ABSTRACT
Abstract Objective: To evaluate the effect that external cooling of the salivary glands (ECSG) has on the uptake of gallium-68-labeled prostate-specific membrane antigen (68Ga-PSMA), as an indirect assessment of the capacity of ECSG to reduce the local dose in lutetium-177-PSMA-617 radioligand therapy. Materials and Methods: Ten patients with prostate cancer were submitted to 68Ga-PSMA positron emission tomography/computed tomography with unilateral ECSG. The ECSG was started at 30 min before the injection of the radiotracer and maintained until the end of image acquisition (1 h after injection). Each salivary gland was assessed by determining the maximum, mean, and peak standardized uptake values (SUVmax, SUVmean, and SUVpeak, respectively). The volume of each gland was determined in a volume of interest delineated by a threshold SUVmax of 10%. Paired Student's t-tests were used in order to compare the results. Results: In terms of the SUV parameters, there were no statistically significant differences between the cooled and contralateral salivary glands. However, the mean volume was 27% lower in the cooled parotid glands than in the contralateral parotid glands (p = 0.004). Conclusion: The use of ECSG does not appear to reduce 68Ga-PSMA uptake by the salivary glands. In addition, there is yet no evidence that ECSG is effective in preventing salivary gland toxicity.
Resumo Objetivo: Avaliar o impacto do resfriamento externo de glândulas salivares (REGS) na captação de 68Ga-PSMA como marcador indireto dessa intervenção para redução da dose local na terapia com 177Lu-PSMA. Materiais e Métodos: Dez pacientes com câncer de próstata foram submetidos a PET/CT com 68Ga-PSMA com REGS unilateral. O resfriamento se iniciou 30 minutos antes da injeção do radiofármaco até o fim da aquisição de imagem, 1 hora após a injeção. Cada glândula foi avaliada para os valores de captação padronizados máximo, médio e pico (SUVmáx, SUVmédio e SUVpico, respectivamente). O volume foi definido por um isocontorno usando 10% do SUVmáx. Os resultados foram comparados com o teste t de Student. Resultados: Não houve diferença estatisticamente significante entre os valores de SUV das glândulas resfriadas e seus controles. Houve 27% de redução volumétrica (p = 0,004) nas parótidas resfriadas em comparação ao controle. Conclusão: Não houve redução da captação de 68Ga-PSMA nas glândulas salivares ao REGS. Atualmente não há evidências que suportem essa prática clínica.
ABSTRACT
We report a case of a 47-year-old female known with metastatic papillary thyroid cancer. Her treatment history included total thyroidectomy and 3 previous radio ablations with a cumulative dose of 950 mCi of ¹³¹I. On follow-up, her thyroglobulin levels had demonstrated a rising trend (from 3789.0 to 4240.0 ug/L) despite a ¹²³I whole-body scan demonstrating a reduction in tracer avid lesions. She was suspected of having radio-resistant disease. The patient underwent both ¹⁸F-FDG and ⁶⁸Ga-PSMA PET/CT imaging with both scans demonstrating congruent lesions however with far greater intensity on the ⁶⁸Ga-PSMA study.
Subject(s)
Female , Humans , Middle Aged , Follow-Up Studies , Iodine , Positron Emission Tomography Computed Tomography , Thyroglobulin , Thyroid Gland , Thyroid Neoplasms , ThyroidectomyABSTRACT
Abstract Objective: To show the initial (first-year) experience with 68Ga-PSMA PET/CT at a clinic in Brazil. Materials and Methods: Over a one-year period, 96 examinations with 68Ga-PSMA PET/CT (85 related to prostate cancer and 11 related to kidney cancer) were performed in 90 patients. Results: In the prostate and kidney cancer patients alike, the main clinical indication for 68Ga-PSMA PET/CT was suspicion of recurrence during follow-up (in 65.8% and 63.0% of the cases, respectively). Among the prostate cancer patients, 38.5% of those with a prostate specific antigen (PSA) < 0.5 ng/mL tested positive for recurrence on 68Ga-PSMA PET/CT, compared with 71.0% of those with a PSA of 0.5-0.99, 85.7% of those with a PSA of 1.0-1.99, and 92.6% of those with a PSA > 1.99. Conclusion: Although 68Ga-PSMA PET/CT is a technique that has only recently been applied in clinical settings, despite its high cost, 68Ga-PSMA PET/CT shows great promise as a tool in the clinical management of patients with kidney and prostate cancer, especially in those with prostate cancer whose PSA levels are elevated even after treatment.
