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PURPOSE: To evaluate the relationship between delivered radiation (RT) and post-RT inversion-recovery ultrashort-echo-time (IR-UTE) MRI signal-intensity (SI) in gynecologic cancer patients treated with high-dose-rate (HDR) brachytherapy (BT). METHODS: Seven patients underwent whole-pelvis RT (WPRT) followed by BT to the high-risk clinical target volume (HR-CTV). MR images were acquired at three time-points; pre-RT, post-WPRT/pre-BT, and 3-6 months post-BT. Diffuse-fibrosis (FDiffuse) was imaged with a non-contrast dual-echo IR (inversion time [TI] = 60 ms) UTE research application, with image-subtraction of the later echo, only retaining the ultrashort-echo SI. Dense-fibrosis (FDense) imaging utilized single-echo Late-Gadolinium-Enhanced IR-UTE, acquired ∼ 15 min post-Gadavist injection. Resulting FDiffuse and FDense SI were normalized to the corresponding gluteal-muscle SI. Images were deformably registered between time-points based on normal tissue anatomy. The remnant tumor at both time-points was segmented using multi-parametric MRI. Contours corresponding to the 50%, 100%, 150%, and 200% isodose lines (IDLs) of the prescription BT-dose were created. Mean FDiffuse and FDense SI within (i) each IDL contour and (ii) the remnant tumor were calculated. Post-BT FDiffuse and FDense SI were correlated with prescribed BT-dose. To determine the relationship between BT-dose and IR-UTE SI, the differences in the post-BT FDense across IDLs was determined using paired t-tests with Bonferroni correction. RESULTS: FDense was higher in regions of higher dose for 6/7 patients, with mean ± SD values of 357 ± 103% and 331 ± 97% (p = .03) in the 100% and 50% IDL, respectively. FDense was higher in regions of higher dose in the responsive regions with mean ± SD values of 380 ± 122% and 356 ± 135% (p = .03) in the 150% and 50% IDL, respectively. Within the segmented remnant tumor, an increase in prescribed dose correlated with an increase in FDense post-BT (n = 5, r = .89, p = .04). Post-BT FDiffuse inversely correlated (n = 7, r = -.83, p = .02) with prescribed BT-dose within the 100% IDL. CONCLUSIONS: Results suggest that FDense SI 3-6 months post-BT is a sensitive measure of tissue response to heterogeneous BT radiation-dose. Future studies will validate whether FDiffuse and FDense are accurate biomarkers of fibrotic radiation response.

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Evaluating gynecological mass lesions and reviewing their morphological characteristics based on their imaging appearance on magnetic resonance imaging (MRI), and correlating the MRI findings with histopathological findings, was the central theme of our study. This observational cross-sectional study was conducted on 60 female patients with clinically suspected gynecological mass lesions upon physical examination and/or ultrasonography, referred for MRI at a tertiary care hospital over a 1-year period between June 2022 and July 2023. A broad spectrum of differential diagnoses of gynecological masses was observed. In our study, the ratio of benign versus malignant disease was 1.6:1, with 37 benign and 23 malignant masses identified. The most common benign masses were uterine fibroids (n = 14; 23.3%), followed by endometriosis (n = 8; 13.3%), and ovarian dermoid cysts (n = 4; 6.6%). Among the malignant lesions, cervical cancer was the most common (n = 11; 18.3%), followed by endometrial carcinoma (n = 7; 11.6%), ovarian carcinoma (n = 3; 5%), and vaginal carcinoma (n = 2; 3%). Benign lesions mostly appeared hypo- to isointense on T1-weighted imaging and iso- to hyperintense on T2-weighted imaging, while malignant lesions appeared isointense on T1-weighted and hyperintense on T2-weighted imaging. Hemorrhage and fat were well appreciated on MRI and aided in diagnosis. T2 shading was present in 7 out of 8 endometriotic cysts, demonstrating a specificity of 100% and a sensitivity of 83%. For determining parametrial invasion in cervical carcinoma, MRI showed an accuracy of 91%, specificity of 100%, and positive predictive value, negative predictive value, and sensitivity of 100%, 75%, and 88%, respectively. In cases of endometrial carcinoma, MRI demonstrated a sensitivity and specificity of 87% and 91%, respectively, with a positive predictive value of 87% and a negative predictive value of 91% for identifying myometrial invasion greater than 50%. Compared to other modalities, MRI provided substantial information regarding uterine and adnexal masses and surrounding structures, facilitating accurate staging of lesions.

