Radiotherapy For Cervical Cancer Research Articles

A comprehensive evaluation of toxicity after radical hysterectomy or trachelectomy and postoperative pelvic intensity-modulated radiation therapy for cervical cancer

A comprehensive evaluation of toxicity after radical hysterectomy or trachelectomy and postoperative pelvic intensity-modulated radiation therapy for cervical cancer

Consensus Guidelines for Delineation of Clinical Target Volumes for Intensity-Modulated Radiotherapy for Intact Cervical Cancer: An Update.

Accurate target delineation is essential when using intensity-modulated radiotherapy (IMRT) for intact cervical cancer. In 2011, the Radiation Therapy Oncology Group (RTOG) published a consensus guideline using magnetic resonance imaging (MRI). The current project expands on the previous atlas by including computed tomography (CT)-based contours, contours with MRI and positron- emission- tomography (PET) registrations, the addition of common and complex scenarios, and to incorporate information on simulation and treatment planning techniques. Twenty-eight experts in gynecologic radiation oncology contoured three cases, first on a non-contrast CT simulation scan, then with registered diagnostic scans. The cases included (1) FIGO IIIC1 with a bulky tumor and vaginal metastasis, (2) FIGO IIB with calcified uterine fibromas, and (3) FIGO IIIC2 with large lymph nodes. The contours on all six datasets (three CT simulations without diagnostic images and three with registered images) were analyzed for consistency of delineation using an expectation-maximization algorithm for simultaneous truth and performance level estimation (STAPLE) with kappa statistics as a measure of agreement. The contours were reviewed, discussed, and edited in a group meeting prior to finalizing. Contours showed considerable agreement between experts in each of the cases with kappa statistics of 0.67-0.72. For each case, diagnostic PET±MRI was associated with an increase in volume. The largest increase was the CTV primary for Case 2 with a 20% increase in volume and 54% increase in STAPLE estimate volume, which may be due to variance in registration priorities. For the third case, 92.9% increased their CTVs based on the addition of the diagnostic PET scan. The main areas of variance were in determining the superior extent of CTV coverage, coverage of the mesorectum, and simulation and planning protocols. This study shows the value as well as the challenges of using co-registered diagnostic imaging, with an average increase in volumes when incorporating MRI and PET.

Prediction of radiation proctitis in cervical cancer radiotherapy using MRI-based radiomics

Prediction of radiation proctitis in cervical cancer radiotherapy using MRI-based radiomics

Prediction of radiation proctitis in cervical cancer radiotherapy using MRI-based radiomics

Prediction of radiation proctitis in cervical cancer radiotherapy using MRI-based radiomics

Mechanistic study of EPHB2 affecting the sensitivity of cervical cancer radiotherapy by regulating autophagy through AKT/mTOR pathway

Mechanistic study of EPHB2 affecting the sensitivity of cervical cancer radiotherapy by regulating autophagy through AKT/mTOR pathway

The intra-tumoral microbiome as a potential biomarker of response to external beam radiation therapy in cervical cancer

BackgroundWe aimed to determine the potential predictive value of the intra-tumoral microbiome as a marker of the response to external beam radiation therapy (EBRT) in cervical cancer (CC).MethodsA prospective longitudinal trial of 36 CC patients receiving pelvic radiotherapy was designed to investigate microbial characteristic signatures and diversity (alpha and beta) of multiple sites (tumor, vaginal, gut, urethral, and oral) in the superior response (SR) and inferior response (IR) groups of CC patients by 16S rRNA sequencing. Utilized the least absolute shrinkage and selection operator (LASSO) logistic regression method to analyze clinicopathological factors that potentially influenced the efficacy of EBRT. LEfSe analysis highlighted the microbiome features that best distinguished the categorized patient samples. Selected parameters were validated with Spearman correlation analysis, receiver operating characteristic (ROC) area under the curve (AUC) analysis and Kaplan-Meier survival analysis.ResultsFirstly, in our cohort, LASSO logistic regression analysis revealed no association between clinicopathological factors and EBRT efficacy. Subsequently, we employed 16S rRNA sequencing to compare microbiome differences across multiple sites and their correlations with major clinicopathological factors. We discovered that the intra-tumoral microbiome was independent of clinicopathologic features and represented the most direct and reliable reflection of the microbial differences between the SR and IR groups. We found lower alpha diversity in the tumor microbiome of SR group and identified the most relevant microbiome taxa (Bifidobacteriaceae, Beijerinckiaceae, and Orbaceae) associated with the efficacy of the response to EBRT in CC patients. We then conducted ROC analysis, finding that specific microbial taxa had an AUC of 0.831 (95% CI, 0.667–0.995), indicating the potential of these taxa as biomarkers for predicting EBRT efficacy. Kaplan-Meier survival analysis showed a better prognosis for patients with lower alpha diversity and higher relative abundance of Bifidobacteriaceae.ConclusionsOur data suggested that intra-tumoral specific microbiome taxa and lower alpha diversity may play an important role in the CC patient sensitivity to EBRT and offer novel potential biomarkers for predicting the response to EBRT efficacy.

