Ultrasound elastography as an objective diagnostic measurement tool for lymphoedema of the treated breast in breast cancer patients following breast conserving surgery and radiotherapy

Breast lymphedema following breast-conserving treatment for breast cancer: current status and future directions

PURPOSE

To examine the current evidence on breast lymphedema (BL) diagnosis and treatment after breast-conserving surgery, identify gaps in the literature, and propose future research directions.

METHODS

A comprehensive literature review was conducted using Ovid, PubMed, and Cochrane, including studies published between 2000 and 2023. References were reviewed manually for eligible studies. Inclusion criteria were as follows: patients who underwent breast conserving treatment (surgery ± radiation) for breast cancer, goals of the paper included analyzing or reviewing BL measurement with ultrasound or tissue dielectric constant, or BL treatment. Twenty-seven manuscripts were included in the review.

RESULTS

There is variation in incidence, time course, and risk factors for BL. Risk factors for BL included breast size, primary and axillary surgery extent, radiation, and chemotherapy but require further investigation. Diagnostic methods for BL currently rely on patient report and lack standardized criteria. Tissue dielectric constant (TDC) and ultrasound (US) emerged as promising ambulatory BL assessment tools; however, diagnostic thresholds and validation studies with ICG lymphography are needed to establish clinical utility. The evidence base for treatment of BL is weak, lacking high-quality studies.

CONCLUSION

The natural history of BL is not well defined. TDC and US show promise as ambulatory assessment tools for BL; however, further validation with lymphatic imaging is required. BL treatment is not established in the literature. Longitudinal, prospective studies including pre-radiation measurements and validating with lymphatic imaging are required. These data will inform screening, diagnostic criteria, and evidence-based treatment parameters for patients with BL after breast-conserving surgery and radiation.

Time-Dependent Changes of Extremity Volume and Tissue Alterations in Swollen Arms Caused by Taxanes

Background: We aimed to determine the course of arm swelling caused by the use of taxanes and to identify valid predictors of persistent swelling. Methods and Results: A total of 15 patients with unilateral arm swelling that developed during the course, or within 3 months after termination, of postoperative taxane-based chemotherapy were included in the present study. The patients attended follow-up appointments every 3-6 months for 24 months after their initial visit. Their arm circumference was measured at each follow-up appointment, while ultrasonography of the skin and subcutaneous tissues was performed at the 0-, 6-, 12-, and 24-month follow-ups. Of the 15 patients, 12 (80%) saw their taxane-induced arm swelling resolved within a median of 12 months (range, 3-29 months) after their final taxane administration. Of the 12 patients whose swelling resolved, 9 did not use compression sleeves; however, their course of resolution did not differ from the other 3 patients who regularly used compression sleeves. In the three patients with persistent swelling, the excess subcutaneous thickness in the medial upper arm (median, 283%) was significantly greater than that in the patients whose swelling resolved (120%; p < 0.05) during their initial visits. Conclusions: Of the 15 patients included in the present study, 80% saw their taxane-induced arm swelling resolve within a median of 12 months after their final taxane administration, independent of the use of compression therapy. Persistent swelling may be predicted during the initial visit based on subcutaneous thickening of the medial upper arm.

Quantification of breast lymphoedema following conservative breast cancer treatment: a systematic review

PURPOSE

Breast lymphoedema is a possible side effect of breast conserving surgery, but it is poorly understood. This is due, in part, to difficulty assessing the breast. This systematic review described outcome measures that quantify breast lymphoedema signs and symptoms and evaluated the measurement properties for these outcome measures.

METHOD

Seven databases were searched using terms in four categories: breast cancer, lymphoedema and oedema, clinician reported (ClinROM) and patient reported outcome measures (PROM) and psychometric and measurement properties. Two reviewers independently reviewed studies and completed quality assessments. The Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) methodology was used for studies including measurement property evidence.

RESULTS

Fifty-six papers were included with thirteen questionnaires, eight patient-reported rating scales, seven physical measures, seven clinician-rating scales and four imaging techniques used to quantify breast lymphoedema. Based on COSMIN methodology, one ClinROM had sufficient reliability, ultrasound measuring dermal thickness. Tissue dielectric constant (TDC) measuring local tissue water had promising reliability. Four questionnaires had sufficient content validity (BLYSS, BLSQ, BrEQ and LYMQOL-Breast).

CONCLUSIONS

Ultrasound is recommended to reliably assess breast lymphoedema signs. No PROM can be recommended with confidence, but BLYSS, BLSQ, BrEQ and LYMQOL-Breast are promising. Further research is recommended to improve evidence of measurement properties for outcome measures.

IMPLICATIONS FOR CANCER SURVIVORS

There are many approaches to assess breast lymphoedema, but currently, only ultrasound can be recommended for use, with others, such as TDC and questionnaires, showing promise. Further research is required for all approaches to improve evidence of measurement properties.

The role of ultrasound quantitative parameters in the assessment of acute radiodermatitis after breast-conserving surgery

This study aimed to assess the severity of acute radiodermatitis (ARD) by ultrasound quantitative parameters and to try to identify the influencing factors of skin toxicity. A total of 55 patients who underwent radiotherapy after unilateral breast-conserving surgery (BCS) were included in the study. The irradiated side of the breast was used as the research object and the quantitative ultrasound parameters (skin thickness, shear wave elasticity) were evaluated before radiotherapy, every week during radiotherapy. Two weeks after radiotherapy, the patients were divided into two groups, according to the World Health Organization scoring standard: mild (0-2 grade) and severe (3-4 grade). The differences in the parameters between the groups and the changes during radiotherapy were compared, and the relationship between these parameters and the severity of ARD was analyzed. In addition, some clinical factors that may affect ARD were also included in our study. Ninety-eight percent of patients developed different degrees of ARD, and Group 2 accounted for ~31%. At the end of 5 weeks of radiotherapy, the difference in thickness between the two groups was statistically significant (P < 0.05). There was no significant change in the elastic modulus of breast skin between the two groups (P > 0.05). Body mass index >25 kg/m2, breast thickness ≥18 mm, skin basic elastic modulus <23 kPa and skin thickness increment >0.3 mm were considered to be associated with severe skin reactions (P < 0.05). Ultrasound can be a useful tool for the non-invasive and objective assessment of skin changes during radiotherapy, documenting quantitative changes in the skin of breast cancer patients following BCS undergoing radiotherapy.

