Radiotherapy For Cervical Cancer Research Articles

Identifying the optimal deep learning architecture and parameters for automatic beam aperture definition in 3D radiotherapy.

Two-dimensional radiotherapy is often used to treat cervical cancer in low- and middle-income countries, but treatment planning can be challenging and time-consuming. Neural networks offer the potential to greatly decrease planning time through automation, but the impact of the wide range of hyperparameters to be set during training on model accuracy has not been exhaustively investigated. In the current study, we evaluated the effect of several convolutional neural network architectures and hyperparameters on 2D radiotherapy treatment field delineation. Six commonly used deep learning architectures were trained to delineate four-field box apertures on digitally reconstructed radiographs for cervical cancer radiotherapy. A comprehensive search of optimal hyperparameters for all models was conducted by varying the initial learning rate, image normalization methods, and (when appropriate) convolutional kernel size, the number of learnable parameters via network depth and the number of feature maps per convolution, and nonlinear activation functions. This yielded over 1700 unique models, which were all trained until performance converged and then tested on a separate dataset. Of all hyperparameters, the choice of initial learning rate was most consistently significant for improved performance on the test set, with all top-performing models using learning rates of 0.0001. The optimal image normalization was not consistent across architectures. High overlap (mean Dice similarity coefficient=0.98) and surface distance agreement (mean surface distance<2mm) were achieved between the treatment field apertures for all architectures using the identified best hyperparameters. Overlap Dice similarity coefficient (DSC) and distance metrics (mean surface distance and Hausdorff distance) indicated that DeepLabv3+ and D-LinkNet architectures were least sensitive to initial hyperparameter selection. DeepLabv3+ and D-LinkNet are most robust to initial hyperparameter selection. Learning rate, nonlinear activation function, and kernel size are also important hyperparameters for improving performance.

3D Laparoscopic Ureterolysis for Retroperitoneal Fibrosis Secondary to Radical Hysterectomy and Radiation Treatment for Cervical Cancer: Results from the Oncological Institute, Cluj Napoca.

Ureterolysis represents the surgical treatment for retroperitoneal fibrosis. The aim of the study was to review the outcomes of patients who had undergone radical hysterectomy and radiotherapy for cervical cancer that later developed retroperitoneal fibrosis, for whom 3D laparoscopic ureterolysis was performed in our department and to review current published studies. We present a series of cases consisting of 6 patients with secondary retroperitoneal fibrosis. In all cases, the intervention was performed by the same surgeon from the Oncological Institute "Prof. Dr. Ion Chiricuță" Cluj-Napoca, Romania. We carried out a literature review, searching in the PubMed and MEDLINE studies published between 2000 and 2021 relevant to the matter and a total of 12 papers were selected. We reviewed the functional outcomes of patients that underwent minimally invasive ureterolysis. 3D laparoscopic ureterolysis was performed in 6 patients. Mean operative time was 166 minutes and mean blood loss was 203 mL. No surgery required conversion. Five patients showed good functional results after ureteral stent removal. In one case, the patient developed acute pyelonephritis and the ureteral stents were kept. Laparoscopic ureterolysis for retroperitoneal fibrosis secondary to operated and radiation-treated cervical cancer represents one of the most complex and challenging surgeries in the urological field. From personal experience we conclude that in oncological centers with vast experience in laparoscopy this minimally invasive approach is feasible and safe. Published data, even though scarce, strengthens our results and the need for this surgery in patients with retroperitoneal fibrosis with urological impact. The laparoscopic approach comes with good functional results and with the advantages of faster post-operative recovery comparing to open surgery and comparable results with the precision and dexterity offered by the robotic approach, but with lower economic burden.