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High dose-rate brachytherapy is a treatment technique for gynecologic cancers where intracavitary applicators are placed within the patient's pelvic cavity. To ensure accurate radiation delivery, localization of the applicator at the time of insertion is vital. This study proposes a novel method for acquiring, registering, and fusing three-dimensional (3D) trans-abdominal and 3D trans-rectal ultrasound (US) images for visualization of the pelvic anatomy and applicators during gynecologic brachytherapy. The workflow was validated using custom multi-modal pelvic phantoms and demonstrated during two patient procedures. Experiments were performed for three types of intracavitary applicators: ring-and-tandem, ring-and-tandem with interstitial needles, and tandem-and-ovoids. Fused 3D US images were registered to magnetic resonance (MR) and computed tomography (CT) images for validation. The target registration error (TRE) and fiducial localization error (FLE) were calculated to quantify the accuracy of our fusion technique. For both phantom and patient images, TRE and FLE across all modality registrations (3D US versus MR or CT) resulted in mean ± standard deviation of 4.01 ± 1.01 mm and 0.43 ± 0.24 mm, respectively. This work indicates proof of concept for conducting further clinical studies leveraging 3D US imaging as an accurate, accessible alternative to advanced modalities for localizing brachytherapy applicators.

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Purpose. To evaluate the feasibility of use of an 1.5 T magnetic resonance (MR)-linear accelerator MR-linac for imaging in gynaecologic high-dose-rate (HDR) brachytherapy.Method. Commissioning measurements for MR images quality control, geometric distortion, dwell position accuracy, applicator reconstruction and end-to-end test for a tandem-and-ring applicator were performed following the recommendations of American Brachytherapy Society, International Commission on Radiation Units and Measurements and Report of the Brachytherapy Working Group of the Spanish Society of Medical Physics. The values for MR-based IGABT were compared to the corresponding values with computed tomography (CT).Results. Measured distorsions for the MR images were less than 0.50 mm compared to the CT images. The differences between 3D displacements for all dwell positions were 0.66 mm and 0.62 mm for the tandem and ring, respectively. The maximum difference is 0.64 mm for the distances from the applicator tip obtained using the films. The CT and MR dose differences for the right and left 'A' points were 0.9% and -0.7%, respectively. Similar results were observed in terms of dose distribution for CT and Mr The gamma passing rate was 99.3% and 99.5%, respectively.Conclusion. The use of MR images from an MR-linac used in a radiotherapy service for gynaecological brachytherapy was proved to be feasible, safe and precise as the geometrical differences were less than 1 mm, and the dosimetric differences were less than 1% when comparing to the use of CT images for the same purpose.

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PURPOSE: We developed a 3D-printed phantom model for ultrasound-guided caudal block for educational or training purposes because there have been no reports of the 3D-printed phantom model for ultrasound-guided caudal block. This study aimed to identify the needs for the phantom model in a lecture and demonstration at hands-on training (HoT) to promote the use of caudal block for sufficient pain control during high-dose-rate intracavitary/interstitial brachytherapy for gynecological cancers. MATERIALS AND METHODS: The sacrum and formwork were designed by computed tomography imaging. A 3D-modeling software program was used to create the sacrum and formwork. The phantom was solidified by injecting a gelatin-based gel. Ultrasonography was performed to visualize the sacral hiatus and puncture needle in the phantom. In October 2023, 10 radiation oncologists who did not perform caudal block in daily clinical practice from ten Japanese facilities participated in HoT on ultrasound-guided caudal block. After the HoT, questionnaires were distributed to each participant, and feedback was obtained through online channels. RESULTS: After receiving a lecture and demonstration on ultrasound-guided caudal block, 90% of the respondents would like to practice the procedure in their daily clinical practice. Moreover, 100% of the respondents would like to use the 3D-printed phantom model for ultrasound-guided caudal block for educational or training purposes. CONCLUSION: The 3D-printed phantom model for ultrasound-guided caudal block can be used in training and is in demand for facilities introducing caudal block.

