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BACKGROUND AND PURPOSE: Our goal was to develop a workflow to automatically evaluate delivered dose on daily cone beam computed tomography (CBCT) in all breast cancer patients to assess dosimetric impact of anatomical changes and guide decision-making for offline plan adaptation. MATERIALS AND METHODS: The workflow automatically processes the daily CBCTs of all breast cancer patients receiving local and locoregional radiotherapy. The planning-CT is registered to the CBCT to create a synthetic CT and propagate contours. A forward dose calculation is performed, and DVH parameters are extracted and printed in a report. We evaluated the workflow on a group level and in a subset of 30 patients on a patient-specific level, including comparison to clinical evaluation on additional planning-CT in 10 patients. RESULTS: 7454 fractions in 647 patients were analyzed over a period of seven months. Median breast clinical target volume V95% was ≥95 % for 97 % of the patients. The workflow would have provided useful additional insights for decision-making for the requirement of plan adaptation, based on debatable disagreement with the clinical decision in half of the cases with an additional planning-CT. The workflow also identified cases with suboptimal coverage not identified in the clinical procedure. CONCLUSION: We developed a fully automated workflow for dose evaluation on daily CBCT for local and locoregional breast radiotherapy. We have demonstrated its potential for aiding decision-making for plan adaptation in patients with changing anatomy and its capability to highlight patients that may receive suboptimal treatment and require closer clinical evaluation of treatment quality.

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BACKGROUND AND PURPOSE: Over the past decade, tools for automation of various sub-tasks in radiotherapy planning have been introduced, such as auto-contouring and auto-planning. The purpose of this study was to benchmark what degree of automation is possible. MATERIALS AND METHODS: A challenge to perform automated treatment planning for prostate and prostate bed radiotherapy was set up. Participants were provided with simulation CTs and a treatment prescription and were asked to use automated tools to produce a deliverable radiotherapy treatment plan with as little human intervention as possible. Plans were scored for their adherence to the protocol when assessed using consensus expert contours. RESULTS: Thirteen entries were received. The top submission adhered to 81.8% of the minimum objectives across all cases using the consensus contour, meeting all objectives in one of the ten cases. The same system met 89.5% of objectives when assessed with their own auto-contours, meeting all objectives in four of the ten cases. The majority of systems used in the challenge had regulatory clearance (Auto-contouring: 82.5%, Auto-planning: 77%). Despite the 'hard' rule that participants should not check or edit contours or plans, 69% reported looking at their results before submission. CONCLUSIONS: Automation of the full planning workflow from simulation CT to deliverable treatment plan is possible for prostate and prostate bed radiotherapy. While many generated plans were found to require none or minor adjustment to be regarded as clinically acceptable, the result indicated there is still a lack of trust in such systems preventing full automation.

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Objectives: Examine deviations between the digitally planned and actual implant positions in clinical studies using static fully guided surgical guides. Identify potential associated factors and strategies to minimize their likelihood. Materials and Methods: This systematic review was conducted following the PRISMA checklist. The literature search was conducted in the PubMed® and Scopus® databases up to February 2024 following the PICOS search strategy. Clinical trials conducted between 2013 and 2024, evaluating the accuracy of static fully guided surgical guides placed in fully edentulous patients, were included. The studies had to assess at least two of the following parameters: angular deviation, cervical deviation, apical deviation, and depth deviation. Results: Out of the 298 articles initially searched, six randomized clinical trials and three clinical trials were included. All but one article used mucosa-supported guides; the remaining one used bone-supported guides. Apical deviations were more significant than cervical deviations, and implants tended to be placed too superficially. The greatest mean deviations were 2.01 ± 0.77 mm for cervical and 2.41 ± 1.45 mm for apical deviations, with the largest angular deviation recorded at 4.98 ± 2.16°. Conclusions: The accuracy of the surgical guide is influenced by various factors, including the technique of image acquisition and subsequent planning, guide support methods, and the adopted surgical protocol. Apical deviations are influenced by cervical and angular deviations. Additionally, deviations were more pronounced in the mandible. Further studies with similar methodologies are necessary for a more precise assessment of the different factors and for establishing safety margins.