Metachronous Ovarian Cancer after a Radical Hysterectomy with Ovarian Conservation for Early-Stage Cervical Cancer: A Case Report

Introduction: Cervical cancer is the fourth most common disease in women worldwide and the leading cause in Tanzania, with 9,772 new cases and 6,695 deaths annually. Surgery is better than radiation or chemotherapy for early-stage cervical cancer (stages IA2–IIA1). Due to the risks of oophorectomy in young women, ovarian conservation is crucial. Metachronous ovarian cancer is understudied, however, ovarian conservation does not enhance cervical cancer mortality. Clinical presentation: We report a rare case of recurrent metachronous ovarian cancer in a 42-year-old female, Para 3, Living 3, who had her ovaries conserved following a radical hysterectomy and bilateral lymph node dissection for stage IB2 cervical cancer at 37 years old in April 2017. The final biopsy showed a well-differentiated, invasive cervical adenocarcinoma. Stage IV ovarian cancer with significant ascites and pleural effusion was detected in July 2018, 14 months post-surgery. Six chemotherapy treatments and total tumor debulking succeeded. Despite the most effective cytoreduction surgery, the patient experienced two further recurrences in 2020 and 2022. After additional surgeries and chemotherapy, she is currently in complete remission and will be followed up. Conclusion: Young women undergoing radical hysterectomy for early-stage cervical cancer must preserve their ovaries, but metachronous ovarian cancer is a risk. Thus, metachronous ovarian cancer risks, challenges, and outcomes must be understood.

PAX1 hypomethylation as a prognostic biomarker for radioresistance of cervical cancer

BackgroundPAX1 gene methylation plays an important role in the development of cervical cancer. However, its prognostic value after radiotherapy for locally advanced cervical cancer is unknown, so this study aimed to investigate the value of PAX1 gene methylation for predicting the sensitivity of radiotherapy for cervical cancer.MethodsWe selected 125 patients with primary cervical cancer who underwent concurrent chemo-radiotherapy as the study population, quantitative methylation-specific polymerase chain reaction (QMSP) was used for detecting PAX1 methylation status of cervical exfoliated cells. Logistic regression model was used to analyze the risk factors associated with the short-term efficacy and to establish a prediction model of radiotherapy sensitivity based on PAX1 gene methylation. Cell viability after radiation of Hela and SiHa cells transfected with PAX1 or control vector was evaluated by CCK8. Furthermore, RNA-Seq analyses identified different expressed genes (DEGs) in PAX1 overexpressed SiHa cells. Gene Ontology (GO) and pathway enrichment analysis was carried out to determine the biological function of DEGs.ResultsPAX1 methylation level was associated with HPV16/18-positive rate. PAX1 hypomethylation was found to be a risk factor for tumor residual after chemo-radiotherapy. A nomogram containing the risk factors for PAX1 methylation status, lymph node metastasis, pathological type and tumor size was further constructed to predict the probability of tumor residual after chemo-radiotherapy (AUC = 0.823, 95% CI 0.736–0.910). High PAX1 protein level was more likely to cause radioresistance in both Hela and SiHa cells. Transcriptomic sequencing of PAX1 overexpressed and control cells identified 615 differentially expressed genes, and GO enrichment analysis suggested that PAX1 may be involved in the regulation of signaling receptor activity and response to viruses.ConclusionPAX1 hypomethylation status could be used as a promising biomarker to predict radioresistance in cervical cancer. This further provides a new idea for the individualized treatment strategy of simultaneous radiotherapy for cervical cancer.

CBCT-based deformable dose accumulation of external beam radiotherapy in cervical cancer

Background: Delivered radiotherapy doses do not exactly match those planned for a course of treatment, largely due to inter-fraction changes in anatomy. In this study, accumulated delivered dose was calculated for a sample of cervical cancer patients, by deformably registering daily cone beam computed tomography (CBCT) images to the planning computed tomography (CT) scan. Planned and accumulated doses were compared for the clinical target volume (CTV), bladder, and rectum. Material and Methods: For 10 patients receiving 45 Gy in 25 fractions of external beam radiotherapy, daily dose distributions were calculated on CBCT. These images were deformed onto the planning CT and the dose was accumulated using Velocity 4.1 (Varian Medical Systems, Palo Alto, USA). The quality of deformable image registration was evaluated visually and by calculating Dice similarity coefficients and mean distance to agreement. Results: V95%>99% was achieved for the primary CTV in 9/10 patients for the planned dose distribution and 7/10 patients for the accumulated dose distribution. Primary CTV coverage by 95% of the prescription dose was reduced in one patient, due to an increase in anterior-posterior separation. Comparison of planned and accumulated dose volume histograms (DVHs) for the bladder and rectum found agreement within 5% at low and intermediate doses, but differences exceeded 20% at higher doses. Direct addition of CBCT DVHs was seen to be a poor estimate for the accumulated DVH at higher doses. Conclusion: Computation of delivered radiotherapy dose that accounts for inter-fraction anatomical changes is important for establishing dose-effect relationships. Updating delivered dose distributions after each fraction would support informed clinical decision making on any potential treatment interventions.

