Superior vena cava syndrome is most often caused by lung carcinoma. Two cases are described in whom venous obstruction in the superior mediastinum was caused by local vascular fibrosis due to radiotherapy five and seven years earlier. The development of radiation injury to greater vessels is discussed, together with the possibilities for treatment of superior vena cava syndrome. (Thorax 2000;55:245-246) Keywords: venous obstruction; radiation fibrosis; superior vena cava syndrome Compression of the superior vena cava (SVC) can lead to oedema of the face and upper extremities, plethora, dizziness, headache, and syncope. Following compression of the SVC, five major venous collateral pathways via the paravertebral, azygos-hemiazygos, internal mammary, lateral thoracic and anterior jugular veins can develop. Each system is elaborately interconnected, providing many possibilities for variations in flow and, as a result, in the severity and presentation of superior vena cava syndrome (SVCS). Prior to the mid 20th century a large percentage of cases of SVCS were caused by non-malignant diseases such as luetic aortic aneurysms, fibrotic mediastinitis, and tuberculosis. Nowadays SVCS is caused by malignancy in about 90% of cases, predominantly lung cancer. We present two cases, one with SVCS and the other with obstruction of the left brachiocephalic vein, both caused by local vascular fibrosis due to radiotherapy.
Case 1The first patient, aged 47 years, had a central squamous cell carcinoma in the right upper lobe, staged pT2N0M0, which required a pneumonectomy. Two years later he developed general malaise and mediastinal metastases were found in the paratracheal lymph nodes adjacent to the SVC. The tumour and mediastinum were irradiated with a total dose of 60 Gy in 30 fractions, 40 Gy to the tumour and mediastinum followed by a boost dose of 20 Gy to the tumour alone. A three field technique was used with 6 MV photon beams. For several years he remained well and no signs of metastases were found. Five years later he developed dyspnoea and dizziness when leaning forward and swelling of his lower eye lids and neck. Distended veins were found on his lower rib cage. A contrast enhanced computed tomographic (CT) scan showed no mediastinal mass, the azygos vein was filled through the SVC, and directly above the right heart chamber an SVC obstruction of about 4 cm was observed. Venography showed extensive collaterals and, in the same traject of the SVC, a local stenosis was observed without evidence of thrombosis (fig 1). No distant metastases were found. Whole body PET scanning of the thorax showed no activity suspicious for malignancy. A wall stent was placed in the SVC and oral anticoagulation was started with acenocoumarol. Nine months later he remains free from symptoms.
Case 2The second patient, aged 36, had radical resection of the right orbita and ethmoid sinus followed by local postoperative radiotherapy because of a carcinoma of the right maxillary sinus. Two years later he developed a cervical lymph node...
