SUPERIOR VENA CAVA SYNDROME& MALIGNANT SPINAL CORD COMPRESSION By: Eman Mahmoud Abd El-Ghaffar Shoaib M.B.B.CH. Resident of Clinical Oncology & Nuclear medicine, Faculty of Medicine, Mansoura University

objectives  Anatomy and physiology of SVC.  Etiology.  Clinical presentation.  Investigations.  Management of SVC syndrome.

Anatomy and Physiology  The superior vena cava is formed by the union of the right and left brachiocephalic veins.  It is located in the middle mediastinum, to the right of the aorta and anterior to the trachea.  The superior vena cava carries blood from the head, arms, and upper half of the body to the heart; it carries approximately one third of the venous return to the heart.

When the superior vena cava is obstructed, blood flows through a collateral vascular network to the lower body and the inferior vena cava or the azygos vein.

The superior vena cava is vulnerable to obstruction due to the following factors :  its strategic location in the visceral compartment of the mediastinum, surrounded by rigid structures (such as the sternum, trachea, right mainstem bronchus, aorta and right pulmonary artery).  its thin, easily compressed walls.  the transport of blood at low pressures; and completely circumscribed by the mediastinal (subcarinal, perihilar and paratracheal) lymph nodes.

Superior vena cava syndrome  Superior vena cava syndrome (SVCS) results from obstruction of SVC and is a common occurrence in cancer patients and can lead to life-threatening complications such as cerebral or laryngeal edema

Etiology  Malignant causes - Primary intrathoracic malignancies -Metastatic disease  Nonmalignant causes

Malignant causes  Primary intrathoracic malignancies  Cause of 87%-97%.  The most frequent malignancy associated with the syndrome is lung cancer, followed by lymphomas and solid tumors that metastasize to the mediastinum.  Lung cancer ….SVCS develops in approximately 3%-15% of patients with bronchogenic carcinoma, and it is four times more likely to occur in patients with right- vs left-sided lesions.

Metastatic disease  Breast and testicular cancers are the most common metastatic malignancies causing SVCS, accounting for > 7% of cases.  Metastatic disease to the thorax is responsible for SVCS in ~3%-20% of patients.

Nonmalignant causes  Thrombosis The most common nonmalignant cause of SVCS in cancer patients is thrombosis secondary to venous access devices.  cystic hygroma.  substernal thyroid goiter.  benign teratoma, dermoid cyst.  thymoma, tuberculosis, actinomycosis.  Syphilis.  pyogenic infections.  silicosis, and sarcoidosis.

Symptoms Dyspnoea Neck and facial swelling Head fullness / headache Trunk and arm swelling Cough Dysphagia

Signs Thoracic vein distension 65% Neck vein distension 55% Tachypnoea. Plethora 15% Facial / conjunctival oedema 55% Central / peripheral cyanosis 15% Arm oedema 10% Vocal cord paresis &Horner’s syndrome 3%

Neck vein distension

Investigations Assess for hypoxia CXR …… bulky mediastinal shadow, pleural/pericardial effusion CT chest …. assess level of obstruction differentiate between thrombosis and tumour differentiate between compression and infiltration Venous angiogram Blood tests ….blood gases FBC, U&E, LFT. Clotting screen. Serum calcium. Uric acid. tumour markers…… Beta HCG, AFP, LDH, CEA, CA15-3.

a chest x-ray of a patient with small cell lung cancer and superior vena cava syndrome. (b) Contrast-enhanced CT scan in the same

CT chest

Pathology  it is necessary to have histological confirmation before starting treatment.  CT guided core biopsy: % positive histology Mediastinal biopsy: % positive histology Bronchoscopic biopsy: 60% positive histology  Sputum cytology: 40% positive histology

Management  Management of the superior vena cava syndrome associated with malignant conditions involves both treatment of the cancer and relief of the symptoms of obstruction  The median life expectancy among patients with obstruction of the superior vena cava is approximately 6 months; but estimates vary widely according to the underlying malignant condition.

Management  Supportive Care and Medical Management  Radiotherapy  Chemotherapy  Surgery  Placement of an Intravascular Stent

Supportive Care and Medical Management  Dexamethasone 16 mg pO or 8mg b.d PO If unable to tolerate oral medication prescribe Dexamethasone 16mg IV /24 hours.  Analgesics as required but avoid oversedation.  If thrombosis is found, thrombolysis and anticoagulation may be indicated

Radiotherapy  Its use requires a tissue diagnosis.  The majority of the tumor types causing the superior vena cava syndrome are sensitive to radiotherapy.  complete relief of the symptoms occcur in 78% of patients with small-cell lung cancer and 63% of those with non–small-cell lung cancer at 2 weeks after ttt with radiotherapy.  Improvement is often apparent within 72 hours.

Technique of RT 3D Conformal RT GTV…..defined on CT scan as mediastinal mass and site of SVCO. PTV….+1-2cm SM. 2D RT fied size 12x12cm &upper border is SSN By anterior&posterior beams.

dose of radiotherapy  2000 cGy /5ttt or 3000cGy/10ttt.  For chemosenstive tumers single fraction 4Gy with chemotherapy give immediate palliation.  depend on…… the histological nature of the tumor, whether the radiotherapy was or was not combined with chemotherapy and whether the therapeutic objective was palliative or curative.