Resumo Objetivo: Mostrar a experiência inicial de exames de PET/CT com 68Ga-PSMA em uma clínica brasileira durante um ano. Materiais e Métodos: No período de um ano foram realizados 96 exames de PET/CT com 68Ga-PSMA, sendo 85 relacionados ao câncer de próstata e 11 relacionados ao câncer de rim, com o envolvimento de 90 pacientes. Resultados: Tanto no câncer prostático como no câncer renal, a principal indicação clínica foi suspeita de recidiva durante acompanhamento (65,8% e 63,0%, respectivamente). Nos casos de câncer de próstata, os exames foram positivos em 38,5% com o antígeno específico da próstata (PSA) menor que 0,5 ng/mL, em 71,0% com o PSA entre 0,5 e 0,99, em 85,7% com o PSA entre 1,0 e 1,99, e em 92,6% com o PSA maior que 1,99. Conclusão: O exame de PET/CT com 68Ga-PSMA, embora seja uma técnica de aplicação clínica recente e de custo elevado, é uma ferramenta bastante promissora no manuseio clínico de pacientes com câncer de rim e de próstata, principalmente para os casos de câncer de próstata já tratados e que apresentam elevação do PSA.
ABSTRACT
PURPOSE: The aim of the study was to compare response evaluation criteria in solid tumours 1.1 (RECIST 1.1), positron emission tomography response criteria in solid tumours (PERCIST), European organisation for research and treatment of cancer (EORTC), andMDAnderson (MDA) criteria for response assessment by Gallium 68-prostate-specific membrane antigen positron emission tomography-computed tomography (Ga68-PSMA PET-CT) in metastatic adenocarcinoma prostate cancer (mPCa) patients with biochemical progression.METHODS: Eighty-eight mPCa patients with pre and post treatment Ga68-PSMA PET-CTwere included. A ≥ 25% increase and ≥ 2 ng/ml above the nadir if prostate specific antigen (PSA) drop or ≥ 2 ng/ml above the baseline if PSA does not drop was considered as biochemical progression. RECIST 1.1 and MDA criteria for morphology and PERCIST and EORTC criteria for molecular response were investigated. Percentages of progressive disease (PD), partial response (PR), and stable disease (SD) were calculated. Chi-square test was used for statistical significance.RESULTS: Proportion of PD, SD, and PR by RECIST 1.1 and MDA criteria were 44 (50.57%), 39 (44.83%), 4 (4.6%), and 33 (39.76%), 48 (57.83%), 2 (2.41%) respectively. Proportion of PD, SD, and PR by PERCIST and EORTC criteria were 71 (80.68%), 11 (12.50%), 6 (6.82%), and 74 (84.09%), 8 (9.09%), 6 (6.82%) respectively. Chi-square test showed statistically significant (P < 0.05) higher proportion of progression detected by both molecular criteria as compare to both morphological criteria.CONCLUSION: We concluded that for Ga68-PSMA PET-CT response evaluation, molecular criteria performed better than morphological criteria in mPCa patient with PSA progression.
Subject(s)
Humans , Adenocarcinoma , Electrons , Gallium , Membranes , Positron-Emission Tomography , Prostate , Prostate-Specific Antigen , Prostatic Neoplasms , Response Evaluation Criteria in Solid TumorsABSTRACT
A patient with a history of adenoid cystic carcinoma of the nasal cavity presented himself with bone pain and an elevated PSA level. On suspicion of metastatic prostate cancer a ⁶⁸Ga-PSMA PET-CT was performed. The PET-CT showed numerous lung and non-sclerotic bone metastasis. Biopsy of a bone metastasis was performed and pathology showed adenoid cystic carcinoma instead of prostate cancer. Immunohistochemical PSMA staining of the primary tumour showed intense PSMA expression in adenoid cystic carcinoma tumour cells. Because of the high PSMA expression of adenoid cystic carcinoma, ⁶⁸Ga-PSMA PET-CT might be a promising imaging modality for this malignancy.