The role of ultrasound in detection and management of regional disease in melanoma patients

Ultrasound-Induced Drug Release from Stimuli-Responsive Hydrogels

Stimuli-responsive hydrogel drug delivery systems are designed to release a payload when prompted by an external stimulus. These platforms have become prominent in the field of drug delivery due to their ability to provide spatial and temporal control for drug release. Among the different external triggers that have been used, ultrasound possesses several advantages: it is non-invasive, has deep tissue penetration, and can safely transmit acoustic energy to a localized area. This review summarizes the current state of understanding about ultrasound-responsive hydrogels used for drug delivery. The mechanisms of inducing payload release and activation using ultrasound are examined, along with the latest innovative formulations and hydrogel design strategies. We also report on the most recent applications leveraging ultrasound activation for both cancer treatment and tissue engineering. Finally, the future perspectives offered by ultrasound-sensitive hydrogels are discussed.

Skin cancer detection using non-invasive techniques

Skin cancer is the most common form of cancer and is globally rising. Historically, the diagnosis of skin cancers has depended on various conventional techniques which are of an invasive manner. A variety of commercial diagnostic tools and auxiliary techniques are available to detect skin cancer. This article explains in detail the principles and approaches involved for non-invasive skin cancer diagnostic methods such as photography, dermoscopy, sonography, confocal microscopy, Raman spectroscopy, fluorescence spectroscopy, terahertz spectroscopy, optical coherence tomography, the multispectral imaging technique, thermography, electrical bio-impedance, tape stripping and computer-aided analysis. The characteristics of an ideal screening test are outlined, and the authors pose several points for clinicians and scientists to consider in the evaluation of current and future studies of skin cancer detection and diagnosis. This comprehensive review critically analyses the literature associated with the field and summarises the recent updates along with their merits and demerits.

The Tail and the String Sign: New Sonographic Features of Subcutaneous Melanoma Metastasis

No highly specific sonographic imaging findings to evaluate melanoma spread along the lymphatic vessels have ever been described. Between January 2009 and December 2012, a consecutive group of 531 melanoma patients at their initial stage or during follow-up for nodal or extra-nodal superficial metastasis were evaluated retrospectively to assess the presence of two sonographic findings demonstrating superficial lymphatic metastasis: a "tail" sign (a thin hypoechoic prolongation from one or both poles of a superficial metastasis) and a "string" sign (multiple in-transit lesions connected to each other in a rosary image). The total number of superficial metastatic lesions was 222. The tail sign was seen in 13 of the 222 lesions (5.9%). The string sign was detected in four patients (4.5%). These signs showed a low sensitivity with a very high specificity (100%). Tail and string signs may represent an additional finding of high specificity to be employed in the differential diagnosis of melanoma patients.

Previously reported sonographic appearances of regional melanoma metastases are not likely due to necrosis

OBJECTIVES

Sonography has proven to be a reliable tool in early detection of lymph node and in-transit cutaneous-subcutaneous metastases. Those metastases normally appear as hypoechoic or even anechoic lesions on sonography. It has been assumed that this appearance is due to necrosis of the lesions, but so far, that assumption has never been proven. The purpose of this retrospective study was to evaluate whether the hypoechoic appearance of melanoma metastasis is really due to tumor necrosis.

METHODS

From a radiographic database, we retrieved 212 melanoma cases imaged with sonography over a 2-year period for disease staging or follow-up. We selected 37 positive cases with 84 nodal and extranodal (satellite and in-transit) metastatic lesions and reviewed the sonograms and pathologic slides (slides available for 40 of 84 lesions). We retrospectively assessed the vascularization pattern (color Doppler images available for 78 of 84 lesions), categorizing it as poor, intermediate, or consistent. We also looked for necrosis on the histopathologic material, categorizing it into scores of 0, 1, 2, and 3 for absence of necrosis, less than 20% necrosis, 20% to 40% necrosis, and greater than 40% necrosis, respectively.

RESULTS

Despite their gray scale appearance, most melanoma lesions were vascularized on color Doppler imaging and showed limited necrosis at histopathologic analysis. Consistent vascularization on Doppler imaging, excluding substantial necrosis, was found in 44 of 78 lesions (56.4%). Poor vascularization on Doppler imaging, suggesting necrosis, was present in only 14% of the lesions. Substantial necrosis (scores of 2 and 3) was found pathologically in only 10% of the lesions.