The effect of adjuvant radiotherapy on skin biophysical properties in patients with breast cancer at risk for breast lymphedema: A prospective study

Breast cancer (BC) is the most common type of cancer among women. Radiotherapy (RT) is one of the main and primary treatment options for BC, especially in breast-conserving surgery (BCS). BC patients who underwent RT experience a wide range of symptoms, in which breast oedema and irritation of the skin take the lion's share. Breast oedema/lymphedema, which is also a prominent side effect after RT should be well determined in earlier settings due to the chronicity of lymphedema. Therefore, this study aimed to analyze the biophysical parameters of skin on the ipsilateral (IL) and contralateral (CL) sites via Tissue dielectric constant (TDC) and Transepidermal water loss (TEWL) methods in terms of oedema and skin barrier function (SBF). The following reference points before and after the RT were measured: (R1: Pectoralis muscle, R2: Upper breast, R3: Lower breast, R4: Lateral site of the thorax). A total of 24 BC patients (mean age and BMI: 52.78 ± 9.85 years and 28.42 ± 5.64 kg/m² ) were evaluated. In the IL site, the SBF was not found significant in R1-R3, whereas significantly lower SBF was observed in R4 after RT (t = -3.361, p = 0.003). A significant increase in TDC was observed in R2 at the 5.0 mm depth (t = -2.500, p = 0.02). We suggest that a longer period of follow-up should be carefully carried out to track changes in terms of SBF and oedema in the irradiated breast. The increased need for early detection of changes associated with breast lymphedema can be achievable via noninvasive, safe, cheap, and easily repeatable devices.

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.

Breast Tissue Dielectric Constant as a Potential Breast Edema Assessment Parameter

Background: Many methods can quantitatively assess limb lymphedema, but methods to assess breast edema/lymphedema are quite limited. Thus, there is a need for a convenient and accurate way to quantify and track changes in this condition. Herein, breast tissue dielectric constant (TDC) values that depend on tissue water were used to obtain reference TDC values and interbreast TDC ratios. Methods and Results: TDC was measured in both breasts of 61 women who were about to undergo an ultrasound-guided diagnostic biopsy of a single mass (tumor) in 1 breast. Patient age and body mass index were (mean ± SD) 65.1 ± 11.6 (41-87 years) and 28.9 ± 5.1 (19.1-43.7 kg/m2). TDC was measured at a standardized site (12 o'clock position) with the TDC probe placed with its outer edge at the periphery of the subareolar region. TDC values of healthy breasts versus tumor breasts showed tumor breasts 3% greater (30.4 ± 4.6 vs. 29.5 ± 4.6, p = 0.02). Patients with benign tumors (N = 33) showed no difference between breasts (30.5 ± 4.4 vs. 30.8 ± 4.6 p = 0.434) and had an interbreast TDC ratio (tumor breast/healthy breast) of 1.013 ± 0.077. Patients with malignant tumors (N = 28) had tumor breast values 5% greater (29.8 ± 4.8 vs. 28.4 ± 4.6, p = 0.018) and an interbreast ratio of 1.056 ± 0.117. The overall interbreast ratio (N = 61) was 1.033 ± 0.099. Conclusion: Breast TDC values from nonedematous breasts provide the basis for calculating potential edematous/lymphedematous threshold values based on the measured means +2.5 standard deviation (SD). Accordingly, a TDC threshold value of 41 and an interbreast ratio of 1.28 were determined. These parameters have potential applicability for early detection in at-risk patients and those suspected of having breast edema/lymphedema.

Ultrasound: Assessment of breast dermal thickness: Reliability, responsiveness to change, and relationship to patient-reported outcomes

BACKGROUND

The current study assessed the level of reliability of ultrasound to assess dermal thickness, a clinical feature of breast lymphedema. Additionally, the relationship of dermal thickness to patient-reported outcomes was investigated.

METHODS

Women (n = 82) with unilateral breast edema secondary to treatment of breast cancer were randomized to an exercise or control group. Ultrasound measurements of the unaffected and affected breasts were taken at baseline and 12 weeks later at 3-4 cm superior, medial, inferior, and lateral to the nipple. Additionally, women completed breast-related questions from the European Organization Research and Treatment Committee Quality of Life breast cancer module (EORTC-BR23) and Lymphedema Symptom Intensity and Distress Questionnaire (LSIDS). Reliability of ultrasound measurements was determined on the unaffected breast.

RESULTS

Intraclass correlation coefficients (2,1) ranged from 0.66 (95% CI: 0.52-0.77) for the lateral location to 0.84 (0.77-0.90) for the superior location. Percent close agreement (80%) on the unaffected breast ranged from 0.20 to 0.27 mm compared to 0.57 to 0.93 mm on the affected breast. The standard error of measurement (%) on the unaffected breast varied from 9% to 13% with smallest real difference 0.34-0.41 mm. Dermal thickness of the affected breast was not-to-poorly associated with EORTC BR23 and LSIDS scores.

CONCLUSION

Reliability of dermal thickness measurements of the breast was excellent for the superior, medial, and inferior locations, and fair to good for the lateral location. However, these measurements were not related to the symptom's women perceive and measured with the EORTC BR23 or LSIDS.

Breast edema, from diagnosis to treatment: state of the art

Introduction

Breast edema can arise from different etiologies; however, it is mostly seen after breast conserving surgery and/or radiotherapy. Combining breast conserving surgery and radiotherapy can cause damage to the lymphatic system and reactions to surrounding tissues, which can lead to breast edema; hereby, the breast size can increase by more than one cup size. Swelling of the breast is not the only criterion associated with breast edema. Other common criteria found in literature are peau d’orange, heaviness of the breast, skin thickening, breast pain, redness of the skin, hyperpigmented skin pores and a positive pitting sign. Despite the benefits of breast conserving surgery, breast edema can be uncomfortable, and can negatively influence quality of life in suffering patients. In contrast to lymphedema of the arm, which is well known in clinical practice and in research, breast edema is often underestimated and far less explored in literature. Currently, many aspects still need to be reviewed.

Purpose and importance to practice

This masterclass aims at providing the state of the art of breast edema for all health care workers and researchers involved in the treatment and monitoring of breast cancer patients. It includes current and future perspectives on its diagnosis, longitudinal course and treatment. Furthermore, recommendations for clinical practice and future research are discussed.

Clinical implications

It is recommended to closely monitor those patients in whom breast edema symptoms do not decline within 6 months after termination of radiotherapy and provide them with the appropriate therapy. Since evidence concerning the treatment of breast edema is currently lacking, we recommend the complex decongestive therapy (CDT) to the utmost extent, by analogy with the lymphedema treatment of the extremities. This treatment involves skin care, exercise therapy and compression. Additionally, all patients should be informed about the normal course of breast edema development.