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Background: There has been an increasing number of fragility fractures of the sacrum in the recent decade. With rates of up to 28%, the complication rates after surgical treatment are still at an unacceptably high level, and new treatment strategies are urgently needed. Therefore, the purpose of this study was to evaluate the potential of 3D-navigated trans-sacral bar osteosynthesis in the surgical treatment of fragility fractures of the sacrum. Methods: Retrospectively, from 2017 to 2023, all cases with confirmed fragility fractures of the sacrum in patients > 65 years of age that were surgically treated with navigated 3D-navigated trans-sacral bar osteosynthesis were included, and epidemiological data and the course of treatment analyzed in comparison to a matched control group. Results: Finally, 21 patients (18 women and 3 men) were included in this study. The average age of the patients was 82.6 (SD 6.3) in the intervention group and 79.4 (SD 6.7) in the control group. There were postoperatively detected complications in two cases (18%) in the intervention group and in four cases (40%, p = 0.362) in the control group. The postoperative in-hospital stay was 10 days (SD 3.8) vs. 11.4 days (SD 3.8) in the control. None of the patients in the intervention group and two in the control group needed revision surgery. Conclusions: Overall, 3D-navigated trans-sacral bar osteosynthesis seems to be a promising technique, enabling an accurate implant positioning while offering a low complication rate with an excellent short-term outcome in elderly patients with fragility fractures of the sacrum.

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PURPOSE: To provide risk estimations for vaginal morbidity with regard to vaginal dilation (summarizing the use of dilators and/or sexual activity) in locally advanced cervical cancer patients (LACC) treated with definitive radiochemotherapy and image-guided adaptive brachytherapy (IGABT) within the prospective, multi-institutional EMBRACE-I study. MATERIAL/METHODS: Physician-assessed vaginal morbidity (CTCAEv3.0), use of vaginal dilators and patient-reported sexual activity (EORTC-CX24) were prospectively assessed at baseline and during regular follow-up. Frequency analysis for vaginal dilation was performed in a sub-cohort of patients with ≥3 follow-ups. Regular dilation was defined if reported in ≥50% of follow-ups, no/infrequent dilation if reported in <50%. Actuarial estimates were calculated with Kaplan-Meier method; comparisons evaluated with the log-rank test. Univariate and multivariable Cox proportional hazard regression were used to evaluate risk factors for vaginal stenosis G≥2. RESULTS: The EMBRACE-I study included a total of 1416 patients (2008-2015); 882 were evaluated in the present report with a median follow-up of 60 months. Of those, 565 (64%) reported regular dilation. This was associated with a significantly lower 5-year risk of vaginal stenosis G≥2 compared to no/infrequent dilation (23% vs. 37%, p≤0.001). This univariate finding was confirmed by multivariable analysis, after adjusting for other risk factors (HR=0.630, p=0.001). Regular vaginal dilation was also associated with a significantly higher risk for vaginal dryness G≥1 (72% vs. 67%, p=0.028) and bleeding G≥1 (61% vs. 34%, p≤0.001). CONCLUSION: Vaginal stenosis represents irreversible fibrotic changes that can cause pain during gynecological examination and dyspareunia in LACC survivors. Regular vaginal dilation (defined as the use of dilators and/or sexual activity) is associated with a significantly lower risk for G≥2 vaginal stenosis, suggesting a potential improvement of vaginal patency. It is also associated with a significantly higher risk for mild G≥1 dryness and bleeding (no higher risk for G≥2), which both can be clinically managed.

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PURPOSE: The present study aimed to analyze the operative duration of image-guided brachytherapy (IGBT) for cervical cancer performed at our institution. METHODS: We enrolled cervical cancer patients who had undergone tandem and ovoid-based intracavitary brachytherapy (ICBT) or intracavitary and interstitial brachytherapy (IC/ISBT) between 2020 and 2024. Cone beam computed tomography (CBCT), CT, or CT + MRI were used for IGBT. For each IGBT session, we retrospectively reviewed the following: application time (AT-defined as the duration from entry into the operating room to the initial image acquisition); planning time (PT-defined as the duration from the initial image acquisition to the start of irradiation); and total operation time (TOT- defined as the duration from entry to exit of the operating room). RESULTS: We analyzed a total of 126 sessions in 36 patients, consisting of 99 ICBT-only sessions and 27 IC/ISBT sessions. The IC/ISBT sessions had a significantly longer mean operative duration than the ICBT-only sessions. The IC/ISBT sessions with three or more interstitial needles had significantly longer AT and TOT. However, the IC/ISBT sessions with one needle showed no significant difference in operative duration compared to ICBT-only sessions. CBCT, CT, and CT + MRI were used in 42, 76, and 8 sessions, respectively. In the ICBT patients, CT + MRI had the longest PT. However, there was no significant differences in TOT among CBCT, CT, and CT + MRI. CONCLUSIONS: IC/ISBT sessions with one needle had no significant difference in operative duration compared to ICBT-only sessions. There was no significant difference in TOT between CT + MRI-based IGBT and CT-based IGBT.

