Effectiveness of retinoic acid treatment for redifferentiation of thyroid cancer in relation to recovery of radioiodine uptake.

BACKGROUND: Retinoic acid (RA) treatment has been used for redifferentiation of metastatic thyroid neoplasia that have lost radioiodine (131I) uptake with heterogeneous results. AIM: Retrospective analysis of the recovery rate of 131I uptake after RA treatment in patients from 11 Spanish hospitals. METHODS: Twenty-seven patients (14 men, 13 women) with papillary [21], follicular [4], and oncocytic [2] thyroid cancer initially treated with total thyroidectomy plus 131I, and with 131I negative metastatic disease, were given 13-cis RA (0.66-1.5 mg/kg for 5-12 weeks) followed by a therapeutic 131I dose (3700-7400 MBq); 3 months later thyroglobulin levels and computed tomography imaging were performed. RESULTS: In 9 out 27 cases (33%) (8 papillary, 1 follicular) optimal positive 131I scan was observed after RA treatment; in the remaining 18, 10 had a suboptimal uptake (7 papillary, 2 follicular, 1 oncocytic) and in the rest there was no 131I uptake recovery (6 papillary, 1 follicular, 1 oncocytic). In 17 positive responses to RA (either optimal or suboptimal) in which image follow-up was available, decrease or stabilization of metastatic growth was observed in 7, while tumor mass increased at short term in the remaining 10. No major side effects were detected. CONCLUSION: Quite a high rate of 131I uptake recovery after RA treatment may be obtained in advanced differentiated thyroid cancer, but the potential modification of the natural course of the disease is uncertain. A better biological characterization of these tumors allowing the identification of potential responders to RA may improve the outcome of RA coadjuvant therapy.

[SPECT-CT 67Ga studies in lymphoma disease. Contribution to staging and follow-up]. / Estudios SPECT-TAC con Ga de la enfermedad linfomatosa. Su aportación en la estadificación y seguimiento de la enfermedad.

INTRODUCTION: 67Ga scintigraphy is an established method for the staging and follow-up of patients diagnosed of lymphomas. The aim of this study is to evaluate advantages of 67Ga SPECT-CT study over planar, SPECT and high resolution CT studies in lymphoma disease. MATERIAL AND METHODS: One hundred and one 67Ga studies corresponding to 74 patients (46 men) were obtained, mean age 44 years. Thirty-eight patients (51 %) were diagnosed of Hodgkin's lymphoma and 36 were non-Hodgkin's lymphoma. All patients were evaluated with 67Ga and high-resolution CT studies. 67Ga studies were performed in a hybrid system, obtaining planar, SPECT and fused SPECT-CT imaging. Findings obtained from 67Ga studies were correlated with findings obtained from CT studies, both much in number of tumoral lesions and in their localization. RESULTS: Planar, SPECT, SPECT-CT and CT studies detected 123, 146, 155 and 132 lesions respectively. SPECT-CT and CT were concordant in 52 studies, while there was no concordance between SPECT-CT and CT in the remaining 49 studies, SPECT-CT detecting more lesions than CT in 28 of them. These findings changed the disease stage 18 times (18 % of whole studies). CONCLUSION: These results show better efficiency of 67Ga SPECT-CT compared to the other acquisition methods of 67Ga study and to CT for detection of tumoral lymphomatous lesions. 67Ga SPECT-CT study improves the diagnostic yield of the study with 67Ga in patients with lymphoma, providing better anatomical localization of tumoral lesions and detection of extraganglionar disease.

[123I-MIBG SPECT-CT combined with gamma probe for radioguided localization of pheochromocytoma]. / SPECT-TC con 123I-MIBG y sonda gamma portátil en la localización radioguiada de un feocromocitoma.

We report a case of a 56-year-old male with high suspicion of an intraabdominal catecholamine-producer tumor. The patient underwent different diagnostic procedures including 123I-meta-iodobenzylguanidine (123I-MIBG) scintigraphy, with subsequent SPECT and low resolution CT for attenuation correction and anatomic and functional image fusion. After practicing a new 123I-MIBG scintigraphy the patient was taken to the operating room, where a hand-held gamma probe detector helped to localize the lesion.