Future research priorities

A consensus should be reached among clinicians and researchers concerning the definition, assessment methods and best treatment of breast edema. Furthermore, high quality studies are necessary to prove the effectiveness of the CDT for breast edema.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40945-021-00103-4.

Diagnostic Contribution of Ultrasonography in Breast Cancer-Related Lymphedema

Background: Many assessments have been reported and used in evaluating lymphedema. The aim of this study was to investigate the diagnostic contribution of ultrasonography in unilateral breast cancer-related lymphedema. Methods and Results: Upper extremity circumferences were measured with a measuring tape from ulnar styloid at the wrist to the axilla at 4 cm intervals. The point with the highest difference between the upper extremities and the control point with no difference between the lower extremities were marked. Skin and subcutaneous thicknesses were measured from four quadrants (volar medial-lateral and dorsal medial-lateral) at the marked points and also subcutaneous tissue changes were graded according to the subcutaneous echogenicity grade (SEG) scale ultrasonographically. The correlations between circumferential and ultrasonographic measurements were investigated. Receiver operating characteristic curve analysis was made to estimate the diagnostic accuracy of the difference in ultrasonographic subcutaneous thickness measurements between the two arms. The study was completed with 34 female patients. Circumferential and subcutaneous tissue thickness measurements were moderately positively correlated in the volar quadrants and strongly positively correlated in the dorsal quadrants of the affected extremity. In the unaffected extremity, a strong positive correlation was identified in all quadrants. The clinical stages of lymphedema and SEG were weakly positively correlated in the volar medial quadrant. The difference between the two upper extremities was found to have a high (0.83%) sensitivity, and an acceptable (0.75%) specificity in the differentiation of Grade II and Grade III lymphedema. Conclusion: A correlation was established between circumferential measurements and ultrasonographic measurements. Ultrasonography can be used complementary to circumferential measurements in diagnosing lymphedema. Clinical trial registration number: NCT04213001.

Breast Lymphedema After Conservative Breast Surgery: An Up-to-date Systematic Review

Although arm lymphedema following breast cancer treatment is a common complication; breast lymphedema following treatment is not uncommon. Several risk factors were found to contribute to breast lymphedema, including axillary surgery, high body mass index (BMI), increased bra cup size, adjuvant chemotherapy, locoregional and radiotherapy boost, and upper outer quadrant tumors. We aimed to provide a review to help avoiding or management of breast lymphedema. The search term 'breast lymphedema' was combined with 'breast conservative surgery' and was used to conduct a literature research in PubMed and Medline. The term lymphedema was combined with breast, conservative, and surgery to search the Embase database. All papers published in English were included with no exclusion date limits. A total of 2155 female patients were included in this review; age ranged from 26 to 90 years. The mean BMI was 28.4 of the studies that included patients who underwent conservative breast surgery. Incidence of breast lymphedema ranged from 24.8% to 90.4%. Several risk factors were linked to breast lymphedema after conservative breast surgery, such as BMI, breast size, tumor size, tumor site, type of surgery, and adjuvant therapy. Treatment options focused on decongestive lymphatic therapy, including manual lymphatic drainage, self-massaging, compression bras, or Kinesio taping. Breast lymphedema is a relatively common complication, yet there is no clear consensus on the definition or treatment options.

Anatomical Theories of the Pathophysiology of Cancer-Related Lymphoedema

Lymphoedema is a well-known concern for cancer survivors. A crucial issue in lymphoedema is that we cannot predict who will be affected, and onset can occur many years after initial cancer treatment. The variability of time between cancer treatment and lymphoedema onset is an unexplained mystery. Retrospective cohort studies have investigated the risk factors for lymphoedema development, with extensive surgery and the combination of radiation and surgery identified as common high-risk factors. However, these studies could not predict lymphoedema risk in each individual patient in the early stages, nor could they explain the timing of onset. The study of anatomy is one promising tool to help shed light on the pathophysiology of lymphoedema. While the lymphatic system is the area least investigated in the field of anatomical science, some studies have described anatomical changes in the lymphatic system after lymph node dissection. Clinical imaging studies in lymphangiography, lymphoscintigraphy and indocyanine green (ICG) fluorescent lymphography have reported post-operative anatomical changes in the lymphatic system, including dermal backflow, lymphangiogenesis and creation of alternative pathways via the deep and torso lymphatics, demonstrating that such dynamic anatomical changes contribute to the maintenance of lymphatic drainage pathways. This article presents a descriptive review of the anatomical and imaging studies of the lymphatic system in the normal and post-operative conditions and attempts to answer the questions of why some people develop lymphoedema after cancer and some do not, and what causes the variability in lymphoedema onset timing.

Assessing breast lymphoedema following breast cancer treatment using indocyanine green lymphography

PURPOSE

Breast lymphoedema is a largely unrecognised survivorship issue for women following breast cancer treatment. While a few objective methods have previously been applied to assess breast lymphoedema, none are capable of imaging breast lymphatics or identifying lymphatic morphological changes indicative of breast lymphoedema. The purpose of this study was to determine if indocyanine green (ICG) lymphography, a validated assessment technique in breast cancer-related lymphoedema), can visualise breast lymphatics and identify breast lymphoedema. Additionally, ICG lymphography was utilised to investigate lymphatic drainage pathways of the affected breast following breast-conserving therapy.

METHODS

Twenty female participants (10 breast lymphoedema and 10 healthy controls) were recruited for this pilot study. All underwent a medical history, physical breast assessment, tissue dielectric constant measures of breast water content, and ICG lymphography.

RESULTS

ICG lymphography identified lymphatic morphological changes in all breast lymphoedema participants (dermal backflow patterns = 10, collateral lymphatic drainage = 9) and none in the control group. The dominant lymphatic drainage pathway to the ipsilateral axilla was observed in all control participants but in only four breast lymphoedema participants. Collateral drainage pathways in the breast lymphoedema group were to: parasternal (6/10); contralateral axilla (4/10); intercostal (3/10); and clavicular (2/10) regions.

CONCLUSION

These findings suggest ICG lymphography, through the identification of morphological lymphatic changes, is a potential qualitative objective assessment technique for breast lymphoedema. Furthermore, in this group of breast lymphoedema patients it identified changes to the normal drainage pathway of the breast. Understanding these changes will have implications for clinical management.

Development and clinimetric properties of the Dutch Breast Edema Questionnaire (BrEQ-Dutch version) to diagnose the presence of breast edema in breast cancer patients

PURPOSE

To develop a diagnostic tool, the Breast Edema Questionnaire (BrEQ) and to determine its clinimetric properties.