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BACKGROUND: Stereotactic ablative body radiation (SABR) is a well-recognized treatment option for hepatocellular carcinoma (HCC). Due to the inherent motion of liver tumors, effective motion management is crucial for successful SABR. In the motion-encompassing motion management technique, all 10 respiratory phase image datasets are delineated and designated as the internal target volume (ITV). Some treatment centers use single or combination image sets to delineate the target volume. This study determines which specialty image set most closely matches an all-phase ITV contour on a synchronized contrast-enhanced 4DCT. MATERIALS AND METHODS: Synchronized 4DCT contrast and delayed scans were acquired for 10 patients in the study. The maximum intensity projection (MiP), average intensity projection (AvgIP), and minimum intensity projection (MinIP) images were generated. The ITV delineation was done in all 10 phases (ITV_all_phase). The ITV_2phase combines the peak inhale and exhale phase, ITV_2 M combines MiP and MinIP, and ITV_3 M combines MiP, MinIP, and AvgIP. All ITVs were compared to ITV_all_phase with Dice similarity index (DSI) and volumes. RESULTS: Using ITV_all_phase as the reference, the DSI and the mean ITV volumes for the different ITVs were as follows: ITV_all_phase (1 and 116.69 cc), ITV_2phase (0.87 and 105.27 cc), MiP (0.76 and 98.24 cc), AvgIP (0.72 and 94.54 cc), ITV_MinIP (0.67 and 81.08 cc), ITV_2 M (0.84 and 106.26 cc), and ITV_3 M (0.86 and 112.51 cc). CONCLUSION: The study demonstrates that in the motion-encompassing technique of motion management, the target volume generated by delineating all phases of 4DCT provides the most accurate representation for patients with HCC. Specialty image sets and their combinations, while sometimes close, tend to result in less accurate targeting. Hence, the all-phase 4DCT method should be preferred to avoid geographical misses and ensure optimal treatment outcomes. However, our conclusion may be limited by the technique we employed.

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Background and Objective: Magnetic resonance guided radiotherapy (MRgRT) is an emerging technological innovation with more and more institutions gaining clinical experience in this new field of radiation oncology. The ability to better visualize both tumors and healthy tissues due to excellent soft tissue contrast combined with new possibilities regarding motion management and the capability of online adaptive radiotherapy might increase tumor control rates while potentially reducing the risk of radiation-induced toxicities. As conventional computed tomography (CT)-based image guidance methods are insufficient for adaptive workflows in abdominal tumors, MRgRT appears to be an optimal method for this tumor site. The aim of this narrative review is to outline the opportunities and challenges in magnetic resonance guided radiation therapy in gastrointestinal cancers. Methods: We searched for studies, reviews and conceptual articles, including the general technique of MRgRT and the specific utilization in gastrointestinal cancers, focusing on pancreatic cancer, liver metastases and primary liver cancer, rectal cancer and esophageal cancer. Key Content and Findings: This review is highlighting the innovative approach of MRgRT in gastrointestinal cancer and gives an overview of the currently available literature with regard to clinical experiences and theoretical background. Conclusions: MRgRT is a promising new tool in radiation oncology, which can play off several of its beneficial features in the specific field of gastrointestinal cancers. However, clinical data is still scarce. Nevertheless, the available literature points out large potential for improvements regarding dose coverage and escalation as well as the reduction of dose exposure to critical organs at risk (OAR). Further prospective studies are needed to demonstrate the role of this innovative technology in gastrointestinal cancer management, in particular trials that randomly compare MRgRT with conventional CT-based image-guided radiotherapy (IGRT) would be of high value.

