Imaging in cutaneous melanoma. Nucl Med Commun. 2008;29:847-876. [PMID: 18769303 DOI: 10.1097/mnm.0b013e32830439fb]

Predicting Regional Lymph Node Recurrence in the Modern Age of Tumor-Positive Sentinel Node Melanoma: The Role of the First Postoperative Ultrasound

BACKGROUND

The Multicenter Selective Lymphadenectomy Trial II (MSLT-II) led to a change in the management of tumor-positive sentinel lymph nodes (SLNs) from completion node dissection (CLND) to nodal observation. This study aimed to evaluate prognostic factors for predicting sentinel node basin recurrence (SNBR) using data from MSLT-II trial participants.

METHODS

In MSLT-II, 1076 patients were treated with observation. Patients were included in the current study if they had undergone a post-sentinel node basin ultrasound (PSNB-US) within 4 months after surgery. The study excluded patients with positive SLN by reverse transcription-polymerase chain reaction (RT-PCR) or incomplete SLN pathologic data. Primary tumor, patient, PSNB-US, and SLN characteristics were evaluated. Multivariable regression analyses were performed to determine independent prognostic factors associated with SNBR.

RESULTS

The study enrolled 737 patients: 193 (26.2%) patients with SNBR and 73 (9.9%) patients with first abnormal US. The patients with an abnormal first US were more likely to experience SNBR (23.8 vs. 5.0%). In the multivariable analyses, increased risk of SNBR was associated with male gender (adjusted hazard ratio [aHR], 1.38; 95% confidence interval [CI], 1.00-1.9; p = 0.049), increasing Breslow thickness (aHR, 1.10; 95% CI, 1.01-1.2; p = 0.038), presence of ulceration (aHR, 1.93; 95% CI, 1.42-2.6; p < 0.001), sentinel node tumor burden greater than 1 mm (aHR, 1.91; 95% CI, 1.10-3.3; p = 0.022), lymphovascular invasion (aHR, 1.53; 95% CI, 1.00-2.3; p = 0.048), and presence of abnormal PSNB-US (aHR, 4.29; 95% CI, 3.02-6.1; p < 0.001).

CONCLUSIONS

The first postoperative US together with clinical and pathologic factors may play an important role in predicting SNBR.

Predictive value of FDG-PET imaging for relapse in metastatic melanoma patients treated with immunotherapy

BACKGROUND

Anti-PD1 immunotherapy has shown a sustainable clinical activity in patients with metastatic melanoma. However, strong predictive factors of the long-term response or risk of relapse remain to be identified.

OBJECTIVES

To determine whether FDG-PET imaging could be superior to CT scan in distinguishing residual tumours versus the absence of tumour in patients with a partial response (PR) or stable disease (SD) and whether a complete metabolic response (CMR) was associated with better outcomes.

METHODS

Retrospective study conducted in all patients with metastatic melanoma treated with anti-PD1 immunotherapy between October 2014 and October 2017 considered to be in complete remission. The primary outcome was the occurrence of a relapse during the follow-up. CT scan and FDG-PET scan had to be performed within a maximum of 2 months of treatment discontinuation. For CT imaging, the Response Evaluation Criteria in Solid Tumours (RECIST) 1.1 were used and included progressive disease (PD), SD, PR and complete response (CR). For FDG-PET imaging, the metabolic responses were classified as progressive metabolic disease, stable metabolic disease, residual FDG avidity (RFA) and CMR.

RESULTS

Twenty-six patients were in complete remission after collegial decision. Two patients had a SD on CT scan and a CMR on FDG-PET scan, and none of them relapsed. Ten patients had a PR on CT scan and a CMR on FDG-PET scan, and none of them relapsed. The mean treatment duration to achieve a complete remission was 7 months (3-23). A univariate analysis showed that a RFA assessed on the FDG-PET scan was significantly associated with a relapse (P = 0.00231).

CONCLUSIONS

Most patients with a PR on the CT scan and a CMR on the FDG-PET scan should be considered with a CR. Our study showed that FDG-PET imaging could play a crucial role in predicting the long-term outcome and help to decide whether treatment should be discontinued.

Surgical management of the neck in patients with metastatic melanoma in parotid lymph nodes

BACKGROUND

The role and extent of neck dissection in patients with parotid metastatic cutaneous head and neck melanoma remain unclear. The aims of this study were to determine the incidence and patterns of cervical node involvement in patients with parotid metastatic melanoma, and to determine if a limited lymphadenectomy of the clinically negative neck is appropriate.

METHODS

Patients who underwent parotidectomy and neck dissection for clinically apparent parotid metastatic melanoma, irrespective of neck status, were identified from two prospectively maintained databases.

RESULTS

A total of 276 patients fulfilled the study criteria. Median follow-up was 23 months. A total of 185 necks were clinically negative, 82 were clinically positive. A total of 36 elective neck-dissection specimens harbored occult metastases; these were found in levels I (16.7%), II (58.3%), III (36.1%), IV (13.9%), and V (30.6%). Regional recurrence occurred in 32 patients with a clinically negative neck, the majority being in-transit metastases (n = 15). Only one case of recurrence could have potentially been avoided by a comprehensive lymphadenectomy.

CONCLUSIONS

In patients with clinically apparent parotid melanoma metastases, elective comprehensive neck dissection reduces failure rates in cervical nodes, and provides more accurate staging and prognostic information. However, our findings support the emerging trend for more limited elective neck dissection. Levels I and IV can probably be safely omitted.

