Incidence Of Radiation-induced Complications Research Articles

Late complications after brachytherapy of I-125 uveal melanoma.

Purpose: To assess the late complications after the I-125 brachytherapy of uveal melanoma. Material and methods: 129 patients (71 women – 55%, and 58 men – 45%) treated at the Department of Ophthalmology andOcular Oncology of the University Hospital in Krakow between January 2005 and December 2009 were evaluated. I-125 isotope applicators were used for tumor irradiation. The mean follow-up was 42.5 months. Results: The following complications were observed: radiation cataract, secondary glaucoma, radiation retinopathy, radiation maculopathy, necrosis of sclera, retinal and vitreous hemorrhages and retinal detachment. Post-radiation cataract was the most common late complication (90.5–94.7%). Conclusions: Despite the undoubted effectiveness in the treatment of uveal melanomas, I-125 brachytherapy poses a high risk of complications. Tumor location in the proximity of critical visual structures negatively affected ultimate visual function. Thetumor size and the dose of irradiation significantly affected the incidence of radiation-induced complications.

Late-onset radiation-induced optic neuropathy after radiotherapy for nasopharyngeal carcinoma

Radiation-induced optic neuropathy (RION) is a rare but devastating late complication of radiotherapy, usually manifesting months to years after cancer treatment of the head and neck, resulting in rapidly progressive blindness in one or both eyes. The incidence of radiation-induced complications following radiotherapy, especially RION, is correlated with survival time of patients. Nasopharyngeal carcinoma (NPC), the most common type of cancer in southern China, has been primarily treated with radiotherapy, with associated neural injuries. To our knowledge, there are few reports of RION among patients with NPC who have undergone radiotherapy. To study this further, we reviewed nine patients with NPC and RION after radiotherapy and examined the clinical manifestations of RION, characteristics of the ophthalmologic examination, MRI results and the treatments used. Of the nine patients with RION, the most frequent clinical presentation was a decline of vision with visual field defects in one or both eyes. Ophthalmologic examinations showed flame hemorrhages in the retina, optic nerve atrophy and cotton wool spots. T1-weighted enhanced MRI showed enhancement of the optic nerve and optic chiasm in six patients. Treatment with corticosteroids, anticoagulation and hyperbaric oxygen (HBO) treatment did not reduce visual loss or blindness in patients.

Radiation-Induced Complications in Endovascular Neurosurgery

The incidence of radiation-induced complications is increasingly part of the informed consent process for patients undergoing neuroendovascular procedures. Data guiding these discussions in the era of modern radiation-minimizing equipment is lacking. To quantify the rates of skin and hair effects at a modern high-volume neurovascular center, and to assess the feasibility of accurately quantifying the risk of future central nervous system (CNS) tumor formation. We reviewed a prospectively collected database of endovascular procedures performed at our institution in 2008. The entrance skin dose and brain dose were calculated. Patients receiving skin doses >2 Gy were contacted to inquire about skin and hair changes. We reviewed several recent publications from leading radiation physics bodies to evaluate the feasibility of accurately predicting future cancer risk from neurointerventional procedures. Seven hundred two procedures were included in the study. Of the patients receiving >2 Gy, 39.6% reported subacute skin or hair changes following their procedure, of which 30% were permanent. Increasing skin dose was significantly associated with permanent hair loss. We found substantial methodological difficulties in attempting to model the risk of future CNS tumor formation given the gaps in our current understanding of the brain's susceptibility to low-dose ionizing radiation. Radiation exposures exceeding 2 Gy are common in interventional neuroradiology despite modern radiation-minimizing technology. The incidence of side effects approaches 40%, although the majority is self-limiting. Gaps in current models of brain tumor formation after exposure to radiation preclude accurately quantifying the risk of future CNS tumor formation.

Stereotactic radiosurgery for cavernous malformations: Kjellberg's experience with proton beam therapy in 98 cases at the Harvard Cyclotron.

The lack of treatment options for surgically inaccessible cavernous malformations has made radiosurgery a possible alternative to conservative management. The few previous reports of radiosurgical efficacy have been limited by small numbers, short follow-up, or lack of attention to the full spectrum of end points, including neurological disability. In an attempt to elucidate the risk-to-benefit ratio of radiosurgery for cavernous malformations, we undertook a retrospective analysis of of 95 patients with 98 lesions treated by the late Raymond N. Kjellberg. Patients were followed for an average of 5.4 years (range, 0.3-12.3 yr), and data regarding hemorrhage, seizure, neurological disability, and incidence of radiation-induced complications were gathered. The analysis revealed a drop in annual hemorrhage rates from 17.3% per lesion per year before treatment to 4.5% per lesion per year after a latency period of 2 years. Improvement in seizure control was evident. However, a 16% incidence of permanent neurological deficit and a 3% mortality rate were attributable to radiographically confirmed radiation-induced complications. Neurological disability scores, measured by the modified Rankin disability scale, indicated a significant decline in neurological functioning during the follow-up interval, a result of the combined effects of radiation-related injury, hemorrhage, and clinical progression of the lesion. We conclude that although radiosurgery does seem to reduce hemorrhage, there is potential for complications and continued lesion progression after radiosurgery. These risks and benefits must be carefully balanced against the natural history of untreated lesions if the use of radiosurgery is considered.

Changes in the radiation treatment of cancer of the anus in Glasgow

The survival and complication rate of two groups of patients with carcinoma of anus were compared. The first group of 20 patients were treated between 1974 and 1983 by double plane implantation using radium or equivalent caesium needles and supplementary external beam radiotherapy to groin nodes if present. The second group of 26 patients were treated between 1984 and 1990 by external beam radiotherapy followed by a jig implant using afterloading iridium needles. 5-year survival was superior in the second group (73% vs. 40%) with a lower incidence of radiation-induced complications.

Complications of definitive radiotherapy for carcinoma of the prostate

Treatment morbidity associated with definitive radiotherapy is analyzed in a group of 267 patients treated between 1967 and 1978. Minimum follow-up is 2 years, median is 4 years. The majority (82%) of the patients were treated with 22 MV photon beam to a pelvic dose of approximately 5000 rad followed by a boost to gradually reduced fields to a total of 6500–7000 rad to the prostate. The most frequent complications were urethral stricture (5.2% of the patients), proctitis (4.5%), bladder injuries (3.4%) and leg edema (3.0%). The incidence of radiation-induced complications did not correlate with the total dose, previous transurethral resection or patients' age. Pelvic lymphadenectomy was associated with a 25% incidence of leg and genital edema. Small bowel obstruction developed in 2 of 3 patients who had transperitoneal laparotomy prior to treatment. Symptoms secondary to bladder and rectal injuries were reversible in over 50% of patients within the first year after the onset.

Radiation necrosis after treatment of solitary intracranial metastases.

During the period from July 1977 to June 1980, 75 patients underwent the surgical excision of solitary brain metastases, and 61 of these patients received whole brain radiation. Three patients developed chronic radiation necrosis. In the 3 patients with necrosis, computed tomography suggested recurrent tumor; the histological diagnosis of necrosis only was obtained at operation in 2 of these patients and by autopsy in the third. Radiation damage resulted in the death of 1 patient, a chronic vegetative state in another, and severe neurological deficit in the third. An additional 4 patients had neurological complications probably related to radiation therapy. As the survival of such patients is prolonged by aggressive treatment, the incidence of radiation-induced complications is likely to increase. The optimal dose of radiation necessary to destroy microscopic foci of tumor after the surgical resection of a single brain metastasis is unknown. Because of the significant incidence of damage after radiation as currently delivered, studies using graded, lower doses are indicated.