Whole body PET/CT in the follow-up of asymptomatic patients with stage IIB-IIIB cutaneous melanoma. Acta Oncol 2016;55:1355-1359. [PMID: 27553064 DOI: 10.1080/0284186x.2016.1213879]

Diagnostic Performance of [18F]F-FDG Positron Emission Tomography (PET) in Non-Ophthalmic Malignant Melanoma: A Systematic Review and Meta-Analysis of More Than 10,000 Melanoma Patients

We described the diagnostic performance of [18F]F-FDG-PET in malignant melanoma by conducting a comprehensive systematic review and meta-analysis of the existing literature. The study was designed following PRISMA-DTA. Original articles with adequate crude data for meta-analytic calculations that evaluated [18F]F-FDG-PET and compared it with a valid reference standard were considered eligible. The pooled measurements were calculated based on the data level (patient/lesion-based). Regarding sub-groups, diagnostic performances were calculated for local, regional and distant involvement. The bivariate model was employed to calculate sensitivity and specificity. The initial search resulted in 6678 studies. Finally, 100 entered the meta-analysis, containing 82 patient-based (10,403 patients) and 32 lesion-based (6188 lesions) datasets. At patient level, overall, [18F]F-FDG-PET had pooled sensitivity and specificity of 81% (95%CI: 73-87%) and 92% (95%CI: 90-94%), respectively. To detect regional lymph node metastasis, the pooled sensitivity and specificity were 56% (95%CI: 40-72%) and 97% (95%CI: 94-99%), respectively. To detect distant metastasis, they were 88% (95%CI: 81-93%) and 94% (95%CI: 91-96%), respectively. At lesion level, [18F]F-FDG-PET had a pooled sensitivity and specificity of 70% (95%CI: 57-80%) and 94% (95%CI: 88-97%), respectively. Thus, [18F]F-FDG-PET is a valuable diagnostic modality for melanoma assessment. It was accurate in various clinical scenarios. However, despite its high specificity, it showed low sensitivity in detecting regional lymph node metastasis and could not replace lymph node biopsy.

Patterns of Recurrence of Cutaneous Melanoma: A Literature Review

The incidence of melanoma has been dramatically increasing over the last decades. Melanoma is considered to have a high metastatic potential and it can progress via lymphatic vessels or through hematogenous metastasis. Different patterns of recurrence have been described, namely, local, satellite, and in transit metastasis (LCIT), lymphatic metastasis, and systemic metastasis. With a more advanced melanoma stage at diagnosis, there is a higher risk for systemic metastasis in comparison to LCIT; in contrast, early-stage melanoma tends to recur more frequently as LCIT and less commonly as systematic metastasis. The aim of this review was to summarize the patterns of recurrence of cuta-neous melanoma, giving the clinician a practical summary for diagnosis, prognosis, and surveillance. There is a knowledge gap of the common patterns of recurrence that needs to be addressed to better identify patients at high risk of disease recurrence and personalize surveillance strategies as well as patient counseling.

Surveillance After a Previous Cutaneous Melanoma Diagnosis: A Scoping Review of Melanoma Follow-Up Guidelines

INTRODUCTION

Cutaneous melanoma accounts for more than 70% of all skin cancer deaths. Follow-up surveillance is an integral part of melanoma patient care, to facilitate early detection of recurrences and subsequent primary melanomas. The purpose of this scoping review is to provide an overview of recently published melanoma surveillance guidelines from regional and national melanoma working groups.

METHODS

A systematic search for relevant studies in MEDLINE and Embase was conducted in September 2022 and was limited to publications from 2010 or later.

