OBJECTIVE: To determine uterine artery resistance index (RI) and pulsatility index (PI) during the first and second trimesters of pregnancy. MATERIALS AND METHODS: The authors developed a prospective longitudinal study with 44 healthy women at their 8th-12th and 22nd gestational weeks. Doppler velocimetry was utilized for evaluating RI and PI of both uterine arteries, with a sample volume of 1 to 2 mm, a 50-70 Hz filter, and an insonation angle < 60°. RESULTS: At 8th-12th gestational weeks, the uterine artery RI and PI were higher than at the 22nd gestational week. At the first trimester uterine artery RI and PI were, respectively, 0.83 ± 0.07 and 2.32 ± 0.79 with a notch, and 0.71 ± 0.16 and 1.61 ± 0.78, without a notch. At the second trimester, uterine artery RI and PI were, respectively, 0.59 ± 0.09 and 1.03 ± 0.32 with a notch, and 0.44 ± 0.09 and 0.63 ± 0.19 without a notch. CONCLUSION: Reference values for uterine arteries RI and PI at the first and second trimesters of pregnancy were established.

Keywords: Doppler effect, Uterine artery, Preeclampsia

OBJECTIVE: To evaluate, by means of magnetic resonance imaging, the standardized field borders in radiotherapy for malignant neoplasm of uterine cervix, and to determine the role of this method in the reduction of possible planning errors related to the conventional technique. MATERIALS AND METHODS: Magnetic resonance imaging studies for planning of treatment of 51 patients with uterine cervix cancer were retrospectively analyzed. The parameters assessed were the anterior and posterior field borders on sagittal section. RESULTS: The anterior field border was inappropriate in 20 (39.2%) patients and geographic miss was observed in 37.3% of cases in the posterior border. The inappropriateness of both field borders did not correlate with clinical parameters such as patients' age, tumor staging, histological type and degree. CONCLUSION: The evaluation of standardized field borders with the use of magnetic resonance imaging has demonstrated high indices of inappropriateness of the lateral field borders, as well as the relevant role of magnetic resonance imaging in the radiotherapy planning for patients with uterine cervix cancer with a view to reduce the occurrence of geographic miss of the target volume.

Keywords: Uterine cervix cancer, Radiotherapy planning, Magnetic resonance imaging, Geographic miss, Tumor volume

OBJECTIVE: The present study was aimed at developing a thermoluminescent dosimetric system capable of assessing the doses delivered to the rectum of patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. MATERIALS AND METHODS: LiF:Mg,Ti,Na powder was the thermoluminescent material utilized for evaluating the rectal dose. The powder was divided into small portions (34 mg) which were accommodated in a capillary tube. This tube was placed into a rectal probe that was introduced into the patient's rectum. RESULTS: The doses delivered to the rectum of six patients submitted to high-dose-rate brachytherapy for uterine cervix cancer evaluated by means of thermoluminescent dosimeters presented a good agreement with the planned values based on two orthogonal (anteroposterior and lateral) radiographic images of the patients. CONCLUSION: The thermoluminescent dosimetric system developed in the present study is simple and easy to be utilized as compared to other rectal dosimetry methods. The system has shown to be effective in the evaluation of rectal doses in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer.

Keywords: Rectum, Brachytherapy, HDR, Thermoluminescent dosimetry, Uterine cervix cancer

OBJECTIVE: To evaluate an alternative brachytherapy technique for uterine cervix cancer involving the distal vagina, without increasing the risk of toxicity. MATERIALS AND METHODS: Theoretical study comparing three different high-dose rate intracavitary brachytherapy applicators: intrauterine tandem and vaginal cylinder (TC); tandem/ring applicator combined with vaginal cylinder (TR+C); and a virtual applicator combining both the tandem/ring and vaginal cylinder in a single device (TRC). Prescribed doses were 7 Gy at point A, and 5 Gy on the surface or at a 5 mm depth of the vaginal mucosa. Doses delivered to the rectum, bladder and sigmoid colon were kept below the tolerance limits. Volumes covered by the isodoses, respectively, 50% (V50), 100% (V100), 150% (V150) and 200% (V200) were compared. RESULTS: Both the combined TR+C and TRC presented a better dose distribution as compared with the TC applicator. The TR+C dose distribution was similar to the TRC dose, with V150 and V200 being about 50% higher for TR+C (within the cylinder). CONCLUSION: Combined TR+C in a two-time single application may represent an alternative therapy technique for patients affected by uterine cervix cancer involving the distal vagina.