CONCLUSIONS

Necrosis seems to be an uncommon event in melanoma metastasis and is probably not the basis for its low-level echo pattern on sonography. The hypoechoic appearance is very typical of melanoma metastasis and is likely due to massive melanomatous infiltration (with the poor echo reflectivity of melanin). However, confirmation in larger pathologically proven series is required.

Critical analysis of the ultrasonographic criteria for diagnosing lymph node metastasis in patients with cutaneous melanoma: a systematic review

The purpose of this systematic review of the literature was to evaluate the use of ultrasonography (US) in the assessment of lymph node metastasis in patients with cutaneous melanoma. A multimodal strategy was used, which was mainly based on a PubMed database search. Among the 201 cumulative articles collected (years 1989-2009), 31 were found to match all of the inclusion criteria and to provide a description of the use of US scanning in lymph node melanoma metastasis. Data extracted included the author's name and country, journal and year of publication, prospective or retrospective nature of the study, single-center or multicenter nature of the study, period when US studies were performed, US transducers used, gray scale and color Doppler criteria used for diagnosis, and data on US accuracy. The diagnostic criteria used in the 31 selected articles were critically reviewed, illustrating to the reader the discrepancies and unclear aspects identified. On the basis of this review, the need to establish definitive, clearly defined, and univocal diagnostic criteria to be applied in daily clinical practice as well as to be used in articles to be published is emphasized.

Metachronous melanoma in breast reconstruction patients

The incidence and mortality due to malignant melanoma has increased three- to four-fold across males and females in England and Wales over the past thirty years. Ninety percent of patients with primary melanoma have no clinical evidence of lymphadenopathy at presentation. In this paper we describe our management of impalpable axillary melanoma deposits in a patient with a pedicled latissimus dorsi (LD) flap reconstruction to the ipsilateral breast. No such case has been previously described in the literature.

Sonography for locoregional staging and follow-up of cutaneous melanoma: how we do it

OBJECTIVE

Sonography is being used with increasing frequency in the assessment of locoregional tumor spread in patients with melanoma. Nevertheless, to maximize its practical impact, sonography should be performed with state-of-the-art equipment, by specifically trained operators, and using a careful exploration technique and well-defined diagnostic criteria. In this "how I do it"-type article, we illustrate our practical approach to sonography of cutaneous melanoma.

METHODS

We first illustrate the basic and advanced technical requirements; then we describe our exploration methods and our image interpretation approach; and finally, we report on our use of sonography as a guidance tool for interventional procedures. Special emphasis is given to methodological and interpretative clues, tricks, and pitfalls.

RESULTS

Sonography can be used in the initial staging of patients with melanoma, particularly in the screening of patients scheduled for a sentinel lymph node biopsy procedure. Additionally, sonography can be used during patient follow-up to detect locoregional recurrence earlier than palpation.

CONCLUSIONS

Sonography plays a growing role in the assessment of the superficial spread of melanoma. Nevertheless, state-of-the-art equipment and careful exploration by trained operators are necessary.

[Ultrasonographic findings validity in the identification of metastatic regional lymph nodes in patients with cutaneous melanoma]

BACKGROUND/AIM. Early identification of lymph node (LN) metastases has both therapeutic and prognostic significance in patients with cutaneous melanoma. Ultrasonographic (US) examination of LN morphological characteristics and US of LN morphological and vascular characteristics are diagnostic methods used in identification of regional LN metastases, thus rendering a base for lymphonododisection indication. The aim of this study was to determine validity of these two US diagnostic methods and eventual statistically significant difference between them. METHODS. The study included the two groups of the patients with clinical stage III melanoma. The group I included 31 patients followed up by the use of US of LN morphological characteristics due to the fact that US findings described them only. The group II included 30 patients in whom morphological and vascular LN characteristics were followed up. The patients of both groups were examined in the Institute for Radiology, Military Medical Academy using an ultrasonographic unit type Akuson Sequoia Model 2000. After that, therapeutic and elective radical disections were performed. Sensitivity, specificity and accuracy of US examination of LN were checked by histopathological examination.

