Underdosing of the maxillary sinus for small fields used in newer radiotherapy techniques: Comparison of thermoluminescent dosimeter and Monte Carlo data.

AIMS: To evaluate the underdosing of the maxillary sinus at its distal end produced by air cavity in the path of the 6 MV photon beam. MATERIALS AND METHODS: A cubic solid water slab phantom of dimensions 18 cm × 18 cm × 18 cm with 4 cm × 4 cm × 4 cm air cavity 3 cm away from its anterior surface was used in this study. The percentage depth dose (PDD) for 6 MV X-rays along the central axis of the cubical air cavity was measured using thermoluminescent dosimeter-100 chips. The EGSnrc/DOSXYZnrc Monte Carlo (MC) code was used to estimate the PDD values in both homogeneous and inhomogeneous conditions. The dose data were generated for 1 cm × 1 cm, 2 cm × 2 cm, 3 cm × 3 cm, and 5 cm × 5 cm field sizes. RESULTS: Average percentage dose reductions at 1 mm beyond the distal surface of the maxillary sinus for the field sizes 1 × 1, 2 × 2, and 3 × 3 cm2 are 42.4%, 39.5%, and 29.4%, respectively. However, for 5 cm × 5 cm field size, there is a dose enhancement (i.e., overdosing) at 1 mm from the distal surface of the maxillary sinus and the average percentage dose enhancement is 5.9%. Also, beyond 1 cm from the air-water interface, there is dose enhancement for all the field sizes. CONCLUSION: This study showed that the significant dose reduction occurs near the air-water interface for the treatment techniques using small photon fields such as intensity-modulated radiotherapy or other newer techniques. MC-based treatment planning calculation predicts realistic dose distribution while using small photon fields in the treatment of maxillary sinus.

Maxillary sinus mucoceles and other side effects of external-beam radiation in the pediatric patient: A cautionary tale.

A sinonasal mucocele can develop after the obstruction of a sinus ostium, which can occur secondary to trauma, infection, a neoplasm, or an iatrogenic cause. These mucoceles typically arise in the frontal and ethmoid sinuses. Sinonasal mucoceles are epithelium-lined cysts that can gradually expand to fill a paranasal sinus. They can present with ophthalmologic, rhinologic, and neurologic symptoms. There are reports in the literature of sinonasal mucocele development after radiation for nasopharyngeal carcinoma. However, these cases are rare; when they do occur, they tend to arise in the sphenoid sinus. We describe the case of a 21-year-old man who had undergone external-beam radiotherapy for a right maxillary sinus rhabdomyosarcoma at the age of 4 years and who subsequently developed bilateral maxillary sinus mucoceles and multiple other known complications of radiation therapy. To the best of our knowledge, this is the first case of postirradiation bilateral maxillary sinus mucoceles to be reported in the literature.

Sinus mucosa status in patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy: A 5-year follow-up.

BACKGROUND: Sinus mucosa abnormalities on image studies, which is the major diagnostic measure for sinusitis, were investigated in patients with nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy (IMRT). METHODS: A retrospective review of the MRIs for patients with NPC was conducted. Sinus mucosa abnormalities were staged by the Lund-Mackay system. RESULTS: A total of 94 patients were enrolled in this study. The rate and severity of sinus abnormalities were highest on the third postradiotherapy month (p < .005, t test). There was no significant increase in the incidence of abnormalities on the fifth postradiotherapy year (t test). The anterior ethmoid and maxillary sinuses were the most affected sinuses before and after radiotherapy (p < .005, chi-square test). CONCLUSION: Our data showed that the anterior ethmoid and maxillary sinuses were the most vulnerable sinuses for therapeutic toxicity after IMRT in patients with NPC. In the long run, however, the application of IMRT does not significantly increase the incidence of sinus toxicities.

Efficacy of lead foil for reducing doses in the head and neck: a simulation study using digital intraoral systems.

OBJECTIVES: To assess the efficacy of lead foils in reducing the radiation dose received by different anatomical sites of the head and neck during periapical intraoral examinations performed with digital systems. METHODS: Images were acquired through four different manners: phosphor plate (PSP; VistaScan(®) system; Dürr Dental GmbH, Bissingen, Germany) alone, PSP plus lead foil, complementary metal oxide semiconductor (CMOS; DIGORA(®) Toto, Soredex(®), Tuusula, Finland) alone and CMOS plus lead foil. Radiation dose was measured after a full-mouth periapical series (14 radiographs) using the long-cone paralleling technique. Lithium fluoride (LiF 100) thermoluminescent dosemeters were placed in an anthropomorphic phantom at points corresponding to the tongue, thyroid, crystalline lenses, parotid glands and maxillary sinuses. RESULTS: Dosemeter readings demonstrated the efficacy of the addition of lead foil in the intraoral digital X-ray systems provided in reducing organ doses in the selected structures, approximately 32% in the PSP system and 59% in the CMOS system. CONCLUSIONS: The use of lead foils associated with digital X-ray sensors is an effective alternative for the protection of different anatomical sites of the head and neck during full-mouth periapical series acquisition.