RESULTS

A total of 1047 articles were retrieved, and after abstract and full text review, 26 articles from 19 different organizations met inclusion criteria. Life-long annual skin surveillance with a physician was recommended by 53% (9/17) of guidelines. Routine laboratory investigations were recommended by 7/19 guidelines. Regional lymph node ultrasound was recommended by 9/16 guidelines, most often in stage IB or higher, and was optional in 7/16 for patients who met specific criteria. Surveillance with PET-CT or CT and MRI was recommended by 15 and 11 guidelines, respectively, most commonly in stage IIC or higher, with a variable frequency and total duration. Five out of 9 guidelines indicated a preference for skin surveillance to be completed with a dermatologist.

CONCLUSION

Guidelines were highly variable for many aspects of melanoma surveillance, which may be partly attributed to regional differences in healthcare workforce distribution and availability of imaging technologies. Further high-level studies are recommended to provide more evidence on the most effective clinical and imaging follow-up surveillance protocols.

"The Benefit Of Positron Emission Tomography/Computed Tomography In Stage I And Stage II Melanomas With High-Risk Decisiondx-Melanoma Scores"

INTRODUCTION

Early detection of melanoma is instrumental as the 5-year survival decreases from 93.3% to <50% when metastases are present.^1-3 Distinguishing which patients require closer follow-up can be difficult for melanoma patients. Developments by Castle Biosciences' (Friendswood, TX) DecisionDx-Melanoma (DDx-M) use 31 melanoma associated genes to stratify melanomas into 4 classes with 1A having lowest risk of morbidity and mortality and 2B the highest.⁵ We assessed the benefit of providing additional ¹⁸FDG-PET-CT and brain MRI to genetically high-risk patients who may have otherwise been overlooked.

METHODS

297 patients at our institution had biopsies sent for DDx-M between 2014 and 2021. Patients found to have Class 2 melanomas received additional screening with yearly ¹⁸FDG-PET-CT scans and brain MRIs. Patients with Class 2 DDx-M scores and negative SLNB were included in the study. 66 met inclusion criteria and received imaging.

RESULTS

Within 3 years of follow-up, 8/66 (12.1%) patients had metastases detected by ¹⁸FDG-PET-CT scans. No patients with stage IA or IB went on to develop metastases.

DISCUSSION

¹⁸FDG-PET-CT scans detect metastases in < 3% of the time when all stage I and II patients are scanned; however, by using DDx-M in our screening protocols, we achieved a detection rate of 12.1%.^6,7 These patients went on to receive treatment and would have otherwise progressed undetected, leading to higher morbidity and mortality.

CONCLUSION

We suggest all patients with initial stage II or above melanomas receive a DDx-M score and those with class 2 receive yearly ¹⁸FDG-PET-CT/brain MRI imaging.

18 F-FDG positron emission tomography-computed tomography has a low positive predictive value for detecting occult recurrence in asymptomatic patients with high-risk Stages IIB, IIC, and IIIA melanoma

BACKGROUND AND OBJECTIVES

High recurrence rates of Stages II and IIIA melanoma make close follow-up essential, especially with new adjuvant therapies for metastatic disease. However, there are currently no consensus guidelines for routine imaging for Stages IIB, IIC, and IIIA melanoma. The study's aim is to determine the utility of 18 F-fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) for detecting asymptomatic recurrence of melanoma after primary surgical resection.

METHODS

This retrospective cohort study included 158 patients with the American Joint Committee on Cancer 8th edition Stages IIB, IIC, or IIIA cutaneous melanoma who underwent an 18 F-FDG PET/CT from 2010 to 2020. We retrospectively analyzed clinical data after a median follow-up time of 39 months.

RESULTS

We calculated a positive predictive value (PPV) of 32% (95% confidence interval: 11%-53%) for 154 routine PET/CTs, including six true positives and 13 false positives (FPs). PPV was 33% for Stage IIB, 50% for Stage IIC, and 14% for Stage IIIA. FPs were mostly benign or inflammatory foci (75%), and some other malignancies were found (21%).

CONCLUSIONS

This cohort of patients imaged for high-risk melanoma demonstrated a high FP rate and low PPV. These findings suggest that routine surveillance with 18 F-FDG PET/CT may not be indicated for monitoring recurrence in this population.

