Project description:MR Imaging is regarded asthe gold standardfor Image Gudied Adaptive Brachytherapy (IGABT) for cervical cancer. However, its wide applicability is limited by its availability, logistics and financial implications. Use of alternative imaging like CTand Ultrasound (US) for IGABT has been attempted. In order to arrive at a systematic, uniform and international approach for CT based definition and contouring of target structures, GEC ESTRO, IBS and ABS agreed to jointly develop such recommendations based on the concepts and terms as published in the ICRU Report 89. The minimum requirements are clinical examination & documentation, CT or MR imaging at diagnosis and at a minimum, CT imaging with the applicator in place. The recommendations are based on (i) assessment of the GTV at diagnosis and at brachytherapy, (ii) categorizing the response to external radiation into different clinical remission patterns, (iii) defining various clinico-radiological environments and (iv) definition & delineation of a target on CT imaging at the time of brachytherapy with the applicator in situ. CT based target contouring recommendations based on 4 remission categories within 8 defined environments, aim at improving the contouring accuracy for IGABT using CT, US and MRI as available. For each clinico-radiological environment, there is an attempt to minimize the specific uncertainties in order to arrive at the best possible contouring accuracy. Evaluating feasibility & reproducibility, to achieve a benchmark towards a gold standard MR IGABT and further clinical research including outcomes with CT Based IGABT will become the next steps.
Project description:This investigation studies the use of volumetric-modulated arc therapy (VMAT) to deliver the following conceptual gynecological brachytherapy (BT) dose distributions: Type 1, traditional pear-shaped dose distribution with substantial dose gradients; Type 2, homogeneous dose distribution throughout PTV (BT prescription volume); and Type 3, increased dose to PTV without organ-at-risk (OAR) overdose. A tandem and ovoid BT treatment plan, with the prescription dose of 6 Gy to point A, was exported into the VMAT treatment planning system (TPS) and became the baseline for comparative analysis. The 200%, 150%, 130%, 100%, 75%, and 50% dose volumes were converted into structures for optimization and evaluation purposes. The 100% dose volume was chosen to be the PTV. Five VMAT plans (Type 1) were created to duplicate the Ir-192 tandem and ovoid inhomogeneous dose distribution. Another five VMAT plans (Type 2) were generated to deliver a homogeneous dose of 6 Gy to the PTV. An additional five VMAT plans (Type 3) were created to increase the dose to the PTV with a homogeneous dose distribution. In the first set of plans, the dose given to 99% of the 200%-100% dose volumes agreed within 2% of the BT plan on average. Additionally, it was found that the 75% dose volumes agreed within 5% of the BT plan and the 50% dose volumes agreed within 6.4% of the BT plan. In the second set of comparative analyses, the 100% dose volume was found to be within 1% of the original plan. Furthermore, the maximum increase of dose to the PTV in the last set of comparative analyses was 8 Gy with similar doses to OARs as the other VMAT plans. The maximum increase of dose was 2.50 Gy to the rectum and the maximum decrease of dose was 0.70 Gy to the bladder. Henceforth, VMAT was successful at reproducing brachytherapy dose distributions demonstrating that alternative dose distributions have the potential to be used in lieu of brachytherapy. It should also be noted that differences in radiobiology need to be further investigated.
Project description:Manual delineation of liver segments on computed tomography (CT) images for primary/secondary liver cancer (LC) patients is time-intensive and prone to inter/intra-observer variability. Therefore, we developed a deep-learning-based model to auto-contour liver segments and spleen on contrast-enhanced CT (CECT) images. We trained two models using 3d patch-based attention U-Net ([Formula: see text] and 3d full resolution of nnU-Net ([Formula: see text] to determine the best architecture ([Formula: see text]. BA was used with vessels ([Formula: see text] and spleen ([Formula: see text] to assess the impact on segment contouring. Models were trained, validated, and tested on 160 ([Formula: see text]), 40 ([Formula: see text]), 33 ([Formula: see text]), 25 (CCH) and 20 (CPVE) CECT of LC patients. [Formula: see text] outperformed [Formula: see text] across all segments with median differences in Dice similarity coefficients (DSC) ranging 0.03-0.05 (p < 0.05). [Formula: see text], and [Formula: see text] were not statistically different (p > 0.05), however, both were slightly better than [Formula: see text] by DSC up to 0.02. The final model, [Formula: see text], showed a mean DSC of 0.89, 0.82, 0.88, 0.87, 0.96, and 0.95 for segments 1, 2, 3, 4, 5-8, and spleen, respectively on entire test sets. Qualitatively, more than 85% of cases showed a Likert score [Formula: see text] 3 on test sets. Our final model provides clinically acceptable contours of liver segments and spleen which are usable in treatment planning.
Project description:The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment.