Use of customized-mold brachytherapy in the management of malignancies arising in the maxillary antrum after maxillectomy: a dosimetric analysis.

PURPOSE: To explore the feasibility of a intraoral mold high-dose rate (HDR) brachytherapy in the treatment of tumors arising in the maxillary antrum after maxillectomy and to describe the dosimetric profile of HDR brachytherapy in such an unusual location. METHODS AND MATERIALS: A customized mold with four 6-French catheters was designed and produced in transparent acrylic resin. The catheters formed a soft loop that allowed the passage of the HDR source. CT-based dose evaluation in several volumes of interest, including the gross tumor volume (GTV) and several organs at risk (OARs), such as the skin of the cheek, eyeball, lens, optic nerve, optic chiasm, and spinal cord was performed. RESULTS: Treatments were delivered uneventfully. A favorable OAR/GTV ratio was observed. The GTV D(90) was covered by the 3.8 Gy isodose (95% of the prescription isodose of 4 Gy) and the doses received by the OARs varied between 4% and 43% of the prescription isodose for the V1 cc of spinal cord and eyeball, respectively. The only structure that could not be adequately spared was the skin overlying the tumoral lesion that received between 94% and 107% of the prescription isodose (1.0 and 0.5 cm(2) of skin, respectively). CONCLUSIONS: Intraoral mold-based HDR brachytherapy can be used to treat tumors involving the maxillary antrum provided that access is possible through a previous maxillectomy. A dose reduction of 4-43% in several OARs, such as the spinal cord, pituitary gland, optic chiasm, optic nerve, eyeball, and lens, is obtained.

Use of precontoured positioning plates and pericranial flaps in midfacial reconstruction to optimize aesthetic and functional outcomes.

OBJECTIVES: To present our experience with reconstruction of midfacial defects using "precontoured positioning plates" with or without pericranial flaps and to describe our technique in detail. METHODS: Thirty-two consecutive patients with midfacial defects subsequent to oncologic resection that were reconstructed primarily with cranial bone grafts and precontoured positioning plates were reviewed for type of defect, functional outcome, complications, and postoperative appearance. RESULTS: Primary reconstruction of all defects in this series was performed. Defects involved the orbital rim, orbital floor, or both in 28 patients (88%), the body of the zygoma in 24 patients (75%), and extended to the skull base in 16 patients (50%). Pericranial flaps were used to cover the bone grafts in 22 patients (69%). Postoperative radiotherapy was performed in 22 patients (69%), preoperative radiotherapy in 5 (16%), and the other 5 (16%) had no radiotherapy. There were no intraoperative complications, and postoperative complications included plate exposure (n = 2), ectropion (n = 3), and partial bone graft loss or resorption subsequent to completion of radiotherapy (n = 2). Postoperatively, appearance was excellent in 24 patients, fair in 6 patients, and poor in 2 patients. Secondary reconstructive procedures were performed in 4 patients (12%). Follow-up ranged from 12 months to 6 years (median, 4.2 years). CONCLUSIONS: Precontoured positioning plates with or without pericranial flaps enable precise reconstruction of midfacial defects with precise incorporation of cranial bone grafts. In our series we routinely covered the bone grafts with well-vascularized tissues, leading to a low incidence of complications and excellent aesthetic results.

[Trans-facial distraction of the facial skull at the LeFort III level]. / Transfaziale Distraktion des Gesichtsschädels in der LeFort-III-Ebene.

BACKGROUND: Several craniofacial deformities and syndromes feature hypoplasia of the midface skeleton. Until now different treatment options were based primarily on a modified LeFort III osteotomy: (1) the conventional LeFort III osteotomy with bone transplantation and intraoperative osteosynthesis, (2) distraction using subcutaneous distraction devices fixed on both sides at the os zygomaticum, and (3) bone distraction using a rigid external distraction device (RED distractor), which is fixed to the skull and pulling at the maxilla or the upper teeth. METHODS AND RESULTS: A modification of the distraction technique using the RED distraction device is presented. The tensile forces are applied to the ramus infraorbitalis or the apertura piriformis, and the tensile wires penetrate through the skin laterally to the nose. By using this new approach near the center of rotation or the center of resistance, optimal control of the vector of distraction is guaranteed. With sufficient distraction of the midface, overcorrection of the os zygomaticum can be avoided. Clinical data of seven patients are presented. DISCUSSION: Due to the good clinical results, external transfacial distraction with tensile forces pulling at the apertura piriformis seems to improve the treatment of these complex facial deformities.