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The diagnosis of occult inguinal lymph node metastasis in clinically node-negative invasive penile squamous cell carcinoma (PSCC) has remained a challenge, with substantial perioperative complications. The recent refinements in the technique of dynamic sentinel lymph node biopsy (DSLNB) demonstrated high diagnostic accuracy with considerably lower morbidity compared to conventional open modified/superficial inguinal lymph node dissection (ILND). Although DSLNB, if available, has been endorsed as the preferred method for nodal staging in patients with invasive PSCC and no palpable inguinal lymphadenopathy in the recent penile cancer guidelines, its utilization has been quite limited so far. Laparoscopic and robotic-assisted ILND have emerged as alternatives for nodal staging in this patient population and are shown to improve the rate of wound infections and postoperative pain. For management of nodal metastasis in patients with clinically palpable inguinal lymph nodes, minimally invasive ILND has shown promising results as well. Nonetheless, given the rarity of PSCC and the absence of prospective studies and clinical trials, nodal staging and treatment of nodal metastasis in clinical practice will likely continue to vary across the medical centers in the following years. In this review, we first summarize the evolution of DSLNB and minimally invasive ILND and discuss the advantages and drawbacks of each management strategy. We further discuss the remaining challenges and future perspectives in the management of inguinal lymph nodes in patients with PSCC.

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PURPOSE: To investigate the effect of different source dwell positions on dose distribution in the treatment of cervical cancer with brachytherapy. METHODS: Treatment planning data for cervical cancer patients were used. Treatment plans were created at 1 mm intervals, varying up to 5 mm. For intracavitary brachytherapy and intracavitary and interstitial brachytherapy, the following dose parameters were evaluated: 90% high-risk clinical target volume (HR-CTV D90%), rectum 2 cm3 dose (Rectum D2 cc), small intestine 2 cm3 dose (Small D2 cc), sigmoid colon 2 cm3 dose (Sigmoid D2 cc), bladder 2 cm3 dose (Bladder D2 cc), point A dose. RESULTS: In intracavitary brachytherapy, the HR-CTV D90%, Rectum D2 cc, Small D2 cc, and Sigmoid D2 cc doses increased as the source dwell position changed in the direction. On the other hand, the dose of Bladder D2 cc increased when the source position changed in the outward direction. The same trend was observed in the case of intracavitary and interstitial brachytherapy. CONCLUSION: It was shown that a 1 mm change in the source dwell position can affect the dose by up to 2% or more. The accuracy of the source dwell position is very important and should be checked before using the device.

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BACKGROUND: The implementation of population screening for prostate cancer has increased the number of patients with biochemical suspicion. Prediction models may reduce the number of unnecessary biopsies by identifying patients who benefit the most from them. Our aim is to develop a prediction model that is easily applicable in patients with suspicion of prostate cancer in the urology clinic setting to avoid unnecessary biopsies. METHODS: We developed prediction models based on risk scores for the detection of prostate cancer and clinically significant prostate cancer using the TRIPOD guidelines. For this, we conducted an observational and retrospective review of computerised medical records of 204 patients undergoing prostate fusion biopsy between 2018 and 2021. We also reviewed other prediction models for prostate cancer including radiological parameters and targeted sampling of suspicious lesions. RESULTS: A total of 204 patients underwent a biopsy, 138 were diagnosed of prostate cancer, and from them, 60 of clinically significant prostate cancer. Multivariate regression and random forest analysis were performed. Age, PSA density, diameter of the index lesions and PIRADS score on MRI were identified as predictors with an Area Under the Curve ranging between 0.71 and 0.80 and acceptable calibration results. Risk scores may avoid between 21.7% and 48.1% of biopsies. CONCLUSION: Our prediction models are characterised by ease of use and may reduce unnecessary biopsies with satisfactory discrimination and calibration results while bringing benefits to the healthcare system and patients.