METHODS

The BrEQ was developed based on information from literature, experts and breast edema patients. Content validity, construct validity, test-retest reliability, internal consistency and cut-off point were investigated in a group of breast cancer patients. Construct validity made up two parts; convergent and known-groups validity. Convergent validity was tested by correlating the BrEQ with skin thickness measured with ultrasound (US).

RESULTS

In part 1 of the BrEQ, symptoms of breast edema were scored from 0 to 10: pain, heaviness, swelling, tensed skin, redness, pitting sign, enlarged skin pores and hardness. Taking into account the International Classification of Functioning, Disability and Health, several activity limitations and participation restrictions were scored from 0 to 10 in part 2. Clinimetric properties of part 1 were examined in 55 patients. US showed that 35 women had breast edema. Content validity was good. Regarding convergent validity, all breast symptoms correlated moderately with skin thickness. The total symptom score had a strong correlation with skin thickness. Concerning known-groups validity, patients with breast edema had a higher total symptom score. Test-retest reliability ranged between moderate and strong. The internal consistency was good for all items and the total symptom score. We identified that a score cut-off point of ≥ 8.5 discriminates between patients with breast edema and those without.

CONCLUSION

Part 1 of the BrEQ-Dutch version is a valid and reliable tool for assessing clinical indicators of breast edema.

Ultrasound Real-Time Tissue Elastography Improves the Diagnostic Performance of the ACR Thyroid Imaging Reporting and Data System in Differentiating Malignant from Benign Thyroid Nodules: A Summary of 1525 Thyroid Nodules

BACKGROUND

To explore the correlation between the ultrasound elasticity score (ES) of real-time tissue elastography (RTE) and the malignant risk stratification of the Thyroid Imaging Reporting and Data System (TI-RADS) and to evaluate the added value of RTE to TI-RADS in differentiating malignant nodules from benign ones.

METHODS

A total of 1,498 patients (885 women and 613 men; mean age of 43.5 ± 12.4 years) with 1,525 confirmed thyroid nodules (D = maximum diameter, D ≤ 2.5 cm) confirmed by fine-needle aspiration (FNA) and/or surgery were included. The nodules were divided into four groups based on their sizes (D ≤ 0.5 cm, 0.5 < D ≤ 1.0 cm, 1.0 < D ≤ 2.0 cm, and 2.0 < D ≤ 2.5 cm). We assigned an ES of RTE and malignant risk stratification of the TI-RADS category to each nodule. The correlation between the ES of RTE and the malignant risk stratification of TI-RADS category was analyzed by the Spearman's rank correlation. The diagnostic performances of RTE, TI-RADS, and their combination were compared by the receiver operator characteristic (ROC) analysis.

RESULTS

The ES of RTE and the malignant risk stratification of TI-RADS showed a strong correlation in the size intervals of 0.5 < D ≤ 1.0 cm, 1.0 < D ≤ 2.0 cm, and 2.0 < D ≤ 2.5 cm (r = 0.768, 0.711, and 0.743, respectively). The diagnostic performance of their combination for each size interval was always better than RTE or TI-RADS alone (for all, P < 0.001).

CONCLUSIONS

Overall, The ES of RTE was strongly correlated with the malignant risk stratification of TI-RADS. The diagnostic performance of the combination of RTE and TI-RADS outperformed RTE or TI-RADS alone. Therefore, RTE may be an adjunctive tool to the current TI-RADS system for differentiating malignant from benign thyroid nodules.

Ultrasound Elastography Use in Lower Extremity Lymphedema: A Systematic Review of the Literature

Lower extremity lymphedema (LEL) is mainly assessed clinically. Ultrasound elastography (UE) is a promising imaging tool to assess this disorder. We conducted a systematic literature review to describe the studies evaluating the use of UE in LEL. The PubMed database was queried for studies that evaluated the use of UE in LEL. The keywords "elastography" AND "lymphedema" were used for the search. Original articles in English were included in our study, whereas reviews were excluded. Our search resulted in 12 articles, 4 of which met the inclusion criteria. UE methods included free-hand real-time tissue elastography and UE with transducer in B mode. The imaging parameters applied were the tissue strains and the area of red region, respectively. All studies tested UE use in the assessment of LEL, and only one considered its use for staging. All studies but one found a difference in strain parameters for assessment of patients with LEL. Our systematic review has shown that UE appears to be a great tool in the assessment of LEL in moderate-to-advanced stages of disease. However, further studies using new effective methods are needed to evaluate patients with early lymphedema.

Evaluation of a 3D surface imaging system for deep inspiration breath-hold patient positioning and intra-fraction monitoring

PURPOSE

To determine the accuracy of a surface guided radiotherapy (SGRT) system for positioning of breast cancer patients in breath-hold (BH) with respect to cone-beam computed tomography (CBCT). Secondly, to evaluate the thorax position stability during BHs with SGRT, when using an air-volume guidance system.

METHODS AND MATERIALS

Eighteen left-sided breast cancer patients were monitored with SGRT during CBCT and treatment, both in BH. CBCT scans were matched on the target volume and the patient surface. The setup error differences were evaluated, including with linear regression analysis. The intra-fraction variability and stability of the air-volume guided BHs were determined from SGRT measurements. The variability was determined from the maximum difference between the different BH levels within one treatment fraction. The stability was determined from the difference between the start and end position of each BH.

RESULTS

SGRT data correlated well with CBCT data. The correlation was stronger for surface-to-CBCT (0.61) than target volume-to-CBCT (0.44) matches. Systematic and random setup error differences were ≤ 2 mm in all directions. The 95% limits of agreement (mean ± 2SD) were 0.1 ± 3.0, 0.6 ± 4.1 and 0.4 ± 3.4 mm in the three orthogonal directions, for the surface-to-CBCT matches. For air-volume guided BHs, the variability detected with SGRT was 2.2, 2.8 and 2.3 mm, and the stability - 1.0, 2.1 and 1.5 mm, in three orthogonal directions. Furthermore, the SGRT system could detect unexpected patient movement, undetectable by the air-volume BH system.

CONCLUSION

With SGRT, left-sided breast cancer patients can be positioned and monitored continuously to maintain position errors within 5 mm. Low intra-fraction variability and good stability can be achieved with the air-volume BH system, however, additional patient position information is available with SGRT, that cannot be detected with air-volume BH systems.

Perioperative variations in indices derived from noninvasive assessments to detect postmastectomy lymphedema

OBJECTIVE

This study aimed to clarify the variations in indices derived from noninvasive assessments for the early detection of postmastectomy lymphedema (LE) from 1 month preoperatively until 2 years postoperatively.

