ABSTRACT
Introduction@#Prostate cancer is the third most common cancer among Filipino males. Ga-68 PSMA PET-CT and Lu-177 PRLT have been introduced in the Philippines for the diagnostics and therapy of prostate cancer. @*Objective@#The aim of this study is to compare treatment outcomes of standard therapy plus Lu-177 PSMA radioligand therapy and standard therapy alone among patients with prostatic cancer status-post castration using Ga-68 PET-CT as an outcome indicator. @*Methodology@#This is an ambispective cohort study on Ga-68 PSMA PET-CT scans performed between January 1, 2018 and July 31, 2021. Serum PSA data taken within one month of the PET-CT scans were also collected when available. The PET-CT images were reviewed by a radiologist for RECIST response, and by a nuclear medicine physician for PERCIST response . @*Results@#A total of 11 participants were included in the study. Six participants (55.5%) received standard therapy, while five participants (45.5%) received Lu-177 PSMA radioligand therapy plus standard therapy. There was no significant difference in the baseline and follow-up CT as shown by all p values > 0.05. A trend towards higher number of participants with non-complete/non-progressive RECIST response was noted in the control group than the treatment group, as well as higher number of participants with progressive or stable disease using the PERCIST response. @*Conclusion@#There were no significant differences noted in the clinical outcomes of participants who received Lu-177 PRLT and those with standard therapy alone. A trend towards decreasing serum PSA, CT and PET measurements were noted among patients given Lu-177 PRLT than those with standard therapy.
Subject(s)
Prostatic NeoplasmsABSTRACT
Background@#PSMA-targeted radiopharmaceuticals have been widely studied for their theragnostic role in prostate cancer and were introduced in the Philippines in 2018. The optimal administered activity of 177Lu-PSMA for targeted endoradiotherapy has not yet been established and is thought to be influenced by several factors, including tumor burden. This study investigates the effect of tumor burden on the normal tissue PSMA uptake among Filipino patients with prostate cancer using its diagnostic counterpart, 68Ga-PSMA I&T @*Methods@#One hundred four patients imaged with 68Ga-PSMA I&T PET/CT in our institution from January 2018 to May 2020 were included. Patients were visually classified into low, medium, and high tumor burden groups. Maximum and mean standardized uptake values (SUVmax and SUVmean) of the lacrimal glands, parotid glands, submandibular glands, kidneys, liver, spleen, and bone were measured and compared among tumor burden groups. @*Results and Conclusions@#68Ga-PSMA I&T uptake in the kidneys, the salivary glands, and the liver, were significantly reduced by approximately 25-50% in patients with high tumor burden. This finding supports the hypothesis that patients with higher tumor load can tolerate higher activity doses of 177Lu-PSMA for endoradiotherapy before developing significant damage to the critical organs. This may serve as a guide towards optimizing and personalizing 177Lu-PSMA I&T administered activity dose for radionuclide therapy
Subject(s)
Positron-Emission Tomography , Prostatic Neoplasms , Tumor BurdenABSTRACT
Introdução: este estudo trata do controle de qualidade do radiofármaco utilizado em estudos de PET-CT para diagnóstico e/ou estadiamento de pacientes acometidos pelo câncer de próstata. Objetivo: avaliar a qualidade do radiofármaco PSMA-11, marcado com uso de gerador de Ge68-Ga68 itinerante. Metodologia: análise do aspecto visual, pH e pureza radioquímica do radiofármaco marcado a cada recebimento do gerador de Ge68-Ga68. Resultado: todas as marcações realizadas se apresentaram límpidas quanto ao aspecto visual, o pH ficou entre 5,0 e 6,0 e a pureza radioquímica apresentou em 92% dos casos valores ≥ 96%. Conclusão: com os devidos controles de qualidade, pode ser uma opção para uso na clínica médica, em serviços que não disponham de condição para adquirir um sistema, por ser importado.
Introduction: this study works with the quality control of the radiopharmaceutical used in PET-CT studies for diagnosis and / or staging of patients affected with prostate cancer. Objective: evaluate the quality of the PSMA-11 marked radiopharmaceutical using a Ge68-Ga68 itinerant generator. Methodology: analysis of the visual aspect, pH and radiochemical purity of the marked radiopharmaceutical on each receiving of the Ge68-Ga68 generator. Results: all performed markings were clear in terms of visual appearance, pH was between 5.0 and 6.0 and radiochemical purity was 92% with value ≥ 96%. Conclusion: with proper quality controls it can be an option for application in the medical clinic, services centers unable to purchase a system due to importation process.