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Background: This prospective longitudinal study compares outcomes for Medicare beneficiaries receiving outpatient percutaneous image-guided lumbar decompression (PILD) using the mild® procedure to patients undergoing outpatient laminectomy. All patients were diagnosed with lumbar spinal stenosis (LSS) with neurogenic claudication (NC). Methods: All medical claims for 100 % of Medicare beneficiaries were reviewed, with study subjects identified using Centers for Medicare and Medicaid Research Identifiable Files. Baseline data were extracted individually to allow for longitudinal analysis through two-year follow-up. The index procedure was defined as the first mild or outpatient laminectomy during the enrollment period. The rate of subsequent surgical procedures and incidence of harms were used as study outcomes. Results: Cohorts included 2197 mild and 7416 laminectomy patients. mild patients were significantly older (76.7 years versus 73.4 years, respectively; p < 0.0001), and 57.4 % of mild were female, compared to 43.3 % of laminectomy (p < 0.0001). mild patients presented with significantly more baseline comorbidities compared to laminectomy patients (mean of 5.7 versus 4.8, respectively; p < 0.0001). Subsequent surgical procedure rate of 9.0 % for mild was significantly higher than 5.5 % for laminectomy (p < 0.0001). mild experienced harms at a significantly lower rate than laminectomy (1.9 % versus 5.8 %, respectively; p < 0.0001). The composite rate of subsequent surgical procedures and harms was similar between groups at 10.8 % for mild and 11.0 % for laminectomy. Conclusions: mild can be considered a viable option for treatment of LSS with NC as evidenced by real-world data in this study. At two-years, mild patients experienced fewer harms and underwent more subsequent surgical procedures than laminectomy patients. The higher rate of subsequent surgical procedures for mild may be attributable to its position earlier in the LSS treatment algorithm. The overall rate of harms and subsequent surgical procedures was similar between groups, suggesting that mild should be considered as a treatment option, particularly for older patients with multiple comorbidities.

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PURPOSE: Surgical robotics have demonstrated their significance in assisting physicians during minimally invasive surgery. Especially, the integration of haptic and tactile feedback technologies can enhance the surgeon's performance and overall patient outcomes. However, the current state-of-the-art lacks such interaction feedback opportunities, especially in robotic-assisted interventional magnetic resonance imaging (iMRI), which is gaining importance in clinical practice, specifically for percutaneous needle punctures. METHODS: The cable-driven 'Micropositioning Robotics for Image-Guided Surgery' (µRIGS) system utilized the back-electromotive force effect of the stepper motor load to measure cable tensile forces without external sensors, employing the TMC5160 motor driver. The aim was to generate a sensorless haptic feedback (SHF) for remote needle advancement, incorporating collision detection and homing capabilities for internal automation processes. Three different phantoms capable of mimicking soft tissue were used to evaluate the difference in force feedback between manual needle puncture and the SHF, both technically and in terms of user experience. RESULTS: The SHF achieved a sampling rate of 800 Hz and a mean force resolution of 0.26 ± 0.22 N, primarily dependent on motor current and rotation speed, with a mean maximum force of 15 N. In most cases, the SHF data aligned with the intended phantom-related force progression. The evaluation of the user study demonstrated no significant differences between the SHF technology and manual puncturing. CONCLUSION: The presented SHF of the µRIGS system introduced a novel MR-compatible technique to bridge the gap between medical robotics and interaction during real-time needle-based interventions.

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PURPOSE: To demonstrate the possibility of using a lower imaging rate while maintaining acceptable accuracy by applying motion prediction to minimize the imaging dose in real-time image-guided radiation therapy. METHODS: Time-series of three-dimensional internal marker positions obtained from 98 patients in liver stereotactic body radiation therapy were used to train and test the long-short-term memory (LSTM) network. For real-time imaging, the root mean squared error (RMSE) of the prediction on three-dimensional marker position made by LSTM, the residual motion of the target under respiratory-gated irradiation, and irradiation efficiency were evaluated. In the evaluation of the residual motion, the system-specific latency was assumed to be 100 ms. RESULTS: Except for outliers in the superior-inferior (SI) direction, the median/maximum values of the RMSE for imaging rates of 7.5, 5.0, and 2.5 frames per second (fps) were 0.8/1.3, 0.9/1.6, and 1.2/2.4 mm, respectively. The median/maximum residual motion in the SI direction at an imaging rate of 15.0 fps without prediction of the marker position, which is a typical clinical setting, was 2.3/3.6 mm. For rates of 7.5, 5.0, and 2.5 fps with prediction, the corresponding values were 2.0/2.6, 2.2/3.3, and 2.4/3.9 mm, respectively. There was no significant difference between the irradiation efficiency with and that without prediction of the marker position. The geometrical accuracy at lower frame rates with prediction applied was superior or comparable to that at 15 fps without prediction. In comparison with the current clinical setting for real-time image-guided radiation therapy, which uses an imaging rate of 15.0 fps without prediction, it may be possible to reduce the imaging dose by half or more. CONCLUSIONS: Motion prediction can effectively lower the frame rate and minimize the imaging dose in real-time image-guided radiation therapy.