[Tumor redifferentiation in papillary thyroid carcinoma alter retinoic acid administration]. / Rediferenciación tumoral en carcinoma papilar de tiroides tras la administración de ácido retinoico.

Male patient, 73 year old, with papillary thyroid carcinoma treated by surgery, 131I and L-Tyroxine, with bone metastasis, detected by bone scintigraphy and CT scan, which negative radioiodine uptake. In order to induce tumoral redifferentiation, retinoic acid (70 mg/day) was administered for three months before 131I treatment. A radioiodine scan performed after treatment showed uptake in some of the bone metastasis. Nine months later, and due to disease progression, a second induction with retinoic acid was performed before 131I treatment. The radioiodine scan performed after treatment showed greater uptake and higher number of bone lesions than the previous scan.

[Role of direct radionuclide cystography and renal study by dimercaptosuccinic acid (DMSA) in the diagnosis and follow-up of vesicoureteral reflux]. / La cistografía isotópica directa y la gammagrafía renal con ácido dimercaptosuccínico (DMSA) en el diagnóstico y seguimiento del reflujo vesicoureteral.

AIM: To evaluate the role of isotopic studies in the diagnosis and follow-up of vesicoureteral reflux (VUR) and to present the results of our current protocol. MATERIAL AND METHODS: Forty three patients with VUR were retrospectively studied with a mean follow-up of 43 years (1-11 years). VUR was diagnosed by voiding cystourethrography and followed-up by direct radionuclide cystography. During the follow-up all patients were studied by means of renal DMSA scintigraphy (21 were also studied during the acute phase of febrile urinary tract infection). RESULTS: Eighty three renal units were examined. Voiding cystourethrography was positive for VUR in 49 renal units (59%; 8 grade I, 18 grade II, 15 grade III, and 8 grade IV). During the follow-up, direct radionuclide cystography showed decrease or disappearance of VUR in 29 renal units (35%; 4 grade I, 16 grade II, 7 grade III, and 2 grade IV). DMSA studies performed during the follow-up showed cortical lesions in 17 renal units (5 with VUR grade II, 7 with grade III, and 5 grade IV). Nine of 21 patients examined by DMSA during the acute phase of febrile urinary tract infection showed cortical damage (43%), and 6 of them (67%) progressed to cortical lesion in the follow-up DMSA. CONCLUSIONS: The present protocol allows for the correct diagnosis and control of VUR, the early detection of acute renal damage, and the control of its evolution.

[(123)I-MIBG myocardial scintigraphy in the diagnosis of Lewy body dementia]. / Gammagrafía miocárdica con I-MIBG en el diagnóstico de la demencia con cuerpos de Lewy.

INTRODUCTION: Lewy body dementia (LBD) is the second most common cause of neurodegenerative dementia after Alzheimer's disease (AD). A cardiac post-ganglionic sympathetic denervation has been described in this condition which can be quantified by MIBG (metaiodobenzylguanidine) myocardial scintigraphy. The aim of our work was to retrospectively evaluate cardiac MIBG uptake (expressed as the heart-to-mediastinum ratio at 4h (HMR) in patients with suspected LBD, and to examine its relationship with clinical and para-clinical data. MATERIAL AND METHODS: A total of 77 patients with clinical suspicion of LBD evaluated at our centre between September 2005 and June 2008 to whom a MIBG myocardial scintigraphy has been performed were retrospectively reviewed. International Consensus Criteria of LBD were applied to divide the sample into probable LBD, possible LBD and non-LBD. HMR values and their relationships with clinical and neuropsychological data were analysed. A subgroup of patients had FP-CIT (fluoropropyl-carbomethoxy-3ß-4-iodophenyltropane) SPECT as a part of the evaluation. RESULTS: Mean HMR values were significantly lower in probable LBD group than in possible LBD and non-LBD groups. Low HMR values were associated only with reduced FP-CIT uptake in the striatum, but not with any clinical or neuropsychological item. CONCLUSIONS: Low MIBG myocardial scintigraphy uptake is a robust measure in LBD, and it is not largely affected by medical conditions, or by the stage of the disease. In LBD reduced MIBG myocardial uptake is associated with nigrostriatal degeneration.