Update on Current Treatment Recommendations for Primary Cutaneous Melanoma

Primary cutaneous melanoma describes any primary melanoma lesion of the skin that does not have evidence of metastatic disease. This article reviews the current workup, treatment, and follow-up recommendations for primary cutaneous melanoma (stages 0, I, and II). Specific attention is focused on recent updates with regard to staging, sentinel lymph node biopsy, and surgical modalities.

Ultrasound, CT, MRI, or PET-CT for staging and re-staging of adults with cutaneous melanoma

BACKGROUND

Melanoma is one of the most aggressive forms of skin cancer, with the potential to metastasise to other parts of the body via the lymphatic system and the bloodstream. Melanoma accounts for a small percentage of skin cancer cases but is responsible for the majority of skin cancer deaths. Various imaging tests can be used with the aim of detecting metastatic spread of disease following a primary diagnosis of melanoma (primary staging) or on clinical suspicion of disease recurrence (re-staging). Accurate staging is crucial to ensuring that patients are directed to the most appropriate and effective treatment at different points on the clinical pathway. Establishing the comparative accuracy of ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET)-CT imaging for detection of nodal or distant metastases, or both, is critical to understanding if, how, and where on the pathway these tests might be used.

OBJECTIVES

Primary objectivesWe estimated accuracy separately according to the point in the clinical pathway at which imaging tests were used. Our objectives were:• to determine the diagnostic accuracy of ultrasound or PET-CT for detection of nodal metastases before sentinel lymph node biopsy in adults with confirmed cutaneous invasive melanoma; and• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for whole body imaging in adults with cutaneous invasive melanoma:○ for detection of any metastasis in adults with a primary diagnosis of melanoma (i.e. primary staging at presentation); and○ for detection of any metastasis in adults undergoing staging of recurrence of melanoma (i.e. re-staging prompted by findings on routine follow-up).We undertook separate analyses according to whether accuracy data were reported per patient or per lesion.Secondary objectivesWe sought to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for whole body imaging (detection of any metastasis) in mixed or not clearly described populations of adults with cutaneous invasive melanoma.For study participants undergoing primary staging or re-staging (for possible recurrence), and for mixed or unclear populations, our objectives were:• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of nodal metastases;• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of distant metastases; and• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of distant metastases according to metastatic site.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included studies of any design that evaluated ultrasound (with or without the use of fine needle aspiration cytology (FNAC)), CT, MRI, or PET-CT for staging of cutaneous melanoma in adults, compared with a reference standard of histological confirmation or imaging with clinical follow-up of at least three months' duration. We excluded studies reporting multiple applications of the same test in more than 10% of study participants.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2)). We estimated accuracy using the bivariate hierarchical method to produce summary sensitivities and specificities with 95% confidence and prediction regions. We undertook analysis of studies allowing direct and indirect comparison between tests. We examined heterogeneity between studies by visually inspecting the forest plots of sensitivity and specificity and summary receiver operating characteristic (ROC) plots. Numbers of identified studies were insufficient to allow formal investigation of potential sources of heterogeneity.

MAIN RESULTS

We included a total of 39 publications reporting on 5204 study participants; 34 studies reporting data per patient included 4980 study participants with 1265 cases of metastatic disease, and seven studies reporting data per lesion included 417 study participants with 1846 potentially metastatic lesions, 1061 of which were confirmed metastases. The risk of bias was low or unclear for all domains apart from participant flow. Concerns regarding applicability of the evidence were high or unclear for almost all domains. Participant selection from mixed or not clearly defined populations and poorly described application and interpretation of index tests were particularly problematic.The accuracy of imaging for detection of regional nodal metastases before sentinel lymph node biopsy (SLNB) was evaluated in 18 studies. In 11 studies (2614 participants; 542 cases), the summary sensitivity of ultrasound alone was 35.4% (95% confidence interval (CI) 17.0% to 59.4%) and specificity was 93.9% (95% CI 86.1% to 97.5%). Combining pre-SLNB ultrasound with FNAC revealed summary sensitivity of 18.0% (95% CI 3.58% to 56.5%) and specificity of 99.8% (95% CI 99.1% to 99.9%) (1164 participants; 259 cases). Four studies demonstrated lower sensitivity (10.2%, 95% CI 4.31% to 22.3%) and specificity (96.5%,95% CI 87.1% to 99.1%) for PET-CT before SLNB (170 participants, 49 cases). When these data are translated to a hypothetical cohort of 1000 people eligible for SLNB, 237 of whom have nodal metastases (median prevalence), the combination of ultrasound with FNAC potentially allows 43 people with nodal metastases to be triaged directly to adjuvant therapy rather than having SLNB first, at a cost of two people with false positive results (who are incorrectly managed). Those with a false negative ultrasound will be identified on subsequent SLNB.Limited test accuracy data were available for whole body imaging via PET-CT for primary staging or re-staging for disease recurrence, and none evaluated MRI. Twenty-four studies evaluated whole body imaging. Six of these studies explored primary staging following a confirmed diagnosis of melanoma (492 participants), three evaluated re-staging of disease following some clinical indication of recurrence (589 participants), and 15 included mixed or not clearly described population groups comprising participants at a number of different points on the clinical pathway and at varying stages of disease (1265 participants). Results for whole body imaging could not be translated to a hypothetical cohort of people due to paucity of data.Most of the studies (6/9) of primary disease or re-staging of disease considered PET-CT, two in comparison to CT alone, and three studies examined the use of ultrasound. No eligible evaluations of MRI in these groups were identified. All studies used histological reference standards combined with follow-up, and two included FNAC for some participants. Observed accuracy for detection of any metastases for PET-CT was higher for re-staging of disease (summary sensitivity from two studies: 92.6%, 95% CI 85.3% to 96.4%; specificity: 89.7%, 95% CI 78.8% to 95.3%; 153 participants; 95 cases) compared to primary staging (sensitivities from individual studies ranged from 30% to 47% and specificities from 73% to 88%), and was more sensitive than CT alone in both population groups, but participant numbers were very small.No conclusions can be drawn regarding routine imaging of the brain via MRI or CT.

