Texture Analysis of Post Breast Cancer Lymphedema Ultrasound Images Obtained Using a Portable Device—A Pilot Study

Exploring Indicators of Subcutaneous Tissue Fluid Accumulation in Breast Cancer-Related Lymphedema Patients Using Fractal Analysis with Virtual Volume

Background: Breast cancer treatment sometimes causes a chronic swelling of the arm called breast cancer-related lymphedema (BCRL). Its progression is believed to be irreversible and is accompanied by tissue fibrosis and lipidosis, so preventing lymphedema from progressing by appropriate intervention at the site of fluid accumulation at an early stage is crucial. The tissue structure can be evaluated in real time by ultrasonography, and this study aims at assessing the ability of fractal analysis using virtual volume in detecting fluid accumulation within BCRL subcutaneous tissue via ultrasound imaging. Methods and Results: We worked with 21 women who developed BCRL (International Society of Lymphology stage II) after unilateral breast cancer treatment. Their subcutaneous tissues were scanned with an ultrasound system (Sonosite Edge II; Sonosite, Inc., FUJIFILM) using a 6- to 15-MHz linear transducer. Then, a 3-Tesla MR system was used to confirm fluid accumulation in the corresponding area of the ultrasound system. Significant differences in both H + 2 and complexity were observed among the three groups (with hyperintense area, without hyperintense area, and unaffected side) (p < 0.05). Post hoc analysis (Mann-Whitney U test; Bonferroni correction p < 0.0167) revealed a significant difference for "complexity." The evaluation of the distribution in Euclidean space showed that the variation of the distribution decreased in the order of unaffected, without hyperintense area, and with hyperintense area. Conclusion: The "complexity" of the fractal using virtual volume seems to be an effective indicator of the presence or absence of subcutaneous tissue fluid accumulation in BCRL.

Segmentation of Arm Ultrasound Images in Breast Cancer-Related Lymphedema: A Database and Deep Learning Algorithm

OBJECTIVE

Breast cancer treatment often causes the removal of or damage to lymph nodes of the patient's lymphatic drainage system. This side effect is the origin of Breast Cancer-Related Lymphedema (BCRL), referring to a noticeable increase in excess arm volume. Ultrasound imaging is a preferred modality for the diagnosis and progression monitoring of BCRL because of its low cost, safety, and portability. As the affected and unaffected arms look similar in B-mode ultrasound images, the thickness of the skin, subcutaneous fat, and muscle have been shown to be important biomarkers for this task. The segmentation masks are also helpful in monitoring the longitudinal changes in morphology and mechanical properties of tissue layers.

METHODS

For the first time, a publicly available ultrasound dataset containing the Radio-Frequency (RF) data of 39 subjects and manual segmentation masks by two experts, are provided. Inter- and intra-observer reproducibility studies performed on the segmentation maps show a high Dice Score Coefficient (DSC) of 0.94±0.08 and 0.92±0.06, respectively. Gated Shape Convolutional Neural Network (GSCNN) is modified for precise automatic segmentation of tissue layers, and its generalization performance is improved by the CutMix augmentation strategy.

RESULTS

We got an average DSC of 0.87±0.11 on the test set, which confirms the high performance of the method.

CONCLUSION

Automatic segmentation can pave the way for convenient and accessible staging of BCRL, and our dataset can facilitate development and validation of those methods.

SIGNIFICANCE

Timely diagnosis and treatment of BCRL have crucial importance in preventing irreversible damage.

The Use of Ultrasound Imaging for Upper Extremity Lymphedema after Breast Cancer: A Systematic Review

BACKGROUND

 The aim of this study was to analyze the different applications of ultrasound (US) in upper extremity lymphedema (UEL) after breast cancer.

METHODS

 A systematic review of the literature was performed in line with the PRISMA statement using MEDLINE/PubMed databases from January 1970 to December 2021. Articles describing the application of US in patients with UEL after breast cancer were included. The quality of the study, the level of reproducibility, and the different applications and type of US technique were analyzed.

RESULTS

 In total, 30 articles with 1,193 patients were included in the final review. Five different applications were found: (1) diagnosis of UEL (14 studies found a direct correlation between lymphedema and morphological and/or functional parameters); (2) staging/severity of UEL (9 studies found a direct correlation between the clinical stage and the soft-tissue stiffness/texture/thickness); (3) therapeutic assessment (3 studies found an improvement in the circulatory status or in the muscle/subcutaneous thickness after conservative treatments); (4) prognosis assessment of UEL (1 study found a correlation between the venous flow and the risk of UEL); and (5) surgical planning (3 studies determined the location of the lymphatic vessel for lymphovenous anastomosis [LVA] surgery).

