High-risk Clinical Target Volume Research Articles

MRI-Guided Multi-Catheter High-Dose-Rate Interstitial Brachytherapy for Uterine Cervical Cancer.

Background/Objectives To evaluate the efficacy and safety of unique magnetic resonance imaging (MRI)-guided interstitial brachytherapy (ISBT) for locally advanced cervical cancer that is unsuitable for intracavitary brachytherapy (ICBT) or intracavitary/interstitial brachytherapy (ICISBT). Methods: We analyzed the clinical outcomes, including toxicity, of 68 previously untreated patients with cervical cancer treated between 2014 and 2024. Results: The median high-risk clinical target volume (HR-CTV) was 53.20 cc (range, 16.34-147.03 cc) with ISBT. With a median follow-up time of 37.5 months (7-115 months), the three-year local control, progression-free survival, and overall survival rates were 89.8%, 52.4%, and 70.9%, respectively. Multivariate analyses showed significant associations of histology with local control, overall treatment times, HR-CTV volume with overall survival rate, over all treatment times, and HR-CTV volume and M category with progression-free survival. Toxicity grade 3 occurred in 12 patients (17.6%) and consisted of four genitourinary (5.8%) and seven gastrointestinal (10.2%) toxicities. Conclusions: MRI-guided ISBT is an effective treatment strategy for obtaining a favorable local control rate for selected advanced diseases with an acceptable complication rate. Future research is warranted to elucidate who would be good candidates for MRI-guided ISBT.

Quality control study of cervical cancer interstitial brachytherapy treatment plans using statistical process control.

Quality control study of cervical cancer interstitial brachytherapy treatment plans using statistical process control.

IMPROVING PLAN QUALITY IN CERVICAL CANCER BRACHYTHERAPY USING KNOWLEDGE-BASED PLANNING FOR DIRECTION MODULATED BRACHYTHERAPY TANDEM APPLICATOR

IMPROVING PLAN QUALITY IN CERVICAL CANCER BRACHYTHERAPY USING KNOWLEDGE-BASED PLANNING FOR DIRECTION MODULATED BRACHYTHERAPY TANDEM APPLICATOR

Efficacy and safety of 3-dimensional printing noncoplanar template (3D-PNCT)-assisted high-dose-rate interstitial brachytherapy (HDR-ISBT) for reirradiation of recurrent cervical cancer: a prospective cohort.

This study aimed to investigate the efficacy and safety of 3-dimensional printing noncoplanar template (3D-PNCT)-assisted computed tomography (CT)-guided high-dose-rate interstitial brachytherapy (HDR-ISBT) for reirradiation of pelvic recurrent cervical carcinoma after external beam radiotherapy. From January 2019 to August 2023, 45 eligible patients were enrolled in this prospective cohort. All patients underwent 3D-PNCT-assisted CT-guided HDR-ISBT with a prescribed dose of 4-7 Gy/fraction to the high-risk clinical target volume (HR-CTV) over 3-8 fractions, either for curative or palliative purposes. The primary endpoints were local progression-free survival (LPFS) and tumor response rate (TRR). The secondary outcome measures included overall survival (OS), toxicities, and symptom resolution. Forty-five patients received 261 fractions of 3D-PNCT-assisted HDR-ISBT. Twenty-nine patients had isolated pelvic recurrence, and 16 patients had simultaneous extra-pelvic or distant recurrences. The TRR was 66.7%. The 2- and 5-year LPFS rates were 30.0% and 25.7%, respectively. The median OS was 23.2 months, and 2- and 5-year OS rates were 49.5% and 34.0%, respectively. The multivariate analysis indicated that squamous cell carcinoma, radical surgery, recurrence-free interval≥12 months, tumor diameter, pelvic recurrence type, and HR-CTV D90≥45 Gy were independent factors influencing LPFS (all p<0.05). D100≥21 Gy, V100≥83%, and V150≥45% were associated with better LPFS (all p<0.05). Tumor diameter and metastasis were independent predictive factors for OS (all p<0.05). The pain relief rate was 66.7% (10/15). Grade 3-4 toxicities occurred in 20.0% of patients. 3D-PNCT-assisted HDR-ISBT for reirradiation of recurrent cervical cancer proved to be an effective and safe alternative to radical surgery.

