18F-FDG PET/CT performed immediately after percutaneous ablation to evaluate outcomes of the procedure: preliminary results.

OBJECTIVE: To determine whether 18F-fluorodeoxyglucose positron emission tomography/computed tomography performed immediately after percutaneous ablation (iPA 18F-FDG PET/CT) is useful in evaluating the outcomes of the procedure. MATERIALS AND METHODS: This was a retrospective study of 20 patients (13 males, 7 females; mean age, 65.8 ± 12.1 years) submitted to percutaneous ablation of metastases. All of the lesions treated had shown focal uptake on a 18F-FDG PET/CT scan obtained at baseline. The primary tumors were mainly colorectal cancer (in 45%) or lung cancer (in 40%). iPA 18F-FDG PET/CT was performed to identify any residual viable tumor cells. The treatment was considered a success (no viable tumor cells present) if no uptake of 18F-FDG was noted on the iPA 18F-FDG PET/CT scan. RESULTS: Twenty-six lesions were submitted to percutaneous ablation with either cryoablation (n = 7) or radiofrequency ablation (n = 19). The mean lesion diameter was 2.52 ± 1.49 cm. For the detection of viable tumor cells, iPA 18F-FDG PET/CT had a sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 66.7%, 95%, 88.5%, 80%, and 90.5%, respectively. There was a significant correlation between the iPA 18F-FDG PET/CT findings and the results of the follow-up studies (kappa = 0.66; p < 0.01). CONCLUSION: iPA 18F-FDG PET/CT studies appear to constitute a useful means of evaluating the outcomes of percutaneous ablation. By detecting residual viable tumor cells, this strategy might allow early re-intervention, thus reducing morbidity. Studies involving larger numbers of patients are needed in order to confirm our findings.

OBJETIVO: Demonstrar se a tomografia por emissão de pósitrons acoplada a tomografia computadorizada usando-se fluorodesoxiglicose marcada com flúor-18 realizada imediatamente após ablação percutânea (iAP 18F-FDG PET/CT) pode ser útil na avaliação do resultado desse tratamento. MATERIAIS E MÉTODOS: Foram avaliados, retrospectivamente, 20 pacientes (13 homens e 7 mulheres; média de idade: 65,8 ± 12,1 anos) submetidos a ablação percutânea de metástases apresentando captação de 18F-FDG no exame de PET/CT. Os tumores primários foram, principalmente, câncer colorretal (45%) ou câncer de pulmão (40%). A iAP 18F-FDG PET/CT foi realizada para avaliar tumor residual viável. O tratamento foi considerado sucesso (sem lesão viável) se nenhuma captação de 18F-FDG fosse observada na iAP 18F-FDG PET/CT. RESULTADOS: Vinte e seis lesões foram submetidas a ablação percutânea por meio de crioablação (n = 7) ou radiofrequência (n = 19). O tamanho médio das lesões era de 2,52 ± 1,49 cm. A iAP 18F-FDG PET/CT detectou tumor viável com sensibilidade, especificidade, acurácia, valor preditivo positivo e valor preditivo negativo de 66,7%, 95%, 88,5%, 80% e 90,5%, respectivamente. Houve correlação significativa entre os achados da iAP 18F-FDG PET/CT e os resultados do seguimento clínico dos pacientes (kappa = 0,66; p < 0,01). CONCLUSÃO: A iAP 18F-FDG PET/CT é capaz de avaliar o resultado da ablação percutânea e poderá permitir reintervenção precoce de lesões residuais viáveis, reduzindo a morbidade. Um número maior de pacientes é necessário para confirmar esses achados.

18F-FDG PET/CT performed immediately after percutaneous ablation to evaluate outcomes of the procedure: preliminary results / 18F-FDG PET/CT realizada imediatamente após ablação percutânea para avaliar os desfechos do procedimento: resultados preliminares