Staged operations of acquired lymphangiectasia of the vulva: 10 cases clinical analysis

Objective: To investigate the characteristics, diagnosis and therapeutic effect of acquired lymphangiectasia of the vulva (ALV). Methods: A retrospective analysis of clinicopathological and follow-up data was conducted on the patients treated in Capital Medical University Affiliated Beijing Shijitan Hospital due to female ALV from July 2009 to July 2023. The patients who completed the staged operations [partial labiectomy and reconstruction + thoracic ductplasty and (or) perineal lymphovenous anastomosis] were included in the study and followed up. The improvement of perineal swelling, blister range, fluid leakage volume and frequency were evaluated through outpatient visits by the symptom rating scale of ALV (hereinafter referred to as the symptom rating scale) before and after surgery. Results: A total of 48 patients were treated due to ALV from July 2009 to July 2023, of which 98% (47/48) were postoperative pelvic malignant tumors and 94% (45/48) had a history of radiotherapy. A total of 10 patients with ALV who completed the staged operations were included in this study. (1) Clinical characteristics and diagnosis: 10 patients had a median age of 60 years old (50, 63 years old ). The median duration from cervical cancer surgery and radiation therapy to vulvar swelling was 1.5 years (0.0, 2.0 years), and the median duration from vulvar swelling to blister formation and leakage was 0.0 years (0.0, 4.8 years). Seven patients (7/10) had a history of recurrent erysipelas; 7 patients (7/10) had the most severe symptom (widespread blisters, persistent fluid leakage, and large amount of fluid leakage); noncontrast magnetic resonance lymphography (NCMRL) showed edema signals in the perineal region of all the patients, and increase of agent in the perineal region was observed in lymphoscintigram (LS). (2) Surgical treatment and postoperative pathological examination: of the 10 ALV patients who completed staged surgical treatment, 6 cases (6/10) were diagnosed with thoracic duct outlet obstruction and underwent thoracic ductplasty and partial labiectomy and reconstruction. Perineal lymphovenous anastomosis and partial labiectomy and reconstruction were performed in 4 cases (4/10) without thoracic duct outlet obstruction. Postoperative routine pathological examination of 10 patients (10/10) showed dermal papilla lymphangiectasia. Immunohistochemical tests were performed on 5 patients, all of which were positive for D2-40 and negative for CD34. (3) Efficacy: 8 patients completed the postoperative follow-up, and the median follow-up time was 31.0 months (17.5, 78.3 months). The perineal swelling and the blister fluid leakage were all significantly improved after the staged operations. All indexes of the symptom rating scale, including the degree of perineal swelling, blister range, fluid leakage volume and frequency, were significantly improved in 8 follow-up patients, and 3 (3/8) of them were cured; the median symptom score decreased significantly from 11.0 before surgery to 3.0 after surgery (P<0.001). The incidence of erysipelas was significantly reduced from 7/10 before surgery to 2/8 after surgery (P=0.035). Conclusions: The main causes of female ALV are pelvic tumor surgery and radiotherapy. The clinical diagnosis is made from relevant medical history, clinical manifestations, LS and magnetic resonance imaging. The diagnosis is confirmed by histopathological findings. Pathological results show lymphangiectasia in the dermal papilla, and immunohistochemical staining show positive for D2-40 and negative for CD34. The effect of staged surgery on ALV is remarkable and even cured, and could effectively reduce the incidence of erysipelas.