Routine PET-CT scans provide early and accurate recurrence detection in asymptomatic stage IIB-III melanoma patients

INTRODUCTION

The use of routine imaging with 18F-FDG PET-CT (PET-CT) in melanoma surveillance is debated and evidence of its diagnostic value and yield in asymptomatic patients is limited. Denmark introduced nationwide routine surveillance with PET-CT in high-risk patients in 2016. The aim of this study was to examine the sensitivity, specificity, negative and positive predictive values, numbers-needed-to-scan and clinical impact of routine PET-CT in the surveillance of asymptomatic stage IIB-III melanoma patients.

MATERIALS AND METHODS

Data was retrieved from the population-based Danish Melanoma Database and patient records. All patients diagnosed with stage IIB-III melanoma at two University Hospitals in 2016 and 2017 were included. Patients underwent surveillance with clinical examinations and PET-CT scans at 6, 12, 24 and 36 months.

RESULTS

In 138 patients, 243 routine PET-CTs were performed within a median follow-up time of 17.7 months. Routine PET-CT detected recurrence at least once in 25 patients (18.1%), including distant recurrence in 19 patients (13.8%). Stage IIB patients had the lowest recurrence rate (11.1%). Numbers-needed-to-scan to detect one distant recurrence was 12.8 patients and median time-to-recurrence was 6.8 months. Sensitivity was 100%, specificity was 94.7% and negative and positive predictive values were 100% and 74.4%, respectively. False positive findings prompted 22 additional investigations (of which ten invasive) in 17 patients (12.3%).

CONCLUSION

Routine PET-CT has a high sensitivity and specificity when used in high-risk melanoma surveillance. Time-to-recurrence and stage-specific recurrence rates indicate high gain of early routine imaging at six months especially for stage IIC and III patients.

Canadian Melanoma Conference Recommendations on High-Risk Melanoma Surveillance: A Report from the 14th Annual Canadian Melanoma Conference; Banff, Alberta; 20-22 February 2020

Introduction: There are a lack of established guidelines for the surveillance of high-risk cutaneous melanoma patients following initial therapy. We describe a novel approach to the development of a national expert recommendation statement on high-risk melanoma surveillance (HRS). Methods: A consensus-based, live, online voting process was undertaken at the 13th and 14th annual Canadian Melanoma Conferences (CMC) to collect expert opinions relating to “who, what, where, and when” HRS should be conducted. Initial opinions were gathered via audience participation software and used as the basis for a second iterative questionnaire distributed online to attendees from the 13th CMC and to identified melanoma specialists from across Canada. A third questionnaire was disseminated in a similar fashion to conduct a final vote on HRS that could be implemented. Results: The majority of respondents from the first two iterative surveys agreed on stages IIB to IV as high risk. Surveillance should be conducted by an appropriate specialist, irrespective of association to a cancer centre. Frequency and modality of surveillance favoured biannual visits and Positron Emission Tomography Computed Tomography (PET/CT) with brain magnetic resonance imaging (MRI) among the systemic imaging modalities available. No consensus was initially reached regarding the frequency of systemic imaging and ultrasound of nodal basins (US). The third iterative survey resolved major areas of disagreement. A 5-year surveillance schedule was voted on with 92% of conference members in agreement. Conclusion: This final recommendation was established following 92% overall agreement among the 2020 CMC attendees.