Abstract Objective: To determine whether 18F-fluorodeoxyglucose positron emission tomography/computed tomography performed immediately after percutaneous ablation (iPA18F-FDG PET/CT) is useful in evaluating the outcomes of the procedure. Materials and Methods: This was a retrospective study of 20 patients (13 males, 7 females; mean age, 65.8 ± 12.1 years) submitted to percutaneous ablation of metastases. All of the lesions treated had shown focal uptake on a 18F-FDG PET/CT scan obtained at baseline. The primary tumors were mainly colorectal cancer (in 45%) or lung cancer (in 40%). iPA18F-FDG PET/CT was performed to identify any residual viable tumor cells. The treatment was considered a success (no viable tumor cells present) if no uptake of 18F-FDG was noted on the iPA18F-FDG PET/CT scan. Results: Twenty-six lesions were submitted to percutaneous ablation with either cryoablation (n = 7) or radiofrequency ablation (n = 19). The mean lesion diameter was 2.52 ± 1.49 cm. For the detection of viable tumor cells, iPA18F-FDG PET/CT had a sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 66.7%, 95%, 88.5%, 80%, and 90.5%, respectively. There was a significant correlation between the iPA18F-FDG PET/CT findings and the results of the follow-up studies (kappa = 0.66; p < 0.01). Conclusion: iPA18F-FDG PET/CT studies appear to constitute a useful means of evaluating the outcomes of percutaneous ablation. By detecting residual viable tumor cells, this strategy might allow early re-intervention, thus reducing morbidity. Studies involving larger numbers of patients are needed in order to confirm our findings.

Resumo Objetivo: Demonstrar se a tomografia por emissão de pósitrons acoplada a tomografia computadorizada usando-se fluorodesoxiglicose marcada com flúor-18 realizada imediatamente após ablação percutânea (iAP18F-FDG PET/CT) pode ser útil na avaliação do resultado desse tratamento. Materiais e Métodos: Foram avaliados, retrospectivamente, 20 pacientes (13 homens e 7 mulheres; média de idade: 65,8 ± 12,1 anos) submetidos a ablação percutânea de metástases apresentando captação de 18F-FDG no exame de PET/CT. Os tumores primários foram, principalmente, câncer colorretal (45%) ou câncer de pulmão (40%). A iAP18F-FDG PET/CT foi realizada para avaliar tumor residual viável. O tratamento foi considerado sucesso (sem lesão viável) se nenhuma captação de 18F-FDG fosse observada na iAP18F-FDG PET/CT. Resultados: Vinte e seis lesões foram submetidas a ablação percutânea por meio de crioablação (n = 7) ou radiofrequência (n = 19). O tamanho médio das lesões era de 2,52 ± 1,49 cm. A iAP18F-FDG PET/CT detectou tumor viável com sensibilidade, especificidade, acurácia, valor preditivo positivo e valor preditivo negativo de 66,7%, 95%, 88,5%, 80% e 90,5%, respectivamente. Houve correlação significativa entre os achados da iAP18F-FDG PET/CT e os resultados do seguimento clínico dos pacientes (kappa = 0,66; p < 0,01). Conclusão: A iAP18F-FDG PET/CT é capaz de avaliar o resultado da ablação percutânea e poderá permitir reintervenção precoce de lesões residuais viáveis, reduzindo a morbidade. Um número maior de pacientes é necessário para confirmar esses achados.

Influence of bladder fullness on the detection of urinary tract obstruction by dynamic renal scintigraphy.

OBJECTIVE: To investigate the influence of bladder fullness on the diagnosis of urinary tract obstruction during dynamic renal scintigraphy with a diuretic stimulator. MATERIALS AND METHODS: We studied 82 kidneys in 82 patients submitted to dynamic renal scintigraphy with a diuretic stimulator. We compared the proportional elimination of the radiopharmaceutical 99mTc-DTPA from the kidneys before and after bladder emptying in post-diuretic images, classifying each image as representing an obstructed, indeterminate, or unobstructed kidney. RESULTS: The overall elimination of 99mTc-DTPA from the kidneys was 10.4% greater after bladder emptying than before. When the analysis was performed with a full bladder, we classified 40 kidneys as obstructed, 16 as indeterminate, and 26 as unobstructed. When the 40 kidneys classified as obstructed were analyzed after voiding, 11 were reclassified as indeterminate and 3 were reclassified as unobstructed. Of the 16 kidneys classified as indeterminate on the full-bladder images, 13 were reclassified as unobstructed after voiding. CONCLUSION: In dynamic renal scintigraphy with a diuretic stimulator, it is important to obtain images after voiding, in order to perform a reliable analysis of the proportional excretion of 99mTc-DTPA from the kidneys, avoiding possible false-positive results for urinary tract obstruction.