Clinical trial comparing the use of Orcellex® Brush versus Cervex-Brush® on vaginal vault smear cytology adequacy rate in patients treated with radiotherapy for cervical cancer.

This study aims to evaluate and compare the Cervex-Brush® and Orcellex® Brush as sampling devices for vaginal vault smear cytology in cervical cancer patients treated primarily with radiotherapy. A randomized crossover trial was conducted at a gynecological oncology center in Hong Kong to compare the Cervex-Brush® and Orcellex® Brush in terms of their vault smear adequacy rate in cervical cancer patients who underwent radiotherapy. One hundred sixty cervical cancer patients treated with primary radiotherapy and undergoing follow-up surveillance by vaginal vault cytology were recruited. The smear adequacy rate was 90.6% for Cervex-Brush® and 91.9% for Orcellex® Brush. The rates of low cellularity for both brushes were similar (76.8% for Cervex-Brush® vs. 76.1% for Orcellex® Brush). The detection rates of abnormal smears were also not significantly different (2.8% for Cervex-Brush® vs. 4.2% for Orcellex® Brush). The 2 brushes were also not significantly different in terms of pain score and degree of bleeding. It was further observed that the second smear collection was more painful and patients who were on hormonal replacement therapy demonstrated less bleeding. There was no difference between the Orcellex® brush and the Cervex-Brush® in terms of smear adequacy rate, rate of high cellularity and the detection of abnormal smears. There was also no significant difference between the 2 brushes in terms of pain and the degree of bleeding. Therefore, the Orcellex® Brush can be considered a suitable alternative sampling device for vault smear collection in patients who have undergone radiotherapy for cervical cancer. ClinicalTrials.gov Identifier: NCT04461574.

Clinical target volume (CTV) automatic delineation using deep learning network for cervical cancer radiotherapy: A study with external validation.

To explore the accuracy and feasibility of a proposed deep learning (DL) algorithm for clinical target volume (CTV) delineation in cervical cancer radiotherapy and evaluate whether it can perform well in external cervical cancer and endometrial cancer cases for generalization validation. A total of 332 patients were enrolled in this study. A state-of-the-art network called ResCANet, which added the cascademulti-scale convolution in the skip connections to eliminate semantic differences between different feature layers based on ResNet-UNet. The atrous spatial pyramid pooling in the deepest feature layer combined the semantic information of different receptive fields without losing information. A total of 236 cervical cancer cases were randomly grouped into 5-fold cross-training (n=189) and validation (n=47) cohorts. External validations were performed ina separate cohort of 54 cervical cancer and 42 endometrial cancer cases. The performances of the proposed network were evaluated by dice similarity coefficient (DSC), sensitivity (SEN), positive predictive value (PPV), 95% Hausdorff distance (95HD), and oncologist clinical score when comparing them with manual delineation in validation cohorts. In internal validation cohorts, the mean DSC, SEN, PPV, 95HD for ResCANet achieved 74.8%, 81.5%, 73.5%, and 10.5mm. In external independent validation cohorts, ResCANet achieved 73.4%, 72.9%, 75.3%, 12.5mm for cervical cancer cases and 77.1%, 81.1%, 75.5%, 10.3mm for endometrial cancer cases, respectively. The clinical assessment score showed that minor and no revisions (delineation time was shortened to within 30min) accountedforabout 85% of all cases in DL-aided automatic delineation. We demonstrated the problem of model generalizability for DL-based automatic delineation. The proposed network can improve the performance of automatic delineation for cervical cancer and shorten manual delineation time at no expense to quality. The network showed excellent clinical viability, which can also be even generalized for endometrial cancer with excellent performance.

Dose escalation in radical radio(chemo)therapy for cervical and upper thoracic esophageal cancer with 3DCRT/IMRT (ChC&UES): a multicenter retrospective study