CircRNF13, a novel N6-methyladenosine-modified circular RNA, enhances radioresistance in cervical cancer by increasing CXCL1 mRNA stability

BackgroundCircular RNAs (circRNAs) and N6-methyladenosine (m6A) have been shown to play an increasingly critical role in the development of different cancers. However, there is limited evidence on how circRNAs and m6A interact to affect the radiosensitivity of cervical cancer (CC). This study provides a mechanistic understanding of the novel m6A-regulated circRNF13 in enhancing radioresistance in CC.MethodsDifferentially expressed circRNAs were identified from radiosensitive and radioresistant CC tissues. Meanwhile, these circRNAs were subjected to methylated RNA immunoprecipitation (Me-RIP). Finally, the effects of these circRNAs on radiosensitivity were characterized.ResultsCircRNF13 was poorly expressed in CC patients that were sensitive to concurrent radiochemotherapy. Experiments conducted both in vitro and in vivo confirmed that the knockdown of circRNF13 potentiated the radiosensitivity of CC cells. Further mechanistic studies revealed that METTL3/YTHDF2 promoted the degradation of circRNF13 and subsequently affected the stability of CXC motif chemokine ligand 1 (CXCL1), ultimately enhancing the radiosensitivity of CC cells.ConclusionThis study identified circRNF13 as a novel m6A-modified circRNA and validated the METTL3/YTHDF2/circRNF13/CXCL1 axis as a potential target for CC radiotherapy.

Dosimetry study of Auto-VMAT planning and Manual-VMAT planning based on Pinnacle3 9.10 in radiotherapy for cervical cancer.

The purpose of this study was to compare the dose distribution characteristics of automatic volume-modulated arc therapy (Auto-VMAT) planning and manual volume-modulated arc therapy (Manual-VMAT) planning of Philips Pinnacle3 9.10 planning system, to provide a basis for optimal radiation therapy planning for cervical cancer. Ten patients with cervical cancer in our hospital from September to December 2018 were selected, and 2 treatment plans, Auto-VMAT plan and Manual-VMAT plan, were designed using Pinnacle3 9.10 planning system, respectively, to evaluate the maximum dose Dmax, mean dose Dmean, homogeneity index of the target area according to the dose volume histogram, the conformability index, plan optimization time, monitor units (MUs), organ at risk and other indicators. The results were that the Auto-VMAT plan was superior to the Manual-VMAT plan for target area Dmean, conformability index, and homogeneity index, with statistically significant differences (P < .05) and no significant difference in maximum dose Dmax (P > .05); rectal V40, V50, and Dmean in the Auto-VMAT plan, bladder V40, V50, and Dmean, small bowel V30, V40, V50 and Dmean, and right and left femoral V50 and Dmean were all lower than the Manual-VMAT plan, and the difference was statistically significant (P < .05); the mean optimization time for the Auto-VMAT and Manual-VMAT plans was 47 minutes and 35 minutes, respectively, an increase of 34%. The average number of MUs was 519 MUs and 374 MUs, respectively, an increase of 28%. This study concluded that the Pinnacle3 9.10-based Auto-VMAT plan was clinically feasible and significantly superior to the Manual-VMAT plan in terms of improved target area uniformity and conformability and reduced organ endangerment dose while reducing the impact of human factors on the quality of plan design.