AUTHORS' CONCLUSIONS

Review authors found a disappointing lack of evidence on the accuracy of imaging in people with a diagnosis of melanoma at different points on the clinical pathway. Studies were small and often reported data according to the number of lesions rather than the number of study participants. Imaging with ultrasound combined with FNAC before SLNB may identify around one-fifth of those with nodal disease, but confidence intervals are wide and further work is needed to establish cost-effectiveness. Much of the evidence for whole body imaging for primary staging or re-staging of disease is focused on PET-CT, and comparative data with CT or MRI are lacking. Future studies should go beyond diagnostic accuracy and consider the effects of different imaging tests on disease management. The increasing availability of adjuvant therapies for people with melanoma at high risk of disease spread at presentation will have a considerable impact on imaging services, yet evidence for the relative diagnostic accuracy of available tests is limited.

Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in restaging and prognosis of recurrent melanoma after curative surgery

Malignant melanoma is a highly aggressive tumor and surgical resection is the primary treatment. However, the chances of recurrence are quite high despite complete resection. The aim of study was to evaluate the 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography-computed tomography (PET/CT) in detection of recurrent melanoma after curative surgery and its prognostic value. Fifty-four melanoma patients (32 women) with prior primary lesion resection were evaluated with 18F-FDG PET/CT for clinically suspicious recurrent disease. The diagnostic accuracy of 18F-FDG PET/CT (visual interpretation as well as semi-quantitative parameter) was determined on the basis of subsequent imaging and clinical follow-up. Melanoma-specific survival and risk of progression (hazard ratio [HR]) were assessed using Kaplan-Meier method and Cox regression analysis. 18F-FDG PET/CT detected recurrent diseases in 36 (66%) patients including distant metastases in 13 patients and second synchronous malignancy in 2 patients. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT were 91.2%, 80.0%, 88.6%, and 84.2%, respectively, with area under the curve of 0.86 (95% confidence interval: 0.74-0.97; P < 0.05). Positive 18F-FDG PET/CT study was associated with a significantly shorter overall survival than negative study (30.8 ± 4.6 vs. 64.5 ± 6.9 months, P < 0.05). Apart from positive 18F-FDG PET/CT scan, maximum standardized uptake value (SUVmax) >2.7 and combination of both were independently associated with an increased risk of disease progression (HR = 7.72, 21.58, and 11.37, respectively; P < 0.05). 18F-FDG PET/CT showed enhanced diagnostic performance in patients with suspicious recurrent malignant melanoma leading to appropriate management. FDG positivity along with SUVmax >2.7 provides important prognostic value in predicting the survival outcomes and assessing the risk of disease progression.

Guidelines of care for the management of primary cutaneous melanoma

The incidence of primary cutaneous melanoma continues to increase each year. Melanoma accounts for the majority of skin cancer-related deaths, but treatment is usually curative following early detection of disease. In this American Academy of Dermatology clinical practice guideline, updated treatment recommendations are provided for patients with primary cutaneous melanoma (American Joint Committee on Cancer stages 0-IIC and pathologic stage III by virtue of a positive sentinel lymph node biopsy). Biopsy techniques for a lesion that is clinically suggestive of melanoma are reviewed, as are recommendations for the histopathologic interpretation of cutaneous melanoma. The use of laboratory, molecular, and imaging tests is examined in the initial work-up of patients with newly diagnosed melanoma and for follow-up of asymptomatic patients. With regard to treatment of primary cutaneous melanoma, recommendations for surgical margins and the concepts of staged excision (including Mohs micrographic surgery) and nonsurgical treatments for melanoma in situ, lentigo maligna type (including topical imiquimod and radiation therapy), are updated. The role of sentinel lymph node biopsy as a staging technique for cutaneous melanoma is described, with recommendations for its use in clinical practice. Finally, current data regarding pregnancy and melanoma, genetic testing for familial melanoma, and management of dermatologic toxicities related to novel targeted agents and immunotherapies for patients with advanced disease are summarized.

Melanoma patient imaging in the era of effective systemic therapies

Imaging plays a critical role in the current multi-disciplinary management of patients with melanoma. It is used for primary disease staging, surgical planning, and surveillance in high-risk patients, and for monitoring the effects of systemic or loco-regional therapies. Several different imaging modalities have been utilised in the past. Contemporary imaging practises vary geographically depending on clinical guidelines, physician preferences, availability and cost. Targeted therapies and immunotherapies have revolutionised the treatment of patients with metastatic melanoma over the last few years. With this have come new patterns of disease that were not observed after conventional therapies, and new criteria to assess therapeutic responses. In this article we review the role of imaging for patients with melanoma in the era of effective systemic therapies and discuss likely future developments.

Prognostic Value of Volumetric Parameters Measured by Pretreatment 18F FDG PET/CT in Patients With Cutaneous Malignant Melanoma

PURPOSE OF THE REPORT

This study was performed to evaluate the prognostic relevance of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) measured using F FDG PET/CT in patients with primary cutaneous malignant melanoma (CMM).

