Computer-aided diagnosis for screening of lower extremity lymphedema in pelvic computed tomography images using deep learning

Lower extremity lymphedema (LEL) is a common complication after gynecological cancer treatment, which significantly reduces the quality of life. While early diagnosis and intervention can prevent severe complications, there is currently no consensus on the optimal screening strategy for postoperative LEL. In this study, we developed a computer-aided diagnosis (CAD) software for LEL screening in pelvic computed tomography (CT) images using deep learning. A total of 431 pelvic CT scans from 154 gynecological cancer patients were used for this study. We employed ResNet-18, ResNet-34, and ResNet-50 models as the convolutional neural network (CNN) architecture. The input image for the CNN model used a single CT image at the greater trochanter level. Fat-enhanced images were created and used as input to improve classification performance. Receiver operating characteristic analysis was used to evaluate our method. The ResNet-34 model with fat-enhanced images achieved the highest area under the curve of 0.967 and an accuracy of 92.9%. Our CAD software enables LEL diagnosis from a single CT image, demonstrating the feasibility of LEL screening only on CT images after gynecologic cancer treatment. To increase the usefulness of our CAD software, we plan to validate it using external datasets.

Non-Invasive Portable Technologies for Monitoring Breast Cancer Related Lymphedema to Facilitate Telehealth: A Scoping Review

Breast cancer related lymphedema (BCRL) is a common, debilitating condition that can affect up to one in five breast cancer surviving patients (BCSP). BCRL can significantly reduce the quality of life (QOL) of patients and poses a significant challenge to healthcare providers. Early detection and continuous monitoring of lymphedema is crucial for the development of client-centered treatment plans for post-cancer surgery patients. Therefore, this comprehensive scoping review aimed to investigate the current technology methods used for the remote monitoring of BCRL and their potential to facilitate telehealth in the treatment of lymphedema. Initially, five electronic databases were systematically searched and analyzed following the PRISMA flow diagram. Studies were included, specifically if they provided data on the effectiveness of the intervention and were designed for the remote monitoring of BCRL. A total of 25 included studies reported 18 technological solutions to remotely monitor BCRL with significant methodological variation. Additionally, the technologies were categorized by method of detection and wearability. The findings of this comprehensive scoping review indicate that state-of-the-art commercial technologies were found to be more appropriate for clinical use than home monitoring, with portable 3D imaging tools being popular (SD 53.40) and accurate (correlation 0.9, p 0.05) for evaluating lymphedema in both clinic and home settings with expert practitioners and therapists. However, wearable technologies showed the most future potential for accessible and clinical long-term lymphedema management with positive telehealth outcomes. In conclusion, the absence of a viable telehealth device highlights the need for urgent research to develop a wearable device that can effectively track BCRL and facilitate remote monitoring, ultimately improving the quality of life for patients following post-cancer treatment.

Outcomes of Lymphovenous Anastomosis for Lower Extremity Lymphedema: A Systematic Review

Lymphovenous anastomosis (LVA) is a microsurgical treatment for lymphedema of the lower extremity (LEL). This study systematically reviews the most recent data on outcomes of various LVA techniques for LEL in diverse patients.

METHODS

A comprehensive literature search was conducted in the Ovid MEDLINE, Ovid EMBASE, and Scopus databases to extract articles published through June 2021. Studies reporting data on objective postoperative improvement in lymphedema and/or subjective improvement in quality of life for patients with LEL were included. Extracted data comprised demographics, number of patients and lower limbs, duration of symptoms before LVA, surgical technique, duration of follow-up, and objective and subjective outcomes.

RESULTS

A total of 303 articles were identified and evaluated, of which 74 were ultimately deemed eligible for inclusion in this study, representing 6260 patients and 2554 lower limbs. The average patient age ranged from 22.6 to 76.14 years. The duration of lymphedema before LVA ranged from 12 months to 11.4 years. Objective rates of improvement in lymphedema ranged from 23.3% to 100%, with the greatest degree of improvement seen in patients with early-stage LEL.