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OBJECTIVES: Image-guided adaptive brachytherapy (IGABT) is the standard of care for patients with cervical cancer. The objective of this study was to compare the treatment outcomes and adverse effects of computed tomography (CT)-guided and magnetic resonance imaging (MRI)-guided scenarios. MATERIALS AND METHODS: Data of patients with cervical cancer treated using external beam radiotherapy followed by IGABT from 2012 to 2016 were retrospectively reviewed. CT-guided IGABT was compared with the three modes of MRI-guided IGABT: pre-brachytherapy (MRI Pre-BT) without applicator insertion for fusion, planning MRI with applicator in-place in at least 1 fraction (MRI ≥1Fx), and MRI in every fraction (MRI EveryFx). Patient characteristics, oncologic outcomes, and late radiation toxicity were analyzed using descriptive, survival, and correlation statistics. RESULTS: Overall, 354 patients were evaluated with a median follow-up of 60 months. The 5-year overall survival (OS) rates were 61.5%, 65.2%, 54.4%, and 63.7% with CT-guided, MRI PreBT, MRI ≥1Fx, and MRI EveryFx IGABT, respectively with no significant differences (p = 0.522). The 5-year local control (LC) rates were 92.1%, 87.8%, 80.7%, and 76.5% (p = 0.133), respectively, with a significant difference observed between the CT-guided and MRI ≥1Fx (p = 0.018). The grade 3-4 late gastrointestinal toxicity rates were 6% in the CT-guided, MRI ≥1Fx, and MRI EveryFx, and 8% in MRI PreBT. The grade 3-4 late genitourinary toxicity rates were 4% in the CT-guided, 2% in MRI PreBT, 1% in MRI ≥1Fx, and none in MRI EveryFx. No significant differences were observed in the oncologic and toxicity outcomes among MRI PreBT, MRI ≥1Fx, and MRI EveryFx. CONCLUSIONS: CT-guided IGABT yielded an acceptable 5-year OS, LC, and toxicity profile compared with all MRI scenarios and is a potentially feasible option in resource-limited settings.

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PURPOSE: The lack of training is a significant barrier to practicing brachytherapy (BT). Tata Memorial Centre, alongside international BT experts and BrachyAcademy, developed a hybrid gynecological BT training module. This study outlines the preparation, organization, and execution of the 2022-2023 Mumbai training, evaluates its effectiveness, and highlights areas for improvement. MATERIALS AND METHODS: Participants were radiation oncologists (RO) and medical physicists (MP) with experience in gynecological BT aiming to transition to image-guided brachytherapy (IGBT). The training covered cervical, endometrial, vaginal, vulvar, periurethral cancers, and pelvic reirradiation. The hybrid course included online pre and postcourse homework assignments, a live workshop with hands-on training, a 6-month online follow-up, and a 12-month opportunity to share the transition experience. RESULTS: The December 2022 Mumbai live workshop spanned 2.5 days, attracting 39 participants from 8 countries (Asia, Africa, Australia/Oceania). Feedback rated the course 9/10, with 78% fully meeting expectations. Forty-four percent suggested extending hands-on training. At the 6-month follow-up, response rates were low (33% RO, 11% MP). Among responding RO, 70% reported practice changes after attending the course, 40% implemented IGBT concepts in clinical practice, and 50% increased confidence in image-guided procedures. Overall, 45% of respondent sites could strengthen their intracavitary/interstitial program, while others faced limitations due to lack of access to advanced BT applicators. CONCLUSION: The hybrid gynecological BT training concept was successfully executed. Areas for improvement include extending hands-on training and enhancing participant engagement postcourse. Structured steps beyond training may be needed to improve the utilization of advanced brachytherapy for gynecological cancers.