BackgroundCervical and upper thoracic esophageal cancer (ESCA) presents treatment challenges due to limited clinical evidence. This multi-center study (ChC&UES) explores radical radio(chemo)therapy efficacy and safety, especially focusing on radiation dose.MethodWe retrospectively analyzed clinical data from 1,422 cases across 8 medical centers. According to the radiation dose for primary gross tumor, patients were divided into standard dose radiotherapy (SD, 50–55 Gy) or high dose (HD, > 55 Gy) radiotherapy. HD was further subdivided into conventional- high-dose group (HD-conventional, 55–63 Gy) and ultra-high-dose group (HD-ultra, ≥ 63 Gy). Primary outcome was Overall Survival (OS).ResultsThe median OS was 33.0 months (95% CI: 29.401–36.521) in the whole cohort. Compared with SD, HD shown significant improved survival in cervical ESCA in Kaplan-Meier (P = 0.029) and cox multivariate regression analysis (P = 0.024) while shown comparable survival in upper thoracic ESCA (P = 0.735). No significant difference existed between HD-conventional and HD-ultra in cervical (P = 0.976) and upper thoracic (P = 0.610) ESCA. Incidences of radiation esophagitis and pneumonia from HD were comparable to SD (P = 0.097, 0.240), while myosuppression risk was higher(P = 0.039). The Bonferroni method revealed that, for both cervical and upper thoracic ESCA, HD-ultra enhance the objective response rate (ORR) compared to SD (P < 0.05).ConclusionHD radiotherapy benefits cervical but not upper thoracic ESCA, while increasing bone marrow suppression risk. Further dose escalating (≥ 63 Gy) doesn’t improve survival but enhances ORR.

Exploring the impact of network depth on 3D U-Net-based dose prediction for cervical cancer radiotherapy.

The 3D U-Net deep neural network structure is widely employed for dose prediction in radiotherapy. However, the attention to the network depth and its impact on the accuracy and robustness of dose prediction remains inadequate. 92 cervical cancer patients who underwent Volumetric Modulated Arc Therapy (VMAT) are geometrically augmented to investigate the effects of network depth on dose prediction by training and testing three different 3D U-Net structures with depths of 3, 4, and 5. For planning target volume (PTV), the differences between predicted and true values of D98, D99, and Homogeneity were statistically 1.00 ± 0.23, 0.32 ± 0.72, and -0.02 ± 0.02 for the model with a depth of 5, respectively. Compared to the other two models, these parameters were also better. For most of the organs at risk, the mean and maximum differences between the predicted values and the true values for the model with a depth of 5 were better than for the other two models. The results reveal that the network model with a depth of 5 exhibits superior performance, albeit at the expense of the longest training time and maximum computational memory in the three models. A small server with two NVIDIA GeForce RTX 3090 GPUs with 24 G of memory was employed for this training. For the 3D U-Net model with a depth of more than 5 cannot be supported due to insufficient training memory, the 3D U-Net neural network with a depth of 5 is the commonly used and optimal choice for small servers.

Utilizing CT imaging for evaluating late gastrointestinal tract side effects of radiotherapy in uterine cervical cancer: a risk regression analysis

BackgroundRadiotherapy (RT) is effective for cervical cancer but causes late side effects (SE) to nearby organs. These late SE occur more than 3 months after RT and are rated by clinical findings to determine their severity. While imaging studies describe late gastrointestinal (GI) SE, none demonstrate the correlation between the findings and the toxicity grading. In this study, we demonstrated the late GI toxicity prevalence, CT findings, and their correlation.MethodsWe retrospectively studied uterine cervical cancer patients treated with RT between 2015 and 2018. Patient characteristics and treatment(s) were obtained from the hospital’s databases. Late RTOG/EORTC GI SE and CT images were obtained during the follow-up. Post-RT GI changes were reviewed from CT images using pre-defined criteria. Risk ratios (RR) were calculated for CT findings, and multivariable log binomial regression determined adjusted RRs.ResultsThis study included 153 patients, with a median age of 57 years (IQR 49–65). The prevalence of ≥ grade 2 RTOG/EORTC late GI SE was 33 (27.5%). CT findings showed 91 patients (59.48%) with enhanced bowel wall (BW) thickening, 3 (1.96%) with bowel obstruction, 7 (4.58%) with bowel perforation, 6 (3.92%) with fistula, 0 (0%) with bowel ischemia, and 0 (0%) with GI bleeding. Adjusted RRs showed that enhanced BW thickening (RR 9.77, 95% CI 2.64–36.07, p = 0.001), bowel obstruction (RR 5.05, 95% CI 2.30–11.09, p < 0.001), and bowel perforation (RR 3.82, 95% CI 1.96–7.44, p < 0.001) associated with higher late GI toxicity grades.ConclusionsOur study shows CT findings correlate with grade 2–4 late GI toxicity. Future research should validate and refine these findings with different imaging and toxicity grading systems to assess their potential predictive value.