Keywords: Cervical cancer, Radiotherapy, Intracavitary brachytherapy, Dosimetry

Uterine malformations are unusual findings in the clinical practice of gynecology. Statistics regarding this abnormality are flawed, and there is a lack of standardization of the pertinent terminology, besides difficulty in the diagnosis. Starting in the 1980's, ultrasound became a procedure indispensable to the clinical practice in the field of tocogynecology, modifying concepts and procedures, and bringing an important contribution to this specialty. The advent of endocavitary transducers, amplitude and spectral color Doppler, as well as the increasing improvement in the imaging quality, has contributed to this progress. Over the last ten years, much has been studied, published and discussed about the role of the three-dimensional ultrasonography. The authors review the topic and emphasize the importance of this method as a diagnostic modality.

Keywords: Uterine malformations, Müllerian malformations, Three-dimensional ultrasonography

OBJECTIVE: To estimate which is the best period to realize uterine artery Doppler for the prediction of pregnancy complications. MATERIALS AND METHODS: A prospective study was conducted with 45 women without a history of chronic diseases and in their first pregnancy. The uterine artery Doppler was performed between the pregnancy weeks 18-20, 24-26, 28-30 and 34-36, with determination of the resistance index, the pulsatility index, the A/B ratio and presence or absence of notch on the flow velocity waveform, as well as the result of the pregnancy. RESULTS: The Doppler index showed decrease in the course of the pregnancy, more pronounced in the normal pregnancies in comparison with the complicated pregnancies. This was most noticed in the examinations performed between the weeks 24-26. The best sensitivity/specificity relation for detecting pregnancy complications was achieved in the examination performed in this same period. CONCLUSION: The best period to perform uterine artery Doppler for prediction of pregnancy complications is between weeks 24-26 of gestation.

Keywords: Doppler, Uterine artery, Preeclampsia, Intrauterine growth restriction

The measurement of cervical length utilizing transvaginal ultrasound is of help for pregnant women screening for premature labor, the shortening of the cervix being a predictor of higher risk of preterm delivery. Traditional methods for evaluating the uterine cervix during pregnancy are limited and unsatisfactory. Digital examination of cervix, considered as the standard method, demonstrates large variation among different examiners; on the other hand, transvaginal sonography is an effective method of examination during pregnancy. Recently, three-dimensional ultrasound has been used in the clinical practice including the study of uterine cervix. The three-dimensional technology allows acquisition and storage of a large volume of data. Such stored information can be reformatted and analyzed through an unlimited number of planes. The three-dimensional transvaginal ultrasound is the unique imaging method capable of obtaining a true coronal plane by direct correlation of the views in a multiplanar display. This method seems to offer a diagnostic potential because of the cervical ultrasonography increased accuracy.

Keywords: Uterine cervix, Pregnancy, Three-dimensional ultrasonography

OBJECTIVE: To present the solidly established traceability structure for ionometric standards and for thermoluminescent dosimetry system that ensures reliability of the Dosimetry Quality Assurance Program and is aimed to certify the highest level of accuracy of the measurements. MATERIALS AND METHODS: Thermoluminescent powder dosimeters (DTL 937) placed into plastic capsules and packed in specific kits for each intended application were mailed to the participant centers. RESULTS: The results of the intercomparisons performed between "Laboratório de Ciências Radiológicas da Universidade do Estado do Rio de Janeiro" and EQUAL-ESTRO for the beam of 60Co gamma rays, expressed for (1sigma), and the results of the dose absorbed measurements obtained with the chambers of the Program EQUAL and the chambers of the Dosimetry Quality Assurance Program were lower than 0.5%. CONCLUSION: Based on these results we concluded that the Dosimetry Quality Assurance Program reached the desired level of reliability to allow its implementation.

