Superficial vessel-based near infrared-assisted patient position recognition and real-time monitoring system (VIPS) for radiotherapy: A proof-of-concept study

BACKGROUND

The accuracy and precision of patient position in radiotherapy process have dramatic impacts on the tumor local control and therapy-related side effects, and there exist demands to explore effective positioning solutions, particularly in the era with great progress in imaging recognition and matching.

PURPOSE

Superficial vessel-based near infrared-assisted patient position recognition and real-time monitoring system (VIPS) was proposed to develop an automated, operator-independent and skin marker-free imaging system to improve patient setup and intrafractional motion monitoring.

METHODS

VIPS includes two components, the imaging module and the image alignment software. Using a simulated blood vessel model, multiple NIR sources with various wavelength and bolus (pseudo-skin) were evaluated in terms of imaging quality to determine the optimal light source and the upper limit of superficial fatty tissue thickness. Then the performance of VIPS with reference to either CBCT or laser setup system was conducted using 3D phantom and clinical cases enrolled into the registered clinical trial. The position displacement from VIPS and laser system was compared, as well as the systematic and random errors of VIPS setup procedure.

RESULTS

The NIR light source with the combined wavelengths of 760 nm + 940 nm (S760+940 nm ) provided the best performance among multiple tested light sources. The bolus (superficial fatty layer) thickness over 5 mm could dramatically compromise the NIR detection of vessels beneath. In the phantom study, the translational positional displacements according to VIPS guidance were within the submillimeter level with reference to CBCT, indicative of high setup accuracy. The clinical trial showed the prototype VIPS could effectively detect and control position displacement of patients in translational and rotational directions within an acceptable range, which was non-inferior to conventional laser/skin marker system.

CONCLUSION

This proof-of-concept study validated the feasibility and reliability of VIPS in guiding radiotherapy setup. However, limitations and technical challenges should be resolved prior to further clinical evaluation, including isocenter alignment, potential NIR image distortion and the impact of the superficial tissues on the recognition of vessels.

Fat Compartment Gliding Theory - A Novel Technique for the Repositioning of Superficial Fat Compartments for Facial Rejuvenation

Background

Facial fat compartments and their role in facial aging have gained increased recognition and are playing a significant role in facial rejuvenation. The superficial fat compartments glide inferiorly during the aging process, leading to the flattening and elongation of the face and the appearance of facial bulges, folds, and grooves.

Patients and Methods

Ultrasound imaging of the facial soft tissues was performed on nine female volunteers to demonstrate the change in superficial facial fat compartments from an upright to supine position. The net suture jowl and medial cheek fat compartment repositioning technique was operated on 165 Asian patients between September 2020 and July 2021. Volume and projection change of malar and jowl regions, as well as change in elevation of malar protrusion were measured 1, 3, and 6 months postoperatively using a three-dimensional imaging system.

Results

Ultrasound measurements confirmed the medial and middle cheek, nasolabial, and jowl fat compartments changed in thickness during positional changes with age-related differences. Postoperative three-dimensional imaging showed volume and projection increase in the malar region (2.23mL and 1.11mm) and decrease in the jowl region (-0.18mL and -0.52mm) by the 6-month follow-up date, and malar projection saw a superior displacement of 3.08mm.

Conclusion

The superficial fat glide inferiorly within their compartments under the force of gravity and naturally reposition themselves when the effect of gravity is reversed. The net suture technique offers a minimally invasive method for lifting the jowl fat, volumizing the mid-cheek and achieving facial rejuvenation by repositioning the superficial fat compartments.

Techniques and Applications of Lower Extremity Feminization and Masculinization

Background

Significant differences exist between feminine and masculine lower extremities, and this region contributes to gender dysphoria in transgender and nonbinary individuals.

Methods

A systematic review was conducted for primary literature on lower extremity (LE) gender affirmation techniques as well as anthropometric differences between male and female lower extremities, which could guide surgical planning. Multiple databases were searched for articles before June 2, 2021 using Medical Subject Headings. Data on techniques, outcomes, complications, and anthropometrics were collected.

Results

A total of 852 unique articles were identified: 17 met criteria for male and female anthropometrics and 1 met criteria for LE surgical techniques potentially applicable to gender affirmation. None met criteria for LE gender affirmation techniques specifically. Therefore, this review was expanded to discuss surgical techniques for the LE, targeting masculine and feminine anthropometric ideals. LE masculinization can target feminine qualities, such as mid-lateral gluteal fullness and excess subcutaneous fat in the thigh and hips. Feminization can target masculine qualities like a low waist-to-hip ratio, mid-lateral gluteal concavity, calf hypertrophy, and body hair. Cultural differences and patient body habitus, which influence what is considered "ideal" for both sexes, should be discussed. Applicable techniques include hormone therapy, lipo-contouring, fat grafting, implant placement, and botulinum toxin injection, among others.

