JOSE WILLEGAIGNON DE AMORIM DE CARVALHO
Projetos de Pesquisa
Unidades Organizacionais
LIM/43 - Laboratório de Medicina Nuclear, Hospital das Clínicas, Faculdade de Medicina
15 resultados
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- Comparison of different dosimetric methods for red marrow absorbed dose calculation in thyroid cancer therapy(2012) WILLEGAIGNON, Jose; SAPIENZA, Marcelo T.; BUCHPIGUEL, Carlos A.Several dosimetric methods have been proposed for estimating red marrow absorbed dose (RMAD) when radionuclide therapy is planned for differentiated thyroid cancer, although to date, there is no consensus as to whether dose calculation should be based on blood-activity concentration or not. Our purpose was to compare RMADs derived from methods that require collecting patients' blood samples versus those involving OLINDA/EXM software, thereby precluding this invasive procedure. This is a retrospective study that included 34 patients under treatment for metastatic thyroid disease. A deviation of 10 between RMADs was found, when comparing the doses from the most usual invasive dosimetric methods and those from OLINDA/EXM. No statistical difference between the methods was discovered, whereby the need for invasive procedures when calculating the dose is questioned. The use of OLINDA/EXM in clinical routine could possibly diminish data collection, thus giving rise to a simultaneous reduction in time and clinical costs, besides avoiding any kind of discomfort on the part of the patients involved.
- Evaluation of Parotid Salivary Gland Echo Texture by Ultrasound Examinations and Correlation With Whole-Body Scintigraphy After Radioiodine Therapy in Patients With Differentiated Thyroid Carcinoma(2020) LIMA, Graziele Aparecida Simoes; LOPEZ, Rossana Veronica Mendoza; FREITAS, Ricardo Miguel Costa de; WILLEGAIGNON, Jose; SAPIENZA, Marcelo Tatit; CHAMMAS, Maria Christina; COURA-FILHO, George BarberioObjectives This study aimed to evaluate the echo texture of the parotid salivary glands before and after radioiodine therapy (RIT) using ultrasound (US) images in patients with differentiated thyroid cancer and to evaluate the correlations between post-RIT whole-body scintigraphy (WBS) images and US image patterns in salivary and cervical areas. Methods A retrospective study was performed with data on demographic and clinical information, US examinations, and WBS images collected through medical recordings. Results Comparing the US features before and after RIT, significant echo texture heterogeneity was found in 31.3% of all patients evaluated. When evaluated according to the level of iodine 131 (I-131) radioactivity (<5.6, 5.6-<9.3, and >= 9.3 GBq), echo texture heterogeneity was significantly associated with the 5.6-GBq I-131 radioactivity group (P < .001). No association was found for any level of I-131 post-RIT WBS uptake intensity and changes in US feature patterns. Conclusions Ultrasound may be a useful tool for evaluating chronic sialadenitis after RIT, and the I-131 uptake intensity using a routine post-RIT WBS is not associated with US echo texture changes.
- Clinical and Dosimetric Variables Related to Outcome After Treatment of Graves' Disease With 550 and 1110 MBq of I-131(2015) SAPIENZA, Marcelo Tatit; COURA-FILHO, George Barberio; WILLEGAIGNON, Jose; WATANABE, Tomoco; DUARTE, Paulo Schiavom; BUCHPIGUEL, Carlos AlbertoTherapy of Graves' hyperthyroidism (HTG) with I-131 is still mostly performed on an empirical basis. The present study was carried out to evaluate clinical and dosimetric variables associated with outcome in HTG therapy, which could contribute to planning and defining the most appropriate activity to be administered. Methods Patients with HTG were randomly assigned to therapy with 555 MBq (15mci) or 1110 MBq (30 mCi) of I-131. Estimation of thyroid radiation absorbed dose was made according to MIRD methodology. Success was defined as clinical/laboratory euthyroidism or hypothyroidism one year after therapy. The association between clinical, laboratory, and dosimetric variables with 1-year outcome was measured using bivariate analysis, followed by logistic regression. Results Ninety-one patients included completed the follow-up. Therapeutic success was observed in 77 (84.6%) of them, in a greater proportion when 1110 MBq of I-131 was administered as compared with 550 MBq (94.8% vs 77.4%, P = 0.02). Besides administered activity, multivariate analysis indicated that outcome was related to patient age and gland mass. A higher therapeutic success rate was achieved with doses greater than 300 Gy as compared with doses less than 300 Gy (89% vs 60%, P = 0.01). Conclusion Administered activity, age, and gland mass were related to the outcome. Radiation absorbed dose, although not significant according to multivariate analysis, may be used as a quantitative parameter in therapy planning, with a target dose of 300 Gy. In cases where a rapid and efficient response to radioiodine treatment is required, adoption of a simplified protocol employing high activities is justified.