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OBJECTIVE: To demonstrate the feasibility of using a ring array ultrasound (US) transducer, guided by ultrasound tomography (UST), for generating and monitoring mild hyperthermia (MHTh). METHODS: In silico and in vitro experiments were designed to evaluate the efficacy of a ring array US transducer for generating MHTh and monitoring changes in temperature. In a series of in silico studies, we compared the acoustic focal profiles produced by a ring array US transducer transmitting at different frequencies and further investigated the effectiveness of UST-guidance in implementing aberration correction to enhance the focal profile. In vitro experiments evaluated the capability of using a ring array US transducer to generate and maintain MHTh and the accuracy of using UST to monitor temperature changes. RESULTS: The simulations demonstrated that a ring array US transducer achieves symmetrical and localized acoustic focusing. In a heterogenous tissue model, a ring array US transducer achieved a superior acoustic focus by implementing aberration correction with guidance from UST. In vitro experiments demonstrated the capability of a ring array US transducer to generate MHTh in a tissue-mimicking phantom in an average of 117 ± 18 s and subsequently maintain MHTh. Lastly, a ring array US transducer utilized UST to track temperature changes in a preheated water-filled inclusion while it passively cooled from 45 °C to 25 °C, with a maximum error of 0.58 °C. CONCLUSION: A ring array US transducer can noninvasively generate and monitor MHTh, overcoming many limitations of current clinical systems. The closed geometry of the transducer is optimal for acoustic focusing and UST-guidance allows for improved aberration correction in a heterogenous medium. Utilizing UST thermometry with the same ring array US transducer will allow for implementing an image-guided, temperature-controlled, all-acoustic MHTh system.

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INTRODUCTION: Mastectomy skin flap (MSF) necrosis remains a significant complication in breast reconstruction. This study aims to identify a correlation between the qualitative and quantitative analysis of the MSF perfusion grade and the skin necrosis rate 1 month after surgery using indocyanine green angiography (ICGA), focusing on lag time and perfusion metrics. METHODS: Consecutive women scheduled for nipple/skin-sparing/skin-reducing mastectomy between May 2020 and October 2022 were prospectively enrolled. Patients were divided into Group 1 in the absence of superficial and full-thickness necrosis (SN; FTN) and Group 2 in the presence of both. Demographic data, lag time T1 (time between ICG injection and the initial perfusion of the least perfused MSF area), ICG-Q1, and ICG-Q% (absolute and relative perfusion values of the least vascularized area) were collected. RESULTS: 76 breasts were considered. FTN was reported in 8 breasts (10.5%) and SN in 4 (5.2%). The 2 groups statistically differ in T1 (Group2 > Group1), ICG-Q1, and ICG-Q% (Group1 > Group2) (P < 0.05). T1 longer than 170 seconds, body mass index, previous chemo/radiotherapy, arterial hypertension, breast weight, type of surgery, and ICG quantitative values can help in predicting MSF necrosis. CONCLUSIONS: MSF qualitative and quantitative perfusion evaluation can be helpful to prevent MSF necrosis. However, it should be considered together with the patient's characteristics, the type of surgery, and T1. In this way, it is possible to predict the risk of MSF necrosis and plan the best reconstructive strategy.

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Until recently, innovations in surgery were largely represented by extensions or augmentations of the surgeon's perception. This includes advancements such as the operating microscope, tumor fluorescence, intraoperative ultrasound, and minimally invasive surgical instrumentation. However, introducing artificial intelligence (AI) into the surgical disciplines represents a transformational event. Not only does AI contribute substantively to enhancing a surgeon's perception with such methodologies as three-dimensional anatomic overlays with augmented reality, AI-improved visualization for tumor resection, and AI-formatted endoscopic and robotic surgery guidance. What truly makes AI so different is that it also provides ways to augment the surgeon's cognition. By analyzing enormous databases, AI can offer new insights that can transform the operative environment in several ways. It can enable preoperative risk assessment and allow a better selection of candidates for procedures such as organ transplantation. AI can also increase the efficiency and throughput of operating rooms and staff and coordinate the utilization of critical resources such as intensive care unit beds and ventilators. Furthermore, AI is revolutionizing intraoperative guidance, improving the detection of cancers, permitting endovascular navigation, and ensuring the reduction in collateral damage to adjacent tissues during surgery (e.g., identification of parathyroid glands during thyroidectomy). AI is also transforming how we evaluate and assess surgical proficiency and trainees in postgraduate programs. It offers the potential for multiple, serial evaluations, using various scoring systems while remaining free from the biases that can plague human supervisors. The future of AI-driven surgery holds promising trends, including the globalization of surgical education, the miniaturization of instrumentation, and the increasing success of autonomous surgical robots. These advancements raise the prospect of deploying fully autonomous surgical robots in the near future into challenging environments such as the battlefield, disaster areas, and even extraplanetary exploration. In light of these transformative developments, it is clear that the future of surgery will belong to those who can most readily embrace and harness the power of AI.