Factors affecting D90 High-risk Clinical Target Volumes (HR-CTV dose) of intracavitary and interstitial brachytherapy in locally advanced cervical cancer

Factors affecting D90 High-risk Clinical Target Volumes (HR-CTV dose) of intracavitary and interstitial brachytherapy in locally advanced cervical cancer

Partial and full arc with DynamicARC technique in pencil beam scanning proton therapy for bilateral head and neck cancer: A feasibility and dosimetric study.

A novel proton beam delivery method known as DynamicARC spot scanning has been introduced. The current study aims to determine whether the partial proton arc technique, in conjunction with DynamicARC pencil beam scanning (PBS), can meet clinical acceptance criteria for bilateral head and neck cancer (HNC) and provide an alternative to full proton arc and traditional intensity-modulated proton therapy (IMPT). The study retrospectively included anonymized CT datasets from ten patients with bilateral HNC, all of whom had previously received photon treatment. The clinical target volumes (CTV) were categorized into three levels: CTV_7000, CTV_5950, and CTV_5600. IMPT plans included three beams, whereas DynamicARC plans included dual-partial-arcs (DPA), single-partial-arc (SPA), and single-full-arc (SFA). All plans underwent robust optimization considering setup (±3mm) and range (±3%) uncertainties applied to the CTVs. DynamicARC plans were evaluated against the NRG-HN009 criteria and IMPT plans using various metrics. All four techniques-IMPT, DPA, SPA, and SFA-demonstrated substantial compliance with NRG-HN009 dosimetric criteria. DynamicARC produced superior dose conformity, lower hotspot, and improved homogeneity for high-risk CTV compared to IMPT, with comparable performance for intermediate- and low-risk CTVs. DynamicARC reduced the Dmean to the parotid glands by average differences of 14.5%-22.1% and to the oral cavity by an average difference of 15.75% compared to IMPT. DPA and SPA techniques achieved reductions in total integral dose of 3.7%-5.7% relative to IMPT. Overall, DPA yielded dosimetric results comparable to those of SFA while offering more conformal dose distributions and slightly better organ at risk sparing than SPA. On the ProteusOne with a partial gantry system, DPA and SPA, in conjunction with DynamicARC PBS protons, provided clear dosimetric advantages over three-field IMPT. Future clinical implementation and further research into optimizing DynamicARC protocols are warranted to fully realize the benefits of these techniques in clinical settings.

Artificial Intelligence-Empowered Multistep Integrated Radiation Therapy Workflow for Nasopharyngeal Carcinoma.

To establish an artificial intelligence (AI)-empowered multistep integrated (MSI) radiation therapy (RT) workflow for patients with nasopharyngeal carcinoma (NPC) and evaluate its feasibility and clinical performance. Patients with NPC scheduled for MSI RT workflow were prospectively enrolled. This workflow integrates RT procedures from computed tomography (CT) scan to beam delivery, all performed with the patient on the treatment couch. Workflow performance, tumor response, patient-reported acute toxicities, and quality of life were evaluated. From March 2022 to October 2023, 120 newly diagnosed, nonmetastatic patients with NPC were enrolled. Of these, 117 completed the workflow with a median duration of 23.2 minutes (range, 16.3-45.8). Median translation errors were 0.2 mm (from CT scan to planning approval) and 0.1 mm (during beam delivery). AI-generated contours required minimal revision for the high-risk clinical target volume and organs at risk, minor revision for the involved cervical lymph nodes and low-risk clinical target volume (median Dice similarity coefficients (DSC), 0.98 and 0.94), and more revision for the gross tumor at the primary site and the involved retropharyngeal lymph nodes (median DSC, 0.84). Of 117 AI-generated plans, 108 (92.3%) passed after the first optimization, with ≥97.8% of target volumes receiving ≥100% of the prescribed dose. Dosimetric constraints were met for most organs at risk, except the thyroid and submandibular glands. One hundred and fifteen patients achieved a complete response at week 12 post-RT, while 14 patients reported any acute toxicity as "very severe" from the start of RT to week 12 post-RT. AI-empowered MSI RT workflow for patients with NPC is clinically feasible in a single institutional setting compared with standard, human-based RT workflow.

Efficacy and Failure Patterns Following Target Volume and Dose Reduction After Neoadjuvant Therapy in Locoregionally Advanced Head and Neck Squamous Cell Carcinoma.