Subject(s)
Prostatic Neoplasms , Quality Control , Radiopharmaceuticals , Positron Emission Tomography Computed TomographyABSTRACT
Medical managements are becoming personalized while diseases are being understood at the molecular level. Nuclear medicine is one of the fields actively contributing to this development. In particular, theranostics, a combinatorial term for therapy and diagnostics, enables accurate imaging and subsequent targeted radionuclide treatment. Due to its high impact in healthcare, many countries have begun to offer Ga-68 PET/CTscans and Lu-177 therapies. The Philippines has followed suit through the initiative of this author and able support of the administration and staff of St. Luke's Medical Center. The Ga-68 DOTATATE and PSMA PET/CT scans became officially available in January 2018 while the first peptide receptor radionuclide therapy for neuroendocrine tumor and first PSMA radioligand therapy for prostate cancer occurred in May and June 2018, respectively. Amidst past, present, and future challenges, theranostics has emerged in the Philippines, offering hope to cancer patients in the country.
Subject(s)
Humans , Delivery of Health Care , Hope , Neuroendocrine Tumors , Nuclear Medicine , Philippines , Positron Emission Tomography Computed Tomography , Prostatic Neoplasms , Receptors, Peptide , Theranostic NanomedicineABSTRACT
Nuclear medicine has been offering diagnostic and therapeutic solution since the introduction of radioactive iodine for thyroid diseases since decades. However, the concept of theranostics has given a new found impetus to the use of pairs of radiopharmaceuticals for diagnosis and treatment. Presented here is a perspective on theranostics from Pakistan.
Subject(s)
Diagnosis , Iodine , Nuclear Medicine , Pakistan , Radiopharmaceuticals , Theranostic Nanomedicine , Thyroid DiseasesABSTRACT
@#In the Philippines, prostate cancer is the third most common malignancy among men. Over time, it tends to recur and/or progress to metastatic castration-resistant prostate cancer, wherein conventional therapies no longer work. Taking advantage of the high expression of prostate-specific membrane antigen (PSMA) on prostate cancer cells, 68GA- and 177 Lu-PSMA theranostics provides a targeted approach to imaging and therapy. With it's availabity in our country, patients now have an appealing and accessible treatment option. In this paper, we present five cases of metastatic castration-resistant prostate cancer, who have undergone 68Ga-PSMA PET/CT scans and 177Lu-PSMA radioligand therapies in the Philippines, to showcase the usefulness of theranostics in the local setting.
Subject(s)
Positron Emission Tomography Computed Tomography , Precision Medicine , Prostatic Neoplasms , PhilippinesABSTRACT
We report a 28 years old woman consulting for weight gain, progressive muscle weakness and appearance of facial plethora. Laboratory showed high cortisol and ACTH levels. Magnetic resonance of sella turcica was normal and an abdominal magnetic resonance showed a pancreatic mass, suggestive of a neuroendocrine tumor. A PET/CT with somatostatin analogues demonstrated an intense over-expression of somatostatin receptors in the tumor. The patient was subjected to a pancreatectomy and the day after surgery, ACTH levels decreased to less than 5 pg/ml. The patological study of the surgical piece showed a neuroendocrine carcinoma. The patient had a good postoperative evolution.
Subject(s)
Humans , Adult , Female , Organometallic Compounds , Pancreatic Neoplasms , Cushing Syndrome/etiology , Somatostatin/analogs & derivatives , Somatostatin , Neuroendocrine Tumors , Laparoscopy , Pancreatic Neoplasms/surgery , Pancreatectomy , Positron-Emission Tomography , Tomography, X-Ray Computed , Treatment Outcome , Neuroendocrine Tumors/surgeryABSTRACT
PURPOSE: We established radiolabeling conditions of NOTA and DOTA with a generator-produced PET radionuclide 68Ga and studied in vitro characteristics such as stability, serum protein binding, octanol/water distribution, and interference with other metal ions. MATERIALS AND METHODS: Various concentrations of NOTA.3HCl and DOTA.4HCl were labeled with 1 mL 68GaCl3 (0.18~5.75 mCi in 0.1 M HCl) in various pH. NOTA.3HCl (0.373 mM) was labeled with 68GaCl3 (0.183~0.232 mCi/0.1 M HCl 1.0 mL) in the presense of CuCl2, FeCl2, InCl3, FeCl3, GaCl3, MgCl2 or CaCl2 (0~6.07 mM) at room temperature. The labeling efficiencies of 68Ga-NOTA and 68Ga-DOTA were checked by ITLC-SG using acetone or saline as mobile phase. Stabilities, protein bindings, and octanol distribution coefficients of the labeled compounds also were investigated. RESULTS: 68Ga-NOTA and 68Ga-DOTA were labeled optimally at pH 6.5 and pH 3.5, respectively, and the chelates were stable for 4 hr either in the reaction mixture at room temperature or in the human serum at 37 degreesC. NOTA was labeled at room temperature while DOTA required heating for labeling. 68Ga-NOTA labeling efficiency was reduced by CuCl2, FeCl2, InCl2, FeCl3 or GaCl3, however, was not influenced by MgCl2 or CaCl2. The protein binding was low (2.04~3.32%). Log P value of 68Ga-NOTA was -3.07 indicating high hydrophilicity. CONCLUSION: We found that NOTA is a better bifunctional chelating agent than DOTA for 68Ga labeling. Although, 68Ga-NOTA labeling is interfered by various metal ions, it shows high stability and low serum protein binding.