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

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

The Current use of Adaptive Strategies for External Beam Radiotherapy in Cervical Cancer: A Systematic Review

AimsVariability in the target and organs at risk (OARs) in cervical cancer treatment presents challenges for precise radiotherapy. Adaptive radiotherapy (ART) offers the potential to enhance treatment precision and outcomes. However, the increased workload and a lack of consensus on the most suitable ART approach hinder its clinical adoption. This systematic review aims to assess the current use of adaptive strategies for cervical cancer and define the optimal approach. Materials and methodsA systematic review of current literature published between January 2012 and May 2023 was conducted. Searches used PubMed/Medline, Cochrane Library, and Web of Science databases, supplemented with the University of Manchester, Google Scholar, and papers retrieved from reference lists. The review assessed workflows, compared dosimetric benefits, and examined resources for each identified strategy. Excluded were abstracts, conference abstracts, reviews, articles unrelated to ART management, proton therapy, brachytherapy, or qualitative studies. A narrative synthesis involved data tabulation, summarizing selected studies detailing workflow for cervical cancer and dosimetric outcomes for targets and OARs. ResultsSixteen articles met the inclusion criteria; these were mostly retrospective simulation planning studies, except four studies that had been clinically implemented. We identified five approaches for ART radiotherapy for cervical cancer: reactive and scheduled adaptation, internal target volume (ITV)-based approach using library of plans (LOP), fixed-margin approach using LOP, and real-time adaptation, with each approach reducing irradiated volumes without compromising target coverage compared to the non-ART approach. The LOP-based ITV approach is the most used and clinically assessed. ConclusionIdentifying the optimal strategy is challenging due to dosimetric assessment limitations. Implementing cervical cancer ART necessitates strategic optimization of clinical benefits and resources through research, including studies to identify the optimal frequency, and prospective evaluations of toxicity.

Retrospective analysis of efficacy and safety of recombinant human Rh-endostatinstatin combined with concurrent radiotherapy for cervical cancer.

Retrospective study and analysis of the safety and efficacy of Rh-Rh-endostatinstatin combined with simultaneous radiotherapy in the treatment of cervical cancer. A retrospective study was used to enroll cervical cancer patients who received Rh-endostatin combined with simultaneous radiotherapy (observation group) or radiotherapy alone (control group) from January 2019 to December 2022 in the Affiliated Hospital of Hebei University, and RECIST 1.1 criteria were used to evaluate the recent efficacy, and the WHO Adverse Reaction Scale for Anti-cancer Drugs to evaluate the toxic and side effects. The difference between PR, SD, PD, ORR and DCR of the two groups was not statistically significant(P>0.05), and the CR of the observation group was significantly higher than that of the control group(P<0.05). The proportion of neutropenia, hypertension, arrhythmia, hemoglobin reduction in the observation group was significantly higher than that in the control group, and the proportion of nausea and vomiting was significantly lower than that in the control group(P<0.05), and there was no significant difference in other adverse reactions(P>0.05). After intervention, the CD3+, CD3-CD19+, CD16+CD56+, CEA, CY211 of both groups were significantly lower than before treatment(P<0.05). After treatment, CD3+, CD3-CD19+, CD16+CD56+ were significantly higher in the observation group than in the control group, and WBC and PLT were significantly lower than before treatment(P<0.05). The HPV conversion rate of the observation group was significantly higher than that of the control group(P<0.05). Our finding revealed that Rh-endostatinstatin combined with simultaneous radiotherapy showed better clinical outcomes and favorable toxic profile than that of radiotherapy alone in the treatment of cervical cancer.

846: Adaptive strategies for external beam radiotherapy in cervical cancer: a systematic review.

846: Adaptive strategies for external beam radiotherapy in cervical cancer: a systematic review.