CONCLUSIONS

LVA is a safe and effective technique for the treatment of LEL of all stages. Several emerging techniques and variations may lead to improved patient outcomes.

Imaging biomarkers for diagnosis and treatment response in patients with lymphedema

Lymphedema is defined as a dysfunction of the lymphatic system producing an accumulation of lymphatic fluid in the surrounding tissue, as well as edema and fibrosis. A total of 250 million people worldwide are affected by this condition. Greater than 99% of these cases are related to a secondary cause. As there is a lack of curative therapy, the goal involves early diagnosis, in order to prevent the progression of the disease. Additionally, early diagnosis can aid in decreasing the demand for more complex surgical procedures. Currently, there is an impressive breadth of diagnostic tests available for these patients. We aimed to review the available literature in relation to the utilization of imaging biomarkers for the early diagnosis and treatment response in lymphedema.

Relationship Between Lymphaticovenular Anastomosis Outcomes and The Number and Types of Anastomoses

BACKGROUND

Lymphaticovenular anastomosis (LVA) is the first-line treatment for lymphedema in many hospitals. However, many aspects of its effects remain unclear. This study aimed to analyze problems with regard to the relationship between lymphaticovenular anastomosis and outcomes of surgery for lymphedema in the upper and lower extremities.

METHODS

Eighteen articles were selected for review. The following information was extracted from these articles as factors associated with LVA for lymphedema in the upper and lower extremities: number of cases, average patient age, mean number of bypasses, lymphedema stage, duration and type of lymphedema, anastomotic technique, follow-up period, type of scale, and treatment outcomes.

RESULTS

Upper extremity lymphedema: The average age of patients was 54.2 (range: 41.3-60.1) years. The mean number of anastomoses was 3.91 (range: 1.0-7.2). Six of nine articles provided data for volume change, and the mean volume change was 29% (-5%-50%). Lower extremity lymphedema: The average age of patients was 50.3 (range: 34-64 years). The mean number of anastomoses was 4.6 (range: 2.1-9.3). Comparison was difficult as different methods were used for postoperative evaluation (lower extremity lymphedema index in three patients, limb circumference in one, volume change in two, and restaging in three).

CONCLUSIONS

We obtained useful information with regard to the effects of LVA in this review. An increased number of anastomoses between the lymphatic ducts and veins did not seem to improve the effectiveness of LVA. With regard to the stage of lymphedema, LVA may be useful for both early and advanced stages.

Lymphaticovenous Anastomosis for Lower Extremity Lymphedema: A Systematic Review

Background  Lymphedema is an accumulation of protein-rich fluid in the interstitial spaces resulting from impairment in the lymphatic circulation that can impair quality of life and cause considerable morbidity. Lower extremity lymphedema (LEL) has an overall incidence rate of 20%. Conservative therapies are the first step in treatment of LEL; however, they do not provide a cure because they fail to address the underlying physiologic dysfunction of the lymphatic system. Among several surgical alternatives, lymphaticovenous anastomosis (LVA) has gained popularity due to its improved outcomes and less invasive approach. This study aims to review the published literature on LVA for LEL treatment and to analyze the surgical outcomes.

Methods  PubMed database was used to perform a comprehensive literature review of all articles describing LVA for treatment of LEL from Novemeber 1985 to June 2019. Search terms included “lymphovenous” OR “lymphaticovenous” AND “bypass” OR “anastomosis” OR “shunt” AND “lower extremity lymphedema.”

Results  A total of 95 articles were identified in the initial query, out of which 58 individual articles were deemed eligible. The studies included in this review describe notable variations in surgical techniques, number of anastomoses, and supplementary interventions. All, except one study, reported positive outcomes based on limb circumference and volume changes or subjective clinical improvement. The largest reduction rate in limb circumference and volume was 63.8%.

