Virtual Rehabilitation in Parkinson Disease: A Dopamine Transporter Imaging Study.

OBJECTIVE: The aim of the study was to verify the effect of a virtual rehabilitation protocol for patients with Parkinson disease, primarily assessing striatal dopamine transporters and secondarily motor symptoms and quality of life. DESIGN: Nineteen patients with Parkinson disease underwent an 8-wk virtual rehabilitation protocol using XBOX 360S. Evaluation of dopamine transporters was performed by single-photon emission computed tomography using TRODAT-1 as the radioligand. Participants were clinically assessed using the Unified Parkinson Disease Rating Scale to quantify motor symptoms. Moreover, the Parkinson Disease Questionnaire and Short-Form Health Status Survey were used to assess quality of life and the Berg Balance Scale to assess balance. RESULTS: Regarding our primary outcome, dopamine transporter was significantly increased in the putamen contralateral to the clinically most affected body side (P = 0.034) considering preintervention and postintervention measurements. Furthermore, we observed significant improvement in Unified Parkinson Disease Rating Scale (10-point reduction, P = 0.001), Parkinson Disease Questionnaire (11.3-point reduction, P = 0.001), Short-Form Health Status Survey ("Functional capacity," P = 0.001; "Pain," P = 0.006; and "Mental Health" domains, P < 0.001), and Berg Balance Scale (5-point increase, P = 0.015). CONCLUSIONS: In our group of Parkinson disease patients, this virtual rehabilitation protocol enabled a dopamine transporter increase in the region of the putamen contralateral to the clinically most affected body side. Moreover, motor signs and quality of life were significantly improved.

Impaired brain dopamine transporter in chemobrain patients submitted to brain SPECT imaging using the technetium-99m labeled tracer TRODAT-1.

PURPOSE: "Chemobrain" is a medical secondary effect of cancer chemotherapy treatment characterized by a general decline in cognition affecting visual and verbal memory, attention, complex problem-solving skills, and motor function. Dopamine (DA) central nervous system neurotransmitters serve an important role in cognition, and changes in DA could potentially explain impaired cognition associated with chemotherapy. Therefore, our objective was to assess in vivo dopaminergic dysfunction in the central nervous system (CNS) of a group of female breast cancer survivors with cognitive impairment following chemotherapy. METHODS: Twenty-eight women reporting chemobrain were recruited for this study and compared to 22 healthy reference women. Striatal dopamine transporter (DAT) binding ratio was determined by 99mTc-TRODAT-1 (a highly selective radiotracer for DAT in the dorsal striatum) single-photon emission computed tomography and a quantitative evaluation was obtained by DatQUANT™ software (GE Healthcare). The DAT binding ratio (BRDAT) in the patient and control groups was compared using the Student's t test, a multivariate analysis of variance (MANOVA) was used to compare age, years of schooling and BRDAT. The relationship between continuous variables, such as cognitive impairment and BRDAT was assessed using Pearson correlation test. RESULTS: There was a difference in BRDAT between the chemobrain patients and control group. Patients had statistically significant (p < 0.05) lower concentrations of the radiopharmaceutical in the striatum. CONCLUSIONS: We identified a significant dopaminergic decrease in all regions of the dorsal striatum within the patients reporting cognitive dysfunction after chemotherapy. Therefore, our results indicate a possible role of dopamine transporter in the physiopathology of chemobrain, even out of the acute phase of symptoms.

68Ga-DOTATATE PET/CT in recurrent medullary thyroid carcinoma: a lesion-by-lesion comparison with 111In-octreotide SPECT/CT and conventional imaging.

PURPOSE: The aim of this study was to prospectively compare the detection rate of 68Ga-DOTATATE PET-CT with 111In-octreotide SPECT-CT and conventional imaging (CI) in medullary thyroid carcinoma (MTC) patients with increased calcitonin (Ctn) levels but negative CI after thyroidectomy. METHODS: Fifteen patients with raised Ctn levels and/or CI evidence of recurrence underwent 68Ga-DOTATATE PET-CT, 111In-octreotide SPECT-CT and CI. Histopathology, CI and biochemical/clinical/imaging follow-up were used as the reference standard. PET/CT, SPECT/CT and CI were compared in a lesion-based and organ-based analysis. RESULTS: PET/CT evidenced recurrence in 14 of 15 patients. There were 13 true positive (TP), 1 true negative (TN), 1 false positive (FP) and no false negative (FN) cases, resulting in a sensitivity and accuracy of 100% and 93%. SPECT/CT was positive in 6 of 15 cases. There were 6 TP, 2 TN, 7 FN and no FP cases, resulting in a sensitivity of 46% and accuracy of 53%. CI procedures detected tumor lesions in 14 of 15 patients. There were 13 TP, 1TN, 1 FP and no FN cases with a sensitivity of 100% and accuracy of 93%. A significantly higher number of lesions was detected by PET/CT (112 lesions, p = 0.005) and CI (109 lesions, p = 0.005) in comparison to SPECT/CT (16 lesions). There was no significant difference between PET/CT and CI for the total number of detected lesions (p = 0.734). PET/CT detected more lesions than SPECT/CT regardless of the organ. PET/CT detected more bone lesions but missed some neck nodal metastases evidenced by CI. The number of lesions per region demonstrated by PET/CT and CI were similar in the other sites. CONCLUSION: 68Ga-DOTATATE PET/CT is superior to 111In-octreotide SPECT/CT for the detection of recurrent MTC demonstrating a significantly higher number of lesions. 68Ga-DOTATATE PET/CT showed a superior detection rate compared to CI in demonstrating bone metastases.