In this study, we aimed to analyze the efficacy and failure patterns of contouring target volume based on the residual tumor and decreasing the dose to the area of tumor regression after neoadjuvant therapy in locoregionally advanced head and neck squamous cell carcinoma (HNSCC). We retrospectively analyzed the patients with locoregionally advanced HNSCC treated by our group from May 2011 to June 2023. All patients received neoadjuvant therapy followed by intensity-modulated radiation therapy. Gross tumor volumes for the primary tumor and metastatic lymph nodes were delineated according to postneoadjuvant extension. The tumor shrinkage after neoadjuvant therapy was included in the high-risk clinical target volume (CTV1) and prescribed a dose of 60 Gy. Kaplan-Meier analysis was employed to calculate local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), overall survival (OS), and distant metastasis-free survival (DMFS). Failure patterns were analyzed by mapping the location and extent of locoregional recurrence onto pretreatment planning CT. This study included a total of 114 patients, with a median follow-up of 34 months. The 5-year LRFS, RRFS, OS, and DMFS rates were 70.2%, 70.7%, 74.8%, and 73.8%, respectively. Among the 14 patients with recurrences, there were 5 local failures, 6 regional recurrences, and 3 both local and regional recurrences. All local recurrences occurred within the 95% isodose line, classified as in-field failures. Only one regional recurrence was marginal failure. No out-of-field failure was observed. Reduction of target volume after neoadjuvant therapy and distribution of 60 Gy of dose to the tumor regression area may be feasible.

Assessment of dose contribution to pelvic lymph nodes in patients undergoing brachytherapy for carcinoma cervix

Background: The inclusion of pelvic lymph node (PLN) metastasis in the FIGO staging system has impacted disease classification and patient survival. Brachytherapy is a key component in managing carcinoma cervix; however, the dose contribution of brachytherapy to PLNs remains unclear. Aims and Objectives: This study aims to quantify the dose contribution of high-dose rate (HDR) brachytherapy to individual pelvic nodal groups. Materials and Methods: We included 40 biopsy-proven carcinoma cervix patients, stages IIA to IVA. All patients underwent external beam radiotherapy (EBRT) with concurrent cisplatin chemotherapy, followed by HDR brachytherapy, either intracavitary brachytherapy (ICBT) or interstitial brachytherapy (ISBT). A total dose of 21 Gy in 3 fractions (7 Gy per fraction) was prescribed to the high-risk clinical target volume. Results: For ICBT, the mean absolute doses received by the external iliac, internal iliac, and obturator groups were 0.56 Gy, 1.02 Gy, and 1.22 Gy, corresponding to EQD2 (α/β=10) values of 0.49 Gy, 0.93 Gy, and 1.14 Gy, respectively. In the ISBT group, the mean absolute doses were 0.49 Gy, 0.86 Gy, and 1.11 Gy, with corresponding EQD2s of 0.43 Gy, 0.85 Gy, and 1.02 Gy. Conclusion: PLNs received significant dose contributions from HDR brachytherapy in cervical cancer patients, providing valuable reference data for determining the EBRT boost dose in cases of enlarged PLNs.

Assessment of dose contribution to pelvic lymph nodes in patients undergoing brachytherapy for carcinoma cervix

Background: The inclusion of pelvic lymph node (PLN) metastasis in the FIGO staging system has impacted disease classification and patient survival. Brachytherapy is a key component in managing carcinoma cervix; however, the dose contribution of brachytherapy to PLNs remains unclear. Aims and Objectives: This study aims to quantify the dose contribution of high-dose rate (HDR) brachytherapy to individual pelvic nodal groups. Materials and Methods: We included 40 biopsy-proven carcinoma cervix patients, stages IIA to IVA. All patients underwent external beam radiotherapy (EBRT) with concurrent cisplatin chemotherapy, followed by HDR brachytherapy, either intracavitary brachytherapy (ICBT) or interstitial brachytherapy (ISBT). A total dose of 21 Gy in 3 fractions (7 Gy per fraction) was prescribed to the high-risk clinical target volume. Results: For ICBT, the mean absolute doses received by the external iliac, internal iliac, and obturator groups were 0.56 Gy, 1.02 Gy, and 1.22 Gy, corresponding to EQD2 (α/β=10) values of 0.49 Gy, 0.93 Gy, and 1.14 Gy, respectively. In the ISBT group, the mean absolute doses were 0.49 Gy, 0.86 Gy, and 1.11 Gy, with corresponding EQD2s of 0.43 Gy, 0.85 Gy, and 1.02 Gy. Conclusion: PLNs received significant dose contributions from HDR brachytherapy in cervical cancer patients, providing valuable reference data for determining the EBRT boost dose in cases of enlarged PLNs.