Forecasting patient-specific dosimetric benefit from daily online adaptive radiotherapy for cervical cancer

Objective. Adaptive Radiotherapy (ART) is an emerging technique for treating cancer patients which facilitates higher delivery accuracy and has the potential to reduce toxicity. However, ART is also resource-intensive, Requiring extra human and machine time compared to standard treatment methods. In this analysis, we sought to predict the subset of node-negative cervical cancer patients with the greatest benefit from ART, so resources might be properly allocated to the highest-yield patients. Approach. CT images, initial plan data, and on-treatment Cone-Beam CT (CBCT) images for 20 retrospective cervical cancer patients were used to simulate doses from daily non-adaptive and adaptive techniques. We evaluated the coefficient of determination (R2) between dose and volume metrics from initial treatment plans and the dosimetric benefits to the and from adaptive radiotherapy using reduced 3 mm or 5 mm CTV-to-PTV margins. The LASSO technique was used to identify the most predictive metrics for The three highest performing metrics were used to build multivariate models with leave-one-out validation for Main results. Patients with higher initial bowel doses were correlated with the largest decreases in Bowel from daily adaptation (linear best fit R2 = 0.77 for a 3 mm PTV margin and R2 = 0.8 for a 5 mm PTV margin). Other metrics had intermediate or no correlation. Selected covariates for the multivariate model were differences in the initial and using standard versus reduced margins and the initial bladder volume. Leave-one-out validation had an R2 of 0.66 between predicted and true adaptive benefits for both margins. Significance. The resulting models could be used to prospectively triage cervical cancer patients on or off daily adaptation to optimally manage clinical resources. Additionally, this work presents a critical foundation for predicting benefits from daily adaptation that can be extended to other patient cohorts.

Fan beam CT-guided online adaptive external radiotherapy of uterine cervical cancer: a dosimetric evaluation

PurposeTo discuss the dosimetric advantages and reliability of the accurate delivery of online adaptive radiotherapy(online ART) for uterine cervical cancer(UCC).Methods and materialsSix UCC patients were enrolled in this study. 95% of the planning target volume (PTV) reached 100% of the prescription dose (50.4 Gy/28fractions/6weeks) was required. The patients were scanned with uRT-Linac 506c KV-FBCT then the target volume (TV) and organs at risk (OARs) were delineated by doctors. The dosimeters designed and obtained a routine plan (Plan0). KV-FBCT was used for image guidance before subsequent fractional treatment. The online ART was processed after registration, which acquired a virtual nonadaptive radiotherapy plan (VPlan) and an adaptive plan (APlan). VPlan was the direct calculation of Plan0 on the fractional image, while APlan required adaptive optimization and calculation. In vivo dose monitoring and three-dimensional dose reconstruction were required during the implementation of APlan.ResultsThe inter-fractional volumes of the bladder and rectum changed greatly among the treatments. These changes influenced the primary gross tumor volume (GTVp) and the position deviation of GTVp and PTV and positively affected the prescription dose coverage of TV. GTVp decreased gradually along with dose accumulation. The Dmax, D98, D95, D50, and D2 of APlan were superior to those of VPlan in target dose distribution. APlan had good conformal index, homogeneity index and target coverage. The rectum V40 and Dmax, bladder V40, the small bowel V40 and Dmax of APlan were better than that of VPlan. The APlan’s fractional mean γ passing rate was significantly higher than the international standard and the mean γ passing rate of all cases after the three-dimensional reconstruction was higher than 97.0%.ConclusionOnline ART in external radiotherapy of UCC significantly improved the dose distribution and can become an ideal technology to achieve individualized precise radiotherapy.

Dosimetric impact of bladder volume on organs at risk during external beam radiotherapy of cervical cancer.