OBJETIVO: Verificar a influência da repleção vesical no diagnóstico da obstrução do trato urinário durante a cintilografia renal dinâmica com estímulo de diurético. MATERIAIS E MÉTODOS: Foram estudados, retrospectivamente, 82 rins de 82 pacientes submetidos a cintilografia renal dinâmica. Compararam-se as porcentagens de excreção do radiofármaco DTPA-99mTc pelos rins antes e após o esvaziamento vesical nas imagens pós-diurético, classificando-os como obstruídos, indeterminados ou não obstruídos. RESULTADOS: A avaliação da excreção do radiofármaco pelos rins mostrou que houve aumento de 10,4% na taxa de excreção global quando a bexiga foi esvaziada. Dos 82 rins estudados, 40 foram considerados obstruídos, 16 indeterminados e 26 como não obstruídos, na análise com a bexiga repleta. Na análise das imagens após micção, dos 40 classificados como obstruídos, 11 passaram a ser classificados como indeterminados e 3 como não obstruídos. Além disso, dos 16 rins apontados como indeterminados nas imagens com a bexiga repleta, 13 passaram a ser considerados não obstruídos com a bexiga vazia. CONCLUSÃO: É fundamental uma imagem após a micção na cintilografia renal dinâmica para uma análise fidedigna da porcentagem de excreção do radiofármaco pelo rim, evitando-se possíveis falso-positivos para obstrução do trato urinário.

Influence of bladder fullness on the detection of urinary tract obstruction by dynamic renal scintigraphy / Influência da repleção vesical na pesquisa de obstrução do trato urinário utilizando cintilografia renal dinâmica

Abstract Objective: To investigate the influence of bladder fullness on the diagnosis of urinary tract obstruction during dynamic renal scintigraphy with a diuretic stimulator. Materials and methods: We studied 82 kidneys in 82 patients submitted to dynamic renal scintigraphy with a diuretic stimulator. We compared the proportional elimination of the radiopharmaceutical 99mTc-DTPA from the kidneys before and after bladder emptying in post-diuretic images, classifying each image as representing an obstructed, indeterminate, or unobstructed kidney. Results: The overall elimination of 99mTc-DTPA from the kidneys was 10.4% greater after bladder emptying than before. When the analysis was performed with a full bladder, we classified 40 kidneys as obstructed, 16 as indeterminate, and 26 as unobstructed. When the 40 kidneys classified as obstructed were analyzed after voiding, 11 were reclassified as indeterminate and 3 were reclassified as unobstructed. Of the 16 kidneys classified as indeterminate on the full-bladder images, 13 were reclassified as unobstructed after voiding. Conclusion: In dynamic renal scintigraphy with a diuretic stimulator, it is important to obtain images after voiding, in order to perform a reliable analysis of the proportional excretion of 99mTc-DTPA from the kidneys, avoiding possible false-positive results for urinary tract obstruction.

Resumo Objetivo: Verificar a influência da repleção vesical no diagnóstico da obstrução do trato urinário durante a cintilografia renal dinâmica com estímulo de diurético. Materiais e métodos: Foram estudados, retrospectivamente, 82 rins de 82 pacientes submetidos a cintilografia renal dinâmica. Compararam-se as porcentagens de excreção do radiofármaco DTPA-99mTc pelos rins antes e após o esvaziamento vesical nas imagens pós-diurético, classificando-os como obstruídos, indeterminados ou não obstruídos. Resultados: A avaliação da excreção do radiofármaco pelos rins mostrou que houve aumento de 10,4% na taxa de excreção global quando a bexiga foi esvaziada. Dos 82 rins estudados, 40 foram considerados obstruídos, 16 indeterminados e 26 como não obstruídos, na análise com a bexiga repleta. Na análise das imagens após micção, dos 40 classificados como obstruídos, 11 passaram a ser classificados como indeterminados e 3 como não obstruídos. Além disso, dos 16 rins apontados como indeterminados nas imagens com a bexiga repleta, 13 passaram a ser considerados não obstruídos com a bexiga vazia. Conclusão: É fundamental uma imagem após a micção na cintilografia renal dinâmica para uma análise fidedigna da porcentagem de excreção do radiofármaco pelo rim, evitando-se possíveis falso-positivos para obstrução do trato urinário.