CONCLUSION

 Morphological and functional parameters have been correlated with the diagnosis, stage, therapeutic effect, prognosis of UEL, and surgical planning of LVA.

Relationship between lymphedema after breast cancer treatment and biophysical characteristics of the affected tissue

The treatment of breast cancer is often complicated by lymphedema of the upper limbs. Standard lymphedema evaluation methodologies are not able to measure tissue fibrosis. The ultrasound aspects related to tissue microstructures of lymphedema are neglected in clinical evaluations. The objective of this study was to identify and measure the degree of impairment, topography, and biophysical alterations of subcutaneous lymphedema tissue secondary to the treatment of breast cancer by ultrasonography. Forty-two women at a mean age of 58 (±9.7) years, with unilateral lymphedema due to breast cancer treatment, were evaluated. The upper limbs were divided into affected (affected by lymphedema) and control (contralateral limb). Each limb was subdivided into seven areas, defined by perimetry, evaluated in pairs. The biophysical characteristics thickness, entropy, and echogenicity were evaluated by ultrasonography. The results showed a significant difference in the echogenicity and thickness variables between the affected and unaffected upper limb, in all the extent of the upper limb, while entropy showed no significant difference. The findings indicate that the data presented were consistent both in identifying and measuring the degree of impairment and biophysical changes in the subcutaneous tissue of lymphedema secondary to the treatment of breast cancer.

Prediction of the Presence of Fluid Accumulation in the Subcutaneous Tissue in BCRL Using Texture Analysis of Ultrasound Images

Background: Breast cancer-related lymphedema (BCRL) is a chronic swelling of the arm due to breast cancer treatment. Lymphedema is diagnosed and staged on the basis of limb circumference measurements and the patient's subjective symptoms, which have poor reproducibility and objectivity: these cannot detect any fluid accumulation in the tissue. Ultrasonography is a feasible noninvasive technique that can be used to evaluate tissue structure in real time. This study aimed to assess the ability of texture features for discriminating the presence of accumulated fluid within the subcutaneous tissue of BCRL using ultrasound (US) imaging. Methods and Results: This study included 20 women who were treated for unilateral breast cancer and who subsequently developed BCRL (International Society of Lymphology stage II). Subcutaneous tissue was scanned through an US system (Sonosite Edge II; Sonosite, Inc., FUJIFILM) using a 6- to 15-MHz linear transducer to assess the ability of texture features for discriminating the presence of accumulated fluid within the subcutaneous tissue of BCRL. Fluid accumulation was observed using a 3-Tesla MR system under double-echo steady-state conditions. There was a significant difference among the three groups (with hyperintense area, without hyperintense area, and unaffected side) in 11 of 14 textural features (p < 0.05). Post hoc analysis (Mann-Whitney U test; Bonferroni correction p < 0.0167) revealed significant differences in seven textural features within the hyperintense area. Conclusions: This study revealed that seven texture features quantified by US imaging data can provide information regarding fluid accumulation in the subcutaneous tissue of lymphedema.

Dermal thickness and echogenicity using DermaScan C high frequency ultrasound: Methodology and reliability testing in people with and without primary lymphoedema

BACKGROUND

DermaScan C high frequency ultrasound was investigated for image capture and analysis of dermal measures in people with and without primary lymphoedema.

METHOD

Three repeated images were taken at six sites in people without lymphoedema (NLO). Intra-rater reliability was assessed by taking three sets of measures on images from 10 people and inter-session reliability by capturing three images, lifting the probe from the skin in between. Methods were adjusted, and repeated images from four sites were taken in people with primary lymphoedema (PLO) and reliability re-assessed.

RESULTS

Intra-rater reliability in NLO and PLO for echogenicity measures were excellent (NLO ICC_(3,1) : .989; PLO .997) across all sites and specific to each site (calf: ICC_(3,1) : .989; and foot: ICC_(3,1) : .999, respectively). Inter-session reliability was moderate for NLO (ICC_(3,1) : .727), improving after method modifications for PLO (ICC_(3,1) : .916). When investigated by site, inter-session reliability was good in the foot (ICC_(3,1) : .811) and moderate in the calf (ICC_(3,1) : .616). Mean thickness analysed by site resulted in good inter-session reliability only in the foot (ICC_(3,1) .838).

CONCLUSION

Intra-rater reliability was excellent using the DermaScan C for dermal measures in people with primary lymphoedema. Inter-session reliability required particular attention to method and gain settings.