This study aimed to investigate the effect of bladder volume on the dosimetry of pelvic organs at risk (OARs) in patients treated with external beam radiation therapy. Twenty patients with locally advanced cervical cancer were selected. Two computed tomography-simulation scans were obtained, one with an empty bladder followed by one with a full bladder. The acquired images were transferred to the treatment planning system. Target and OARs were contoured in both images, and treatment plans were performed for each computed tomography image. The delivered doses to target and OARs were determined using dose-volume histograms. The mean dose of the bowel bag in the empty and full bladder were 35.06±4.13 (Gy) and 31.59±3.86 (Gy), respectively. Furthermore, the V45 of the bowel bag in the empty bladder was 364.27±154.39 (cc) and in the full bladder, it was 240.84±129.66 (cc). The mean dose of the rectum in the empty and full bladder were 49.50±1.95 (Gy) and 49.18±1.03 (Gy), respectively. The rectal V50 (%) was 52.82±21.84 (%) in the empty bladder and 45.49±29.55 (%) in the full bladder. The mean dose and V45 of the bowel bag, also V50 of the rectum, had significantly decreased in the full bladder status (p-value<0.05). The results showed that the bladder volume significantly affected the delivered dose to the bowel bag and rectum. The average bowel bag V45 and rectum V50 in the full bladder were significantly decreased. Bladder distention is an effective method to improve the dosimetric parameters of pelvic OARs.

ESGO/ESTRO quality indicators for radiation therapy of cervical cancer

BackgroundThe European Society of Gynaecological Oncology (ESGO) has previously defined and established a list of quality indicators for the surgical treatment of cervical cancer. As a continuation of this effort to improve overall quality of care for cervical cancer patients across all aspects, ESGO and the European SocieTy for Radiotherapy and Oncology (ESTRO) initiated the development of quality indicators for radiation therapy of cervical cancer. ObjectiveTo develop a list of quality indicators for radiation therapy of cervical cancer that can be used to audit and improve clinical practice by giving to practitioners and administrators a quantitative basis to improve care and organizational processes, notably for recognition of the increased complexity of modern external radiotherapy and brachytherapy techniques. MethodsQuality indicators were based on scientific evidence and/or expert consensus. The development process included a systematic literature search for identification of potential quality indicators and documentation of scientific evidence, consensus meetings of a group of international experts, an internal validation process, and external review by a large international panel of clinicians (n = 99). ResultsUsing a structured format, each quality indicator has a description specifying what the indicator is measuring. Measurability specifications are detailed to define how the quality indicators will be measured in practice. Targets were also defined for specifying the level which each unit or center should be aiming to achieve. Nineteen structural, process, and outcome indicators were defined. Quality indicators 1–6 are general requirements related to pretreatment workup, time to treatment, upfront radiation therapy, and overall management, including active participation in clinical research and the decision making process within a structured multidisciplinary team. Quality indicators 7–17 are related to treatment indicators. Quality indicators 18 and 19 are related to patient outcomes. DiscussionThis set of quality indicators is a major instrument to standardize the quality of radiation therapy in cervical cancer. A scoring system combining surgical and radiotherapeutic quality indicators will be developed within an envisaged future ESGO accreditation process for the overall management of cervical cancer, in an effort to support institutional and governmental quality assurance programs.

RT-PACE: Phase I/II study of adjuvant whole pelvic hypofractionated radiotherapy for non-metastatic cervical and endometrial cancer.