Exploring the dosimetric impact of systematic and random setup uncertainties in robust optimization of head and neck IMPT plans

Exploring the dosimetric impact of systematic and random setup uncertainties in robust optimization of head and neck IMPT plans

Application value of personalized 3D printing vaginal model for the Image-guided adaptive brachytherapy of cervical cancer.

To explore the application value of using 3-dimensional (3D) printing (3DP) technology to create individualized vaginal molds for brachytherapy (BT) in high-dose-rate 3D cervical cancer through reverse engineering of needle placement. Prospectively, 11 patients with cervical cancer were treated with 3DP-intracavitary/interstitial (IC/IS) BT using 3DP to create individualized vaginal molds. All patients were performed BT after completion of external beam radiotherapy (EBRT). Each patient was treated with BT 5 times, the prescription dose was 600 cGy/F, which was performed once or twice a week, 2 of them were freehand IC/IS BT, and 3 were 3DP-IC/IS BT. The relevant planning parameters (bladder, rectum, sigmoid colon, and small intestine) and target conformity index (CI) for high-risk clinical target volume (HR-CTV) and organs at risk (OARs) were compared between the groups. There were significant advantages in the 3DP-IC/IS BT group compared with the freehand IC/IS BT group: HR-CTV D90 (629.40±19.34 vs. 613.03±15.93 cGy, p=0.002), D95 (580.74±18.31 vs. 567.44±23.94 cGy, p=0.032), bladder D2cc (431.11±23.27 vs. 458.07±23.27 cGy, p<0.001), bladder D1cc and bladder D0.1cc. There was no statistically significant difference (p>0.05) between the 2 groups in rectal D2cc (352.30±42.42 vs. 361.29±42.42 cGy, p=0.470), sigmoid colon D2cc (236.73±78.95 vs. 246.50±58.17 cGy, p=0.621), CI (0.79±0.04 vs. 0.79±0.039 p=0.773), HR-CTV V100, V200, D98, D100 and other OARs parameters (p>0.05). Compared with IC/IS BT, 3DP-IC/IS BT has apparent advantages with simple operation and high safety. In addition, individualized mold helps to improve the tumor target area's radiation dose while meeting the dose-limiting requirements for organs at risk and reduces the clinical proficiency requirements for operating physicians.

External beam radiotherapy followed by image-guided adaptive brachytherapy in locally advanced cervical cancer: a multicenter retrospective analysis.

To evaluate oncological outcomes and toxicities in patients with locally advanced cervical cancer (LACC) treated with concurrent chemoradiotherapy followed by image-guided adaptive brachytherapy at two Italian centres. A retrospective analysis was conducted on 122 patients with LACC treated between 2010 and 2022. Primary endpoints were local control (LC), pelvic control (PC), and nodal control (NC). Secondary endpoints included disease-free survival (DFS), metastasis-free survival (MFS), overall survival (OS), and late toxicity. Correlations between patient characteristics and oncological outcomes were conducted. Brachytherapy planning was CT and MRI-based in 88 (72.1%) and 34 patients (27.9%), respectively. The mean total dose (EQD2) delivered to high-risk clinical target volume was 82Gy. Overall treatment time was ≤ 50days and > 50days in 48 (39.3%) and 74 patients (60.7%), respectively. At a mean follow up of 101months, 3 and 5-year LC rates were 87% and 85%, respectively. Five-year PC and NC rates were 77% and 85.1%. Five-year DFS and OS were 61% and 65.4%, respectively, with significant correlations between these outcomes and FIGO stage and nodal status at diagnosis. Gastrointestinal, genitourinary and vaginal adverse effects were the most reported late toxicities and 8 (6.5%) grade 3-5 events were observed. 32 patients (26.2%) had vaginal stenosis and it was significantly related to 3D imaging used for brachytherapy planning. The study confirmed the efficacy and safety of chemoradiotherapy and IGABT for LACC. Full implementation of MRI treatment planning and interstitial techniques could further enhance personalized treatment and outcomes.