Tc-99m sestamibi thyroid imaging in patients on chronic amiodarone treatment: a comparison with Tc-99m pertechnetate imaging.

PURPOSE OF THE REPORT: To compare thyroid imaging using Tc-99m sestamibi with the standard Tc-99m pertechnetate scintigraphy in patients on chronic use of amiodarone. MATERIALS AND METHODS: A total of 23 patients on oral amiodarone for at least 4 months had thyroid scintigraphy and uptake measurement using Tc-99m pertechnetate and Tc-99m sestamibi. Thyroid function was evaluated by measuring serum concentrations of thyrotropin, free thyroxine, and free triiodothyronine, and antithyroglobulin and antithyroperoxidase antibodies. RESULTS: Ten of the 23 patients were euthyroid, 9 hypothyroid, and 4 hyperthyroid, with normal, increased, and decreased serum thyrotropin, respectively. All euthyroid patients had markedly decreased thyroid Tc-99m pertechnetate uptake and normal or slightly increased Tc-99m sestamibi uptake, except for one patient who had increased uptake of both radiotracers. One of the 4 hyperthyroid patients had Graves' disease and markedly increased thyroid uptake of both tracers. The other 3 hyperthyroid patients had normal or decreased Tc-99m pertechnetate uptake and increased Tc-99m sestamibi uptake. Differently than expected, all 9 hypothyroid patients had normal or increased uptake of both radiopharmaceuticals. CONCLUSIONS: This study suggests that Tc-99m sestamibi may be an alternative tracer for thyroid scintigraphy and uptake measurement of patients on chronic use of amiodarone. Tc-99m sestamibi seems to be better than Tc-99m pertechnetate for the scintigraphic evaluation of the thyroid of euthyroid and hyperthyroid patients.

Systemic Radionuclide Therapy of Painful Prostate Cancer Bone Metastases With Samarium-153-edtmp

Most patients with prostate cancer (PC) will develop painful bone metastases, which alters their quality of life. Objective: This study aimed to evaluate the efficacy and toxic hematological profile of samarium for the treatment of PC metastases’ bone pain. Methods: Twenty-nine PC patients (median age: 69 years, range: 46-84; Gleason score equal to or higher than 7 in 66.7% and under 7 in 33.3% of patients presenting multiple painful bone metastases were treated with intravenous injection of 153Sm-EDTMP. Response to treatment was defined as either a reduction of at least 25% in patient’s pain score, using a 0 to 10 scale (score 0: no pain, score 10: maximum pain), or in daily analgesic dosage. Complete blood counts were performed before 153Sm–EDTMP administration and 4 and 8 weeks after treatment with the purpose of evaluating hematological side effects of the agent. Results: Twenty-five patients (86.2%) responded to treatment (median time: 1.5 month, range: 1.0 to 2.0 months). A reduction equal to or higher than 25% in post-treatment values compared to baseline values was seen in hemoglobin (Hb) of 3 (12.0%) patients, in leukocytes (Lo) of 16 (64.0%) patients, and in platelets (Pl) of 19 (76.0%) patients. Hb under 10g/dl, Lo under 2.0x103/ul, and Pl under than 50.0x103/ul were seen in 7 (28.0%), 3 (12.0%) and 2 (8.0%) out of 25 patients analyzed after 153Sm–EDTMP, respectively. No infectious or bleeding episodes were seen in any patient during the study. Conclusion: 153Sm-EDTMP is effective for acute control of PC patients’ bone pain. However, additional studies with bone marrow assessment before and after 153Sm–EDTMP are necessary to clarify the origin of cytopenias found in our cases.

Treatment of bone pain secondary to metastases using samarium-153-EDTMP.