Monitoring the Response of Skin Melanoma Cell Line (A375) to Treatment with Vemurafenib: A Pilot In Vitro Optical Spectroscopic Study

Objective: The aim of this study was to investigate the feasibility of optical spectroscopy as a nondestructive approach in monitoring the skin melanoma cancer cell response to treatment. Background: Owing to the growing trend of personalized medicine, monitoring the treatment response individually is particularly crucial for optimizing cancer therapy efficiency. In the past decade, optical sensing, using diffuse reflectance spectroscopy, has been used to improve the identification of cancerous lesions in various organs. Until now, surveys have mainly focused on the nondestructive application of optical sensing used to diagnose and discriminate normal and abnormal biomedical lesions or samples. Meanwhile, the response to the treatment might be monitored using these nondestructive technologies, thereby enabling further therapeutic modification. Methods: The human skin melanoma cell line (A375) donated from Switzerland (University Hospital Basel) was cultured. Vemurafenib (Zelboraf; Genentech/Roche, South San Francisco, CA) was used for cell treatments. The visible-near-infrared reflectance spectroscopy was conducted at different time intervals (before treatment, and at 1, 2, 7, and 14 days post-treatment for three drug doses 5, 25, and 75 μM) on cell plates using the portable CCD-based fiber optical spectrometer (USB2000; Ocean Optics). After data collection, the refractive index analysis for the fore-mentioned doses and days in one selected wavelength of 620 nm was examined using the previously developed computer program. Then, biological assays were selected as gold standard of cell death, apoptosis, and drug resistance gene expression. Results: There was a considerable decrease in the refractive index of cell samples in which biological assay confirmed cell death. Based on the flow cytometry data, a drug dose of 25 μM on day 7 seemed to induce necrosis. These findings show that spectroscopic findings strongly agree with concurrent biological studies and might lead to their use as an alternative method for monitoring treatment response to achieve more optimized cancer treatment. Conclusions: The findings show that reflectance spectroscopy, as a nondestructive real-time label-free way, is capable of providing quantitative information for treatment response determination that corresponds with biological assays.

Performance of Long-Term CT and PET/CT Surveillance for Detection of Distant Recurrence in Patients with Resected Stage IIIA-D Melanoma

BACKGROUND

Follow-up for patients with resected stage IIIA-D melanoma may include computed tomography (CT) or positron emission tomography (PET)/CT imaging to identify distant metastases. The aim of this study was to evaluate the test performance over follow-up time, of structured 6- and 12-monthly follow-up imaging schedules in these patients.

METHODS

We conducted a retrospective analysis of consecutive resected stage IIIA-D melanoma patients from Melanoma Institute Australia (2000-2017). Patients were followed until a confirmed diagnosis of distant metastasis, end of follow-up schedule, or death. Test accuracy was evaluated by cross-classifying the results of the test against a composite reference standard of histopathology, cytology, radiologic imaging, and/or clinical follow-up, and then quantified longitudinally using logistic regression models with random effects.

RESULTS

In total, 1373 imaging tests were performed among 332 patients. Distant metastases were detected in 110 (33%) patients during a median follow-up of 61 months (interquartile range 38-86), and first detected by imaging in 86 (78%) patients. 152 (68%) patients had at least one false-positive result. Sensitivity of the schedule over 5 years was 79% [95% confidence interval (CI) 70-86%] and specificity was 88% (95% CI 86-90%). There was no evidence of a significant difference in test performance over follow-up time or by American Joint Committee on Cancer (AJCC) substage. The positive predictive value ranged between 33 and 48% over follow-up time, reflecting a ratio of 1:2 false-positives per true-positive finding.

CONCLUSIONS

Regular 6- or 12-monthly surveillance imaging using CT or PET/CT has reasonable and consistent sensitivity and specificity over 5-year follow-up for resected stage IIIA-D melanoma patients. These data are useful when discussing the risks and benefits of long-term follow-up.

S-100B as an extra selection tool for FDG PET/CT scanning in follow-up of AJCC stage III melanoma patients

Background and Objectives

This current study assessed the value of S‐100B measurement to guide fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scanning for detecting recurrent disease in stage III melanoma patients.

Methods

This study included 100 stage III melanoma patients in follow‐up after curative lymph node dissection. Follow‐up visits included physical examination and S‐100B monitoring. FDG PET/CT scanning was indicated by clinical symptoms and/or elevated S‐100B.