Upper limb secondary lymphedema ultrasound mapping and characterization

BACKGROUND

Ultrasound investigation potentials in lymphedema are still to be fully used in everyday practice. Aim of the present study was to report the sonographic characterization of the dermo-epidermal complex (DEC) and of the subcutaneous (SUBC) tissue, assessing the feasibility of a related mapping, in upper limb secondary lymphedema.

METHODS

In this retrospective study 287 patients affected by monolateral upper limb post-mastectomy lymphedema (M5/F282; mean age 64±4.24) were enrolled and scanned by ultrasound, considering the healthy contralateral limb as control. In order to standardize the assessment, the limb was divided in sectors: 4 anterior, 4 posterior below the elbow, 4 anterior and 4 posterior above the elbow, plus the hand. DEC and SUBC regions B-mode appearance were reported, both in the healthy and in the pathological arms. DEC thickness was measured and compared among the same sectors of the healthy and pathological limbs.

RESULTS

DEC and SUBC sonographic appearance was differentiated in fluid and sclerotic. DEC included a third category characterized by differentiation loss. The different sectors showed significantly different lymphatic involvement in the affected limb. In the comparison with the contralateral unaffected segments a significantly thicker DEC was reported in the forearm affected by lymphedema (P<0.005), while no significant difference was reported at the arm level.

CONCLUSIONS

Traditional ultrasonography can provide a secondary upper limb lymphedema characterization with related mapping and useful data for a better lymphatic physiopathology understanding and for a properly addressed therapeutic protocol.

Ultrasound and Clinical Measures for Lymphedema

BACKGROUND

Treatment for breast cancer has increased patient survivorship exponentially over the past few decades. With increased survivorship, more women are living with the longstanding effects of breast cancer treatment, such as lymphedema. Patients, health care providers, and payers depend on practical and efficient clinical measures to accurately diagnose and monitor disease progression or regression. However, current clinical measures do not include objective measures that assess lymphedetamous tissue accurately. This study compared current measures to a novel use of ultrasound (US) imaging to quantify tissue texture.

METHODS AND RESULTS

Seventeen women diagnosed with lymphedema completed self-report questionnaires and then were tested twice by two lymphedema physical therapists who measured edema, fibrosis, and limb volume differences. One therapist measured subjects' limbs using US imaging and derived measures of entropy and average pixel intensity. Volume measures were consistent between therapists (p < 0.01) but palpation was not (0.01 < p < 0.72). Therapists' measures correlated better to subjects' self-report of edema (0.01 < p > 0.32) as compared to fibrosis (0.23 < p > 0.90). US measures were reliable (Cronbachs's α = 0.7 and 0.91 for entropy and API, respectively). Entropy measures demonstrated significant differences between subjects' involved versus uninvolved forearms (p = 0.03).

CONCLUSIONS

Therapists were not consistent with each other when rating edema or fibrosis; however, they were consistent when measuring limb volume differences. US measures (entropy) demonstrated a significant difference between involved and uninvolved. US imaging, as a tool to quantify subcutaneous tissues, holds promise to be a safe, mobile, and effective method to measure lymphedema tissue texture.

Quantitative and morphologic change associated with breast cancer-related lymphedema. Comparison of 3.0T MRI to external measures

Abstract Introduction: Lymphedema is a chronic disease of increasing importance to cancer survivors. A tape measurement tool used for lymphedema relies on indirect volume calculations based on external circumference, which may not reflect the true extent of abnormal fluid accumulation accurately. Fluid-sensitive MRI sequences may be able to delineate the severity of this condition more precisely and thus also monitor response to therapy.

METHODS AND RESULTS

Eight patients being followed by physical therapy for clinically diagnosed breast cancer-related lymphedema were recruited to participate in this study. External measurements and upper extremity MRI were performed on all subjects. Arm circumference, arm volume, and lymphedema volumes were calculated for each method. MR imaging detected lymphedema in all study subjects. Correlation was found between external circumferential measurements and with the 3.0T MRI (r=0.9368). There was poor correlation between lymphedema volumes calculated from clinical measurements and MR imaging (r=0.5539).

CONCLUSIONS

External measurements were not found to be an accurate measure of lymphedema volume associated with breast cancer lymphedema. MRI is a reliable means to obtain upper extremity circumferential and volume measurements. MRI is able to evaluate morphologic change associated with breast cancer-related lymphedema. Lymphedema research requires integrated use of tools to further describe the disease process over time, quantitate the distribution of tissue changes, and improve the sensitivity and specificity of the measurements.