TPS5631 Background: Whole pelvic radiation therapy (WPRT) improves locoregional control in women with high-intermediate and high-risk endometrial cancer. The standard treatment course consists of 25-28 fractions (5-5.5 weeks) of 1.8-2 Gy/fraction, and is delivered using intensity-modulated radiation therapy (IMRT), which allows for superior sparing of normal tissue with a subsequent lower rate of acute and late toxicity compared to less conformal treatment techniques. Moderate hypofractionation (HF, &gt;2 Gy/fraction) has been studied in other disease sites, such as breast and prostate cancer, and is associated with lower or comparable toxicity, improved patient convenience, and greater cost savings compared to standard fractionation. However, HF has not been well-studied in the setting of WPRT for gynecologic cancers. Methods: This phase I/II multi-institutional study evaluates the feasibility, safety, and toxicity profile of HF-WPRT in women with non-metastatic cervical or endometrial cancers who have undergone curative hysterectomy and are recommended adjuvant WPRT by their treating physician. Concurrent chemotherapy is not allowed, but can be administered sequentially prior to or after WPRT. Para-aortic radiation or nodal boosts are not allowed, however vaginal brachytherapy boost is permissible. Phase I is a safety study of increasing dose-per-fraction. All treatment regimens have an approximate biologic effective dose of 53 Gy (α/β =10). A keyboard design is utilized to identify the maximum tolerated dose-per-fraction (MTD), defined in this study as the regimen that is associated with a CTCAE grade 3+ gastrointestinal/genitourinary toxicity rate of ≤10% on the last day of WPRT. There are 3 dose cohorts of increasing dose-per-fraction. Phase II will accrue 64 evaluable patients to HF-WPRT using the MTD determined in phase I. The primary endpoint is to evaluate the change in patient-reported gastrointestinal toxicity from baseline to the last day of WPRT using the EPIC bowel score. The study is powered to compare results to the RTOG 1203 IMRT standard fractionation arm. The phase 1 portion of the study completed accrual; the phase II portion opened in April 2022 with a fractionation of 42.56 Gy in 16 fractions. Secondary endpoints include genitourinary toxicity (EPIC, CTCAE), quality of life (FACT-Cx, PRO-CTCAE), financial toxicity (FACIT-COST), and decision-making (Decision Regret Scale). Pelvic control at 2 years is an exploratory endpoint. Clinical trial information: NCT04683653 .

Efficacy and safety of camrelizumab in combination with radiation and chemotherapy for recurrent or metastatic cervical cancer.

5542 Background: Cisplatin-based concurrent chemoradiation regimens have been suggested to be beneficial in recurrent or metastatic cervical cancer. Immunotherapy has also shown good therapeutic efficacy in recurrent or metastatic cervical cancer. Among them, Pembrolizumab in combination with chemotherapy has been used for first-line treatment of advanced PD-L1-positive cervical cancer. Meanwhile, Camrelizumab has shown good anti-tumor activity and manageable toxicity in patients with locally advanced cervical cancer. The primary objective of this study is to evaluate the efficacy and safety of Camrelizumab in combination with concurrent chemoradiation in patients with recurrent or metastatic cervical cancer. Methods: Patients diagnosed with recurrent or metastatic cervical cancer received Camrelizumab combined with concurrent chemoradiotherapy, radiotherapy:External beam radiotherapy (EBRT) 1.8-2.15 Gy/f, a total of 28 fractions; Brachytherapy: high-risk CTV using image guidance 28 Gy in 4 fractions (18 Gy in 3 fractions for posthysterectomy recurrent patients); chemotherapy regimen used TP regimen (paclitaxel: 175 mg/m2, cisplatin: 75 mg/m2, Q3W 6 cycles); Camrelizumab 200 mg Q3W 6 cycles. The primary endpoint of this trial was objective response rate (ORR), and secondary endpoints were progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and incidence of adverse reactions. Results: From September 16, 2020 to September 30, 2022, a total of 29 patients were recruited. 27 of these patients completed 6 cycles of planned treatment. 27 patients had a median age of 53 years (33-73 years), ECOG PS 0 (n = 8), ECOG PS 1 (n = 14), ECOG PS 2 (n = 1). The ORR rate was 96.30% (26/27), including 17 patients with CR, 9 patients with PR, and 1 patient with SD Treatment-related AEs were mainly lymphocyte count decreased, anemia, and white blood cell count decreased, with overall safety manageable and no treatment-related deaths. Conclusions: Camrelizumab combined with concurrent chemoradiation in patients with recurrent or metastatic cervical cancer has good efficacy, low side effects and acceptable toxicity. Clinical trial information: NCT04884906 .

ESGO/ESTRO quality indicators for radiation therapy of cervical cancer

BackgroundThe European Society of Gynaecological Oncology (ESGO) has previously defined and established a list of quality indicators for the surgical treatment of cervical cancer. As a continuation of this effort...