Conclusion  LVA demonstrated a considerable reduction in limb volume and improvement in subjective findings of lymphedema in the majority of patients. The maintained effectiveness of this treatment modality in long-term follow-up suggests great efficacy of LVA in LEL treatment.

Histological features of skin and subcutaneous tissue in patients with breast cancer who have received neoadjuvant chemotherapy and their relationship to post-treatment edema

BACKGROUND

Lymphedema is a major complication of treatment for breast cancer. Although chemotherapy can cause lymphedema, there have been few reports about histological changes in skin and subcutaneous tissue after chemotherapy. The aim of our study was to determine whether chemotherapy affects blood and lymphatic vessels in the skin and subcutaneous fat and to investigate the relationship between these changes and extent of post-chemotherapy edema.

METHODS

We compared histological findings in skin and subcutaneous fat of mastectomy specimens from 38 patients who had received NAC (neoadjuvant chemotherapy) and 56 who had not (non-NAC) attending our institution from 2007 to 2016. Patients whose tumor may have affected the area examined were excluded. Blood and lymphatic vessels were identified by CD31 and D2-40, respectively. We assessed microvessel density (MVD), lymphatic microvessel density (MLVD), lumen cross-sectional area (LA), and amount of endothelium (AE) in blood and lymphatic vessels. To minimize surgical effects, we measured edema, defined as ≥ 15% thicker dorsal subcutaneous tissue than baseline, on the contralateral side.

RESULTS

MVD, LA, and AE of blood vessels were greater and MLVD not significantly different in the skin of NAC patients than in that of non-NAC patients. MVD was greater and AE of blood vessels less in subcutaneous fat of NAC patients than in that of non-NAC patients. Patients with edema had significantly less AE of blood vessels in skin than did those without it.

CONCLUSIONS

These pathological findings can help to identify patients who will develop edema and improve their treatment.

Near-infrared fluorescence imaging for the prevention and management of breast cancer-related lymphedema: A systematic review

Sentinel lymph node identification by near infrared (NIR) fluorescence with indocyanine green (ICG) is recognized in the literature as a useful technique. NIR fluorescence technology could become key in the prevention and management of lymphedema after axillary dissection for breast cancer. Here, we conducted a systematic review focusing on ICG imaging to improve lymphedema prevention and treatment after axillary surgery. A systematic literature review was performed using MEDLINE and Embase to identify articles focused on ICG imaging for breast-cancer-related lymphedema (BCRL). Qualitative analysis was performed to summarize the characteristics of reported ICG procedures. In situ tissue identification and functionality assessment based on fluorescence signal were evaluated. Clinical outcomes were appraised when reported. Studies relating to axillary reverse mapping, lymphography and upper limb supermicrosurgery combined with ICG imaging were identified. We included a total of 33 relevant articles with a total of 2016 patients enrolled. ICG imaging for axillary reverse mapping was safe for all 951 included patients, with identification of arm nodes in 80%-88% of patients with axillary lymph nodes dissection. However, the papers discuss the oncologic safety of the approach and how - regardless of the contrast agent - concerns limit its adoption. ICG lymphography is openly supported in BCRL management, with 1065 patients undergoing this procedure in 26 articles. The technique is reported for lymphedema diagnosis, with high sensitivity and specificity, staging, intraoperative mapping and patency control in lymphaticovenular anastomosis. The substantial advantages/disadvantages of ICG imaging procedures are finally described.

Lymphovenous Anastomosis Bypass Surgery

The field of lymphedema surgery has witnessed tremendous advancements over the years and has been coupled to the rapid growth of supermicrosurgical techniques. A lymphovenous bypass or lymphaticovenular anastomosis is a new technique that requires identification of patent, residual lymphatic channels and performing an anastomosis to a recipient venule, thereby allowing outflow of lymphatic fluid and improvement in a patient's lymphedema. This article provides a summary of the maturation of the technique, as well as the technical aspects of the approach and the current outcomes in the treatment of postmastectomy lymphedema.