MATERIALS AND METHODS

We conducted a retrospective review (July 2005 to November 2010) of 41 patients with a histological diagnosis of CMM who underwent pretreatment F FDG PET/CT. PET parameters (maximum standardized uptake value [SUVmax], MTV, and TLG) of the primary tumor were measured. Clinical variables such as age, sex, clinical stage, location and thickness of the primary lesion, and existence of ulceration were also assessed. Univariate and multivariate analyses for disease-free survival (DFS) and melanoma-specific survival (MSS) were performed using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

SUVmax and TLG were found to be significantly higher in patients with recurrence than in patients without recurrence (3.98 ± 2.91 vs 1.89 ± 1.35, P = 0.0145; 9.16 ± 8.44 vs 3.72 ± 3.64, P = 0.0249). SUVmax and TLG were also found to be significantly higher in nonsurvivors than in survivors (4.21 ± 3.06 vs 2.00 ± 1.46, P = 0.0260; 10.53 ± 8.83 vs 3.67 ± 3.44, P = 0.0170). The optimal cutoff values for DFS determined using a time-dependent receiver operating characteristic (ROC) curve were 1.8 for SUVmax, 6.07 cm for MTV, and 4.046 for TLG. Sixteen (39%) of the 41 patients experienced recurrence during the follow-up period. In univariate analysis, age (P = 0.0382), male sex (P = 0.0187), ulceration of the primary lesion (P = 0.0001), stage ≥ III (P = 0.0011), SUVmax greater than 1.8 (P = 0.0006), MTV greater than 6.07 cm (P = 0.0136), and TLG greater than 4.046 (P = 0.0010) affected DFS, whereas the other variables (location of the primary lesion and thickness of primary lesion) did not. After adjustment for the effects of the clinical parameters (age, sex, clinical stage, and existence of ulceration), SUVmax, MTV, and TLG were all significant predictors of DFS, and the best predictive factor was SUVmax. Thirteen (32%) of the 41 patients died because of CMM during the follow-up period. The optimal cutoff values for MSS determined using a time-dependent ROC curve were 2.2 for SUVmax, 4.02 cm for MTV, and 4.352 for TLG. In univariate analysis, ulceration of the primary lesion (P = 0.0005), SUVmax greater than 2.2 (P = 0.0001), MTV greater than 4.02 cm (P = 0.0071), and TLG greater than 4.352 (P = 0.0001) affected MSS, whereas the other variables (age, sex, clinical stage, primary lesion site, and thickness of the primary lesion) did not. After adjustment for the effect of the clinical parameter (existence of ulceration), MTV and TLG were significant predictors of MSS, and the best predictive factor of MSS was TLG.

CONCLUSIONS

Pretreatment MTV and TLG may be useful in stratifying the likelihood of recurrence and melanoma-specific death, and TLG was found to be the best predictive marker for predicting melanoma-specific death.

Breslow thickness and (18)F-FDG PET-CT result in initial staging of cutaneous melanoma: Can a cut-off point be established?

AIM

To establish a Breslow Thickness (BT) cut-off point for indication of PET-CT of cutaneous melanoma in early stages and evaluate its prognostic value.

MATERIAL AND METHODS

Retrospective analysis of 347 PET-CT studies with diagnosis of melanoma, of which 108 were performed for initial staging. Thirty-one patients were excluded, and a final sample of 77 patients remained. A ROC curve analysis was performed to establish an optimal cut-off point. A survival analysis was performed, considering death assignable to melanoma as the main event, for the evaluation of its prognostic value.

RESULTS

Forty-seven (61.04%) of all 77 patients selected were men, and 11 (14.29%) had a positive PET-CT result. Mean age was 65.17±15.00 years. The median BT in patients with a negative PET-CT result was 2.75 mm (IQR 1.83-4.50) and in the positive group 6.25 mm (IQR 5.40-7.50) (P=.0013). In the ROC curve analysis (AUC 0.804, SE 0.054), an optimal value of 5 mm BT with the following values was obtained: sensitivity 90.91%, specificity 78.79%, negative predictive value (NPV) 98.1%, positive predictive value (PPV) 41.7%, diagnostic OR 37.1, and accuracy 80.52%. Mean follow-up was 18.66±14,35 months, detecting 2/53 (3.77%) deaths in the BT<5 mm group, and 7/24 (29.17%) in the BT≥5 mm group. Survival curves between both groups were significantly different (P=.0013).

CONCLUSIONS

A 5 mm cut-off point correctly distinguishes those patients with positive PET-CT from those with negative results in the early stages of cutaneous melanoma; therefore it could be included in initial staging of this subgroup of patients.

FDG PET/CT in cancer: comparison of actual use with literature-based recommendations

Purpose

The Region of Southern Denmark (RSD), covering 1.2 of Denmark’s 5.6 million inhabitants, established a task force to (1) retrieve literature evidence for the clinical use of positron emission tomography (PET)/CT and provide consequent recommendations and further to (2) compare the actual use of PET/CT in the RSD with these recommendations. This article summarizes the results.

