Implant brachytherapy: a novel treatment for recurrent orbital rhabdomyosarcoma

Brachytherapy for rhabdomyosarcoma: Survey of international clinical practice and development of guidelines

BACKGROUND AND PURPOSE

The purpose of this study was to address the lack of published data on the use of brachytherapy in pediatric rhabdomyosarcoma by describing current practice as starting point to develop consensus guidelines.

MATERIALS AND METHODS

An international expert panel on the treatment of pediatric rhabdomyosarcoma comprising 24 (pediatric) radiation oncologists, brachytherapists and pediatric surgeons met for a Brachytherapy Workshop hosted by the European paediatric Soft tissue Sarcoma Study Group (EpSSG). The panel's clinical experience, the results of a previously distributed questionnaire, and a review of the literature were presented.

RESULTS

The survey indicated the most common use of brachytherapy to be in combination with tumor resection, followed by brachytherapy as sole local therapy modality. HDR was increasingly deployed in pediatric practice, especially for genitourinary sites. Brachytherapy planning was mostly by 3D imaging based on CT. Recommendations for patient selection, treatment requirements, implant technique, delineation, dose prescription, dose reporting and clinical management were defined.

CONCLUSIONS

Consensus guidelines for the use of brachytherapy in pediatric rhabdomyosarcoma have been developed through multicenter collaboration establishing the basis for future work. These have been adopted for the open EpSSG overarching study for children and adults with Frontline and Relapsed RhabdoMyoSarcoma (FaR-RMS).

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.

Local Resection and Brachytherapy for Primary Orbital Rhabdomyosarcoma: Outcome and Failure Pattern Analysis

PURPOSE

Survival in patients with orbital rhabdomyosarcoma (RMS) is excellent. Therefore, new local treatment modalities, such as brachytherapy, have been developed to minimize adverse events. Since 1990, patients with orbital RMS and a residual tumor after induction chemotherapy were eligible for resection and brachytherapy. Otherwise patients received external beam radiotherapy. In this study, the authors describe the outcome for 20 patients with primary orbital RMS. The aim was to assess risk factors for treatment failure in this single center cohort.

METHODS

In this retrospective cohort study, the authors reviewed imaging studies, surgery reports, histology reports, and radiotherapy plans in a multidisciplinary setting. The authors included 20 consecutive patients with orbital RMS, treated between 1990 and 2007, (median age: 7.4 years, range: 0.7-16.1; median follow up: 11.5 years).

RESULTS

After induction chemotherapy, 12 patients were treated with surgery and brachytherapy, 2 with external beam radiotherapy, and in 5 patients who achieved complete remission, local treatment was withheld. In 1 patient, brachytherapy was incorrectly withheld after delayed surgery. Seven patients relapsed (no local treatment, N = 2; surgery and brachytherapy, N = 2; external beam radiotherapy, N = 2; surgery only, N = 1). The authors found no patient, tumor, or treatment characteristics that predisposed for treatment failure. Ten-year-overall survival and event-free survival were 89% and 65%, respectively.

CONCLUSIONS

Overall survival in this cohort of orbital RMS patients was good, including surgery and brachytherapy as treatment modality for orbital RMS resulted in an effective local treatment approach with fewer adverse events than external beam radiotherapy. The authors could not identify factors predisposing for treatment failure.

Exenteration and Custom Implant Brachytherapy as a Treatment for Recurrent Primary Extraskeletal Orbital Ewing Sarcoma

A 6-year-old boy initially presented to an outside hospital with a right orbital mass with biopsy positive for translocation involving EWS RNA-binding protein 1 gene and imaging consistent with primary extraskeletal Ewing sarcoma (ES). There was no evidence of metastatic disease. Patient underwent gross tumor resection and adjuvant chemotherapy (VAdriaC/IE) followed by postoperative 45-Gy proton beam radiation. After 19 months, a solitary in-field local recurrence occurred, which was unsuccessfully surgically resected. Thereafter, treatment commenced with irinotecan and temozolomide, and the patient presented to the center of the authors. MRI showed locally recurrent disease without evidence of metastatic disease. Right orbital exenteration was performed, and an orbital mold was fashioned to deliver brachytherapy. There were no complications. The patient had no evidence of recurrent disease at 37-month follow up. This is the first report of orbital implant brachytherapy for recurrent primary ES of the orbit, and an additional report of primary extraskeletal ES of the orbit, which is a rare primary orbital tumor.

Orbital rhabdomyosarcomas: A review

Rhabdomyosarcoma (RMS) is a highly malignant tumor and is one of the few life-threatening diseases that present first to the ophthalmologist. It is the most common soft-tissue sarcoma of the head and neck in childhood with 10% of all cases occurring in the orbit. RMS has been reported from birth to the seventh decade, with the majority of cases presenting in early childhood. Survival has changed drastically over the years, from 30% in the 1960's to 90% presently, with the advent of new diagnostic and therapeutic modalities. The purpose of this review is to provide a general overview of primary orbital RMS derived from a literature search of material published over the last 10 years, as well as to present two representative cases of patients that have been managed at our institute.

[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.

Rhabdomyosarcoma: review for the ophthalmologist

Rhabdomyosarcoma is a malignant neoplasm that is composed of cells with histopathologic features of striated muscle in various stages of embryogenesis. It can occur in several sites in the body, including the ocular region. Ocular rhabdomyosarcoma is defined as the occurrence of this tumor in the area of the eye. Most ocular rhabdomyosarcomas arise in the soft tissues of the orbit but they can rarely occur in the other ocular adnexal structures and even within the eye. The purpose of this review is to provide a brief overview of rhabdomyosarcoma and a more detailed review of orbital rhabdomyosarcoma, with emphasis on changing concepts in the diagnosis and management of this ophthalmic neoplasm.

Dosimetry of the I-Plant Model 3500 iodine-125 brachytherapy source

125I brachytherapy sources have been widely used for interstitial implants for a number of years in several tumor sites, especially the prostate. The design of the new I-Plant Model 3500 iodine source is novel, yet its characteristics are similar to those of two existing designs, Model 6711 and the Symmetra. Dosimetry parameters (including dose rate constant, radial dose function, and anisotropy function, as defined by AAPM Task Group 43) were measured with LiF thermoluminescent dosimeters in water-equivalent plastic phantoms. The dose rate constant was found by direct comparison of calibrated I-Plant Model 3500 and Model 6711 seeds in a solid water phantom, to be 1.01 (cGy/h)/U. The radial dose function and anisotropy function are similar to those of the Model 6711 and Symmetra seeds.