METHODS

In total, 120 patients who underwent surgery for breast cancer in our institution were prospectively followed up with a questionnaire for arm swelling as well as with tape measurements, bioimpedance analysis (BIA), and skin and subcutaneous tissue ultrasound at 1 month before and 3, 6, 12, 18, and 24 months after surgery.

RESULTS

Ninety-seven patients completed the study. Among 93 patients who did not present with LE, 9% complained of arm swelling even before surgery, and the incidence peaked at 17% at 6 months after surgery. There were no differences in the circumferences of the upper arm, forearm, and hand between sides throughout the study period. However, the postoperative circumference values of the upper arm only on the operation side were slightly increased compared with the preoperative values. The mean excess fluid in the arm on the operation side compared with the contralateral side, as assessed by BIA, was nearly zero throughout the study period. There were no differences in subcutaneous echogenicity or skin and subcutaneous thicknesses between the sides throughout the study period. However, time-dependent increases in subcutaneous thicknesses were noticed on both sides. Four patients (4.1%) developed LE. In three of these patients, abnormality in the BIA was recorded 6 to 12 months before presentation. Immediately after presentation, the common findings included BIA abnormality and increased subcutaneous echogenicity and skin thickness in the medial forearm.

CONCLUSIONS

In this study, a complaint of arm swelling was not sensitive enough for detection of the early onset of LE because a certain number of patients constantly complained of this symptom. Measurements of circumference might help in the diagnosis of LE onset, but this method is not specific enough because these measurements are also affected by various factors. However, BIA and skin and subcutaneous ultrasound were identified as potential tools for the early detection of LE.

Predictive factors for persistent and late radiation complications in breast cancer survivors

PURPOSE

With improved diagnostic techniques and treatments of breast cancer, overall survival times are longer, giving more opportunity for normal tissue complications of treatment to manifest. Radiation late effects (RLEs) could have profound long-term impacts on the quality of life of the survivors. The aim of this study was to identify predictive factors influencing timing and types of complications in patients referred to the Adult Radiation Late Effects Clinic (ARLEC).

METHODS

In a period of 16 years, 296 breast cancer patients were referred to the ARLEC. The clinical records were retrospectively studied to collect epidemiologic, medical and treatment data. Associations were sought between candidate predictive factors and time to the first complication after radiation treatment (RT) completion (primary outcome), and pain or swelling (secondary outcomes) using univariable and multivariable linear and logistic regression analyses. All analyses were performed in SAS, version 9.4.

RESULTS

All patients were female with a mean age of 56.3 years. The first treatment-related complication occurred after a median of 3 months. Patients were followed at ARLEC for a median of 18 months. Older age and delay from surgery to RT (S-RT delay) were associated with earlier onset of complications (both p < 0.001). The most common complications were breast pain (62.1%) and swelling (45.9%). Histology and RT boost were associated with pain (p = 0.035 and 0.013). RT boost and S-RT delay on the other hand were associated with swelling (p = 0.013 and 0.005).

CONCLUSIONS

Clinical factors identified could help recognize the patients at high risk for developing RLEs and alert physicians to initiate earlier diagnostic and therapeutic measures.

Upcoming imaging concepts and their impact on treatment planning and treatment response in radiation oncology

For 2018, the American Cancer Society estimated that there would be approximately 1.7 million new diagnoses of cancer and about 609,640 cancer-related deaths in the United States. By 2030 these numbers are anticipated to exceed a staggering 21 million annual diagnoses and 13 million cancer-related deaths. The three primary therapeutic modalities for cancer treatments are surgery, chemotherapy, and radiation therapy. Individually or in combination, these treatment modalities have provided and continue to provide curative and palliative care to the myriad victims of cancer.

Today, CT-based treatment planning is the primary means through which conventional photon radiation therapy is planned. Although CT remains the primary treatment planning modality, the field of radiation oncology is moving beyond the sole use of CT scans to define treatment targets and organs at risk. Complementary tissue scans, such as magnetic resonance imaging (MRI) and positron electron emission (PET) scans, have all improved a physician’s ability to more specifically identify target tissues, and in some cases, international guidelines have even been issued. Moreover, efforts to combine PET and MR to define solid tumors for radiotherapy planning and treatment evaluation are also gaining traction.

Keeping these advances in mind, we present brief overviews of other up-and-coming key imaging concepts that appear promising for initial treatment target definition or treatment response from radiation therapy.

Biotechnologies toward Mitigating, Curing, and Ultimately Preventing Edema through Compression Therapy

For a century-old problem, edema and its treatment have gone remarkably unnoticed by the biomedical community. Given the prevalence of lymphedema and its debilitating repercussions, there is an acute need for both efficacy-based measures and clinical standards to guide compression garment design and therapeutic application. This review outlines the current state of the art in compression treatment and suggests an integrated biomedical engineering approach going forward. Characterizing the pressure gradient profiles of commercial compression sleeves is necessary to better understand the role of compression treatment in the mitigation of swelling. Integration of pressure sensor technologies with advanced materials design and manufacture provides a critical path not only to elucidate the mechanisms of but also to improve on current compression-based therapies and associated therapeutic devices.

Evaluation of Stiffness in Postmastectomy Lymphedema Using Acoustic Radiation Force Impulse Imaging: A Prospective Randomized Controlled Study for Identifying the Optimal Pneumatic Compression Pressure to Reduce Stiffness

PURPOSE

We aimed to assess the improvement in stiffness in patients with postmastectomy lymphedema (PMLE) after intermittent pneumatic compression (IPC) using acoustic radiation force impulse (ARFI) imaging and evaluate the effects of different IPC pressures.

METHODS

We randomly assigned 45 patients with PMLE (stage II) to three groups based on the IPC pressure: 25, 35, and 45 mmHg. Patients received a single session of IPC for 30 minutes. We recorded the subcutaneous tissue thickness of the proximal upper limbs using ultrasonography and circumference of the upper limbs and stiffness using ARFI before and immediately after IPC.

RESULTS

Arm circumference and subcutaneous tissue thickness were significantly decreased after IPC in all groups. The shear wave velocity (SWV) decreased after IPC in all groups, but significantly decreased only in the 35 mmHg group. The subcutaneous tissue thickness and SWV in the 35 mmHg group were significantly decreased compared to the other groups.

CONCLUSION

IPC can reduce stiffness and subcutaneous tissue thickness of the proximal upper arm in patients with PMLE. A pressure of 35 mmHg yields the largest improvement of stiffness; higher compression pressure did not yield any additional improvement.