Methods

A Work Group appointed a professional Subgroup which made Clinician Groups conduct literature reviews on six selected cancers responsible for 5,768 (62.6 %) of 9,213 PET/CT scans in the RSD in 2012. Rapid Evidence Assessment was applied, using the methodology of systematic reviews with predefined limitations to search PubMed, Embase and the Cochrane Library for articles published in English/Danish/Swedish/Norwegian since 2002. PICO questions were defined, data recorded and quality appraised and rated with regard to strength and evidence level. Consequent recommendations for applications of PET/CT were established. The actual use of PET/CT was compared with these, where grades A and B indicated “established” and “useful” and grades C and D “potentially useful” and “non-recommendable” indications, respectively.

Results

Of 11,729 citations, 1,729 were considered for review, and 204 were included. The evidence suggested usefulness of PET/CT in lung, lymphoma, melanoma, head and neck, and colorectal cancers, whereas evidence was sparse in gynaecological cancers. The agreement between actual use of PET/CT and literature-based recommendations was high in the first five mentioned cancers in that 96.2 % of scans were made for grade A or B indications versus only 22.2 % in gynaecological cancers.

Conclusion

Evidence-based usefulness was reported in five of six selected cancers; evidence was sparse in the sixth, gynaecological cancers. Actual use of PET/CT agreed well with recommendations.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-015-3217-0) contains supplementary material, which is available to authorized users.

Estimation of radioactivity in single-photon emission computed tomography for sentinel lymph node biopsy in a torso phantom study

OBJECTIVE

The number of lymph nodes to be removed is determined from residual counts. Advance estimation of residual radioactivity in lymphatic nodes before a biopsy is useful for reducing surgical operation time. The purpose of this study was to estimate the total radioactivity of a small hotspot in single-photon emission computed tomography (SPECT) of a torso phantom.

METHODS

A cross-calibration study was performed to convert counts in SPECT images to radioactivity. A simulation study was performed to estimate the size of the volume of interest (VOI) covering a hotspot corrupted with full-width at half-maximum between 8 and 16 mm. The estimation of total radioactivity was validated in a torso phantom study using small sources.

RESULTS

True radioactivity was approximately equal to integrated values of hotspots using the VOI with a diameter of 40 mm in our simulation study. The difference was less than 18% in cases of more than 9.4 kBq.

CONCLUSION

The total radioactivity in small sources simulating a typical sentinel node was estimated from SPECT images using a VOI of 40 mm in a torso phantom study. Because the difference from actual values was less than 10% on average when radioactivities were more than 9.4 kBq, the total radioactivity of a lymph node can be estimated in a clinical examination.

Deep lymph node metastases in the groin significantly affects prognosis, particularly in sentinel node-positive melanoma patients

BACKGROUND

In order to define patients eligible for only a superficial groin dissection or a combined superficial and deep groin dissection, this study aimed to determine the incidence of deep lymph node metastases (LNM) in patients with melanoma metastasized to the groin, to identify patient and melanoma factors that predict deep nodal involvement, and to analyze the impact of deep nodal involvement on survival and recurrence.

METHODS

Patients who underwent a combined superficial (inguinal) and deep (iliac and obturator) complete (CLND) or therapeutic lymph node dissection (TLND) of the groin between 1994 and 2012 were analyzed.

RESULTS

QueryDeep LNM were found in 8 of 62 CLND patients (13 %) and in 21 of 67 TLND patients (31 %). More than three superficial LNM was the only independent predictor for deep LNM in both CLND and TLND patients. The 5-year melanoma-specific survival (MSS) for CLND and TLND patients with deep LNM was 14.3 and 16.6 %, respectively, and was significantly worse (hazard ratio [HR] 3.39, 95 % CI 1.34-8.58, p = 0.010; and HR 2.01, 95 % CI 1.04-3.88, p = 0.039) compared with CLND and TLND patients without deep LNM (5-year MSS: 54.1 and 37.2 %, respectively). Distant recurrence was significantly associated with deep LNM in CLND patients (p = 0.032).

CONCLUSIONS

The present study showed that LNM in the deep area of the groin are fairly common in both CLND and TLND patients and significantly affect prognosis, especially in CLND patients. The number of superficial LNM is the only factor that was found to predict a finding of deep nodal metastases.

The clinical use of PET/CT in the evaluation of melanoma

Positron emission tomography combined with computed tomography (PET/CT) has emerged in the last decade as a dominant imaging modality used for staging, monitoring response and surveillance of various cancers, including melanoma. Using 2-deoxy-2-((18)F)fluoro-D-glucose ((18)F-FDG) as the radiopharmaceutical, PET/CT has demonstrated its efficacy and its utility in the management of patients with advanced melanoma. Nonetheless, challenges remain in the early stage evaluation of melanoma and in the development of novel radiotracers to better characterize lesions found on PET/CT. This chapter focuses on the advantages and limitations of this imaging modality in melanoma. We also detail and describe the approach to perform (18)F-FDG PET/CT, the methods to accurately quantify lesions, as well as the pearls/pitfalls of image interpretation. Finally, an overview of preclinical and investigational clinical radiopharmaceuticals is presented.

Preoperative imaging for early-stage cutaneous melanoma: predictors, usage, and utility at a single institution

BACKGROUND

Preoperative imaging for early-stage cutaneous melanoma is not recommended by current guidelines. Our goal was to investigate our institutional usage and utility.

METHODS

Patients with clinically node-negative cutaneous melanoma undergoing surgery with sentinel lymph node biopsy were identified retrospectively. Any melanoma-related imaging after diagnosis and before surgery was considered a staging study.