Dual convolution-transformer UNet (DCT-UNet) for organs at risk and clinical target volume segmentation in MRI for cervical cancer brachytherapy

Objective. MRI is the standard imaging modality for high-dose-rate brachytherapy of cervical cancer. Precise contouring of organs at risk (OARs) and high-risk clinical target volume (HR-CTV) from MRI is a crucial step for radiotherapy planning and treatment. However, conventional manual contouring has limitations in terms of accuracy as well as procedural time. To overcome these, we propose a deep learning approach to automatically segment OARs (bladder, rectum, and sigmoid colon) and HR-CTV from female pelvic MRI.Approach. In the proposed pipeline, a coarse multi-organ segmentation model first segments all structures, from which a region of interest is computed for each structure. Then, each organ is segmented using an organ-specific fine segmentation model separately trained for each organ. To account for variable sizes of HR-CTV, a size-adaptive multi-model approach was employed. For coarse and fine segmentations, we designed a dual convolution-transformer UNet (DCT-UNet) which uses dual-path encoder consisting of convolution and transformer blocks. To evaluate our model, OAR segmentations were compared to the clinical contours drawn by the attending radiation oncologist. For HR-CTV, four sets of contours (clinical + three additional sets) were obtained to produce a consensus ground truth as well as for inter/intra-observer variability analysis.Main results. DCT-UNet achieved dice similarity coefficient (mean ± SD) of 0.932 ± 0.032 (bladder), 0.786 ± 0.090 (rectum), 0.663 ± 0.180 (sigmoid colon), and 0.741 ± 0.076 (HR-CTV), outperforming other state-of-the-art models. Notably, the size-adaptive multi-model significantly improved HR-CTV segmentation compared to a single-model. Furthermore, significant inter/intra-observer variability was observed, and our model showed comparable performance to all observers. Computation time for the entire pipeline per subject was 12.59 ± 0.79 s, which is significantly shorter than the typical manual contouring time of >15 min.Significance. These experimental results demonstrate that our model has great utility in cervical cancer brachytherapy by enabling fast and accurate automatic segmentation, and has potential in improving consistency in contouring. DCT-UNet source code is available athttps://github.com/JHU-MICA/DCT-UNet.

Retrospective Evaluation of GEC-ESTRO Constraints for Definitive Radiochemotherapy with Brachytherapy and Correlation with Oncologic Outcome in Cervical Cancer: A Monocenter Study.

This study aims to evaluate patients with locally advanced cervical cancer who underwent definitive radiochemotherapy, including brachytherapy, at the University Hospital of Muenster (UKM), focusing on target volume coverage, oncologic outcome parameters, and organs at risk (OAR) toxicities. Results are compared with the Gyn GEC-ESTRO (GGE) recommendations. Of a cohort of 48 patients, treated between 2013 and 2023, the physical radiation treatment planning with application of CT and MRI and oncologic follow-up data was analyzed. Target volume structures, comprising the high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume (IR-CTV), Point A, and corresponding EQD2(α/β=10) doses were determined. Endpoints included local tumor control, overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS). Total OAR (D2cc) EQD2(α/β=3) doses were correlated with adverse events defined by CTCAE v5.0 and LENT-SOMA criteria. Median follow-up was 58.0 months (95% CI [27.6, 88.4]). FIGO stage I was present in 7 (15%) patients, II in 13 (27%), and III in 28 (58%) patients. A total of 38 (79%) patients showed a complete remission 3 months after treatment. The 5-year event-free rate was 67.4% (95% CI [49.3, 80.3]) for OS, 77.0% (95% CI [56.7, 88.6]) for RFS and 68.1% (95% CI [49.7, 80.9]) for PFS. Incomplete radiation treatment and advanced tumor stages led to worse outcomes. Meeting Point A GGE recommendations increased chances for complete remission and could decrease chances of an event occurring for OS, PFS, and RFS. Compliance with GGE recommendations lowered the chances of OAR toxicity occurring. MRI-based target volume definition for brachytherapy in cervical cancer may improve patients' OS, PFS, and RFS. Time-to-event endpoints are consistent with comparable studies, and adherence to current ESGO/ESTRO/ESP guidelines is endorsed.