Tratamento do carcinoma diferenciado da tireóide com iodo-131: intervenções para aumentar a dose absorvida de radiação / Radioiodine therapy for differentiated thyroid carcinoma: methods used to increase the radiation absorbed dose

OBJETIVO: Analisar medidas tomadas para aumentar a dose de radiação absorvida (DOSE) durante o tratamento do carcinoma diferenciado da tireóide (CDT) com iodo-131. MÉTODOS: As abordagens para aumentar a DOSE na radioiodoterapia são: redução da competição com iodo não-radioativo, estímulo da captação/retenção celular e aumento da atividade administrada. Revisaram-se os fundamentos e resultados de cada um destes métodos. RESULTADOS: Apesar de ser difícil confirmar aumento de sobrevida, existe relação direta entre a DOSE e a resposta no CDT. Diferentes abordagens permitem o aumento da DOSE nos tecidos, inferindo-se uma possível melhora na resposta dos tumores ao tratamento com iodo-131. Apesar do prognóstico relativamente benigno da doença, a melhoria da resposta é importante nos casos de alto risco, em que as alternativas de tratamento são limitadas. CONCLUSÕES: As intervenções descritas permitem aumentar a DOSE durante o tratamento do CDT, podendo ser empregadas para casos de alto risco.

[Radioiodine therapy for differentiated thyroid carcinoma: methods used to increase the radiation absorbed dose]. / Tratamento do carcinoma diferenciado da tireóide com iodo-131: intervenções para aumentar a dose absorvida de radiação.

OBJECTIVES: Our aim was to analyze measures taken to increase the radiation absorbed dose (DOSE) during treatment of well-differentiated thyroid cancer (DTC) with iodine-131. METHODS: An increase in DOSE is achieved by: avoiding competition with non-radioactive iodine, stimulating cellular uptake/retention, increasing the administered activity. Basis and results of each one of these methods were reviewed. RESULTS: Although it is difficult to demonstrate an increase in survival, there is a direct relation between DOSE and tumoral response in DTC. Different approaches can be used aiming an increase in DOSE, with a possible improvement in tumoral response for treatment with iodine-131. Although DTC is a relatively benign disease, a better response to treatment is highly desirable in high-risk patients, who have few other options of therapy. CONCLUSIONS: An increase in DOSE during treatment of DTC can be achieved using the described interventions, which should be used in high-risk cases of DTC.

Pesquisa do linfonodo sentinela em pacientes com melanoma: experiência com fitato marcado com Tecnécio-99m e revisão da literatura / The role of sentinel node mapping in malignant melanoma: experience with 99mTc-phytate and a review of the literature

FUNDAMENTOS: A progressão linfática do melanoma maligno habitualmente se inicia pelo linfonodo sentinela (LNS), cuja análise histopatológica permite predizer o acometimento de toda a cadeia. OBJETIVO: O trabalho tem por objetivo descrever a utilização do 99mTc-Fitato na detecção do LNS em pacientes com melanoma maligno, revisando as indicações e informações fornecidas por sua biópsia. MÉTODO: A pesquisa de LNS foi realizada por meio da linfocintilografia com 99mTc-Fitato em 92 pacientes com melanoma (54,0±14,3 anos). Após 18-24 horas, 88 pacientes foram submetidos à localização intra-operatória com detector portátil, seguida da ressecção e análise histopatológica do LNS. RESULTADOS: A linfocintilografia permitiu a identificação do LNS em todos os estudos, havendo detecção intra-operatória em 98,8% dos casos. O LNS estava acometido em 23 pacientes (26%). O valor preditivo negativo foi de 100% e não se observaram reações adversas pelo uso do 99mTc-Fitato. CONCLUSÃO: A detecção do LNS pode ser realizada com diferentes radiofármacos, incluindo o 99mTc-Fitato, que apresenta vantagens de custo e disponibilidade no Brasil. A pesquisa de LNS resulta em maior acurácia e menor morbidade no estadiamento de pacientes com melanoma maligno.