RESULTS

Five hundred fifteen studies were performed in 409 of 546 (75%) patients. Chest x-rays was performed in 70% and advanced imaging in 14% (computed tomography imaging, magnetic resonance imaging, ultrasound, and positron-emission computed tomography imaging). No metastatic lesions were identified. A Breslow thickness greater than 4 mm (odds ratio = 6.46 vs <1 mm; 95% confidence interval, 2.07 to 20.15) and male sex (odds ratio = 2.62 vs female; 95% confidence interval, 1.26 to 5.46) were associated with an increased likelihood of advanced imaging.

CONCLUSIONS

Preoperative imaging was performed in the majority of patients with node-negative melanoma, with 14% undergoing advanced studies. No metastatic lesions were identified, confirming the limited utility in this setting.

Clinical impact of (18)F-FDG PET-CT in recurrent stage III/IV melanoma: a tertiary centre Specialist Skin Cancer Multidisciplinary Team (SSMDT) experience

Objectives

To assess the clinical impact of ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) compared with contrast-enhanced computed tomography (CECT) in patients referred via the Specialist Skin Cancer Multidisciplinary Team (SSMDT) with recurrent stage III/IV malignant melanoma (MM).

Methods

Forty-five patients were referred for further evaluation with FDG PET-CT. Findings on FDG PET-CT were compared with prior CECT and the clinical impact on subsequent management decisions was determined retrospectively. A major clinical impact was defined as a change in treatment plan resulting from identification of additional sites of disease or by characterisation of indeterminate findings on prior imaging. A minor impact was defined as confirmation of known sites of disease as identified on prior CECT.

Results

Fifty-one PET-CT examinations were performed. FDG PET-CT had a major clinical impact in 21 cases (41.2 %), of which 18 examinations were performed in patients with proven or suspected stage IV MM. FDG PET-CT had a minor impact in 23 cases (45.1 %), and there were five false-positive cases (9.8 %) and two false-negative cases (3.9 %).

Conclusion

FDG PET-CT is an effective tool in recurrent stage III/IV MM with a significant clinical impact on management decisions in patients who are appropriately referred via the highly specialised forum of the SSMDT.

Key Points

• FDG PET-CT is an effective tool in recurrent stage III/IV malignant melanoma.

• FDG PET-CT has a significant clinical impact on management decisions.

• Effective use of FDG PET-CT is via referral from the Specialist Skin Cancer Multidisciplinary Team.

Successful treatment of triple primary tumor

INTRODUCTION

The occurrence of multiple primary tumors is rare. Only limited number of cases with triple malignancy have been reported. We report here a rare case of a woman presented synchronous triple tumors, in her lung, breast, skin.

PRESENTATION OF CASE

A 56-year-old woman presented with invasive ductal carcinoma of breast, non-small cell lung cancer and malignant melanoma. The patient undergone mastectomy and malignant melanoma tumor excision on-site. After operation stereotactic radiotherapy was given to her lung tumor. Six course of chemotherapy was given to her. She is alive with no progression.

DISCUSSION

The patient was diagnosed with melanoma and staging by FDG/PET. There is not any study about routine using PET/CT in the melanoma staging.

CONCLUSION

This is a very rare synchronous triple tumor case.

In vivo and in silico pharmacokinetics and biodistribution of a melanocortin receptor 1 targeted agent in preclinical models of melanoma

The melanocortin 1 receptor (MC1R) is overexpressed in most melanoma metastases, making it a promising target for imaging of melanomas. In this study, the expression of MC1R in a large fraction of patients with melanoma was confirmed using mRNA and tissue microarray. Here, we have characterized the in vivo tumor and tissue distribution and pharmacokinetics (PK) of uptake and clearance of a MC1R specific peptidomimetic ligand conjugated to a near-infrared fluorescent dye. We propose an interdisciplinary framework to bridge the different time and space scales of ligand-tumor-host interactions: intravital fluorescence microscopy to quantify probe internalization at the cellular level, a xenograft tumor model for whole body pharmacokinetics, and a computational pharmacokinetic model for integration and interpretation of experimental data. Administration of the probe into mice bearing tumors with high and low MC1R expression demonstrated normalized image intensities that correlated with expression levels (p < 0.05). The biodistribution study showed high kidney uptake as early as 30 min postinjection. The PK computational model predicted the presence of receptors in the kidneys with a lower affinity, but at higher numbers than in the tumors. As the mouse kidney is known to express the MC5R, this hypothesis was confirmed by both coinjection of a ligand with higher MC5R affinity compared to MC1R and by injection of lower probe concentrations (e.g., 1 nmol/kg), both leading to decreased kidney accumulation of the MC1R ligand. In addition, through this interdisciplinary approach we could predict the rates of ligand accumulation and clearance into and from organs and tumors, and the amount of injected ligand required to have maximum specific retention in tumors. These predictions have potential to aid in the translation of a targeted agent from lab to the clinic. In conclusion, the characterized MC1R-specific probe has excellent potential for in vivo detection of melanoma metastases. The process of cell-surface marker validation, targeted imaging probe development, and in vitro, in vivo, and in silico characterization described in this study can be generally applied to preclinical development of targeted agents.

Melanoma metastases in the abdomen and pelvis: Frequency and patterns of spread

AIM: To investigate the frequency, typical and atypical locations and patterns of melanoma metastases identifiable by computed tomography (CT) in the abdomen and pelvis.

METHODS: We performed a retrospective review of index CT examinations of the abdomen and pelvis in patients with melanoma and recorded all findings suggestive of metastatic disease.

