An afterloading brachytherapy device utilizing thermoplastic material

Iodine-125 interstitial brachytherapy for malignant lacrimal sac tumours: an innovative technique

OBJECTIVES

Primary malignant tumours of the lacrimal sac are rare, surgery and radiotherapy may induce substantial side effects for patients. Here, this article reports an innovative technique of interstitial brachytherapy developed for the treatment of malignant lacrimal sac tumours.

PATIENTS AND METHODS

Four patients (male 3, female 1), with an average age of 52.7 years (range 41-72 years), were individually diagnosed with squamous cell carcinoma, adenocarcinoma, adenoid cystic carcinoma and lymphoma. All patients received Iodine-125 interstitial brachytherapy after surgical resection for malignant lacrimal sac tumours. Visual function examination (vision, intraocular tension, fundus photography, fluorescein angiography, and optical coherence tomography) and CT/MRI/PET-MRI were performed to look for signs of recurrent tumours or metastasis.

RESULTS

Four patients were followed for an average of 28 months (range, 23-37 months). All patients were free from local disease. Their visual function was normal, and CT/MRI did not reveal any tumour recurrence.

CONCLUSIONS

Iodine-125 interstitial brachytherapy can be used as an alternative to wide excision or exenteration of these tumours. There was good local control, reasonable maintenance of vision, and good cosmesis.

[Brachytherapy in combination with function-preserving surgery. An interdisciplinary challenge]

A multimodal, interdisciplinary approach known as intensity-modified brachytherapy is a promising alternative for patients with advanced head and neck cancer infiltrating the orbita and skull base. An 87-year-old man presented with a recurrence of squamous cell carcinoma of the medial corner of the left eye that had been locally resected and irradiated by external beam radiotherapy multiple times. The cancer was resected with preservation of the eye with close margins, implantation of afterloading catheters, and reconstruction of the defect with a median forehead flap. The patient was irradiated with a total radiation dose of 30 Gy IMBT. After 1 year, there was no evidence of locoregional recurrence. The background of this therapeutic process and analysis of the current literature regarding this interdisciplinary treatment of head and neck cancer infiltrating the orbita and skull base are discussed based on this case report.

Plaque radiotherapy for selected orbital malignancies: preliminary observations: the 2002 Montgomery Lecture, part 2

PURPOSE

To describe the principles and preliminary results of plaque brachytherapy for selected orbital malignancies.

METHODS

A custom-designed Iodine-125 plaque, designed to deliver a target dose of 50 Gray, was placed surgically in the region from which an orbital malignancy was partially resected. The mean dose to the target area was 50 Gray. The initial and follow-up patient data were reviewed.

RESULTS

Of the 8 patients, the diagnosis was adenoid cystic carcinoma of the lacrimal gland (4 cases), orbital invasion by basal cell carcinoma (2), orbital extension of conjunctival melanoma (1), and metastatic carcinoma (1). Of the 4 with adenoid cystic carcinoma, there was microscopic residual tumor after excision and orbital exenteration was considered. Three have tumor control with follow-up of 1, 3, and 6 years. One patient required exenteration for recurrence separate from the field of brachytherapy and is free of tumor after 10 years. All 4 patients are alive and well with tumor control. Of the 2 patients with orbital extension of basal cell carcinoma, tumor control without recurrence has been achieved in both after 2 years. The patient with orbital metastasis responded to plaque radiotherapy, with no orbital recurrence, but died of systemic metastasis. The patient with orbital melanoma had local orbital recurrence separate from the area of irradiation and is currently being treated for systemic metastasis.

CONCLUSIONS

Based on preliminary observations, plaque radiotherapy appears to be a reasonable alternative to exenteration and external irradiation for selected orbital malignancies.

A new method for the placement of brachytherapy probes in paranasal sinus and nasopharynx neoplasms

PURPOSE

In afterloading therapy, the exact placement of the applicator is crucial for the result of radiotherapy. A deviation of few millimeters from the target leads to a significant reduction of radiation energy to the tumor.

METHODS AND MATERIALS

We present a new method using a computer-assisted device for three-dimensional placing of afterloading probes based on CT scans that allows for the exact placement.

RESULTS

Target points have been reached with an accuracy of 0.6 mm. Since 1991 we have used this technique for 24 clinical applications in 11 patients with recurrent neoplasms in the region of the paranasal sinuses and nasopharynx for palliative treatment.

CONCLUSIONS

The presented method is a reliable and precise procedure for the positioning of afterloading probes, avoiding the inaccuracy of the traditional methods.

A noninvasive thermoplastic head immobilization system. Technical note

The authors have developed a noninvasive head immobilization system for use in neuroimaging (magnetic resonance imaging, computerized tomography, single photon emission computerized tomography, and projection angiography), neurosurgical planning, and neurosurgery. These diagnostic and surgical procedures require patient immobilization, reproducible patient positioning, and anatomical localization. The thermoplastic system described in this technical note addresses each of these requirements with a high degree of accuracy and with no bone fixation. The reproducibility of positioning and effectiveness of immobilization were evaluated using nine healthy volunteers during repeated sessions of magnetic resonance imaging. The mean axial displacement for repeated positioning was 0.6 mm (variance 0.1 mm); the mean displacement during robust patient motion in the axial direction was 1.8 mm (variance 0.9 mm).