article 3 Citação(ões) na Scopus Correlação entre volume tireoidiano determinado pelo método de ultrassonografia versus cintilografia e sua implicação em cálculos dosimétricos na terapia com radioiodo na doença de Graves(2011) VIEIRA, Lucas de Oliveira; KUBO, Rodrigo; SAPIENZA, Marcelo Tatit; WILLEGAIGNON, Jose; CHAMMAS, Maria Cristina; COURA-FILHO, George Barberio; ONO, Carla Rachel; WATANABE, Tomoco; SADO, Heitor Naoki; BUCHPIGUEL, Carlos AlbertoIntroduction: Graves disease (GD) is the most common cause of hiperthyroidism, and the most common treatment options are surgery, antithyroid drugs and radioiodine therapy. In radiodosimetric calculations to determine radioiodine dosage it is possible to use thyroid volume estimatives based on ultrasound or scintigraphy. Objective: The present study aimed to correlate these methodologies emphasizing volume estimatives and dosimetric implications. Subjects and methods: Were included 103 patients with GD diagnosis and indication of radioiodine treatment. They were submitted to thyroid ultrasound and thyroid scintigraphy. Results and conclusions: Good correlation between both methods was observed, although scintigraphy systematically obtained greater volumes than ultrasound implying in lower estimatives of absorbed dose when scintigraphy is used. Arq Bras Endocrinol Metab. 2011;55(9):696-700- Outpatient Radioiodine Therapy for Thyroid Cancer A Safe Nuclear Medicine Procedure(2011) WILLEGAIGNON, Jose; SAPIENZA, Marcelo; ONO, Carla; WATANABE, Tomoco; GUIMARAES, Maria Ines; GUTTERRES, Ricardo; MARECHAL, Maria Helena; BUCHPIGUEL, CarlosPurposes: To evaluate the dosimetric effect of outpatient radioiodine therapy for thyroid cancer in members of a patient's family and their living environment, when using iodine-131 doses reaching 7.4 GBq. The following parameters were thus defined: (a) whole-body radiation doses to caregivers, (b) the production of contaminated solid waste, and (c) radiation potential and surface contamination within patients' living quarters. Methods: In total, 100 patients were treated on an outpatient basis, taking into consideration their acceptable living conditions, interests, and willingness to comply with medical and radiation safety guidelines. Both the caregivers and the radiation dose potentiality inside patients' residences were monitored by using thermoluminescent dosimeters. Surface contamination and contaminated solid wastes were identified and measured with a Geiger-Muller detector. Results: A total of 90 monitored individuals received a mean dose of 0.27 (+/- 0.28) mSv, and the maximum dose registered was 1.6 mSv. The mean value for the potential dose within all living quarters was 0.31(+/- 0.34) mSv, and the mean value per monitored surface was 5.58 Bq/cm(2) for all the 1659 points measured. The overall production of contaminated solid wastes was at a low level, being about 3 times less than the exemption level indicated by the International Atomic Energy Agency. Conclusions: This study indicates that the treatment of thyroid cancer by applying radioiodine activities up to 7.4 GBq, on an outpatient basis, is a safe procedure, especially when supervised by qualified professionals. This alternative therapy should be a topic for careful discussion considering the high potential for reducing costs in healthcare and improving patient acceptance.
