increase in radiation dose in the mandible and non-significant changes in the os frontale at 3 and 6 months. We consider this to represent the process of on-going fibrosis affecting the local blood flow in the mandible.

Malignant chondroid syringoma of the face with bone invasion.

Malignant chondroid syringoma is a very rare type of malignant sweat gland tumor. Diagnosis is based on pathologic features but is complicated by the low frequency of this tumor. The authors report a new case of malignant chondroid syringoma, initially misdiagnosed as basal cell carcinoma, that exhibited very aggressive local behavior and was located on the face, a rare site for this tumor. The authors describe its histopathologic appearance and highlight the importance of including adenoid cystic carcinoma in the differential diagnosis.

Use of osseointegrated implants in the restoration of head and neck defects.

Osseointegrated implants can be applied to facilitate retention, stability, and support for facial and intraoral prostheses used to restore head and neck defects. At the University of California, Los Angeles, Maxillofacial Prosthetics Clinic, retrospective studies have indicated that in nonirradiated maxillectomy patients, implant survival rates are 82.6 percent. In mandibles reconstructed with fibula free flaps, survival rates are 94.6 percent. Similarly, high implant survival rates have been observed for most sites used to support facial prostheses. Cumulative six-year survival rates for auricular sites exceed 95 percent and for floor of nose sites, success rates exceed 87 percent. However, survival rates are low (53 percent) for implants placed in the frontal bone for retention of orbital prostheses and even lower for irradiated bone sites ranging from 63 percent in the maxilla to 27 percent in the orbit.

Spontaneous regression of a large hepatocellular carcinoma with skull metastasis.

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare phenomenon. This case of a 65-year-old Korean man with HCC and metastatic frontal bone mass that regressed after radiotherapy for frontal bone mass without any other therapeutic modalities is described. The clinical diagnosis of HCC was made because of the presence of a liver mass on abdominal computed tomography (CT) scan, high serum alpha-fetoprotein value and tissue diagnosis on frontal bone biopsy. The patient refused any other recommended treatments, but accepted the radiation therapy due to a painful frontal bone mass, and ingested mushroom called Phellinus linteus for one and a half years. Ten months after radiation therapy, he experienced a reduction in size of the frontal bone mass and improvement of lesions in the liver, sternum and ribs. The patient is alive and in good condition without any symptoms or tumor aggravation in August 2002. It was concluded that a rare case of spontaneous regression of HCC had occurred.

Improved detection of disseminated pheochromocytoma using post therapy I-131 MIBG scanning.

A 50-year-old man had metastatic pheochromocytoma to the left frontal bone. The primary adrenal tumor was removed 12 years previously. Bone scanning and diagnostic I-131 and I-123 MIBG imaging showed metastatic lesions in the right femur and midthoracic spine. However, post-therapy I-131 MIBG scanning showed extensive and widespread metastatic disease. Post-therapeutic I-131 MIBG whole-body scanning was necessary to more fully assess the extent of metastatic pheochromocytoma.

[Information concerning radiation-induced sarcomas. Report on 2 cases]. / Zur Kenntnis strahlenbedingter Sarkome. Mitteilung über 2 Beobachtungen.

Two cases of radiation-induced sarcomas are presented. Osteosarcomas developed in the frontal bone after a latency period of 36 years following operation for brain tumor with post-operative irradiation (48 Gy) in one patient and in the region of the right sacro-iliac joint after ablation of testis for seminoma with post-operative irradiation (60 Gy) in another patient. In the literature, the risk of developing an irradiation-induced sarcoma is considered to be low (0.05-0.2%). Both cases, however, underline the necessity of an exact indication for irradiation to avoid such complications.