Diagnosis of Upper Quadrant Lymphedema Secondary to Cancer: Clinical Practice Guideline From the Oncology Section of the American Physical Therapy Association

The Oncology Section of the American Physical Therapy Association (APTA) developed a clinical practice guideline to aid the clinician in diagnosing secondary upper quadrant cancer-related lymphedema. Following a systematic review of published studies and a structured appraisal process, recommendations were written to guide the physical therapist and other health care clinicians in the diagnostic process. Overall clinical practice recommendations were formulated based on the evidence for each diagnostic method and were assigned a grade based on the strength of the evidence for different patient presentations and clinical utility. In an effort to maximize clinical applicability, recommendations were based on the characteristics as to the location and stage of a patient's upper quadrant lymphedema.

Diagnosis of Upper-Quadrant Lymphedema Secondary to Cancer: Clinical Practice Guideline From the Oncology Section of APTA

INTRODUCTION

The Oncology Section of APTA developed a clinical practice guideline to aid the clinician in diagnosing secondary upper-quadrant cancer-related lymphedema.

METHODS

Following a systematic review of published studies and a structured appraisal process, recommendations were written to guide the physical therapist and other health care clinicians in their diagnostic process. Overall, clinical practice recommendations were formulated on the basis of the evidence for each diagnostic method and were assigned a grade based on the strength of the evidence for different patient presentations and clinical utility.

RECOMMENDATIONS

In an effort to make these clinically applicable, recommendations were based on the characteristics as to the location and stage of a patient's upper-quadrant lymphedema.

Hemodynamic analysis of radiation-induced damage in common carotid arteries by using color Doppler ultrasonography

Purpose

The aim of this study was to assess vascular changes and blood flow abnormalities in the common carotid arteries of patients with head and neck cancers after external radiotherapy, using color Doppler ultrasonography.

Methods

We studied 24 patients treated with external radiotherapy for various head and neck cancers. In order to study the acute effects of irradiation on common carotid blood flow and arterial diameter changes, color Doppler ultrasonography parameters such as peak systolic velocity, end diastolic velocity, mean velocity, systolic-to-diastolic velocity (S/D) ratio, pulsatility index (PI), resistive index (RI), and instantaneous diameter changes were evaluated before and after external radiotherapy. Additionally, the blood volume flow (VF) values in the peak systolic and end diastolic phases, as well as mean velocity, were evaluated throughout three cardiac cycles using B-mode ultrasonic image processing.

Results

The findings showed significant changes in the S/D ratio, PI, and RI of the common carotid arteries before and after external radiotherapy (P<0.05). Moreover, a significant decrease in artery diameter and blood VF was observed after radiotherapy relative to the pretreatment values. A significant correlation was found between the blood VF values estimated using ultrasonic measurements and mathematical methods throughout three cardiac cycles.

Conclusion

The hemodynamic parameters of the common carotid arteries changed during radiotherapy. These arterial changes may lead to late adverse effects of radiotherapy, such as ischemic strokes and ischemic attacks.

Skin and Subcutaneous Tissue Ultrasonography Features in Breast Cancer-Related Lymphedema

Objective: To investigate skin, subepidermal low echogenic band (SELEB), and subcutaneous tissue (SCT) thickness as well as the degree of increase in subcutaneous echogenicity (SEG) and subcutaneous echo-free space (SEFS) in arms with lymphedema (LE). Materials and Methods: The skin and SCT of both arms of 30 patients with unilateral stage II breast cancer-related LE were scanned at five points (medial/lateral upper arm/forearm and dorsum of the hand). SEG and SEFS grades were determined according to severity (range: 0-2). Results: All measured parameters, except the SEFS in the medial upper arm, were significantly higher on the LE side than on the normal (N) side. The parameters differed most remarkably in the medial forearm (MFA; skin: LE 1.7 ± 0.8 mm vs. N 0.8 ± 0.2 mm; SELEB: LE 1.0 ± 0.6 mm vs. N 0.3 ± 0.1 mm; SCT: LE 8.7 ± 3.4 mm vs. N 3.8 ± 2.0 mm; SEG: LE 0.9 ± 0.5 vs. N 0.1 ± 0.3; and SEFS: LE 0.5 ± 0.7 vs. N 0). Conclusion: The differences in the thickness of the skin, SELEB, and SCT and the SEG and SEFS grades between the LE and N arms seemed most evident in the MFA.

Differentiation of functional venous insufficiency and leg lymphedema complicated by functional venous insufficiency using subcutaneous tissue ultrasonography

OBJECTIVE

To use subcutaneous ultrasonography to differentiate legs with edema because of obesity-related functional venous insufficiency (FVI_ob), immobility-related FVI (FVI_im), secondary lymphedema (LE), LE complicated by obesity (LE_ob), and LE complicated by immobility (LE_im).

METHODS

Ninety-nine legs with edema (16 FVI_ob, 32 FVI_im, 22 LE, 9 LE_ob, and 20 LE_im), and 10 normal legs were examined. Subcutaneous tissue ultrasonography was performed at eight points (medial, lateral, upper, lower, thigh, and calf) in each leg. Subcutaneous echogenicity (SEG) and subcutaneous echo-free space (SEFS) were assessed, and each graded as 0, 1, and 2 according to their severity.

RESULTS

In normal legs, SEG and SEFS were graded 0 in almost all parts of the leg. SEG was diffusely increased in FVI_ob, whereas SEG was increased in accordance with gravity in FVI_im (upper medial thigh, 0.6 ± 0.5 vs lower medial calf, 1.2 ± 0.4; P < .001). In LE, SEG was increased in the medial side, particularly evident in upper thigh (upper medial thigh, 1.1 ± 0.4 vs upper lateral thigh, 0.6 ± 0.6; P < .01). SEFS was increased in accordance with gravity in all of these legs (FVI_ob: upper medial thigh, 0.2 ± 0.4 vs lower medial calf, 0.7 ± 0.8; P = .05; FVI_im: upper medial thigh, 0.1 ± 0.2 vs lower medial calf, 1.3 ± 0.7; P < .0001; LE: upper medial thigh, 0.4 ± 0.7 vs lower medial calf, 0.9 ± 0.9; P < .05). The increases of SEG and SEFS in legs with LE_ob or LE_im were diffuse and similar. As determined via stepwise logistic regression analyses, the increases in SEG in the upper medial thigh and SEFS in the lower medial thigh in LE cases, the increases in SEG in the upper lateral thigh and SEFS in the lower lateral thigh in cases with obesity-related leg edema (ie, FVI_ob and LE_ob), and the increase in SEFS in the lower lateral calf in cases with immobility-related leg edema (ie, FVI_im and LE_im) were determined to be significant factors to characterize each leg edema.