CONTEXT: More than 50% of patients with prostate, breast or lung cancer will develop painful bone metastases. The purpose of treating bone metastases is to relieve pain, reduce the use of steroids and to maintain motion. OBJECTIVE: To evaluate the use of samarium-153-EDTMP (153Sm-EDTMP) for the treatment of bone pain secondary to metastases that is refractory to clinical management. TYPE OF STUDY: Retrospective. SETTING: Division of Nuclear Medicine, Universidade Estadual de Campinas (Unicamp). METHODS: Fifty-eight patients were studied (34 males) with mean age 62 years; 31 patients had prostate cancer, 20 had breast cancer, three had lung cancer, one had lung hemangioendothelioma, one had parathyroid adenocarcinoma, one had osteosarcoma and one had an unknown primary tumor. All patients had multiple bone metastases demonstrated by bone scintigraphy using 99mTc-MDP,and were treated with 153Sm-EDTMP. Response to treatment was graded as good (pain reduction of 50-100%), intermediate (25-49%) and poor (0-24%). RESULTS: All patients showed good uptake of 153Sm-EDTMP by bone metastases. Among the patients with prostate cancer, intermediate or good response to therapy occurred in 80.6% (25 patients) and poor response in 19.4% (6). Among the patients with breast cancer, 85% (17) showed intermediate or good response to therapy while 15% (3) showed poor response. All three patients with lung cancer showed poor response to treatment. The lung hemangioendothelioma and unknown primary lesion patients showed intermediate response to treatment; the osteosarcoma and parathyroid adenocarcinoma patients showed good response to treatment. No significant myelotoxicity occurred. DISCUSSION: Pain control is important for improving the quality of life of patients with advanced cancers. The mechanism by which pain is relieved with the use of radionuclides is still not yet completely understood, however, the treatment is simple and provides a low risk of mielotoxicity. CONCLUSION: Treatment with 153Sm-EDTMP can control the pain secondary to bone metastases effectively in most patients with breast and prostate cancer without significant side effects.

Treatment of bone pain secondary to metastases using samarium-153-EDTMP

CONTEXTO: Mais de 50% dos pacientes com câncer de próstata, mama ou pulmão desenvolverão dor óssea secundária a metástases. O tratamento da dor óssea metastática visa minimizar a dor, reduzir o uso de opióides e manter os movimentos. OBJETIVO: Avaliar o uso de EDTMP-153Sm para tratamento da dor óssea secundária a metástases refratária a tratamento com opióides. TIPO DE ESTUDO: Retrospectivo. LOCAL: Divisão de Medicina Nuclear, Universidade Estadual de Campinas (Unicamp). MÉTODOS: 58 pacientes foram estudados (34 homens), com média de idade de 62 anos. 31 pacientes com neoplasia de próstata, 20 com neoplasia de mama, três pacientes com câncer de pulmão, um com hemangioendotelioma de pulmão, um com adenocarcinoma de paratireóide, um com osteosarcoma e um paciente que apresentava um tumor primário desconhecido. Todos apresentavam múltiplas metástases ósseas à cintilografia óssea com MDP-99mTc e foram tratados com EDTMP-153Sm. A resposta ao tratamento foi graduada em boa (redução da dor em 50 - 100%), intermediária (25-49%) e má (0-24%). RESULTADOS: Todos os pacientes apresentavam boa captação de EDTMP-153Sm nas metástases ósseas. Dentre os doentes com câncer de próstata, resposta intermediária ou boa ocorreu em 80.6% (25 pacientes) e má resposta em 19.4% (6). Dentre os pacientes com câncer de mama, 85% (17) apresentaram resposta intermediária ou boa à terapia enquanto 15% (3) apresentaram má resposta. Todos os três pacientes com câncer de pulmão apresentaram resposta pobre ao tratamento. Os doentes com hemangioendotelioma de pulmão e com o tumor primário desconhecido apresentaram resposta intermediária ao tratamento; os pacientes com osteossarcoma e com o adenocarcinoma de paratireóide apresentaram boa resposta. Mielotoxicidade significativa não ocorreu. DISCUSSAO: O controle da dor é importante para melhorar a qualidade de vida do doente com câncer avançado. O mecanismo de alívio da dor com radionuclídeos ainda não foi elucidado, mas o tratamento é de simples administração e baixo risco de mielotoxidade. CONCLUSAO: Tratamento com EDTMP-153Sm pode controlar a dor secundária a metástases ósseas de forma efetiva na maioria dos pacientes com câncer de próstata e câncer de mama sem efeitos colaterais significativos.

Gallium-67 imaging in a patient with paracoccidioidomycosis: a case report

A 26 year-old female was admitted with abdominal pain, fever and weight loss. The clinical and laboratory investigations led to the diagnosis of paracoccidioidomycosis. Gallium-67 whole body images correlated well with the clinical course of the disease and with the patient's prognosis.