Systemic Chemotherapy  Complete relief of symptoms of vena caval obstruction is achieved with chemotherapy in approximately 80% of patients with non- Hodgkin’s lymphoma or small-cell lung cancer and in 40% of those with non–small-cell lung cancer

Placement of an Intravascular Stent  Percutaneous placement of an intravascular stent can be done before a tissue diagnosis is available, it is a useful procedure for patients with severe symptoms such as respiratory distress that require urgent intervention.  Stent placement strongly considered for patients with mesothelioma, which tends not to respond well to chemotherapy or radiation, and may also be particularly useful when obstruction of the superior vena cava is caused by a thrombus associated with an indwelling catheter

 cyanosis is usually relieved within hours, and edema resolves within 48 to 72 hours in most series (response rate, 75 to 100%).  Complications …… infection, pulmonary embolus, stent migration, hematoma at the insertion site, bleeding, and, very rarely, perforation. Late complications include bleeding and death

Surgery  Surgical bypass grafting is infrequently used to treat the superior vena cava syndrome.  The more common approach is sternotomy or thoracotomy with extensive resection and reconstruction of the superior vena cava  Thymomas …………….are relatively resistant to chemotherapy and radiation than lymphomas, so surgery is appropriate when the superior vena cava syndrome is caused by thymoma.

Malignant spinal cord compression (MSCC)

 Spine is the most common site of osseous metastases. It is involved in up to 40% of all cancer.  The most common causes ….. breast cancer (29%) lung cancer (17%), lymphoma, myeloma, prostate cancer and sarcoma.  Thoracic spine is affected in more than 70% of cases, followed by lumbosacral in 20% and cervical in 10% of cases

Pathphysiology  Almost all MSCC (98%) are caused by an epidural compression by one of the following mechanisms 1. Vertebral bone metastasis grows into the epidural space and compresses the spinal cord. 2. Para spinal mass grows through the neural foramina. 3. Metastasis in the vertebral body causes its collapse and bone fragments are displaced in the epidural space. venous plexus compression, which leads to oedema of the spinal cord which cause increased pressure to the small arterioles which results in diminished blood flow causing ischemia of the white matter and, if this continues long enough, cord damage.

Symptoms and signs  pain ….. initial symptom in 96% of patients. present weeks or even months before the development of the true MSCC. Pain is located at the level of compression and can be present with or without the radicular component. Backache worsened by movement, vertebral compression, valsalva manoveure (the percussion of vertebral bodies). pain from MSCC can not be relieved by rest; actually with lying down it worsens.

Symptoms and signs  Neurologic impairment… develops in 80% of patients. It usually involves the lower limbs (thoracic spine involvement) and causes motor weakness. Weakness can progress to paresis or to paraplegia. Impairment Sensory disturbances are present in 50% of the patients. Sympathetic involvement with loss of bowel and bladder function (incontinence, impotence and or retence) appears very late in the course of the disease with the exception of conus medullaris involvement

Diagnosis  MRI with or with out contrast …is the best diagnostic modality is magnetic resonance. Provide information on the three dimensional extension of the tumour and is an essential tool for planning the treatment.  plain radiographs and bone scans have some importance in diagnosis of MSCC.  CT done in patients who have contraindications for MRI.

MRI

Treatment  Medical ttt.  Surgery.  Radiotherpy.  Others… Combined surgery and radiotherapy Stereotactic Radiotherapy

Treatment  Medical ttt …. Unless contraindicated (including a significant suspicion of lymphoma) offer all patients with MSCC a loading dose of at least 16 mg of dexamethasone as soon as possible after assessment, followed by a short course of 16 mg dexamethasone daily while treatment is being planned.MSCCdexamethasone  Continue dexamethasone 16 mg daily in patients awaiting surgery or radiotherapy for MSCC. After surgery or the start of radiotherapy the dose should be reduced gradually over 5–7 days and stopped. If neurological function deteriorates at any time the dose should be increased temporarily.dexamethasoneradiotherapyMSCC  Patients on steroids should be monitored carefully for hyperglycemia, hypertension and electrolyte disorders.  All patients should receive H2 blockers for gastric protection. Steroids must be tapered gradually.

Surgery(decompression) The only method for immediate relief of MSCC. Indications: - Bony fragment causing SCC, spinal instability, single level disese with good bone stock above and below, when need tissue diagnosis, progression during or after RT, prior RT. Vascular tumors—including renal cell carcinoma, thyroid carcinoma and hepatocellular carcinoma—that are approached surgically may be considered for preoperative embolization to diminish intraoperative blood loss.

Radiotherapy Indications: -multiple levels of bony mets, poor performance status, contraindications of surgery, radiosestive tumers, limited life expectancy<3month. Target: GTV…vertebral or soft tissue mass seen on CT or MRI. CTV…spinal canal +width of the vertebra + One vertebra above and one below if planning based on MRI or,two above and two below if based on CT planning. Depth ….5cm in cervical,7 cm on thoracic.7-8cm on lumbar vertebrae. Field arrangement… direct field on dorsal,two paralel opposing fiels on CX and lumbar vertebrae.

Dose of Radiotherapy  2000 cGy /5ttt or 3000cGy/10ttt.  Single fraction(8 Gy).  Studies showed no difference between single fraction RT(8GY/1ttt) and usual fractionation(2000cGy or 3000cGy) in…..  releif of back pain, restoring ambulatiom, bladder function and incidence of field recurrence SCC).  Recommendation…to use single fraction RT in patients with MSSC with short life expectancy(less than 3 month)or in management of pain in patients with established paraplegia for more than 24 hours.

others  Combined surgery and radiotherapy….. RT start 2-3 ws after surgery till healing of the tissue.  Stereotactic Radiotherapy……. In patients who received prior radiotherapy. In patients received 800cGy or 2000cGy, dose can be continued to 2000cGY/8ttt with out harm the spinal cord.