Dosimetric Comparative Analysis of Volumetric Modulated Arc Therapy and Intensity-Modulated Radiation Therapy in Cervical Cancer

Objective: To carry out dosimetric comparison between volumetric modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) in cervical cancer. Methods: 50 postoperative cervical cancer patients were included in this study. The patients were admitted for treatment from January 2021 to January 2022. VMAT and IMRT plans were designed for each patient to analyze the dose distribution in the target area of the two treatment techniques. Results: Comparing the monitor unit for single treatment (638.21 ± 116.21 MU) and time of single treatment (143.21 ± 23.14 s) in the observation group and the monitor unit for single treatment (932.14 ± 74.11 MU) and time of single treatment (223.14 ± 17.26 s) in the control group, there was significant difference (P &lt; 0.05); there was also significant difference (P &lt; 0.05) between the normal tissue (bladder and rectum) of the observation group and that (bladder and rectum) of the control group. Conclusion: VMAT is more effective in cervical cancer, and it has a certain protective effect on normal tissues in patients and can reduce the radiation dose.

Delineation of clinical target volume and organs at risk in cervical cancer radiotherapy by deep learning networks.

Delineation of the clinical target volume (CTV) and organs-at-risk (OARs) is important in cervical cancer radiotherapy. But it is generally labor-intensive, time-consuming, and subjective. This paper proposes a parallel-path attention fusion network (PPAF-net) to overcome these disadvantages in the delineationtask. The PPAF-net utilizes both the texture and structure information of CTV and OARs by employing a U-Net network to capture the high-level texture information, and an up-sampling and down-sampling (USDS) network to capture the low-level structure information to accentuate the boundaries of CTV and OARs. Multi-level features extracted from both networks are then fused together through an attention module to generate the delineationresult. The dataset contains 276 computed tomography (CT) scans of patients with cervical cancer of staging IB-IIA. The images are provided by the West China Hospital of Sichuan University. Simulation results demonstrate that PPAF-net performs favorably on the delineation of the CTV and OARs (e.g., rectum, bladder and etc.) and achieves the state-of-the-art delineation accuracy, respectively, for the CTV and OARs. In terms of the Dice Similarity Coefficient (DSC) and the Hausdorff Distance (HD), 88.61% and 2.25 cm for the CTV, 92.27% and 0.73 cm for the rectum, 96.74% and 0.68 cm for the bladder, 96.38% and 0.65 cm for the left kidney, 96.79% and 0.63 cm for the right kidney, 93.42% and 0.52 cm for the left femoral head, 93.69% and 0.51 cm for the right femoral head, 87.53% and 1.07 cm for the small intestine, and 91.50% and 0.84 cm for the spinalcord. The proposed automatic delineation network PPAF-net performs well on CTV and OARs segmentation tasks, which has great potential for reducing the burden of radiation oncologists and increasing the accuracy of delineation. In future, radiation oncologists from the West China Hospital of Sichuan University will further evaluate the results of network delineation, making this method helpful in clinicalpractice.

Plan quality and treatment efficiency assurance of two VMAT optimization for cervical cancer radiotherapy.