Results

Of 100 patients, 13 (13%) had elevated S‐100B without clinical symptoms, of whom 7 (54%) showed disease evidence upon FDG PET/CT scanning. Twenty‐six patients (26%) had clinical symptoms with normal S‐100B and FDG PET/CT revealed metastasis in 20 (77%). Three patients had clinical symptoms and elevated S‐100B, and FDG PET/CT revealed metastasis in all three (100%). Overall, FDG PET/CT scanning revealed metastasis in 30 of the 42 patients (71.4%). For seven recurrences, elevated S‐100B prompted early detection of asymptomatic disease; 10% of all asymptomatic patients in follow‐up, 23% of all patients with recurrent disease.

Conclusion

S‐100B cannot exclude recurrent disease during follow‐up of stage III melanoma. However, adding S‐100B measurement to standard clinical assessment can guide FDG PET/CT scanning for detecting recurrent melanoma.

Surveillance imaging for metastasis in high-risk melanoma: importance in individualized patient care and survivorship

Most patients newly diagnosed with melanoma have early-stage disease considered of good prognosis. However, with a risk of recurrence, appropriate follow-up may include surveillance imaging for early relapse detection. Previously, surveillance imaging to detect recurrences was considered unjustified, given the lack of effective treatments. Now, systemic therapies have improved, and patients with low tumor burden may derive benefit from surveillance imaging. Despite this, controversy exists regarding the role of surveillance imaging in early-stage melanoma survivorship, in part reflected by the lack of consensus on specific imaging protocols and broad guidelines. This review discusses published evidence on surveillance imaging to detect metastasis in high-risk melanoma, the need for early recurrence detection and implications for value-based clinical decision-making, survivorship care and multidisciplinary patient management.

Cost-effectiveness analysis of imaging strategy for an intensive follow-up of patients with American Joint Committee on Cancer stage IIB, IIC and III malignant melanoma

BACKGROUND

Many follow-up guidelines for patients with high-risk melanoma include expensive imaging studies, serum biomarkers and regular visits to the dermatologist, with little attention to cost-effectiveness.

OBJECTIVES

To establish the cost-effectiveness of chest-abdomen-pelvis computed tomography (CT) and brain magnetic resonance imaging (MRI) in a follow-up protocol for patients at high risk of relapse.

METHODS

This was a prospective single-centre cohort study of 290 patients with clinicopathological American Joint Committee on Cancer (AJCC) stage IIB, IIC and III melanoma. Patients had a body CT scan and brain MRI every 6 months and were withdrawn from the study after completing a 5-year follow-up or when metastases were detected. A cost-effectiveness analysis for each follow-up radiological procedure was performed.

RESULTS

Patients underwent 1805 body CT scans and 1683 brain MRIs. Seventy-six metastases (26·2%) were identified by CT or MRI. CT scan was cost-effective in the first 4 years (cost-effectiveness ratio €4710·70-€14 437·10/patient with metastasis); brain MRI was cost-effective during the first year (cost-effectiveness ratio €14 090·60/patient with metastasis). Limitations included lack of survival analysis and comparisons with willingness-to-pay thresholds.

CONCLUSIONS

Six-monthly CT scan of the chest, abdomen and pelvis is a cost-effective technique for the early detection of metastases in the first 4 years of follow-up in patients with AJCC stage IIC and III melanoma, and in the first 3 years in patients with AJCC stage IIB melanoma. In addition, brain MRI has been shown to be cost-effective only in the first year of follow-up in patients with AJCC stage IIC and III melanoma.