- Ultrasonography Echotexture as a surrogate for Sialadenitis secondary to I-131 Radioiodine Therapy for differentiated Thyroid Cancer: a review and metaanalysis(2020) LIMA, Graziele Aparecida Simoes; LOPEZ, Rossana Veronica Mendoza; OZORIO, Gislaine Aparecida; FREITAS, Ricardo Miguel Costa de; WILLEGAIGNON, Jose; SAPIENZA, Marcelo Tatit; CHAMMAS, Maria Christina; COURA-FILHO, George BarberioTo systematically review and analyze the medical literature to assess ultrasonography echotexture changes in thyroid cancer patients for the detection of chronic sialadenitis caused by radioiodine therapy. Methods: Sources were retrieved from PubMed, Scopus, EMBASE and LILACS through November 2018. All studies that assessed ultrasonographic features before I-131 administration and at 12 months after I-131 administration were selected. After data extraction, statistical analysis was performed by using Stata software. Results: From a total of 435 studies, 4 studies involving 665 patients were considered eligible, and echotexture heterogeneity was found with a significant difference. Conclusions: Ultrasound echotexture may detect chronic sialadenitis secondary to salivary radioiodine therapy.
- Pediatric 131I-MIBG Therapy for Neuroblastoma: Whole-Body 131I-MIBG Clearance, Radiation Doses to Patients, Family Caregivers, Medical Staff, and Radiation Safety Measures(2018) WILLEGAIGNON, Jose; CREMA, Karin Paola; OLIVEIRA, Nathalie Canhameiro; PELISSONI, Rogerio Alexandre; COURA-FILHO, George Barberio; SAPIENZA, Marcelo Tatit; BUCHPIGUEL, Carlos AlbertoPurpose I-131-metaiodobenzylguanidine (I-131-MIBG) has been used in the diagnosis and therapy of neuroblastoma in adult and pediatric patients for many years. In this study, we evaluated whole-body I-131-MIBG clearance and radiation doses received by patients, family caregivers, and medical staff to establish appropriate radiation safety measures to be used in therapy applications. Methods Research was focused on 23 children and adolescents with metastatic neuroblastoma, with ages ranging from 1.8 to 13 years, being treated with I-131-MIBG. Based on measured external dose rates from patients, dosimetric data to patients, family members, and others were calculated. Results The mean SD I-131-MIBG activity administered was 8.55 +/- 1.69 GBq. Percent whole-body retention rates of I-131-MIBG at 24, 48, and 72 hours after administration were 48% +/- 7%, 23% +/- 7%, and 12% +/- 6%, with a whole-body I-131-MIBG effective half-life of 23 +/- 5 hours for all patients. The mean doses for patients were 0.234 +/- 0.096 mGyMBq(-1) to red-marrow and 0.251 +/- 0.101 mGyMBq(-1) to whole body. The maximum potential radiation doses transmitted by patients to others at 1.0 m was estimated to be 11.9 +/- 3.4 mSv, with 97% of this dose occurring over 120 hours after therapy administration. Measured mean dose received by the 22 family caregivers was 1.88 +/- 1.85 mSv, and that received by the 19 pediatric physicians was 43 +/- 51 Sv. Conclusion In this study, we evaluated the whole-body clearance of I-131-MIBG in 23 pediatric patients, and the radiation doses received by family caregivers and medical staff during these therapy procedures, thus facilitating the establishment of radiation safety measures to be applied in pediatric therapy.
- Influence on voxel-based dosimetry: noise effect on absorbed dose dosimetry at single time-point versus sequential single-photon emission computed tomography(2023) FONDA, Uysha de S.; LEITAO, Andre L. A.; PAIVA, Marcia M. D. P.; WILLEGAIGNON, Jose; JOSEFSSON, Anders; BUCHPIGUEL, Carlos A.; SAPIENZA, Marcelo T.ObjectiveThe purpose of this study was to evaluate how statistical fluctuation in single-photon emission computed tomography (SPECT) images propagate to absorbed dose maps. MethodsSPECT/computed tomography (CT) images of iodine-131 filled phantoms, using different acquisition and processing protocols, were evaluated using STRATOS software to assess the absorbed dose distribution at the voxel level. Absorbed dose values and coefficient of variation (COV) were analyzed for dosimetry based on single time-point SPECT images and time-integrated activities of SPECT sequences with low and high counts. ResultsConsidering dosimetry based on a single time-point, the mean absorbed dose was not significantly affected by total counts or reconstruction parameters, but the uniformity of the absorbed dose maps had an almost linear correlation with SPECT noise. When high- and low-count SPECT sequences were used to generate an absorbed dose map, the absorbed dose COV for each of the temporal sequences was slightly lower than the absorbed dose COV based on the single SPECT image with the highest count included in the sequence. ConclusionThe impact of changes in SPECT counts and reconstruction parameters is almost linear when dosimetry is based on isolated SPECT images, but less pronounced when dosimetry is based on sequential SPECTs.