34 cervical cancer patients with definitive radiation were retrospectively analyzed. Each patient has four plans: FMO with fixed jaw plans (FMO-FJ) and no fixed jaw plans (FMO-NFJ); SPO with fixed jaw plans (SPO-FJ) and no fixed jaw plans (SPO-NFJ). Dosimetric parameters, Modulation Complexity Score (MCS), Gamma Pass Rate (GPR) and delivery time were analyzed among the four plans. For target coverage, SPO-FJ plans are the best ones (P≤0.00). FMO plans are better than SPO-NFJ plans (P≤0.00). For OARs sparing, SPO-FJ plans are better than FMO plans for mostly OARs (P≤0.04). Additionally, SPO-FJ plans are better than SPO-NFJ plans (P≤0.02), except for rectum V45Gy. Compared to SPO-NFJ plans, the FMO plans delivered less dose to bladder, rectum, colon V40Gy and pelvic bone V40Gy(P≤0.04). Meanwhile, the SPO-NFJ plans showed superiority in MU, delivery time, MCS and GPR in all plans. In terms of delivery time and MCS, the SPO-FJ plans are better than FMO plans. FMO-FJ plans are better than FMO-NFJ plans in delivery efficiency. MCSs are strongly correlated with PCTV length, which are negatively with PCTV length (P≤0.03). The delivery time and MUs of the four plans are strongly correlated (P≤0.02). Comparing plans with fixed or no fixed jaw in two algorithms, no difference was found in FMO plans in target coverage and minor difference in Kidney_L Dmean, Mu and delivery time between PCTV width≤15.5cm group and>15.5cm group. For SPO plans, SPO-FJ plans showed more superiority in target coverage and OARs sparing than the SPO-NFJ plans in the two groups. SPO-FJ plans showed superiority in target coverage and OARs sparing, as well as higher delivery efficiency in the four plans.

Clinical research of the value of high-risk CTV setting on intensity-modulated radiotherapy for stage IIB-IVA cervical cancer

BackgroundThis study aims to evaluate the clinical efficacy and side effects of setting up a high-risk clinical target volume (CTV-hr) alongside simultaneous integrated boost intensity-modulated radiotherapy (IMRT-SIB) in patients diagnosed with stage IIB-IVA cervical cancer.MethodsThis study retrospectively analysed patients with stage IIB-IVA cervical cancer who received radical radiotherapy at the Affiliated Hospital of Qingdao University between November 2014 and September 2019. The patients were divided into experimental and control groups based on whether CTV-hr was set. All patients received a combined treatment of radiotherapy and chemotherapy. The dosage for paclitaxel was 135 mg/m2, while for cisplatin it was 75 mg/m2 or for carboplatin it was AUC 4–6, given in a cycle of 21 days. Radiotherapy (RT) included external beam radiation therapy (EBRT) and intracavitary brachytherapy (ICBT). In the control group, positive lymph nodes (GTV-n) were treated at a dose of 58–62 Gy/26–28 fractions(f), while clinical target volumes (CTV) were treated with a dose of 46–48 Gy/26-28f. The experimental group received a simultaneous integrated boost (SIB) to CTV-hr at a dose of 54–56 Gy/26-28f, with the same CTV and GTV-n as the control group. Both groups were combined with brachytherapy with a total dose (EQD2, the equivalent dose in 2 Gy/f) of 80-90 Gy. The study measured objective remission rate (ORR), 3-year progression-free survival (PFS) rate, 3-year overall survival (OS) rate, recurrence rate, and side effects as endpoints.ResultsThe study enrolled 217 patients, with 119 in the experimental group and 98 in the control group. Results showed that the experimental group had a higher 3-year OS rate (87.4% vs. 71.4%, p = 0.001) and 3-year PFS rate (72.3% vs. 51.0%, p = 0.000) compared to the control group. Additionally, the experimental group had significantly lower rates of overall recurrence (26.1% vs. 50.0%, p = 0.003), in-field recurrence (15.1% vs. 36.7%, p = 0.000), and out-field recurrence(13.4% vs. 35.7%, p = 0.000) compared to the control group. All observed differences were found to be statistically significant. However, the experimental and control groups had no statistically significant difference in ORR and radiological side effects, such as radiation cystitis and enteritis (p > 0.05).ConclusionsSetting CTV-hr and performing IMRT-SIB on patients with stage IIB-IVA cervical cancer effectively increased the 3-year OS rate, 3-year PFS rate and reduced recurrence rate, with no significant differences in side effects.

Retracted: Dose Prediction Models Based on Geometric and Plan Optimization Parameter for Adjuvant Radiotherapy Planning Design in Cervical Cancer Radiotherapy.

[This retracts the article DOI: 10.1155/2021/7026098.].

MO-0881 Evaluation of plan-of-the-day selection in adaptive radiation therapy of cervical cancer

MO-0881 Evaluation of plan-of-the-day selection in adaptive radiation therapy of cervical cancer