Melanoma & nuclear medicine: new insights & advances

The contribution of nuclear medicine to management of melanoma patients is increasing. In intermediate-thickness N0 melanomas, lymphoscintigraphy provides a roadmap for sentinel node biopsy. With the introduction of single-photon emission computed tomography images with integrated computed tomography (SPECT/CT), 3D anatomic environments for accurate surgical planning are now possible. Sentinel node identification in intricate anatomical areas (pelvic cavity, head/neck) has been improved using hybrid radioactive/fluorescent tracers, preoperative lymphoscintigraphy and SPECT/CT together with modern intraoperative portable imaging technologies for surgical navigation (free-hand SPECT, portable gamma cameras). Furthermore, PET/CT today provides 3D roadmaps to resect 18F-fluorodeoxyglucose-avid melanoma lesions. Simultaneously, in advanced-stage melanoma and recurrences, 18F-fluorodeoxyglucose-PET/CT is useful in clinical staging and treatment decision as well as in the evaluation of therapy response. In this article, we review new insights and recent nuclear medicine advances in the management of melanoma patients.

Is nonmetastatic cutaneous melanoma predictable through genomic biomarkers?

Cutaneous melanoma is a highly aggressive skin cancer whose treatment and prognosis are critically affected by the presence of metastasis. In this study, we address the following issue: which gene transcripts and what kind of interactions between them can allow to predict nonmetastatic from metastatic melanomas with a high level of accuracy? We carry out a meta-analysis on the first gene expression set of the Leeds melanoma cohort, as made available online on 11 May 2016 through the ArrayExpress platform with MicroArray Gene Expression number 4725. According to the authors, primary melanoma mRNA expression was measured in 204 tumours using an illumina DASL HT12 4 whole-genome array. The tumour transcripts were selected through a recently proposed predictive-based regression algorithm for gene-network selection. A set of 64 equivalent models, each including only two gene transcripts, were each sufficient to accurately classify primary tumours into metastatic and nonmetastatic melanomas. The sensitivity and specificity of the genomic-based models were, respectively, 4% (95% confidence interval: 0.11-21.95%) and 99% (95% confidence interval: 96.96-99.99%). The very high specificity coupled with a significantly large positive likelihood ratio leads to a conclusive increase in the likelihood of disease when these biomarkers are present in the primary tumour. In conjunction with other highly sensitive methods, this approach can aspire to be part of the future standard diagnosis methods for the screening of metastatic cutaneous melanoma. The small dimension of the selected transcripts models enables easy handling of large-scale genomic testing procedures. Moreover, some of the selected transcripts have an understandable link with what is known about cutaneous melanoma oncogenesis, opening a window on the molecular pathways underlying the metastatic process of this disease.

Patient Symptoms Are the Most Frequent Indicators of Recurrence in Patients with American Joint Committee on Cancer Stage II Melanoma

BACKGROUND

Patients with stage II melanoma have a considerable risk for recurrence. Current guidelines are imprecise as to optimal follow-up. We hypothesized that by examining recurrence patterns, we could help to better inform guidelines.

STUDY DESIGN

We queried IRB-approved melanoma databases of Thomas Jefferson University and University of North Carolina, identifying 581 patients with stage II melanoma between 1996 and 2015 with at least 1 year of follow-up. Data included location of first recurrence and how recurrence was detected (ie patient symptom, physician examination, or routine surveillance imaging). Cox regression with backward elimination was used for multivariable analysis.

RESULTS

One hundred and seventy-one patients had a recurrence (29.4%), the incidence increased considerably by stage sub-group. Significant predictors of recurrence included male sex (p = 0.003), ulceration (p = 0.03), and stage (p < 0.001). On multivariable analysis, male sex and stage continued to be significant (p < 0.01). For overall survival, regression, ulceration, stage, and age were significant predictors of survival. Stage, regression, and age remained significant by multivariable analysis. Patient symptoms were the most frequent mode of detection (40%), followed by physician examination (30%) and surveillance imaging (26%)-this did not differ significantly by stage. Regional nodes were the most common site of recurrence (30%), followed by lung (27%) and in-transit (18%).

CONCLUSIONS

The majority of recurrences in stage II melanoma are detected by patients and their physicians and rarely by routine imaging. As such, clinical follow-up and patient education are critical factors in detection of recurrence. With the prevalence of regional nodal recurrences, ultrasound might prove to be an important strategy in early recurrence detection.