[Lymph node metastases in paranasal sinus carcinoma: prognostic value and treatment]. / Metastasi linfonodali nei carcinomi dei seni paranasali: valore prognostico e trattamento.

The purpose of this report is to assess, on the basis of a sizeable study, the prognostic value of lymph node metastases in paranasal sinus carcinoma and, in particular, in squamous cell carcinoma of the maxillary sinus. We have reviewed the charts of 601 cases of paranasal sinus carcinoma between 1970 and 1999. All of the patients were treated surgically, alone or associated with chemotherapy and/or radiotherapy. The maxillary sinus tumors numbered 379 (153 squamous cell carcinomas, 15 undifferentiated carcinomas, 94 adenoid cystic carcinomas, 19 adenocarcinomas, 98 mesenchymal tumors and rare forms) and the ethmoidal tumors were 222 (117 adenocarcinomas, 27 squamous cell carcinomas, 16 adenoid cystic carcinomas, 13 undifferentiated carcinomas, 49 other histological forms). Lymph node metastases in ethmoidal tumors were rare, with the exception of undifferentiated carcinoma (46.1%). The percentages of metastatic squamous cell carcinoma of the maxillary sinus upon presentation were: T2 15.5%, T3 7%, and T4 4%. All these patients underwent lymph node excision. The metastases successive to treatment of the primary tumor were: T2 16.9%, T3 8.8%, and T4 12%. 75% of these late metastases occurred contemporaneously with a recurrence of T and only 5 (25%) constituted the single reawakening of disease; four of these patients underwent neck surgery and were cured operatively. One had fixed, inoperable metastases. The NED survival rate at least two years after T therapy in patients free from metastases was 50.4%, against 25% in those with initial or distant metastases (T2 72.9% vs. 30.4%, T3 37.5% vs. 22.2%, and T4 28.6% vs. 0%). In conclusion, squamous cell carcinomas of the maxillary sinus which have extended to the oral cavity (T2) show greater lymph node propagation than those of the superoposterior portion (T3-T4). The presence or successive appearance of lymph node metastases indicates elevated malignancy of the tumor, with a very negative prognosis. N, however, is rarely the cause of death for these patients. Prophylactic lymph node excision in N0 patients is therefore not indicated.

Effects of radiotherapy for nasopharyngeal carcinoma on the paranasal sinuses: study based on computed tomography scanning.

OBJECTIVE: The purpose of this study was to determine if radiotherapy for nasopharyngeal carcinoma causes mucosal disease of the paranasal sinuses. DESIGN: This study was a retrospective study. SETTING: This study was conducted at a tertiary care centre. METHOD: A series of 69 newly diagnosed patients, without pre-existing sinus disease, who were treated with high-dose radiotherapy participated. MAIN OUTCOME MEASURES: The prevalence, severity, and time course of mucosal abnormalities were analyzed, as judged by consecutive computed tomographies (CTs). RESULTS: The CT study revealed that 58.8% of the postirradiation scans had mucosal disease of the sinuses. The maxillary sinus had the highest prevalence (42.3%) without statistical significance (p = .10). The difference by McNemar test for two follow-up scans was not significant (p = .48) and by Kappa test was significant (p = .04). The relationship between the prevalence and the time course post radiotherapy revealed that it remained a high prevalence until after the 4-year follow-up scans. CONCLUSIONS: The results of this study confirm that chronic sinus disease is a common late complication of radiotherapy and it persists for years. Thus, aggressive treatment is indicated.

Radiation-induced malignant fibrous histiocytoma in patients with nasopharyngeal carcinoma.

OBJECTIVE: To evaluate the prevalence, 15-year cumulative incidence, time interval, and prognosis of radiation-induced malignant fibrous histiocytoma of the head and neck in long-term survivors of nasopharyngeal carcinoma. DESIGN: Cohort. SETTING: Tertiary care hospital. PATIENTS: Eight long-term survivors of nasopharyngeal carcinoma with malignant fibrous histiocytoma in the maxillary sinus or nasal cavity. MAIN OUTCOME MEASUREMENT: Survival of postirradiation malignant fibrous histiocytoma in patients with nasopharyngeal carcinoma. RESULTS: The prevalence of radiation-induced malignant fibrous histiocytoma in long-term survivors of nasopharyngeal carcinoma was 0.38%. The 15-year cumulative incidence was 2.2%. Most tumors occurred in the maxillary sinus and were characterized by spindle-shaped tumor cells with plump nuclei arranged in a whorl or storiform pattern in a fibrous stroma. The mean interval between malignant fibrous histiocytoma and nasopharyngeal carcinoma was 121 months. Local recurrence developed in all cases within 9 months after surgery. Six patients died of disease without distant metastasis within 30 months. Two patients were alive with disease for 20 and 32 months, respectively. CONCLUSIONS: Radiation-induced malignant fibrous histiocytoma in the head and neck region in long-term survivors of nasopharyngeal carcinoma is rare. It takes a long time to occur after irradiation and is locally invasive with poor prognosis.