Retrospective assessment of HDR brachytherapy dose calculation methods in locally advanced cervical cancer patients: AcurosBV vs. AAPM TG43 formalism.

This retrospective analysis was completed to investigate the use of a model-based dose calculation algorithm (MBDCA) AcurosBV, for use in HDR BT treatments for locally advanced cervical cancer treated with tandem and ovoid applicators with interstitial needles. A cohort of 32 patients receiving post-EBRT HDR brachytherapy boost with a prescription dose of 5.5Gy × 5 fractions to the high-risk clinical target volume (CTVHR) were selected for this study. For standard TG43 dose calculation, applicators were manually digitized on the planning images, while for AcurosBV calculations, solid renderings of Titanium Fletcher Suite Delclos (FSD) applicators included in BrachyVision were matched to those used clinically and Ti needles were manually digitized. The dose was recalculated using Varian's AcurosBV 13.5 and dose-to-medium-in-medium (Dm,m) was reported. EQD2 values for targets and organs at risk were compared between dose calculation formalisms. D90% and D98% values were reported for the high and intermediate-risk CTVs, and values were reported for OARs including bladder, rectum, sigmoid, bowel, and vagina. Due to variability within the patient cohort, the dosimetric impact of AcurosBV was investigated corresponding to planning image modality (CT vs. CBCT), presence of Ti needles, and contrast within vaginal balloons used to stabilize implants. AcurosBV showed lower dosimetric values for all plans compared to TG43. The average±standard deviation of dosimetric reduction in D90% was 4.33±0.09% for CTVHR and 4.12±0.09% for CTVIR. The reduction to OARs was: 4.99±0.15% for bladder, 7.87±0.16% for rectum, 5.79±0.17% for sigmoid, 6.91±0.14% for bowel, and 4.55±0.14% for vagina. AcurosBV should be utilized for HDR BT GYN cases, treated with tandem and ovoid applicators, with high degrees of heterogeneity and calculated in tandem with TG43.

Deep learning-based segmentation for high-dose-rate brachytherapy in cervical cancer using 3D Prompt-ResUNet

Objective.To develop and evaluate a 3D Prompt-ResUNet module that utilized the prompt-based model combined with 3D nnUNet for rapid and consistent autosegmentation of high-risk clinical target volume (HRCTV) and organ at risk (OAR) in high-dose-rate brachytherapy for cervical cancer patients.Approach.We used 73 computed tomography scans and 62 magnetic resonance imaging scans from 135 (103 for training, 16 for validation, and 16 for testing) cervical cancer patients across two hospitals for HRCTV and OAR segmentation. A novel comparison of the deep learning neural networks 3D Prompt-ResUNet, nnUNet, and segment anything model-Med3D was applied for the segmentation. Evaluation was conducted in two parts: geometric and clinical assessments. Quantitative metrics included the Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (HD95%), Jaccard index (JI), and Matthews correlation coefficient (MCC). Clinical evaluation involved interobserver comparison, 4-grade expert scoring, and a double-blinded Turing test.Main results.The Prompt-ResUNet model performed most similarly to experienced radiation oncologists, outperforming less experienced ones. During testing, the DSC, HD95% (mm), JI, and MCC value (mean ± SD) for HRCTV were 0.92 ± 0.03, 2.91 ± 0.69, 0.85 ± 0.04, and 0.92 ± 0.02, respectively. For the bladder, these values were 0.93 ± 0.05, 3.07 ± 1.05, 0.87 ± 0.08, and 0.93 ± 0.05, respectively. For the rectum, they were 0.87 ± 0.03, 3.54 ± 1.46, 0.78 ± 0.05, and 0.87 ± 0.03, respectively. For the sigmoid, they were 0.76 ± 0.11, 7.54 ± 5.54, 0.63 ± 0.14, and 0.78 ± 0.09, respectively. The Prompt-ResUNet achieved a clinical viability score of at least 2 in all evaluation cases (100%) for both HRCTV and bladder and exceeded the 30% positive rate benchmark for all evaluated structures in the Turing test.Significance.The Prompt-ResUNet architecture demonstrated high consistency with ground truth in autosegmentation of HRCTV and OARs, reducing interobserver variability and shortening treatment times.

Clinical advantages of incorporating predicted weekly anatomy in IMPT optimization with reduced setup error.