RESULTS: Metastases were present on 36% (181/508) of the index examinations and most commonly involved the liver (47%) and pelvic lymph nodes (27%). Lower extremity primaries had the highest rate of metastasis (52%). Ocular and head and neck melanomas have a predilection to metastasize to the liver (hepatic involvement in 70% and 63%, respectively, of patients with metastatic disease) and metastases from lower extremity primaries most commonly involve pelvic lymph nodes (54% of patients with metastatic disease). Metastases to atypical locations were present in 14% of patients and most commonly occurred in the subcutaneous tissue and spleen. Primary tumors of the lower extremity, back and head and neck were most commonly associated with atypical metastases. Pelvic metastases are more common with lower extremity primaries (accounting for 70% of cases with pelvic metastases) but 5% of patients with supraumbilical primaries also had pelvic metastases.

CONCLUSION: The distribution of metastatic melanoma in the abdomen and pelvis that we have defined should help guide the interpretation of CT exams in these patients.

Malignant melanoma

Nuclear medicine plays an essential role in the correct staging of patients suffering from melanoma. Both sentinel lymph node biopsy (SLNB) and positron emission tomography (PET) represent its main diagnostic tools. SLNB is the choice procedure for lymphatic regional staging of these patients, including the result of this technique in the 2002 American Joint Cancer Committee melanoma staging. SLNB sensitivity is superior than PET/CT for the detection of lymphatic micrometastases in early stages of the disease. PET/CT is mainly used in confirming clinical metastases suspected, detection of recurrences, and recurrence restaging. PET/CT has also shown superiority against conventional diagnostic methods in the detection of distant metastases, being able to detect illness even six months earlier than those methods.

Preoperative FDG-PET/CT Is an Important Tool in the Management of Patients with Thick (T4) Melanoma

The yield of preoperative PET/CT (PET/CT) for regional and distant metastases for thin/intermediate thickness melanoma is low. Objective of this study is to determine if PET/CT performed for T4 melanomas helps guide management and alter treatment plans. Methods. Retrospective cohort of 216 patients with T4 melanomas treated at two tertiary institutions. Fifty-six patients met our inclusion criteria (T4 lesion, PET/CT and no clinical evidence of metastatic disease). Results. Fifty-six patients (M: 32, F: 24) with median tumor thickness of 6 mm were identified. PET/CT recognized twelve with regional and four patients with metastatic disease. Melanoma-related treatment plan was altered in 11% of the cases based on PET/CT findings. PET/CT was negative 60% of the time, in 35% of the cases; it identified incidental findings that required further evaluation. Conclusion. Patients with T4 lesions, PET/CT changed the treatment plan 18% of the time. Regional findings changed the surgical treatment plan in 11% and the adjuvant plan in 7% of our cases due to the finding of metastatic disease. Additionally 20 patients had incidental findings that required further workup. In this subset of patients, we feel there is a benefit to PET/CT, and further studies should be performed to validate our findings.

Guidelines for lymphoscintigraphy and F18 FDG PET scans in melanoma

Melanoma has a high potential to develop metastases. Accurate staging is essential for appropriate management. Sentinel node (SN) status is a powerful prognostic factor in early stage melanoma. Staging is assisted by SN biopsy after lymphoscintigraphy to locate all true SNs prior to biopsy. PET using F18-FDG can detect metastases and is used to restage patients with AJCC Stages III and IV disease before planning surgery with curative intent.

Guidelines of care for the management of primary cutaneous melanoma. American Academy of Dermatology

The incidence of primary cutaneous melanoma has been increasing dramatically for several decades. Melanoma accounts for the majority of skin cancer-related deaths, but treatment is nearly always curative with early detection of disease. In this update of the guidelines of care, we will discuss the treatment of patients with primary cutaneous melanoma. We will discuss biopsy techniques of a lesion clinically suspicious for melanoma and offer recommendations for the histopathologic interpretation of cutaneous melanoma. We will offer recommendations for the use of laboratory and imaging tests in the initial workup of patients with newly diagnosed melanoma and for follow-up of asymptomatic patients. With regard to treatment of primary cutaneous melanoma, we will provide recommendations for surgical margins and briefly discuss nonsurgical treatments. Finally, we will discuss the value and limitations of sentinel lymph node biopsy and offer recommendations for its use in patients with primary cutaneous melanoma.

Plasma markers for identifying patients with metastatic melanoma

PURPOSE

With the rising incidence of melanoma, more patients are undergoing surveillance for disease recurrence. Our purpose was to study levels of proteins that might be secreted in the blood of patients with metastatic melanoma that can be used for monitoring these individuals.

METHODS

Genome-wide gene expression data were used to identify abundantly expressed genes in melanoma cells that encode for proteins likely to be present in the blood of cancer patients, based on high expression levels in tumors. ELISA assays were employed to measure proteins in plasma of 216 individuals; 108 metastatic melanoma patients and 108 age- and gender-matched patients with resected stage I/II disease split into equal-sized training and test cohorts.

RESULTS

Levels of seven markers, CEACAM (carcinoembryonic antigen-related cell adhesion molecule), ICAM-1 (intercellular adhesion molecule 1), osteopontin, MIA (melanoma inhibitory activity), GDF-15 (growth differentiation factor 15), TIMP-1 (tissue inhibitor of metalloproteinase 1), and S100B, were higher in patients with unresected stage IV disease than in patients with resected stage I/II disease. About 81% of the stage I/II patients in the training set had no marker elevation, whereas 69% of the stage IV patients had elevation of at least one marker (P < 0.0001). Receiver operating characteristic curves for the markers in combination in these two patient populations had an area under curve (AUC) of 0.79 in the training set and 0.8 in the test set. A CART (Classification and Regression Trees) model developed in the training set further improved the AUC in the test set to 0.898.