- Radionuclide therapy: current status and prospects for internal dosimetry in individualized therapeutic planning(2019) SAPIENZA, Marcelo Tatit; WILLEGAIGNON, JoseThe efficacy and toxicity of radionuclide therapy are believed to be directly related to the radiation doses received by target tissues; however, nuclear medicine therapy continues to be based primarily on the administration of empirical activities to patients and less frequently on the use of internal dosimetry for individual therapeutic planning. This review aimed to critically describe the techniques and clinical evidence of dosimetry as a tool for therapeutic planning and the main limitations to its implementation in clinical practice. The present article is a nonsystematic review of voxel-based dosimetry. Clinical evidence pointing to a correlation between the radiation dose and therapeutic response in various diseases, such as thyroid carcinoma, neuroendocrine tumors and prostate cancer, is reviewed. Its limitations include technical aspects related to image acquisition and processing and the lack of randomized clinical trials demonstrating the impact of dosimetry on patient therapy. A more widespread use of dosimetry in therapeutic planning involves the development of user-friendly dosimetric protocols and confirmation that dose estimation implies good efficacy and low treatment-related toxicity.
- Determining thyroid I-131 effective half-life for the treatment planning of Graves' disease(2013) WILLEGAIGNON, Jose; SAPIENZA, Marcelo T.; COURA FILHO, George Barberio; TRAINO, Antonio C.; BUCHPIGUEL, Carlos A.Purpose: Thyroid I-131 effective half-life (T-eff) is an essential parameter in patient therapy when accurate radiation dose is desirable for producing an intended therapeutic outcome. Multiple I-131 uptake measurements and resources from patients themselves and from nuclear medicine facilities are requisites for determining T-eff, these being limiting factors when implementing the treatment planning of Graves' disease (GD) in radionuclide therapy. With the aim of optimizing this process, this study presents a practical, propitious, and accurate method of determining T-eff for dosimetric purposes. Methods: A total of 50 patients with GD were included in this prospective study. Thyroidal I-131 uptake was measured at 2-h, 6-h, 24-h, 48-h, 96-h, and 220-h postradioiodine administration. T-eff was calculated by considering sets of two measured points (24-48-h, 24-96-h, and 24-220-h), sets of three (24-48-96-h, 24-48-220-h, and 24-96-220-h), and sets of four (24-48-96-220-h). Results: When considering all the measured points, the representative T-eff for all the patients was 6.95 (+/- 0.81) days, whereas when using such sets of points as (24-220-h), (24-96-220-h), and (24-48-220-h), this was 6.85 (+/- 0.81), 6.90 (+/- 0.81), and 6.95 (+/- 0.81) days, respectively. According to the mean deviations 2.2 (+/- 2.4)%, 2.1 (+/- 2.0)%, and 0.04 (+/- 0.09)% found in T-eff, calculated based on all the measured points in time, and with methods using the (24-220-h), (24-48-220-h), and (24-96-220-h) sets, respectively, no meaningful statistical difference was noted among the three methods (p > 0.500, t test). Conclusions: T-eff obtained from only two thyroid I-131 uptakes measured at 24-h and 220-h, besides proving to be sufficient, accurate enough, and easily applicable, attributes additional major cost-benefits for patients, and facilitates the application of the method for dosimetric purposes in the treatment planning of Graves' disease. (c) 2013 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4788660]