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In the Radiotherapy Centre of the National Institute of Oncology, Budapest, a 0.55 T MR scanner (MAGNETOM Free. Max) and a ring-like X-ray machine (ImagingRing) have been in operation since 2022. The MR scanner has a tunnel diameter of 80 cm, the X-ray machine has a ring diameter of 121 cm. The latter can also be used for cone-beam CT (CBCT) imaging. The MR scanner is mainly used for planning gynaecological brachytherapy (BT) treatments. Image distortions in MR imaging were investigated with a special grid phantom. After head and neck and breast implant, image quality of ImagingRing CBCT and planning CT was compared. The position of the radiation source was verified by radiographs taken during treatment. Despite the lower field strength, the image quality of the MR scanner was found to be adequate for treatment planning of gynaecological BT. Image distortions were found to be clinically negligible. On CBCT images obtained with ImagingRing, catheters could always be well identified, and anatomical organs were adequately visualized for head and neck treatments, but not for breast implants. The MR scanner is suitable for treatment planning for gynaecological BT due to its good image quality and low image distortion. The image quality of the ImagingRing is suitable for treatment planning for small body sizes, but not for larger sizes. The device can be used to in vivo check of the radiation source position during treatment.

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PURPOSE OF REVIEW: In the past decade, sentinel lymph node (SLN) mapping has progressively substituted full lymphadenectomies in gynecologic oncology. In this article, we review the most relevant and the latest literature on this topic. RECENT FINDINGS: In endometrial and cervical cancer, the current evidence further support the value of indocyanine green (ICG) as tracer of choice for SLN mapping. Experience in vulvar cancer is more limited, with ICG used together with technetium-99 m (Tc-99m) as a dual tracer but ICG, so far, has not been a game changer in this setting as it has been for cervical and endometrial cancer. SUMMARY: For most gynecologic cancers, ICG fluorescence imaging is considered now a days the tracer of choice for lymphatic mapping. However, in early-stage vulvar cancer, SLN biopsy with radioactive tracer continues to be the standard-of-care in lymph node status assessment.

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OBJECTIVE: To assess the diagnostic performance of transvaginal sonography (TVS) for the preoperative evaluation of lymph-node metastasis in gynecological cancer. METHODS: This was a systematic review and meta-analysis of studies published between January 1990 and May 2023 evaluating the role of ultrasound in detecting pelvic lymph-node metastasis (index test) in gynecological cancer, using histopathological analysis as the reference standard. The quality of included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Pooled sensitivity, specificity and diagnostic odds ratio were estimated. RESULTS: The literature search identified 2638 citations. Eight studies reporting on a total of 967 women were included. The mean prevalence of pelvic lymph-node metastasis was 24.2% (range, 14.0-65.6%). The risk of bias was low for most domains assessed. Pooled sensitivity, specificity and diagnostic odds ratio of TVS were 41% (95% CI, 26-58%), 98% (95% CI, 93-99%) and 32 (95% CI, 14-72), respectively. High heterogeneity was found between studies for both sensitivity and specificity. CONCLUSION: TVS showed a high pooled specificity for the detection of pelvic lymph-node metastasis in gynecological cancer, but pooled sensitivity was low. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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In recent years the role of diagnostic imaging by pelvic ultrasound in the diagnosis and staging of gynecological cancers has been growing exponentially. Evidence from recent prospective multicenter studies has demonstrated high accuracy for pre-operative locoregional ultrasound staging in gynecological cancers. Therefore, in many leading gynecologic oncology units, ultrasound is implemented next to pelvic MRI as the first-line imaging modality for gynecological cancer. The work herein is a consensus statement on the role of pre-operative imaging by ultrasound and other imaging modalities in gynecological cancer, following European Society guidelines.

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Gynecological malignancies, such as ovarian cancers, cervical cancers, and endometrial cancers, have a significant global impact. Women with gynecologic malignancies may receive a single or a combination of treatments, including surgery, chemotherapy, and radiation-based therapies. Radiologists utilize various diagnostic imaging modalities to provide the surgeon with relevant information about the diagnosis, prognosis, optimal surgical strategy, and prospective post-treatment imaging. Computerized Tomography (CT) and magnetic resonance imaging (MRI) may be used initially to evaluate and detect post-treatment complications. Although CT is primarily used for staging, MRI is commonly used for a more accurate evaluation of a tumor's size and detection of local invasion. Complications such as hematoma, abscess, inclusion cyst, seroma, tumor thrombosis, anorectovaginal fistula, and gossypiboma may occur after the three primary treatments, and systems such as the genitourinary, gastrointestinal, neurological, and musculoskeletal may be affected. In order to distinguish between early-onset and late-onset complications following gynecological treatment, radiological findings of the most common post-treatment complications will be presented in this review.