In head and neck (H&N) cancer treatment, a conventional setup error (SE) of 3mm is often used in robust optimization (cRO3mm). However, cRO3mm may lead to excessive radiation doses to organs at risk (OARs) and does not purposefully compensate for interfractional anatomy variations. This study introduces a method using predicted images from an anatomical model and a reduced 1mm SE uncertainty for robust optimization (aRO1mm), aiming to decrease the dose to OARs without affecting the coverage of the clinical target volume (CTV). This retrospective study involved 10 nasopharynx radiotherapy patients. Validation CT scans (vCT) from treatment weeks 1 to 6 were analyzed. A predictive anatomical model, designed to capture the average anatomical changes over time, provided predicted CT images for weeks 1, 3, and 5. We compared three optimization scenarios: (1) aRO1mm, using three predicted images with 1mm setup shift and 3% range uncertainty, (2) cRO3mm, with a robust 3mm setup shift and 3% range uncertainty, and (3) cRO1mm, a robust 1mm setup shift and 3% range uncertainty. The accumulated dose to CTVs and serial organs was evaluated under these uncertainties, while parallel OARs were assessed using the accumulated nominal dose (without errors). The accumulated volume receiving 94% of the prescribed dose (V94) for CTVs in cRO3mm exceeded 98%, meeting the clinical goal. For high-risk CTV, the minimum V94 was 96.44% in aRO1mm and 94.05% in cRO1mm. For low-risk CTV, these values were 97.68% in aRO1mm and 97.15% in cRO1mm. When comparing aRO1mm to cRO3mm on OARs, aRO1mm reduced normal tissue complication probability (NTCP) for grade 2 xerostomia and dysphagia by averages of 3.67% and 1.54%,respectively. aRO1mm lowers the radiation dose to OARs compared to the traditional approach, while maintaining adequate dose coverage on the target area. This method offers an improved strategy for managing uncertainties in radiation therapy planning for H&N cancer, enhancing treatment effectiveness.

Individual curved-needle interstitial template created using three-dimensional printing for brachytherapy for distal parauterine tumor recurrence.

Achieving a clinically acceptable dose distribution with commercial vaginal applicators for brachytherapy of recurrent parauterine tumors is challenging. However, the application of three-dimensional (3D) printing technology in brachytherapy has been widely acknowledged and can improve clinical treatment outcomes. This study aimed to introduce an individual curved-needle interstitial template (ICIT) created using 3D printing technology for high-dose-rate (HDR) brachytherapy with interstitial treatment to provide a clinically feasible approach to distal parauterine and vaginal cuff tumors. The entire workflow, including the design, optimization, and application, is presented. Ten patients with pelvic cancer recurrence were examined at our center. The vaginal topography was filled with gauze strips soaked in developer solution, and images were obtained using computed tomography (CT) and magnetic resonance imaging (MRI). Curved needle paths were designed, and ICITs were 3D-printed according to the high-risk clinical target volume (HRCTV) and vaginal filling model. The dose and volume histogram parameters of the HRCTV (V100, V200, D90, and D98) and organs at risk (OARs) (D2cc) were recorded. All patients completed interstitial brachytherapy treatment with the 3D-printed ICIT. One patient experienced vaginal cuff tumor recurrence, and nine patients experienced parametrial tumor recurrence (four on the left and five on the right). We used two to five interstitial needles, and the maximum angle of the curved needle was 40°. No source obstruction events occurred during treatment of these 10 patients. The doses delivered to the targets and OARs of all patients were within the dose limits and based on clinical experience at our center. The ICIT is a treatment option for patients with distal parauterine tumor recurrence. This method addresses the limitations of vaginal intracavitary and standard interstitial applicators. The ICIT has the advantages of biocompatibility, personalization, and magnetic resonance imaging compatibility.

Treatment Outcomes and Patterns of Disease Recurrence of Patients with Carcinoma of the Buccal Mucosa.