Keywords: Quality assurance, Radiotherapy, Dosimetric intercomparison, Thermoluminescent dosimetry, TLD

OBJECTIVE: To assess the rate of geographic miss on conventional radiotherapy planning of patients with cervical cancer, using magnetic resonance imaging. MATERIALS AND METHODS: Thirty-two patients with squamous cell carcinoma of the uterine cervix were studied. Magnetic resonance imaging of the pelvis was performed after clinical staging. Magnetic resonance imaging findings were compared with the classic fields described for the "box" technique. Target volume within less than 1 cm margins of the fields' limits was considered as geographic miss. RESULTS: Classical radiation field limits were inadequate in 24 cases (75%), all in the anterior (46%) or posterior (40%) border of the lateral fields. CONCLUSION: Magnetic resonance detected a high probability of geographic miss on conventional radiotherapy planning in this population, both in initial and advanced stages of the disease.

Keywords: Uterine cervix cancer, Radiotherapy, Magnetic resonance imaging

PURPOSE: To report the initial clinical experience after the treatment of 100 women suffering of symptomatic fibroids who were submitted to uterine artery embolization as the main form of treatment. We also present an extensive review of literature on the subject in order to determine the indications and contra-indications, and the possible complications of this method.
MATERIAL AND METHOD: One hundred patients with symptomatic fibroids were submitted to uterine artery embolization as the main form of treatment. The main symptoms that justified the intervention were increased menstrual flow in 79 patients and pain related to the fibroids in 21 patients. Diagnosis was made using ultrasound alone in 75 patients and ultrasound and magnetic resonance imaging in 25 patients. The mean uterine volume measured using these imaging methods was 487cm³. The procedure was performed in two Institutions: 56 procedures in a public Institution in patients attended by the public health system, and 46 patients with health insurance treated in a private clinic. Seventy-six patients were followed clinically during 12 weeks after uterine embolization.
RESULTS: The procedure was done with success in 97% of cases using a conventional technique. Clinical follow-up after 12 weeks showed symptomatic improvement in over 90% of the patients. Reductions of the uterine volume of up to 52% were also observed. No relevant technical and/or clinical complications were seen.
CONCLUSION: Uterine artery embolization for the treatment of symptomatic fibroids is a simple, efficient and safe procedure.

Keywords: Fibroids; Uterine embolization; Gynecologic neoplasm; Menorrhagia.

Objective: To evaluate the possible repercussions of the previous cesarean scar at uterine arteries Doppler velocimetry between the 26th and 32nd gestational weeks. Materials and Methods: Prospective cross-sectional study including 45 women between 11 and 14 weeks of gestation, divided into three groups: 17 pregnant women with uterine scar resulting from a previous elective cesarean section (group A); 14 with uterine scar resulting from a previous cesarean section performed during labor (group B); and 14 pregnant women with a single previous vaginal delivery (group C). Uterine arteries Doppler velocimetry was performed with transabdominal approach. Means, medians and standard deviation (SD) were calculated for each group in the study. The groups comparison regarding pulsatility index was performed with the non-parametric Kruskal-Wallis test. Results: In group A, the pulsatility index ranged from 0.60 to 1.60 (mean: 0.90; SD: 0.29), in group B, from 0.53 to 1.43 (mean: 0.87; SD: 0.24), and in group C, from 0.65 to 1.65 (mean: 1.01; SD: 0.37); with p = 0.6329. Conclusion: No repercussion of previous cesarean scar was observed at uterine arteries Doppler velocimetry performed in the period between the 26th and 32nd gestational weeks.

Keywords: Pregnancy; Uterine scar; Previous cesarean section; Uterine arteries Doppler velocimetry.

OBJECTIVE: The present paper is aimed at presenting a comparative dosimetric study of prostate brachytherapy with I-125 and Pd-103 seeds. MATERIALS AND METHODS: A protocol for both implants with 148 seeds was simulated on a heterogeneous three-dimensional pelvic phantom by means of the SISCODES/MCNP5 codes. Dose-volume histograms on prostate, rectum and bladder, dose indexes D₁₀, D₃₀, D₉₀, D_0.5cc, D_2cc and D_7cc, and representations of the spatial dose distribution were evaluated. RESULTS: For a D₉₀ index equivalent to the prescription dose, the initial activity of each I-125 seed was calculated as 0.42 mCi and of Pd-103 as 0.94 mCi. The maximum dose on the uretra was 90% and 108% of the prescription dose for I-125 and Pd-103, respectively. The D_2cc for I-125 was 30 Gy on the rectum and 127 Gy on the bladder; for Pd-103 was 29 Gy on the rectum and 189 Gy on the bladder. The D₁₀ on the pubic bone was 144 Gy for I-125 and 66 Gy for Pd-103. CONCLUSION: The results indicate that Pd-103 and I-125 implants could deposit the prescribed dose on the target volume. Among the findings of the present study, there is an excessive radiation exposure of the pelvic bones, particularly with the I-125 protocol.