Conclusions

Due to lack of existing outcomes-based literature, gender affirmation of the lower extremities will rely on application of an array of existing plastic surgery techniques. However, quality outcomes data for these procedures is required to determine best practices.

The characteristics of oro-cervical necrotizing fasciitis-Comparison with severe cellulitis of oro-cervical region and necrotizing fasciitis of other body regions

Background

Necrotizing fasciitis (NF) is an acute and life-threatening soft-tissue infection however rarely seen in oro-cervical region. Therefore, the details of oro-cervical NF (OCNF) are not well known. The purpose of this study was to investigate the characteristics of OCNF by comparing it with severe cellulitis of oro-cervical region (OCSC) or NF of other body regions (e.g., limb, perineum, and trunk) (BNF), respectively.

Materials and methods

At first, various risk factors for OCNF in oro-cervical severe infection (OCSI; composed of OCNF and OCSC), including neutrophil-to-lymphocyte ratio (NLR) and Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score, were investigated by univariate and multivariate analyses. Next, the differences between OCNF and BNF, including inflammatory markers and mortality, were investigated.

Results

In the present study, 14 out of 231 OCSI patients had OCNF. Multivariate analyses of OCSI patients showed that NLR ≥15.3 and LRINEC score ≥6 points were significantly related to OCNF. During the same period, 17 patients had BNF. The OCNF group had significantly higher inflammatory markers than the BNF group when diagnosis, but significantly lower clinical stages at the time and mortality as outcomes.

Conclusion

We found that compared to BNF, OCNF can be detected at lower clinical stage by using indexes, such as NLR and LRINEC score, besides clinical findings, which may help contributing to patient’s relief.

Furnishing Wound Repair by the Subcutaneous Fascia

Mammals rapidly heal wounds through fibrous connective tissue build up and tissue contraction. Recent findings from mouse attribute wound healing to physical mobilization of a fibroelastic connective tissue layer that resides beneath the skin, termed subcutaneous fascia or superficial fascia, into sites of injury. Fascial mobilization assembles diverse cell types and matrix components needed for rapid wound repair. These observations suggest that the factors directly affecting fascial mobility are responsible for chronic skin wounds and excessive skin scarring. In this review, we discuss the link between the fascia's unique tissue anatomy, composition, biomechanical, and rheologic properties to its ability to mobilize its tissue assemblage. Fascia is thus at the forefront of tissue pathology and a better understanding of how it is mobilized may crystallize our view of wound healing alterations during aging, diabetes, and fibrous disease and create novel therapeutic strategies for wound repair.

The mobility of the superficial and deep midfacial fat compartments: An ultrasound-based investigation

BACKGROUND

Understanding the mobility of the midface and the separate contributions of the superficial and deep fat compartments is essential for natural esthetic outcomes following soft tissue filler or fat grafting procedures. A study was designed that used ultrasound imaging to demonstrate in vivo visualization and quantification of distances and movements in the midface.

METHODS

A total of 48 midfaces of 24 healthy Caucasian volunteers, all naïve of esthetic procedures, (22 females; 46.85 (9.8) years; 22.83 (3.1) kg/m² ) were scanned using 18 MHz ultrasound imaging. Distances between bony landmarks (inferior orbital rim, infraorbital foramen) were used as markers to measure the cranial movement of the superficial (superficial nasolabial and superficial medial cheek fat compartment) and the deep (deep pyriform space, deep medial check fat compartment, deep lateral cheek fat compartment) midfacial fat compartments between resting and smiling facial position.

RESULTS

The superficial midfacial fat compartment moved, on average, 3.7 mm (p < 0.001) cranially, whereas the deep midfacial fat compartments moved, on average, 0.1 mm (p > 0.05) during smiling. No gender differences in mobility were identified (p > 0.05).

CONCLUSION

The results obtained are in line with previous cadaveric investigations and revealed, in a highly statistically significant fashion, that the superficial midfacial fat compartments move in cranial direction whereas the deep fat compartment did not display similar positional changes. These results help to guide facial injectable treatments and to understand why, in the midface, a deep supraperiosteal approach should be favored when augmenting the deep midfacial fat compartments.