Treatment of secondary uterine malignancy following radiotherapy for cervical cancer: a study based on the SEER database

BackgroundRadiotherapy is one of the main treatments for cervical cancer. Long-term complications of radiation exposure include the emergence of secondary tumors. This is a retrospective study based on an American population. We discuss the optimal treatment modality for patients with radiation-induced secondary uterine malignancy based on the Surveillance, Epidemiology, and End Results database.MethodsThe study included patients with a definitive pathological diagnosis of cervical cancer who were diagnosed with a uterine malignant tumor ≥ 1 year later. Patients in whom cervical cancer was not the first tumor or patients with missing data were excluded. Univariate and multivariate analyses were performed using the COX regression model to screen independent prognostic factors affecting overall survival. Kaplan-Meier survival curves were analyzed using the R software package.ResultsWe screened 142 patients with a secondary uterine malignancy after cervical cancer treatment, 115 patients with a secondary uterine malignancy after radiotherapy, and 27 patients with a secondary uterine malignancy who did not receive radiotherapy. The average latency period for developing a secondary tumor was 8 years, and 57.04% of the patients had a second tumor at ≥ 60 years of age. In patients with a secondary uterine malignancy after radiotherapy, surgery improved the prognosis [hazard ratio (HR), 0.374; 95% confidence interval (CI), 0.229–0.612], whereas radiotherapy and chemotherapy did not reduce the risk of death. In the subgroup analysis, the surgery plus chemotherapy group had a significantly better survival prognosis than the other groups (HR, 0.251; 95% CI, 0.122–0.515).ConclusionsThe results suggest that the treatment modality in patients with secondary uterine malignancy after radiotherapy for cervical cancer has a significant impact on survival. The survival outcomes of patients receiving surgery combined with chemotherapy are superior to those of patients receiving other treatments.

The Clinical Course of the Late Toxicity of Definitive Radiotherapy in Cervical Cancer.

Background and Objectives: This study aimed to investigate the clinical course and characteristics of late toxicity over time following the completion of definitive radiotherapy (RT) in patients with cervical cancer. Materials and Methods: We retrospectively reviewed the medical records of 60 patients with cervical cancer who underwent pelvic external beam radiotherapy followed by intracavitary brachytherapy. Late toxicity was assessed for the lower gastrointestinal (GI) tract and bladder organ at 6, 12, 24, 36, and >36 months post-RT. We examined the onset and prevalence of late toxicity at each time point. Clinical remission and interventions for managing late toxicity were also investigated. Results: The peak onset of lower GI toxicity occurred 12 months after RT completion, with a median symptom duration of 9.9 months (range, 0.1-26.3 months), and exhibited its highest prevalence rate of 15.5% at 24 months post-RT. Most GI toxicities developed and resolved within three years post-RT, with a prevalence rate of 8.1% at three years, followed by a decreasing trend. Bladder toxicity first peaked at 24 months post-RT and continued to occur beyond 36 months, showing the re-increasing pattern in the prevalence rate after 36 months (23.5%). In terms of clinical remission, 66.7% of lower GI toxicities (12 of 18 patients) and 60% of bladder toxicities (9 of 15 patients) achieved complete remission by the last follow-up date. Conclusions: Late toxicities of the GI and bladder following definitive RT in cervical cancer are partially reversible and exhibit distinct patterns of onset and prevalence over time. A systematic follow-up strategy should be established for the early detection and timely intervention of late toxicity by understanding these clinical courses.

The Impact of Vaginal Dilator Use on the Quality of Life in Women Treated with Adjuvant Radiotherapy for Cervical Cancer

The Impact of Vaginal Dilator Use on the Quality of Life in Women Treated with Adjuvant Radiotherapy for Cervical Cancer

A potential usefulness of ultra-high-resolution computed tomography in quality assurance of remote after-loading system for cervical cancer.

Intracavitary brachytherapy with a remote after-loading system (RALS) is performed as a part of radical radiation therapy in cervical cancer. The radiation source is delivered directly through an applicator placed inside the uterus or vagina. Thorough quality control is important to prevent accidents that can lead to serious irradiation error, and an applicator check is one such quality control measure. We experienced a clinical situation in which a small volume of water was observed in the lumen of a post-sterilized applicator on treatment-planning CT. Although the submersion test was negative and no air bubbles emerged from the applicator, ultra-high-resolution computed tomography (U-HRCT) showed a linear crack reaching the inside of the applicator. This abnormality was not identified on treatment-planning CT, which has lower spatial resolution than U-HRCT. In addition, no linear cracks were seen on U-HRCT images of eight other applicators considered to be free from damage. U-HRCT may have superior potential to detect applicator damage and could be useful for quality assurance of the RALS procedure.