CONCLUSIONS

Differences in the extent and distribution of SEG and SEFS might help in differentiating LE from FVI_ob and FVI_im, although assessment of LE complicated by obesity vs immobility remains difficult.

Design and Testing of a Single-Element Ultrasound Viscoelastography System for Point-of-Care Edema Quantification

Management of fluid overload in patients with end-stage renal disease represents a unique challenge to clinical practice because of the lack of accurate and objective measurement methods. Currently, peripheral edema is subjectively assessed by palpation of the patient's extremities, ostensibly a qualitative indication of tissue viscoelastic properties. New robust quantitative estimates of tissue fluid content would allow clinicians to better guide treatment, minimizing reactive treatment decision making. Ultrasound viscoelastography (UVE) can be used to estimate strain in viscoelastic tissue, deriving material properties that can help guide treatment. We are developing and testing a simple, low-cost UVE system using a single-element imaging transducer that is simpler and less computationally demanding than array-based systems. This benchtop validation study tested the feasibility of using the UVE system by measuring the mechanical properties of a tissue-mimicking material under large strains. We generated depth-dependent creep curves and viscoelastic parameter maps of time constants and elastic moduli for the Kelvin model of viscoelasticity. During testing, the UVE system performed well, with mean UVE-measured strain matching standard mechanical testing with maximum absolute errors ≤4%. Motion tracking revealed high correlation and signal-to-noise ratios, indicating that the system is reliable.

Review of ultrasound image guidance in external beam radiotherapy part II: intra-fraction motion management and novel applications

Imaging has become an essential tool in modern radiotherapy (RT), being used to plan dose delivery prior to treatment and verify target position before and during treatment. Ultrasound (US) imaging is cost-effective in providing excellent contrast at high resolution for depicting soft tissue targets apart from those shielded by the lungs or cranium. As a result, it is increasingly used in RT setup verification for the measurement of inter-fraction motion, the subject of Part I of this review (Fontanarosa et al 2015 Phys. Med. Biol. 60 R77-114). The combination of rapid imaging and zero ionising radiation dose makes US highly suitable for estimating intra-fraction motion. The current paper (Part II of the review) covers this topic. The basic technology for US motion estimation, and its current clinical application to the prostate, is described here, along with recent developments in robust motion-estimation algorithms, and three dimensional (3D) imaging. Together, these are likely to drive an increase in the number of future clinical studies and the range of cancer sites in which US motion management is applied. Also reviewed are selections of existing and proposed novel applications of US imaging to RT. These are driven by exciting developments in structural, functional and molecular US imaging and analytical techniques such as backscatter tissue analysis, elastography, photoacoustography, contrast-specific imaging, dynamic contrast analysis, microvascular and super-resolution imaging, and targeted microbubbles. Such techniques show promise for predicting and measuring the outcome of RT, quantifying normal tissue toxicity, improving tumour definition and defining a biological target volume that describes radiation sensitive regions of the tumour. US offers easy, low cost and efficient integration of these techniques into the RT workflow. US contrast technology also has potential to be used actively to assist RT by manipulating the tumour cell environment and by improving the delivery of radiosensitising agents. Finally, US imaging offers various ways to measure dose in 3D. If technical problems can be overcome, these hold potential for wide-dissemination of cost-effective pre-treatment dose verification and in vivo dose monitoring methods. It is concluded that US imaging could eventually contribute to all aspects of the RT workflow.

Symptoms: Lymphedema

Lymphedema is one of the main late effects from breast cancer treatment affecting 3-60% of breast cancer survivors. Primarily occurring in the hand, arm, and/or affected breast, symptoms of lymphedema include swelling, pain, redness, restriction of arm/hand movement, tightness and feelings of fullness. These symptoms not only may limit physical functioning but also negatively affect quality of life, body image, social functioning, and financial status of breast cancer survivors with lymphedema. Unfortunately, there are no standardized methods for prevention, diagnosis, and treatment of breast cancer-related lymphedema. Despite its prevalence and lack of clinical guidelines, lymphedema is one of the most poorly understood, relatively underestimated, and least researched complications of cancer treatment. This chapter reviews the current problem of breast cancer-related lymphedema by investigating prevention and risk reduction strategies, diagnosis, and treatment. In addition, this chapter identifies future research opportunities focusing on prevention and risk reduction strategies, quality of life and physical function, surveillance, patient education, cost, diagnosis, and treatment. Challenges and recommendations for future research in these areas, particularly among underserved populations, are discussed.

Vascularized lymph node transfer for treatment of lymphedema: a comprehensive literature review

OBJECTIVE

A comprehensive literature review of VLNT with updates and comparisons on current application, techniques, results, studies and possible future implications.

BACKGROUND

Lymphedema is a debilitating condition that often results secondary to treatment of cancer. Unfortunately there is no cure. However, microsurgical procedures such as VLNT has gained popularity as there have been increasing reports that VLNT may help alleviate the severity of lymphedema.

METHODS

A review of literature was conducted over major medical indices (PubMed-MEDLINE, Factiva, Scopus, Sciencedirect, EMBASE). Search terms were focused on vascularized, lymph node transfer (also autologous, lymph node transplant) to cover both human and animal studies. Each study was verified for the nature of the procedure; a free microsurgical flap containing lymph nodes for the purpose of relieving lymphedema.

RESULTS

There are human and animal studies that individually report clear benefits, but because of methodological shortcomings comparative studies with uniform patient selection and monitoring are lacking.

CONCLUSIONS

Although the results with the use of VLNT for treatment of lymphedema have been largely positive, further exploration into standardized protocols for diagnosis, treatment optimization, and patient outcomes assessment is needed.

Bridging the divide between pathogenesis and detection in lymphedema

While our understanding of the lymphatic system has improved substantially in the past few decades, the translation of this knowledge into improved healthcare solutions for patients suffering from secondary lymphedema has been severely limited. The challenge facing clinicians is two-fold. First, there is no reliable, affordable, diagnostic capable of detecting the disease before symptoms of the lymphedema develop and the efficacy of treatment options becomes limited. Second, our understanding of the disease pathogenesis, its risk factors, and the underlying physiologic mechanisms is still in its infancy. These two challenges go hand in hand as limited diagnostic options have hindered our ability to understand lymphedema progression, and the lack of known underlying mechanisms involved in the disease prohibits the development of new diagnostic targets. This review serves to discuss the recent developments in clinical and lab research settings of both lymphedema diagnostic technologies and our understanding of the mechanisms driving disease risk and progression. We will show how these two lines of research are synergistically working with the ultimate goal of improving patient outcomes for those suffering from this horrible disease, identifying key areas of further research that are warranted to move the field forward and provide clinical relief for this neglected patient population.