Project description:The gynecological cancer mortality rate, including cervical, ovarian, vaginal and vulvar cancers, is more than 20,000 annually in the US alone. In many countries, including the US, external-beam radiotherapy followed by high dose rate brachytherapy is the standard-of-care. The superior ability of MR to visualize soft tissue has led to an increase in its usage in planning and delivering brachytherapy treatment. A technical challenge associated with the use of MRI imaging for brachytherapy, in contrast to that of CT imaging, is the visualization of catheters that are used to place radiation sources into cancerous tissue. We describe here a precise, accurate method for achieving catheter segmentation and visualization. The algorithm, with the assistance of manually provided tip locations, performs segmentation using image-features, and is guided by a catheter-specific, estimated mechanical model. A final quality control step removes outliers or conflicting catheter trajectories. The mean Hausdorff error on a 54 patient, 760 catheter reference database was 1.49? mm; 51 of the outliers deviated more than two catheter widths (3.4? mm) from the gold standard, corresponding to catheter identification accuracy of 93% in a Syed-Neblett template. In a multi-user simulation experiment for evaluating RMS precision by simulating varying manually-provided superior tip positions, 3? maximum errors were 2.44? mm. The average segmentation time for a single catheter was 3?s on a standard PC. The segmentation time, accuracy and precision, are promising indicators of the value of this method for clinical translation of MR-guidance in gynecologic brachytherapy and other catheter-based interventional procedures.
Project description:BackgroundTo validate the Radiation Therapy Oncology Group (RTOG) and European Society for Radiotherapy and Oncology (ESTRO) breast cancer nodal clinical target volumes (CTVs) and to investigate the Radiotherapy Comparative Effectiveness Consortium (RADCOMP) Posterior Neck volume in relation to regional nodal recurrences (RNR).MethodsFrom a population-based database, 69 patients were identified who developed RNR after curative treatment for breast cancer. RNRs were detected with 18-fluorodeoxyglucose-positron emission tomography-computed tomography (PET/CT). All patients were treatment-naïve for RNR when imaged. The RTOG and ESTRO nodal CTVs and RADCOMP Posterior Neck volumes were contoured onto a template patient's CT. RNRs were contoured on each PET/CT and deformed onto the template patient's CT. Each RNR was represented by a 5 mm diameter epicentre, and categorized as 'inside', 'marginal' or 'outside' the CTV boundaries.ResultsSixty-nine patients with 226 nodes (median 2, range 1-11) were eligible for inclusion. Thirty patients had received adjuvant tangent and regional nodal radiotherapy, 16 tangent-only radiotherapy and 23 no adjuvant radiotherapy. For the RTOG CTVs, the RNR epicentres were 70% (158/226) inside, 4% (8/226) marginal and 27% (60/226) outside. They included the full extent of the RNR epicentres in 38% (26/69) of patients. Addition of the RADCOMP Posterior Neck volume increased complete RNR coverage to 48% (33/69) of patients. For the ESTRO CTVs, the RNR epicentres were 73% (165/226) inside, 2% (4/226) marginal and 25% (57/226) outside. They included the full extent of the RNR epicentres in 57% (39/69) of patients. Addition of the RADCOMP Posterior Neck volume increased complete RNR coverage to 70% (48/69) of patients.ConclusionsThe RTOG and ESTRO breast cancer nodal CTVs do not fully cover all potential areas of RNR, but the ESTRO nodal CTVs provided full coverage of all RNR epicentres in 19% more patients than the RTOG nodal CTVs. With addition of the RADCOMP Posterior Neck volume to the ESTRO CTVs, 70% of patients had full coverage of all RNR epicentres.
Project description:ObjectiveIn patients undergoing pelvic exenteration for recurrent gynecological malignancies, we assessed the performance of [(18)F]-FDG PET/CT for delineating disease extent and evaluated the association between quantitative FDG uptake metrics (SUVmax, total lesion glycolysis [TLG] and metabolic tumor volume [MTV]) and progression-free survival (PFS) and overall survival (OS).MethodsRetrospective study of patients undergoing pelvic exenteration for gynecologic malignancies between January 2002 and November 2011 who had FDG PET/CT within 90days before surgery. Two readers (R1, R2) independently determined the presence of bladder, rectum, vagina, cervix and pelvic side wall invasion and measured SUVmax, TLG and MTV in each patient. Areas under the curve (AUCs), for detecting organ invasion were calculated. Kaplan-Meier graphs were used to determine associations between FDG uptake and PFS/OS. Inter-reader agreement was assessed.Results33 patients (mean age 56years, range: 28-81) were included; primary sites of disease were the cervix (n=18), uterus (n=8) and vagina/vulva (n=7). AUCs for organ invasion ranged from 0.74 to 0.96. There was a significant association between FDG uptake metrics incorporating tumor volume (TLG and MTV) and OS (p≤0.001) as well as between MTV and PFS (p=0.001). No significant association was identified between SUVmax and OS/PFS (p=0.604/0.652). Inter-reader agreement for organ invasion was fair to substantial (k=0.36-0.74) and almost perfect for FDG quantification (ICC=0.97-0.99).ConclusionIn patients undergoing pelvic exenteration for recurrent gynecological malignancies, (18)F-FDG PET/CT is useful for preoperative assessment of disease extent. Furthermore, quantitative metrics of FDG uptake incorporating MTV serve as predictive biomarkers of progression-free and overall survival in this population.