Locally advanced buccal mucosa cancer is typically treated with surgery and adjuvant postoperative radiation therapy, which includes concurrent Cisplatin 100mg/m2 on Day 1, plus 5-Fluorouracil 1000mg/m2 from Day 1 to 4 every three weeks. Ipsilateral face radiotherapy is a de-escalated treatment that spares the opposite side of the face, enhancing post-treatment chewing function. The availability of electron beam radiotherapy for treating recurrences on the opposite side has increased the use of ipsilateral face radiotherapy. This retrospective study aimed to assess treatment outcomes and patterns of disease recurrence in patients with carcinoma of the buccal mucosa treated with different schedules. We retrospectively reviewed records of 54 patients with a pathological diagnosis of buccal mucosa cancers treated between 2018 and 2023. We extracted patients' demographic, disease, and treatment criteria. Indications for postoperative radiotherapy included a close margin of less than 3mm and lymph node positivity. The primary tumor (face) and neck were considered separately for radiotherapy treatment. One patient who refused surgery, radiotherapy, and chemotherapy but regularly came for follow-up after receiving Ayurvedic treatment died of the disease after 2 years and 1 month. Fifty-three patients received concurrent chemoradiotherapy with Cisplatin 100mg/m2 on Day 1, plus 5-Fluorouracil 1000mg/m2 from Day 1 to 4 every three weeks for three cycles. Postoperative patients were treated with radiotherapy fields covering the face (bilateral or ipsilateral wedged fields) and the whole neck field with central shielding for the initial 44Gy in 22 fractions over 4.5 weeks followed by a boost dose of 16Gy to the primary tumor and involved neck. For radical radiotherapy, patients received a similar radiation field but the boost dose delivered was 26Gy in 13 fractions over 2.5 weeks. For ipsilateral radiotherapy fields, the average face anterior field size was 6W x 8cm; the thick edge of the wedge laterally; depth 4cm and lateral 8W x 8cm radiation field with a thick edge of the wedge anteriorly; depth 3cm. The median dose to high-risk clinical target volume was 60Gy/30 fractions in postoperative cases. Forty-eight patients received radical radiotherapy with a higher dose (66Gy/33 fractions to 70Gy/35 fractions); twenty-eight patients received radiotherapy fields of bilateral face and neck with a central spinal shield of 2cm. Statistical analysis was conducted at the Community Medicine Department using SPSS software version 21.0. The Chi-square test and Fisher Exact test were applied to compare various groups. Fifty-four patients were analyzed. The median follow-up was 9 months. Surgery consisted of Composite Resection (Commando operation) plus Radical Neck dissection in three (5.5%) patients and non-composite resection surgeries (Wide excision of the lesion plus supra-omohyoid dissection) in nine (16.6%) cases, of which six (50%) cases had lymph node involvement but no patient with positive dissection had extracapsular extension. Tumor thickness by histopathology was found to be between 5 and 15mm. Sixteen (28.1%) patients failed locally and 11 (20.3%) had lymph node recurrences. One patient (1.8%) with mucoepidermoid cancer had bony metastases at D9, L1, and the pelvis after 4 months of treatment. Death occurred in 12 (20.3%; one due to a non-oncologic cause) out of 54 patients during our study. The majority (88%) of patients in our study are male, aged less than 50 (55%). A KPS of 70/>70 was present in 83.3% of patients. The majority of patients in this study are T3 (37%) and T4a (29.6%). Nodal status of patients included 29.6% N0; 27.7% N1, and 35.1% N2. The majority of patients (57.4%) have well-differentiated carcinoma followed by moderately differentiated carcinoma in 38.8% of patients. The difference in death is non-significant when ipsilateral face + neck radiotherapy is compared to bilateral face + neck radiotherapy by Fisher Exact test (statistical value = 0.1246; p > 0.05, statistically not significant), and in other groups, it could not be compared due to the small number of patients. Our results show the non-inferiority of non-composite resection surgery + bilateral face + neck radiotherapy to non-operative radical radiotherapy (bilateral or ipsilateral face wedged radiotherapy + neck radiotherapy), so the majority of patients can be treated by these modalities of treatment. De-escalation of radiotherapy by the use of ipsilateral face wedged + neck radiotherapy is possible as there is no statistically significant difference in local and nodal relapse when compared to bilateral face + neck radiotherapy, and it results in sparing of the opposite side of the face. Buccal mucosa carcinoma in eastern Uttar Pradesh is a very aggressive disease, with 12 (20.3%; one due to a non-oncologic cause) out of 54 patients dying. Our results are different compared to historical data, possibly due to the use of concurrent Cisplatin + 5-Fluorouracil chemotherapy and the lower number of patients in the composite resection group as the majority of patients were frail and did not consent to composite resection.