The role of elastosonography, gray-scale and colour flow Doppler sonography in prediction of malignancy in thyroid nodules

Background

Ultrasound is as a noninvasive method commonly used in the work-up of thyroid nodules. This study aimed to evaluate the usefulness of sonographic and elastosonographic parameters in the discrimination of malignancy.

Patients and methods.

150 thyroid nodules were evaluated by gray-scale, Doppler and elastosonography. The cytological analysis revealed that 141 nodules were benign and 9 were malignant.

Results

Orientation of the nodule was the only sonographic parameter associated with malignancy (p = 0.003). In the strain ratio analysis the best cut-off point was 1.935 to discriminate malignancy (p = 0.000), with 100% sensitivity, 76% specificity, 100% negative predictive value, 78.5% positive predictive value and 78% accuracy rate. There was a statistically significant correlation between the elasticity score and malignancy (p = 0.001). Most of the benign nodules had score 2 and 3, none of them displayed score 5. On the other hand, none of the malignant nodules had score 1 and 2, most of them displaying score 5.

Conclusions

A change in the diagnostic algorithm of the thyroid nodules should be considered integrating the elastosonographic analysis.

Breast edema in breast cancer patients following breast-conserving surgery and radiotherapy: a systematic review

Breast-conserving surgery (BCS) is commonly used in breast cancer treatment. Despite its benefits, some women will be troubled by breast edema. Breast edema may cause an unsatisfactory cosmetic result, influencing the quality of life. The purpose of this systematic review is to investigate the incidence of breast edema and to identify risk factors of breast edema in breast cancer patients following BCS and radiotherapy. A systematic literature search was performed using different electronic databases (PubMed, Web of Science, Cochrane, Embase) until June 2014. Inclusion criteria were as follows: (1) research studies that included female breast cancer patients who were treated with BCS and radiotherapy and (2) studies that investigated the incidence of breast edema and/or risk factors of breast edema. Exclusion criteria were (1) reviews or case studies and (2) studies published before 1995. We identified in total 28 papers which represented 4,011 patients. There was a great variation in the incidence of breast edema (0-90.4 %). We identified several possible risk factors for breast edema namely increasing irradiated breast volume, increasing boost volume, the use of a photon boost, increasing breast separation, a higher density of the breast tissue, a large tumor, a higher specimen weight, postoperative infection, acute postoperative toxicity, and diabetes mellitus. However, their prognostic value remains uncertain. Breast edema is a common complaint after BCS and radiotherapy. A number of possible risk factors associated with breast edema were identified, but further research is warranted.

Visualization, imaging and new preclinical diagnostics in radiation oncology

Innovative strategies in cancer radiotherapy are stimulated by the growing knowledge on cellular and molecular tumor biology, tumor pathophysiology, and tumor microenvironment. In terms of tumor diagnostics and therapy monitoring, the reliable delineation of tumor boundaries and the assessment of tumor heterogeneity are increasingly complemented by the non-invasive characterization of functional and molecular processes, moving preclinical and clinical imaging from solely assessing tumor morphology towards the visualization of physiological and pathophysiological processes. Functional and molecular imaging techniques allow for the non-invasive characterization of tissues in vivo, using different modalities, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, positron emission tomography (PET) and optical imaging (OI). With novel therapeutic concepts combining optimized radiotherapy with molecularly targeted agents focusing on tumor cell proliferation, angiogenesis, and cell death, the non-invasive assessment of tumor microcirculation and tissue water diffusion, together with strategies for imaging the mechanisms of cellular injury and repair is of particular interest. Characterizing the tumor microenvironment prior to and in response to irradiation will help to optimize the outcome of radiotherapy. These novel concepts of personalized multi-modal cancer therapy require careful pre-treatment stratification as well as a timely and efficient therapy monitoring to maximize patient benefit on an individual basis. Functional and molecular imaging techniques are key in this regard to open novel opportunities for exploring and understanding the underlying mechanisms with the perspective to optimize therapeutic concepts and translate them into a personalized form of radiotherapy in the near future.

The usefulness of F-18 FDG PET/CT-mammography for preoperative staging of breast cancer: comparison with conventional PET/CT and MR-mammography

Background

The objective of the study was to compare the diagnostic efficacy of an integrated Fluorine-18 fluorodeoxyglucose (F-18 FDG) PET/CT-mammography (mammo-PET/CT) with conventional torso PET/CT (supine-PET/CT) and MR-mammography for initial assessment of breast cancer patients.

Patients and methods

Forty women (52.0 ± 12.0 years) with breast cancer who underwent supine-PET/CT, mammo-PET/CT, and MR-mammography from April 2009 to August 2009 were enrolled in the study. We compared the size of the tumour, tumour to chest wall distance, tumour to skin distance, volume of axillary fossa, and number of meta-static axillary lymph nodes between supine-PET/CT and mammo-PET/CT. Next, we assessed the difference of focality of primary breast tumour and tumour size in mammo-PET/CT and MR-mammography. Histopathologic findings served as the standard of reference.

Results

In the comparison between supine-PET/CT and mammo-PET/CT, significant differences were found in the tumour size (supine-PET/CT: 1.3 ± 0.6 cm, mammo-PET/CT: 1.5 ± 0.6 cm, p < 0.001), tumour to thoracic wall distance (1.8 ± 0.9 cm, 2.2 ± 2.1 cm, p < 0.001), and tumour to skin distance (1.5 ± 0.8 cm, 2.1 ± 1.4 cm, p < 0.001). The volume of axillary fossa was significantly wider in mammo-PET/CT than supine-PET/CT (21.7 ± 8.7 cm³vs. 23.4 ± 10.4 cm³, p = 0.03). Mammo-PET/CT provided more correct definition of the T-stage of the primary tumour than did supine-PET/CT (72.5% vs. 67.5%). No significant difference was found in the number of metastatic axillary lymph nodes. Compared with MR-mammography, mammo-PET/CT provided more correct classification of the focality of lesion than did MR-mammography (95% vs. 90%). In the T-stage, 72.5% of cases with mammo-PET/CT and 70% of cases with MR-mammography showed correspondence with pathologic results.

Conclusions

Mammo-PET/CT provided more correct definition of the T-stage and evaluation of axillary fossa may also be delineated more clearly than with supine-PET/CT. The initial assessment of mammo-PET/CT would be more useful than MR-mammography because the mammo-PET/CT indicates similar accuracy with MR-mammography for decision of T-stage of primary breast tumour and more correct than MR-mammography for defining focality of lesion.