RESULTS

The presence of LN metastases in the group I was suggested by LN enlargement and its extent, while in the group II it was suggested by the ratio of LN length and width in 83.3% of the patients, echogenicity of LN center in 76.7% of the patients, LN resistance index in 73.3% of the patients, pathologic LN vascularization in 86.7%, and pathologic intranodal arborization in 83.3% of the patients. In 67.7% of the patients in the group I and in 93.3% of the patients in the group II matastatic changes of LN were diagnosed by pathohistology. A difference between validities of the two groups was statistically significant (p < 0.05).

CONCLUSION

LN size without other US morphological and vascular characteristics of LN does not provide enough valid US finding for a reliable preoperative identification of LN with metastatic changes in patients with cutaneous melanoma.

Surgical treatment of advanced melanoma

Primary surgical treatment should be considered for patients with metastatic melanoma. Because of the poor response of melanoma to chemotherapy or radiation therapy, surgery can be the best approach to quickly eliminate detectable disease and return the patient to normal activities. In properly selected patients, surgery can lead to significant palliation and prolongation of survival. This article reviews the principles of patient selection and the potential benefits of surgical management of melanoma metastatic to various sites. Novel adjuvant therapies are being developed to augment the benefits of surgical treatment of advanced melanoma in the future.

Rotterdam Criteria for sentinel node (SN) tumor burden and the accuracy of ultrasound (US)-guided fine-needle aspiration cytology (FNAC): can US-guided FNAC replace SN staging in patients with melanoma?

PURPOSE

Sentinel node (SN) status is the most important prognostic factor for overall survival (OS) for patients with stage I/II melanoma, and the role of the SN procedure as a staging procedure has long been established. However, a less invasive procedure, such as ultrasound (US) -guided fine-needle aspiration cytology (FNAC), would be preferred. The aim of this study was to evaluate the accuracy of US-guided FNAC and compare the results with histology after SN surgery was performed in all patients.

PATIENTS AND METHODS

Four hundred consecutive patients who underwent lymphoscintigraphy subsequently underwent a US examination before the SN procedure. When the US examination showed a suspicious or malignant pattern, patients underwent an FNAC. Median Breslow thickness was 1.8 mm; mean follow-up was 42 months (range, 4 to 82 months). We considered the US-guided FNAC positive if either US and/or FNAC were positive. If US was suggestive of abnormality, but FNAC was negative, the US-guided FNAC was considered negative.

RESULTS

US-guided FNAC identified 51 (65%) of 79 SN metastases. Specificity was 99% (317 of 321), with a positive predictive value of 93% and negative predictive value of 92%. SN-positive identification rate by US-guided FNAC increased from 40% in stage pT1a/b disease to 79% in stage pT4a/b disease. US-guided FNAC detected SN tumors more than 1.0 mm in 86% of cases, SN tumors of 0.1 to 1.0 mm in 46% of cases, and SN tumors less than 0.1 mm in 23% of cases. Estimated 5-year OS rates were 92% for patients with negative US-guided FNAC results and 51% for patients with positive results.

CONCLUSION

US-guided FNAC of SNs is highly accurate. Up to 65% of the patients with SN-positive results in our institution could have been spared an SN procedure.

Impact of Molecular Staging Methods in Primary Melanoma: Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) of Ultrasound-Guided Aspirate of the Sentinel Node Does Not Improve Diagnostic Accuracy, But RT-PCR of Peripheral Blood Does Predict Survival

Purpose

This study analyzes (1) the value of tyrosinase reverse-transcriptase polymerase chain reaction (RT-PCR) of aspirates obtained by ultrasound-guided fine-needle aspiration cytology (US-FNAC) of sentinel nodes (SNs) in patients with melanoma before sentinel lymph node biopsy (SLNB) and (2) the value of RT-PCR of blood samples of all SLNB patients.

Patients and Methods

Between 2001 and 2003, 127 patients with melanoma (median Breslow depth, 2.1 mm) underwent SLNB. FNAC was performed in all SNs of all patients pre- and post-SLNB. The aspirates were partly shock-frozen for RT-PCR and were partly used for standard cytology. Peripheral blood was collected at the time of SLNB and at every outpatient visit thereafter.

