Carotid artery rupture following radioiodine therapy for differentiated thyroid carcinoma / Ruptura de carótida pós-iodoterapia em carcinoma diferenciado de tireoide

INTRODUCTION: Radioiodine therapy for patients with differentiated thyroid cancer aims at reducing tumor recurrence by eradicating residual macro- and microscopic foci. Side effects are generally rare, tenuous and transient, with little clinical significance. OBJECTIVE: To report a rare case of differentiated thyroid carcinoma presenting a large expansive solid mass at the base of the skull, with invasion of the left masticatory muscle and adjacent subcutaneous tissue, and without invasion of the carotid space, which evolved to carotid artery rupture following radioiodine therapy. DISCUSSION: Side effects are uncommon after radioiodine therapy and when present, have mild intensity. Serious adverse events are very rare, especially those arising from structures not directly invaded by metastatic tissue with radioiodine uptake, as occurred in this case. This occurrence serves to raise awareness of the need for increased care when using radioiodine therapy on high-avidity masses located close to important structures.

INTRODUÇÃO: Iodoterapia em pacientes com carcinoma diferenciado da tireoide tem o objetivo de reduzir a recorrência tumoral erradicando focos residuais macro e microscópicos. Os efeitos colaterais, em geral, são raros, tênues e transitórios, com pouca repercussão clínica. OBJETIVO: Relatar um caso raro de carcinoma diferenciado da tireoide apresentando grande massa sólida expansiva na base do crânio, com invasão da musculatura mastigatória esquerda e do tecido subcutâneo adjacente, sem invasão do espaço carotídeo que evoluiu com ruptura de carótida pós-iodoterapia. DISCUSSÃO: Os efeitos colaterais pós-iodoterapia são pouco frequentes e, quando presentes, de intensidade discreta. Os eventos adversos graves são muito raros, em especial, aqueles decorrentes de estruturas não invadidas diretamente pelo tecido metastático iodocaptante, como nesse caso, alertando também para a necessidade do aumento dos cuidados na terapia de grandes massas ávidas pelo radioiodo próximas às estruturas nobres.

Preoperative nodal staging of non-small cell lung cancer using 99mTc-sestamibi spect/ct imaging

OBJECTIVES: The proper nodal staging of non-small cell lung cancer is important for choosing the best treatment modality. Although computed tomography remains the first-line imaging test for the primary staging of lung cancer, its limitations for mediastinum nodal staging are well known. The aim of this study is to evaluate the accuracy of hybrid single-photon emission computed tomography and computed tomography using 99mTc-sestamibi in the nodal staging of patients with non-small cell lung cancer and to identify potential candidates for surgical treatment. METHODS: Prospective data were collected for 41 patients from December 2006 to February 2009. The patients underwent chest computed tomography and single-photon emission computed tomography/computed tomography examinations with 99mTc-sestamibi within a 30-day time period before surgery. Single-photon emission computed tomography/computed tomography was considered positive when there was focal uptake of sestamibi in the mediastinum, and computed tomography scan when there was lymph nodes larger than 10 mm in short axis. The results of single-photon emission computed tomography and computed tomography were correlated with pathology findings after surgery. RESULTS: Single-photon emission computed tomography/computed tomography correctly identified six out of 19 cases involving hilar lymph nodes and one out of seven cases involving nodal metastases in the mediastinum. The sensitivity, specificity, positive predictive value, and negative predictive value for 99mTc-sestamibi single-photon emission computed tomography/computed tomography in the hilum assessment were 31.6 percent, 95.5 percent, 85.7 percent, and 61.8 percent, respectively. The same values for the mediastinum were 14.3 percent, 97.1 percent, 50 percent, and 84.6 percent, respectively. For the hilar and mediastinal lymph nodes, chest tomography showed sensitivity values of 47.4 percent and 57.1 percent, specificity values of 95.5 percent and 91.2 percent, positive predictive values of 90 percent and 57.1 percent and negative predictive values of 67.7 percent and 91.2 percent, respectively. CONCLUSION: Single-photon emission computed tomography/computed tomography with 99mTc-sestamibi showed very low sensitivity and accuracy for the nodal staging of patients with non-small cell lung cancer, despite its high level of specificity. In addition, the performance of single-photon emission computed tomography/computed tomography added no relevant information compared to computed tomography that would justify its use in the routine preoperative staging of non-small cell lung carcinoma.