CONCLUSIONS

Plasma markers, particularly when assessed in combination, can be used to monitor patients for disease recurrence and can compliment currently used lactate dehydrogenase and imaging studies; prospective validation is warranted.

18F-FDG PET/CT imaging in oncology

Accurate diagnosis and staging are essential for the optimal management of cancer patients. Positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography (18F-FDG PET/CT) has emerged as a powerful imaging tool for the detection of various cancers. The combined acquisition of PET and CT has synergistic advantages over PET or CT alone and minimizes their individual limitations. It is a valuable tool for staging and restaging of some tumors and has an important role in the detection of recurrence in asymptomatic patients with rising tumor marker levels and patients with negative or equivocal findings on conventional imaging techniques. It also allows for monitoring response to therapy and permitting timely modification of therapeutic regimens. In about 27% of the patients, the course of management is changed. This review provides guidance for oncologists/radiotherapists and clinical and surgical specialists on the use of 18F-FDG PET/CT in oncology.

Improved detection of regional melanoma metastasis using 18F-6-fluoro-N-[2-(diethylamino)ethyl] pyridine-3-carboxamide, a melanin-specific PET probe, by perilesional administration

The efficacy of differing routes of administration of 18F-6-fluoro-N-[2-(diethylamino)ethyl] pyridine-3-carboxamide (18F-MEL050), a new benzamide-based PET radiotracer for imaging regional lymph node metastasis in melanoma, was assessed.

METHODS

B16-Black/6 metastatic melanoma cells harboring an mCherry transgene were implanted into the left-upper-foot surface of 49 C57 Black/6 mice as a model of popliteal lymph node (PLN) metastasis. Ultrasound scanning of the left PLN was performed at baseline and in combination with 18F-MEL050 PET on days 5, 9, and 14. Mice were divided into 2 groups to compare the results of tracer administration either subcutaneously at the tumor site (local) or in the lateral tail vein (systemic). After PET on each imaging day, 5 mice per group-including any with evidence of metastasis-were sacrificed for ex vivo validation studies including assessment of retained radioactivity and presence of the mCherry transgene as a surrogate of nodal tumor burden.

RESULTS

Nine mice were judged as positive for PLN metastasis by ultrasound at day 5, and 8 PLNs were positive on 18F-MEL050 PET, 3 after systemic and 5 after local administration. Ex vivo analysis showed that ultrasound correctly identified 90% of positive PLNs, with 1 false-positive. 18F-MEL050 PET correctly identified 60% of positive PLNs after systemic administration and 100% after local administration with no false-positive results by either route. The average node-to-background ratio for positive PLNs was 6.8 in the systemic-administration group and correlated with disease burden. In the local-administration group, the mean uptake ratio was 48, without clear relation to metastatic burden. Additional sites of metastatic disease were also correctly identified by 18F-MEL050 PET.

CONCLUSION

In addition to its potential for systemic staging, perilesional administration of 18F-MEL050 may allow sensitive and specific, noninvasive identification of regional lymph node metastasis in pigmented malignant melanomas.

High-contrast PET of melanoma using (18)F-MEL050, a selective probe for melanin with predominantly renal clearance

The aim of this study was to evaluate the novel probe (18)F-6-fluoro-N-[2-(diethylamino)ethyl] pyridine-3-carboxamide ((18)F-MEL050) for the imaging of primary and metastatic melanoma.

METHODS

PET using (18)F-MEL050 was performed in murine models of melanoma. The specificity of (18)F-MEL050 was studied by comparing its accumulation in pigmented B16-F0 allograft tumors with that of human amelanotic A375 xenografts using PET and high-resolution autoradiography. (18)F-MEL050 PET results were compared with (18)F-FDG PET, the current standard in melanoma molecular imaging. To test the ability of (18)F-MEL050 to assess the metastatic spread of melanoma, a murine model of lung metastasis was imaged by PET/CT, and results correlated with physical assessment of tumor burden in the lungs.

RESULTS

In pigmented B16-F0 grafts, (18)F-MEL050 PET yielded a tumor-to-background ratio of approximately 20:1 at 1 h and greater than 50:1 at 2 and 3 h. In the B16-F0 melanoma allograft model, tumor-to-background ratio was more than 9-fold higher for (18)F-MEL050 than for (18)F-FDG (50.9 +/- 6.9 vs. 5.8 +/- 0.5). No uptake was observed in the amelanotic melanoma xenografts. Intense uptake of (18)F-MEL050 was evident in metastatic lesions in the lungs of B16-BL6 tumor-bearing mice on PET at 2 h after tracer injection, with high concordance between (18)F-MEL050 accumulation on PET/CT and tumor burden determined at necroscopy.

CONCLUSION

(18)F-MEL050 has a rapid tumor uptake and high retention with specificity for melanin, suggesting great potential for noninvasive clinical evaluation of suspected metastatic melanoma.

Predicting outcome in melanoma: where are we now?

Melanoma incidence continues to rise in most countries. This is of grave concern, given the mortality rate in a relatively young population. Current staging tools are limited in their ability to predict accurately those at risk of metastatic disease, relapse and treatment failure. This overview comprehensively reviews relevant literature, with the focus on the last 5 years, and discusses the current state of traditional and emerging novel methods of staging for melanoma and their effect on prognosis in this population.