Results

Thirty-four (23%) of 120 SNs were positive for melanoma. SN involvement was predicted by US-FNAC with a sensitivity of 82% and a specificity of 72%. Additional tyrosinase RT-PCR revealed the same sensitivity of 82% and a specificity of 72%. At a median follow-up time of 40 months from first blood sample, peripheral-blood RT-PCR was a significant independent predictor of disease-free survival (DFS) and overall survival (OS; P < .001).

Conclusion

US-FNAC is highly accurate and eliminates the need for SLNB in 16% of all SLNB patients. RT-PCR of the aspirate or excised SN does not improve sensitivity or specificity. RT-PCR of blood samples predicts DFS and OS.

Ultrasound-guided fine needle aspiration cytology prior to sentinel lymph node biopsy in melanoma patients

BACKGROUND

Sentinel lymph node biopsy (SLNB) allows early detection of metastases, thereby enabling early treatment in melanoma patients likely to benefit from adjuvant therapies. This prospective study analyzes the possible benefits of additional ultrasound (US) and fine needle aspiration cytology (FNAC) of sentinel nodes (SN) prior to SLNB.

METHOD

Over a 2-year period 127 melanoma patients with 151 SN were scheduled for SLNB. All SN were initially identified with lymphoscintigraphy, then identified and evaluated by US and the cells aspirated for cytology (FNAC). US findings and FNAC results were compared to surgical findings.

RESULTS

Of 127 patients, 114 had one SN each, 12 had two, and one had three. In vivo US achieved a sensitivity of 79% (95% CI: 62-91%) and a specificity of 72% (95% CI: 62-81%). FNAC showed a sensitivity of 59% (95% CI: 41-76%) and a specificity of 100% (95% CI: 95-100%). The combination of these two in vivo methods achieved an overall sensitivity of 82% (95% CI: 65-93%) and an overall specificity of 72% [95% CI: 62-81%].

CONCLUSION

Combined US and FNAC provides important information prior to SLNB in that both procedures identify metastases in the lymph nodes (sensitivity > 80%). Patients with positive FNAC may proceed directly to complete lymph node dissection (cLND) instead of having initial SLNB. Thus, combined US and FNAC may prevent unnecessary anesthesia and surgical management as well reduce costs. In our study 16% (19/121) fewer SLNB procedures were carried out, subsequently replaced by cLND. For patients with a negative combination of in vivo US and FNAC, SLNB remains the best diagnostic option.

Cutaneous melanoma: baseline and ongoing laboratory evaluation

Numerous laboratory tests and imaging methods are available that can be used in patients who are diagnosed with cutaneous melanoma. The downside risks related to testing are cost and patient anxiety. Therefore, it must be critically considered which examinations are useful and feasible. After a diagnosis of primary cutaneous melanoma, many physicians in Germany perform lymph node ultrasound to detect occult regional metastasis. Whole-body imaging techniques, except the physical examination, are unlikely to detect distant occult metastasis. In tumors that have an intermediate or high risk of recurrence (> 1 mm tumor thickness), baseline whole-body imaging may serve as a reference for ongoing evaluation. During follow-up care, physical examination alone is appropriate when there is a low risk for recurrence (up to 1-mm tumor thickness). In patients whose tumors are > 1 mm thickness, regular lymph node ultrasound examinations and determination of serum tumor marker S-100beta protein are commonly used by physicians in Germany. Whole-body imaging techniques are useful in patients who have locoregional and/or distant metastasis. For consideration of surgical resections in stage IV disease, more advanced examinations techniques such as positron emission tomography-computed tomography or whole body magnetic resonance imaging may be used. Early detection of limited disease using these methods may be helpful for patients who have locoregional metastases and for 10-20% of patients who have distant metastases and whose limited disease may be amenable to surgical resection.

Is ultrasound lymph node examination superior to clinical examination in melanoma follow-up? A monocentre cohort study of 373 patients

BACKGROUND

There is still lack of consensus regarding the most effective follow-up for stage I and II melanoma patients although some consensus conferences have provided guidelines stating that clinical examination should be the standard.

OBJECTIVES

Our aim was to study the value of adding ultrasound lymph node examination (7.5 MHz) to the routine clinical examination recommended by French guidelines in melanoma follow-up.