Cutting into wound repair

The skin is home to an assortment of fibroblastic lineages that shape the wound repair response toward scars or regeneration. In this review, we discuss the distinct embryonic origins, anatomic locations, and functions of fibroblastic lineages, and how these distinct lineages of fibroblasts dictate the skin's wound response across injury depths, anatomic locations, and embryonic development to promote either scarring or regeneration. We highlight the supportive role of the fascia in dictating scarring outcomes; we then discuss recent findings that indicate fascia mobilization by its resident fibroblasts supersede the classical de novo deposition program of wound matrix formation. These recent findings reconfigure our traditional view of wound repair and present exciting new therapeutic avenues to treat scarring and fibrosis across a range of medical settings.

Performing Distance Measurements in Curved Facial Regions: A Comparison between Three-Dimensional Surface Scanning and Ultrasound Imaging

Facial flap surgery depends strongly on thorough preoperative planning and precise surgical performance. To increase the dimensional accuracy of transferred facial flaps, the methods of ultrasound and three-dimensional (3D) surface scanning offer great possibilities. This study aimed to compare different methods of measuring distances in the facial region and where they can be used reliably. The study population consisted of 20 volunteers (10 males and 10 females) with a mean age of 26.7 ± 7.2 years and a mean body mass index of 22.6 ± 2.2 kg/m². Adhesives with a standardized length of 20 mm were measured in various facial regions through ultrasound and 3D surface scans, and the results were compared. Regardless of the facial region, the mean length measured through ultrasound was 18.83 mm, whereas it was 19.89 mm for 3D surface scans, with both p < 0.0001. Thus, the mean difference was 1.17 mm for ultrasound measurements and 0.11 mm for 3D surface scans. Curved facial regions show a great complexity when it comes to measuring distances due to the concavity and convexity of the face. Distance measurements through 3D surface scanning showed more accurate distances than the ultrasound measurement. Especially in "complex" facial regions (e.g., glabella region and labiomental sulcus), the 3D surface scanning showed clear advantages.

Differences in Temporal Volume between Males and Females and the Influence of Age and BMI: A Cross-Sectional CT-Imaging Study

BACKGROUND

 The temple has been identified as one of the most compelling facial regions in which to seek aesthetic improvement-both locally and in the entire face-when injecting soft tissue fillers.

OBJECTIVE

 The objective of this study is to identify influences of age, gender, and body mass index (BMI) on temporal parameters to better understand clinical observations and to identify optimal treatment strategies for treating temporal hollowing.

METHODS

 The sample consisted of 28 male and 30 female individuals with a median age of 53 (34) years and a median BMI of 27.00 (6.94) kg/m². The surface area of temporal skin, the surface area of temporal bones, and the temporal soft tissue volume were measured utilizing postprocessed computed tomography (CT) images via the Hausdorff minimal distance algorithm. Differences between the investigated participants related to age, BMI, and gender were calculated.

RESULTS

 Median skin surface area was greater in males compared with females 5,100.5 (708) mm² versus 4,208.5 (893) mm² (p < 0.001) as was the median bone surface area 5,329 (690) mm² versus 4,477 (888) mm² (p < 0.001). Males had on average 11.04 mL greater temporal soft tissue volume compared with age and BMI-matched females with p < 0.001. Comparing the volume between premenopausal versus postmenopausal females, the median temporal soft tissue volume was 46.63 mL (11.94) versus 40.32 mL (5.69) (p = 0.014).

CONCLUSION

 The results of this cross-sectional CT imaging study confirmed previous clinical and anatomical observations and added numerical evidence to those observations for a better clinical integration of the data.

Nonsurgical Treatment of Postpartum Lower Abdominal Skin and Soft-Tissue Laxity Using Microfocused Ultrasound With Visualization

BACKGROUND

Microfocused ultrasound with visualization (MFU-V) is a well-established treatment modality for skin tightening. There is a paucity of evidence for its use in body treatments, such as the lower abdomen.

OBJECTIVE

To investigate the effectiveness and safety of MFU-V in treating lower abdominal skin and soft-tissue laxity in postpartum women.

METHODS

The lower abdomen of 20 female patients between 6 and 24 months postpartum are treated with MFU-V using 1.5-, 3.0-, and 4.5-mm transducers. Data are prospectively collected and analyzed at 3 and 6 months using subject-reported and investigator-reported outcome measures. One additional patient underwent planned abdominoplasty 6 weeks after MFU-V treatment with tissue assessed intraoperatively and histologically.

RESULTS

There was a mean improvement of 1.0 and 1.3 grades at 6 months using the investigator-reported and patient-reported skin laxity scale, respectively (p < .001). Patient-reported outcomes and satisfaction survey showed consistent improvement at 6 months. Histological examination of pretreated tissue showed increased total collagen, increased number and thickness of fibrous septae, and no change in fat cells within pretreated tissue compared with the control. No significant adverse events were recorded.

CONCLUSION

MFU-V is an effective and safe treatment modality for lower abdominal skin laxity in postpartum patients.