Project description:ObjectivesTo determine if dynamic CT can differentiate local progression from radioactive seed-induced peritumoral reaction (RSIPR) after brachytherapy with iodine-125 radioactive seeds (BIRS) for advanced hepatic malignancies.MethodsEnhanced CT images of seed-implanted lesions between 2006 and 2018 were retrospectively evaluated. Hounsfield units of peritumoral parenchyma were measured and assessed quantitatively. The classification, conversion, consequences, and serological indicators during follow-up were recorded and quantified. Statistical differences were analyzed using a Pearson χ2 test.ResultsRSIPR was observed in 201 of 290 (69.3%) lesions (161 patients; median age, 55 years; range, 26-79 years), while local progression occurred in 53 lesions. The low density of local progression was much lower than that of RSIPR (p < 0.001), and the former did not exhibit iso-/high density in the portal or equilibrium phase. Ring-like enhancement in progressive lesions was also quite different from RSIPR. Local progression rate was lower for lesions with RSIPR than for those without RSIPR (14.9% vs 25.8%; p = 0.03), and their doses were different (397.2 Gy vs 120.3 Gy, p < 0.001).ConclusionsRadioactive seed-induced peritumoral reaction has characteristic manifestations on CT images, which is associated with a higher dose of lesions and lower local progression rate. Notably, the enhancement pattern of local progression was distinct from RSIPR and was clearly distinguishable on dynamic-enhanced CT.Key points• Radioactive seed-induced peritumoral reaction after brachytherapy with 125I seeds for liver malignancies has characteristic manifestations on CT images, which is associated with a higher dose of lesions (397.2 Gy vs 120.3 Gy, p < 0.001), as a focal radiation injury. • Lesions with RSIPR were less likely to develop local progression, while those without RSIPR had a higher rate of local progression (14.9% vs 25.8%; p = 0.03). • The enhancement pattern of local progression after brachytherapy was distinct from radioactive seed-induced peritumoral reaction and was clearly distinguishable on dynamic-enhanced CT.
Project description:Gynecologic malignancies, including ovarian cancer, endometrial cancer, and cervical cancer, affect hundreds of thousands of women worldwide every year. Wnt signaling, specifically Wnt/β-catenin signaling, has been found to play an essential role in many oncogenic processes in gynecologic malignancies, including tumorigenesis, metastasis, recurrence, and chemotherapy resistance. As such, the Wnt/β-catenin signaling pathway has the potential to be a target for effective treatment, improving patient outcomes. In this review, we discuss the evidence supporting the importance of the Wnt signaling pathways in the development, progression, and treatment of gynecologic malignancies.
Project description:ObjectiveTo evaluate the association between body composition and subsequent risk of the major gynecologic malignancies.MethodsThis is a prospective analysis of participants from the UK Biobank. We measured baseline body composition and confirmed cancer diagnosis through linkage to cancer and death registries. We evaluated hazard ratios (HRs) and confidence interval (CIs) with COX models adjusting for potential confounders.ResultsWe document 1430 cases of the top three gynecologic malignancies (uterine corpus cancer 847 cases, ovarian cancer 514 cases, and cervical cancer 69 cases) from 245,084 female participants (75,307 were premenopausal and 169,777 were postmenopausal). For premenopausal women, whole body fat-free mass (WBFFM) was associated with an increased risk of uterine corpus cancer (Adjusted HR per unit increase 1.04, 95% CI 1.02-1.06). For postmenopausal women, compared with the first quartile, the fourth quartile of WBFFM and whole body fat mass(WBFM) was associated with 2.16 (95% CI 1.49-3.13) times and 1.89 (95% CI 1.31-2.72) times of increased uterine corpus cancer risk, respectively. Regarding the distribution of body fat mass (FM)/fat-free mass (FFM), FFM distributed in the trunk was associate with increased uterine corpus cancer risk in premenopausal (HR 1.18,95% CI 1.07-1.31) and postmenopausal women (HR 1.13,95% CI 1.09-1.18). Meanwhile, FM/FFM distributed in the limbs present an U-shaped associations with uterine corpus cancer risk. We did not observe any association between aforementioned body composition indices with ovarian or cervical cancer.ConclusionFM is associated with an increased risk of uterine corpus cancer in postmenopausal women. Meanwhile, FFM is found to be a risk factor for uterine corpus cancer in both premenopausal and postmenopausal women. No association of body composition with ovarian or cervical cancer was observed.