[Primary extramedullary plasmacytomas of the upper respiratory tract. A study of four cases with infrequent localization]. / Plasmocitomas primarios de vías aerodigestivas altas. A propósito de cuatro casos.

OBJECTIVE: Assessment of the incidence, diagnosis and treatment of three patients afflicted of extramedullary plasmacytoma located in the Waldeyer's ring, and one case afflicted of maxillary sinus disease. PATIENTS: The localization of the masses was the palatine amygdala in two cases, and the rhinopharynx and maxillary sinus in the remaining two patients. Major symptoms were dysphagia respiratory failure with closed rhinolalia, and headache. Diagnosis was made by histological study of biopsied tissue. In every case, general illness or other site of localization were ruled out. RESULTS: In our casuistic, the incidence of primary extramedullary plasmacytoma in Waldeyer's ring is 1.2%. The patient's age were 45, 50, 62, and 73 years respectively, and the male/female ratio was 1. In those cases located in the tonsils, a bilateral tonsillectomy was performed. In the case located at the maxillary sinus, a sinus trepanation was performed according the Caldwell-Luc's technique, followed by local radiotherapy at doses of 40 Gy. In the case located at the rhinopharynx, radiotherapy was the only choice. These three different therapeutical procedures led to the disappearance of the disease, and, after a 12 to 53 month-period, patients remain asymptomatic. A patient died due to other causes not related to the illness.

[Ultrahigh-frequency radiometry and endoscopy in the diagnosis of maxillary diseases]. / SVCh-radiometriia i éndoskopiia v diagnostike zabolevanii verkhnecheliustnykh pazukh.

The potential of SHF-radiometry was investigated in the diagnosis of maxillary inflammation. Altogether 90 patients and 30 controls underwent routine infrared thermography and SHF-radiometry. Normal thermal distribution in the maxillary sinuses was featured by its picture in normal subjects. SHF-radiometry proved more informative in bilateral localization of the inflammation foci, in sluggish processes in the maxillary sinuses, allowed more significant follow-up of the thermogenic activity of the maxillary deep tissues. SHF-radiometry findings were verified at maxillary endoscopy. The results correlated in 77.9% of the cases. The method can be introduced to make early diagnosis of maxillary inflammation, in mass health check-ups.

Wound healing in the nose and paranasal sinuses after irradiation with the argon laser. An experimental study in animals.

The wound healing of the mucous membrane of the nose was investigated in rabbits after irradiation with the argon laser. Immediately after application of the laser, a typical lesion showed a zonal appearance. Wound healing began after a delay of 6 days with the formation of granulation tissue. Re-epithelialization began from the margins of the wound and was characterized initially by metaplastic epithelium or squamous epithelium that was subsequently replaced by respiratory epithelium. In the subepithelial tissue plane, particularly following irradiation of the concha, a wider layer of connective tissue developed. The hyaline cartilage of the septum became necrotic over a large area which extended beyond the irradiated area, while the bone of the concha and the wall of the maxillary sinus was destroyed only at the site of the direct laser treatment.

Postirradiation optic neuropathy in antral carcinoma.

A case is described of a patient who developed radiation-induced optic neuropathy 18 months following cobalt-60 irradiation for carcinoma of the left maxillary antrum and ethmoid sinus. This case is unusual because of the early onset of the optic nerve damage following radiation therapy and the ultimate emergence of the eye involved by tumor compression as the better eye in terms of visual acuity.

Comparison of pre- and postoperative radiation in the combined treatment of carcinoma of maxillary sinus.

A series of 50 patients with cancer of the maxillary sinus treated by either preoperative or postoperative radiation from February, 1958 to June, 1974 is presented. In the postoperative group the patients were either free from recurrence, of if there was recurrence, the tumor was less than 0.5 cm in diameter. In the preoperative group, 23 of 36 patients survived for more than five years (64%). In the postoperative group, 4 of 14 patients survived for more than five years (26%). There is an obvious superiority in the preoperative radiation group. The surgical complication rate in the preoperative group was 29% as compared to 14% in the postoperative group. Although the incidence of complications in the preoperative group is higher, we believe it is worth attempting in clinical practice because of the more favourable survival rates.