Valor de la gammagrafía con Tc-99m-tetrofosmín en el diagnóstico del cáncer bien diferenciado de tiroides / Value of (99m)Tc tetrofosmin scan in well-differentiated thyroid cancer

Introducción: Los pacientes con nódulos tiroideos hipocaptantes sin sospecha ultrasonográfica y con citología benigna o indeterminada pueden ser vigilados. El gammagrama con Tc- 99m-tetrofosmín (Tc-99m-TS) identifica pacientes en los que la vigilancia es más segura. La ausencia de captación nunca ocurre en pacientes con carcinoma. El objetivo de este estudio fue conocer el valor predictivo negativo del Tc-99m-TS en pacientes con nódulo tiroideo. Material y métodos: Evaluación preoperatoria con Tc-99m-TS de pacientes con nódulo tiroideo candidatos a cirugía. Tiroidectomía de acuerdo con el diagnóstico en todos. Evaluación de valor predictivo negativo y sensibilidad al comparar con el resultado histopatológico. Se administraron 296-370 MBq (8-10 mCi) de Tc-99m-TS; evaluación de imágenes a los 120 minutos. Resultado reportado con actividad metabólica aumentada (AMA) o sin actividad metabólica aumentada (SAMA). Resultados: Se incluyeron 86 pacientes consecutivos. Sesenta (69.7 %) tuvieron AMA, 20/60 con carcinoma (33 %), en 67 % el diagnóstico fue de nódulo benigno. En 26 (30.2 %) SAMA, 11.5 % tuvo carcinoma y 88.4 % neoplasia benigna. Sensibilidad de 91.43 % (IC 95 % = 80.73-100 %), especificidad de 45.10 % (IC 95 % = 30.46-59.73), valor predictivo positivo de 53.33 % (IC 95 % = 39.8-66.79), valor predictivo negativo de 88.46 % (IC 95 % = 74.26-100). Razón de verosimilitud negativa = 0.19. Conclusiones: Tc-99m-TS con AMA es poco específico en cáncer tiroideo; en pacientes SAMA 13 % tiene carcinoma. La mayoría de los pacientes (70 %) mostró AMA, 33 % con carcinoma. Valor predictivo negativo en grupo SAMA = 88 %. Tc-99m-TS podría ser útil en la decisión terapéutica de pacientes con nódulo tiroideo en los que existe duda de cirugía; su utilidad radica en el valor predictivo negativo.

BACKGROUND: Patients with cold thyroid nodules without ultrasound malignant suspicion and with benign/undetermined cytology may be subjected to follow-up surveillance. 99mTc-tetrofosmin scan (99mTc-TS) may identify patients where this observation can be performed with more certainty. Absence of uptake never occurs in carcinoma patients. Our objective was to determine the 99mTc-TS negative predictive value (NPV) in patients with cold thyroid nodules. METHODS: An evaluation with 99mTc-TS was conducted prior to surgery in patients with thyroid gland tumor who were candidates for surgery. All patients underwent thyroidectomy according to histology; NPV and test sensitivity were evaluated when compared with the histopathological result. Then, 296-370 MBq (8-10 mCi) of 99mTc-tetrofosmin was administered, and scan images were evaluated after 120 min. Scan result was reported as a) with increased metabolic activity (IMA) or b) without increased metabolic activity (WIMA). RESULTS: Included in the study were 86 consecutive patients. In 60 patients the scan showed IMA, 20/60 (33%) with carcinoma, 67% with benign nodule. In 26 (30.2%) the scan was WIMA. In this group, 3/26 (11.5%) had carcinoma and (88.4%) had a benign neoplasia. Sensitivity = 91.43 (95% CI = 80.73-100), specificity = 45.10 (95% CI = 30.46-59.73), positive predictive value = 53.33 (95% CI = 39.8-66.79) and NPV = 88.46 (95% CI 74.26-100). Negative probability ratio = 0.19. CONCLUSIONS: IMA-99mTc-TS is less specific in thyroid cancer; nevertheless, in WIMA patients the possibility of carcinoma is 13%. Most patients (70%) showed IMA, 33% with carcinoma. WIMA-NPV = 30%. 99mTc-TS may be useful in the therapeutic decision of patients with thyroid nodule with concerns about surgery. Its usefulness lies in the NPV.

Faringo-laringectomías parciales para el tratamiento del cáncer faringolaríngeo / Partial pharyngolaryngectomies for treatment of pharyngolaryngeal cancer

BACKGROUND: We undertook this study to evaluate the results obtained with conservation therapy of the larynx in patients with laryngopharyngeal epidermoid carcinoma. METHODS: Patients with stages I and II epidermoid cancer of the larynx and pharynx were included. All patients were evaluated endoscopically, functionally, and with cervical tomography. Results of the procedures were evaluated on the basis of oncological control and laryngeal function (voice, swallowing and ventilation). RESULTS: There were 41 male patients with a median age of 55 years. In 32 patients, surgery was the initial treatment and in nine patients as rescue treatment after radiotherapy. In 58.5% the location was glottic, in 22% supraglottic, in 12% glotto-supraglottic and in 7% vallecular and hypopharynx. Subtotal laryngectomy was performed with cricohyoidepiglottopexy in 18 patients, frontolateral in 11, supraglottic in 5, subglottic-epiglottectomy in 3, hemipharyngolaryngectomy in 3, and in one hemiglottectomy. The time until decannulation and removal of nasogastric catheter depended on the type of surgery. One patient (2%) had to be subjected to a rescue laryngectomy due to constant aspiration. This patient demonstrated residual tumor in the sample. Nine patients had some type of complication, the most frequent being wound infection (7.3%). One patient died postoperatively due to sepsis (2.4%), and another patient died due to systemic causes 4 months after the intervention. Median follow-up time is 25 months and no patient has presented tumor recurrence. CONCLUSIONS: Voice conservation surgery is an alternative to mutilation of the larynx in patients with locally advanced neoplasms of the larynx with a high risk of recurrence if treated with radiotherapy.