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Gynecologic malignancies, consisting of endometrial, cervical, ovarian, vulvar, and vaginal cancers, pose significant diagnostic and management challenges due to their complex anatomic location and potential for rapid progression. These tumors cause substantial morbidity and mortality, often because of their delayed diagnosis and treatment. An estimated 19% of newly diagnosed cancers among women are gynecologic in origin. In recent years, there has been growing evidence supporting the integration of nuclear medicine imaging modalities in the diagnostic work-up and management of gynecologic cancers. The sensitivity of fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) combined with the anatomical specificity of computed tomography (CT) and magnetic resonance imaging (MRI) allows for the hybrid evaluation of metabolic activity and structural abnormalities that has become an indispensable tool in oncologic imaging. Lymphoscintigraphy, using technetium 99m (99mTc) based radiotracers along with single photon emission computed tomography/ computed tomography (SPECT/CT), holds a vital role in the identification of sentinel lymph nodes to minimize the surgical morbidity from extensive lymph node dissections. While not yet standard for gynecologic malignancies, promising therapeutic nuclear medicine agents serve as specialized treatment options for patients with advanced or recurrent disease. This article aims to provide a comprehensive review on the nuclear medicine applications in gynecologic malignancies through the following objectives: 1) To describe the role of nuclear medicine in the initial staging, lymph node mapping, response assessment, and recurrence/surveillance imaging of common gynecologic cancers, 2) To review the limitations of 18F-FDG PET/CT and promising applications of 18F-FDG PET/MRI in gynecologic malignancy, 3) To underscore the promising theragnostic applications of nuclear medicine, 4) To highlight the current role of nuclear medicine imaging in gynecologic cancers as per the National Comprehensive Cancer Network (NCCN), European Society of Surgical Oncology (ESGO), and European Society of Medical Oncology (ESMO) guidelines.

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PURPOSE: The aim of this review is to give an overview of the current status of molecular image-guided surgery in gynaecological malignancies, from both clinical and technological points of view. METHODS: A narrative approach was taken to describe the relevant literature, focusing on clinical applications of molecular image-guided surgery in gynaecology, preoperative imaging as surgical roadmap, and intraoperative devices. RESULTS: The most common clinical application in gynaecology is sentinel node biopsy (SNB). Other promising approaches are receptor-target modalities and occult lesion localisation. Preoperative SPECT/CT and PET/CT permit a roadmap for adequate surgical planning. Intraoperative detection modalities span from 1D probes to 2D portable cameras and 3D freehand imaging. CONCLUSION: After successful application of radio-guided SNB and SPECT, innovation is leaning towards hybrid modalities, such as hybrid tracer and fusion of imaging approaches including SPECT/CT and PET/CT. Robotic surgery, as well as augmented reality and virtual reality techniques, is leading to application of these innovative technologies to the clinical setting, guiding surgeons towards a precise, personalised, and minimally invasive approach.

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PURPOSE: To demonstrate image-guided preplan workflows for high-dose-rate (HDR) brachytherapy for advanced gynecological malignancies. METHODS AND MATERIALS: Two different preplanning scenarios are presented: (1) CT- or MRI-based preplan with partial applicator in place; (2) Preplans generated from prior fractions. The first scenario can be applied to Syed-Neblett template-based implants or hybrid brachytherapy applicators, while the second scenario applies to hybrid applicators. Both scenarios use MRI or CT images acquired with the applicator in place to demonstrate tumor and applicator relative locations and therefore, provide the ability to show optimized suggested needle positions including the implant depths before the actual insertion. RESULTS: The preplanning techniques have demonstrated feasibility and shown five areas of potential improvement: (1) shorter procedure time, (2) decreased number of total needles inserted, (3) shorter physician tumor contour time, (4) shorter planning time, and (5) evaluation of appropriateness for brachytherapy. CONCLUSIONS: The use of image-guided brachytherapy preplanning improves clinical efficiency and is recommended for consideration for adaptation into clinical workflows for HDR interstitial and hybrid brachytherapy.

