Microwave thermoradiotherapy for uveal melanoma: results of a 10-year study.
OBJECTIVE
The purpose of the study is to evaluate clinically the use of microwave-heating (hyperthermia) as an adjuvant to ophthalmic plaque irradiation for treatment of patients with uveal melanoma. Hyperthermia was also used as a radiation sensitizer, allowing for significant dose reductions during ophthalmic plaque radiation therapy.


METHODS
In this case series, 48 patients were treated with microwave plaque thermotherapy for uveal melanoma.


METHODS
Microwave treatment, which involved affixing a miniature microwave dish antenna on the sclera beneath the tumor after completion of plaque brachytherapy, was performed. During hyperthermia treatment, the tumor's apex was targeted to receive a minimum of 42 degrees C for a 45-minute duration. A subset of 38 (79%) were given reduced apical doses of ophthalmic plaque radiation (radioactive isotope of iodine [125I] or palladium-103 [103Pd]) to an average of 52.6 Gy.


METHODS
Patients were evaluated for visual function, microwave toxicity, radiation oculopathy, eye retention, local tumor control, and metastatic disease.


RESULTS
Patients have been observed for up to 10 years and for an average of 60 months (5 years). To date, there have been 3 cases of postoperative tumor enlargement (growth) for a 93.8% local control rate. Two patients were lost to follow-up. Seven eyes have been enucleated: three due to neovascular glaucoma, one due to uveitic neovascular glaucoma, and three due to progressive tumor enlargement. Although 15 patients have died, only 4 deaths were because of metastatic choroidal melanoma. Of the original 48 patients, 33 (69%) have maintained within 2 lines or have better than their preoperative visual acuity. Side effects attributable to heating have included decreased intraocular pressure without hypotony as well as chorioretinal scar formation within and around the targeted zone.


CONCLUSIONS
The results of this series suggest that adjuvant microwave thermotherapy can be used with reduced doses of ophthalmic plaque radiation therapy to control the growth of uveal melanomas. Although the incidence of neovascular glaucoma, enucleation, and tumor regrowth is comparable to that of other series evaluating radiation alone, the visual acuities of microwave plaque thermotherapy-treated eyes were found to be superior.
Finger
P T
PT
The Department of Ophthalmology and Radiology, North Shore University Health System, New York, New York, USA.
D001831:Body Temperature; D001918:Brachytherapy; D002830:Choroid Neoplasms / Q000473:pathology / Q000628:therapy*; D003131:Combined Modality Therapy; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006801:Humans; D006979:Hyperthermia, Induced; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008545:Melanoma / Q000473:pathology / Q000628:therapy*; D008872:Microwaves; D010165:Palladium / Q000627:therapeutic use; D011838:Radiation-Sensitizing Agents; D011868:Radioisotopes / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D016896:Treatment Outcome; D014792:Visual Acuity
D007457:Iodine Radioisotopes; D011838:Radiation-Sensitizing Agents; D011868:Radioisotopes; D010165:Palladium