METHODS

A cohort of melanoma patients was enrolled between 1 July 1995 and 1 July 2000 in a follow-up protocol including clinical examination performed four times a year for thick melanomas (Breslow index > or = 1.5 mm) and twice a year for thin melanomas (Breslow index < 1.5 mm) according to French guidelines, and ultrasound lymph node examination performed every 6 months for thick melanomas and every year for thin melanomas. Follow-up was continued up to 1 July 2003. When clinical or ultrasound examination indicated signs of node recurrence, surgical biopsy of the involved node was performed. When ultrasound examination was only suspicious, another ultrasound examination was performed within the following 3 months. The results of both clinical and ultrasound examinations were compared with histopathology examination when node biopsy was performed.

RESULTS

Ultrasound follow-up was performed for 373 patients (213 females and 160 males). Mean age at diagnosis of melanoma was 59 years (range 14-90, SD 15). In total, 1909 ultrasound examinations combined with clinical examination were analysed. Node biopsy was performed in 65 patients and demonstrated melanoma metastases in 54. Sensitivity of clinical examination and ultrasound examination was 71.4%[95% confidence interval (CI) 55.4-84.3] and 92.9 (95% CI 80.5-98.5), respectively, P = 0.02. Specificity of clinical examination and ultrasound examination was 99.6% (95% CI 99.2-99.8) and 97.8% (95% CI 97.0-98.4), respectively. Despite this apparent superiority of ultrasound examination over palpation, only 7.2% of the patients really benefited from ultrasound examination (earlier lymph node metastasis detection or avoidance of unnecessary surgery), while 5.9% had some deleterious effect from ultrasound examination (unnecessary stress caused by repetition of ultrasound examination for benign lymph nodes, useless removal of benign lymph node).

CONCLUSIONS

This study confirms the greater sensitivity of ultrasound examination to clinical examination in the diagnosis of node metastases from cutaneous melanoma. However, the place of ultrasound in routine follow-up is at least questionable as only a very small proportion of patients (1.3%) really benefited from adding ultrasound examination to clinical examination.

Ultrasound examination of sentinel nodes in the initial assessment of patients with primary cutaneous melanoma

BACKGROUND

The value of targeted high-resolution ultrasound (US) examination in detecting sentinel lymph node metastases in patients with newly diagnosed primary cutaneous melanomas has not yet been fully evaluated. The aim of this study was to determine the threshold size of metastatic melanoma deposits in SLNs able to be detected by targeted US examination before initial melanoma surgery.

METHODS

A total of 304 patients presenting with primary cutaneous melanomas had SLNs identified by lymphoscintigraphy and then examined in situ by the same physician with high-resolution US. Within 24 hours, the SLNs were removed for histopathologic assessment of sections stained conventionally and with immunohistochemical markers for S100 protein and HMB45 antigen.

RESULTS

Metastatic disease was present in SLNs from 33 node fields in 31 patients. The US results in seven of these cases were suggestive of metastatic disease. Twenty-six node fields contained positive nodes not detected by US. Undetected deposits had diameters <4.5 mm.

CONCLUSIONS

These results suggest that a targeted US examination of SLNs can detect metastatic melanoma deposits down to approximately 4.5 mm in diameter. However, most metastatic melanoma deposits in SLNs are considerably smaller than this at the time of initial staging, and US therefore cannot be considered cost-effective in this setting.

Biomarkers in melanoma: staging, prognosis and detection of early metastases

Currently, melanoma remains a surgical disease since early detection and excision of thin melanomas offers the best chance of a cure. Despite intensive clinical investigation, no effective systemic therapies exist for metastatic melanoma. Sentinel lymph node biopsy has greatly aided the staging and prognostic evaluation of primary cutaneous melanoma, however, approximately a third of patients diagnosed with metastatic melanomas present without prior regional lymph node involvement. Additional prognostic biomarkers exist which help determine the risk of advanced melanoma but the accuracy for each current marker is less than 100%. A greater understanding of the biology of melanomas and the development of new methods to identify patients with early (subclinical) metastatic disease may allow for selective and more effective therapy for patients at-risk for advanced disease. In this paper, current and novel potentially more accurate biomarkers for the staging and prognostic evaluation of melanoma patients, and for the detection of subclinical metastases are reviewed.