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PURPOSE: Historical gynecologic interstitial brachytherapy templates block direct tumor visualization during needle placement, presenting an opportunity for clinical innovation to develop a novel interstitial template allowing direct tumor visualization during needle insertion. METHODS AND MATERIALS: We designed and implemented a novel interstitial template, simple needle attachment post placement interstitial template (SNAPP-IT), that allowed direct visualization of the target vaginal tumor during interstitial needle placement while maintaining the ability to individually secure needles to the template, allow a vaginal cylinder, suture holes for securing to the perineum, MRI compatibility and sterilizable for repeat use. Procedure outcomes including procedure time, needle path lengths, and plan dosimetry were prospectively captured in a patient database. RESULTS: Forty gynecologic interstitial brachytherapy cases were recorded (20 SNAPP-IT, 20 traditional templates). Needle insertion depth was reduced using the SNAPP-IT in comparison with traditional interstitial templates (11.8 cm vs. 3.6 cm, p < 0.0001). The average CTV volume was 25.6 cc for SNAPP-IT and 20.7 cc for traditional; both methods averaged a similar number of needles (15.8, 15.6). Dosimetric constraints were similarly met in both treatment groups. Procedures performed using the SNAPP-IT were shorter compared with those performed with traditional interstitial devices (83.4 minutes vs. 100.7 minutes) and there were no post-operative infections in the SNAPP-IT group. CONCLUSIONS: Implementation of a novel gynecologic interstitial brachytherapy template (SNAPP-IT) reduced procedure times, allowed direct tumor visualization, and decreased needle insertion depth. SNAPP-IT provides a useful alternative approach for vaginal interstitial brachytherapy, may increase brachytherapist efficiency with complex procedures and potentially expands access to interstitial brachytherapy.

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PURPOSE: To demonstrate novel clinical implementation of a 3D transvaginal ultrasound (3DTVUS) system for intraoperative needle insertion guidance in perineal template interstitial gynecologic high-dose-rate brachytherapy and assess its impact on implant quality. METHODS AND MATERIALS: Interstitial implants began with preimplant 3DTVUS to visualize the tumor and anatomy, with intermittent 3DTVUS to assess the implant and guide needle adjustment. Analysis includes visualization of the implant relative to anatomy, identification of cases where 3DTVUS is beneficial, dosimetry, and a survey distributed to 3DTVUS clinicians. RESULTS: Seven patients treated between November 2021 and October 2022 were included in this study. Twenty needles were inserted under 3DTVUS guidance. The tumor and vaginal wall were well-differentiated in four and all seven patients, respectively. Patients with tumours below the superior aspect of the vagina are suited for 3DTVUS. Four radiation oncologists responded to the survey. There was general agreement that 3DTVUS improves implant and anatomy visualization and is preferred over standard 2D ultrasound guidance techniques. CONCLUSIONS: Based on qualitative feedback from primary users and a small preliminary patient cohort, 3DTVUS imaging improves tumor and vaginal wall visualization during gynecologic perineal template interstitial needle implant and is a powerful tool for implant assessment in an intraoperative setting.

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Fluorine 18-fluorodeoxyglucose (FDG) PET and MRI independently play a valuable role in the management of patients with gynecologic malignancies, particularly endometrial and cervical cancer. The PET/MRI hybrid imaging technique combines the metabolic information obtained from PET with the excellent soft-tissue resolution and anatomic details provided by MRI in a single examination. MRI is the modality of choice for assessment of local tumor extent in the pelvis, whereas PET is used to assess for local-regional spread and distant metastases. The authors discuss the added value of FDG PET/MRI in imaging gynecologic malignancies of the pelvis, with a focus on the role of FDG PET/MRI in diagnosis, staging, assessing treatment response, and characterizing complications. PET/MRI allows better localization and demarcation of the extent of disease, characterization of lesions and involvement of adjacent organs and lymph nodes, and improved differentiation of benign from malignant tissues, as well as detection of the presence of distant metastasis. It also has the advantages of decreased radiation dose and a higher signal-to-noise ratio of a prolonged PET examination of the pelvis contemporaneous with MRI. The authors provide a brief technical overview of PET/MRI, highlight how simultaneously performed PET/MRI can improve stand-alone MRI and PET/CT in gynecologic malignancies, provide an image-rich review to illustrate practical and clinically relevant applications of this imaging technique, and review common pitfalls encountered in clinical practice. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

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Patients with gynecologic malignancies often require a multimodality imaging approach for initial staging, treatment response assessment, and surveillance. MRI imaging and PET are two well-established and widely accepted modalities in this setting. Although PET and MRI imaging are often acquired separately on two platforms (a PET/computed tomography [CT] and an MRI imaging scanner), hybrid PET/MRI scanners offer the potential for comprehensive disease assessment in one visit. Gynecologic malignancies have been one of the most successful areas for implementation of PET/MRI. This article provides an overview of the role of this platform in the care of patients with gynecologic malignancies.

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