Radiation-Induced Major Vascular Occlusion in a Patient Cured of Widespread Metastases of Nasopharyngeal Origin

Abstract

Acurable course of ionized radiation causes immediate and late results upon treated tissue (1, 2, 5, 6, 11) but rarely affects the vascular tree (9, 13). The reported case describes an unusual immediate response to radiation resulting in a fourteen-year cure from metastatic cancer and late complication from irradiation occlusion of large vessels. Case Report A 32-year-old man entered St. Vincent's Medical Center of Richmond for treatment of ischemia of the right leg of six months duration. Past history revealed that when the patient was sixteen years old, a nasopharyngeal squamous-cell carcinoma was discovered and was complicated by left-sided deafness, enlarged cervical masses, left sixth and fourth nerve palsies, and sphenoid bone erosion. Left radical neck dissection was performed, followed by betatron therapy through 7.5 × 12.5-cm opposing portals with a TSD of 100 cm through a cast to a definitive dose level of 6,500 R given in five weeks with partial exclusion of cervical cord. During the next two years, the patient received full therapeutic doses of conventional x-ray therapy to numerous metastatic destructive lesions involving the right hip, right humerus, right orbit, lumbosacral spine, and ribs. The present pertinent clinical findings after the patient had been “free from cancer” for the last fourteen years are limited to the right lower extremity. An area of telangiectasia and atrophy involved the skin of the right groin in the region of the previously irradiated femoral canal (Fig. 1). The right femoral pulse was hardly palpable, and a bruit was audible. No other arterial pulsation was present in the right leg while pulses remained normal in the left leg. Angiography revealed complete occlusion of the left superficial femoral artery just distal to the deep femoral artery with a patent popliteal segment (Fig. 2). A right iliopopliteal bypass graft utilizing the saphenous vein was inserted with good initial results lasting about two months but associated with edema of the entire affected limb. Eventually, following recurrent thrombosis of the graft and the right external iliac artery with secondary infection, an above-knee amputation was performed with uneventful recovery. The micropathology of the tissue around the occluded superficial femoral artery was reported as follows (Fig. 3): (a) dense bands of hyalinized connective tissue interspersed with areas of fat (scar tissue), (b) scar tissue with arterioles showing increased thickness of their walls by hyalinized material, and (c) thrombus with organization and phlebosclerosis. Discussion The long survival and apparent cure by radiation therapy of a nasopharyngeal carcinoma in an adolescent, complicated by multiple metastatic deposits, is very rare (3). At the same time, extensive fibrosis of the superficial femoral artery following irradiation, as judged from the angiographic and pathological studies, is also a highly unusual finding.