Keywords: Radiotherapy; Dosimetry; Prostate cancer; Brachytherapy; SISCODES; MCNP.

OBJECTIVE: Aiming at contributing to the knowledge on doses in computed tomography (CT), this study has the objective of determining dosimetric quantities associated with pediatric abdominal CT scans, comparing the data with diagnostic reference levels (DRL). MATERIALS AND METHODS: The study was developed with a Toshiba Asteion single-slice CT scanner and a GE BrightSpeed multi-slice CT unit in two hospitals. Measurements were performed with a pencil-type ionization chamber and a 16 cm-diameter polymethylmethacrylate trunk phantom. RESULTS: No significant difference was observed in the values for weighted air kerma index (C_W), but the differences were relevant in values for volumetric air kerma index (C_VOL), air kerma-length product (P_KL,CT) and effective dose. CONCLUSION: Only the C_W values were lower than the DRL, suggesting that dose optimization might not be necessary. However, P_KL,CT and effective dose values stressed that there still is room for reducing pediatric radiation doses. The present study emphasizes the importance of determining all dosimetric quantities associated with CT scans.

Keywords: Pediatric computed tomography scans; Dosimetric quantities; Weighted dose index; Volumetric air kerma index; Air kermalength product.

OBJECTIVE: This article presents a way to obtain estimates of dose in patients submitted to radiotherapy with basis on the analysis of regions of interest on nuclear medicine images. MATERIALS AND METHODS: A software called DoRadIo (Dosimetria das Radiações Ionizantes [Ionizing Radiation Dosimetry]) was developed to receive information about source organs and target organs, generating graphical and numerical results. The nuclear medicine images utilized in the present study were obtained from catalogs provided by medical physicists. The simulations were performed with computational exposure models consisting of voxel phantoms coupled with the Monte Carlo EGSnrc code. The software was developed with the Microsoft Visual Studio 2010 Service Pack and the project template Windows Presentation Foundation for C# programming language. RESULTS: With the mentioned tools, the authors obtained the file for optimization of Monte Carlo simulations using the EGSnrc; organization and compaction of dosimetry results with all radioactive sources; selection of regions of interest; evaluation of grayscale intensity in regions of interest; the file of weighted sources; and, finally, all the charts and numerical results. CONCLUSION: The user interface may be adapted for use in clinical nuclear medicine as a computer-aided tool to estimate the administered activity.

Keywords: Nuclear medicine; Biokinetic distribution; Dosimetric evaluations; Administered activity.

OBJECTIVE: To evaluate the safety and efficacy of using highly compressible calibrated microspheres in uterine artery embolization (UAE) for the treatment of uterine fibroids. MATERIALS AND METHODS: This was a prospective multicenter study. Thirty-two women with symptomatic uterine fibroids were selected for UAE between January 2019 and March 2020. The participants completed the Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire, underwent contrast-enhanced pelvic magnetic resonance imaging (MRI), and were submitted to anti-Müllerian hormone measurement, subsequently undergoing UAE with Embosoft microspheres. After six months, the patients again completed the UFS-QOL questionnaire and underwent pelvic MRI. RESULTS: The most common symptoms were abnormal uterine bleeding (in 81.3% of the cases), pelvic pain (in 81.3%), and compression (in 46.9%). Of the 32 patients evaluated, 12 (37.5%) had anemia due to abnormal uterine bleeding. Thirty patients completed the study. Among those patients, we observed median reductions of 21.4% in uterine volume and 15.9% in dominant fibroid volume. We identified no adverse events that could be attributed to the material itself, although there were events attributed to the UAE procedure in general. CONCLUSION: For the treatment of uterine fibroids, UAE using Embosoft microspheres shows satisfactory results, providing reductions in uterine and dominant fibroid volumes, with a low rate of adverse events, and improving patient quality of life, as well as demonstrating safety and efficacy.

Keywords: Leiomyoma; Uterine artery; Uterine artery embolization; Microspheres.