But we shouldn’t be too put off by the findings, according to one expert.
A new Australian trial has reported that 3D total body photography with sequential digital dermatology imaging in high-risk melanoma patients resulted in lower rates of melanoma detection and was more expensive compared to usual care.
Australian clinical practice guidelines recommend people with an increased risk of developing melanoma should undergo a full skin check every six months – including the use of total body photography, were possible – but that population-level melanoma screening should not be used.
“Other cancers that are screened for have a test, like a mammogram or a Pap smear, whereas melanoma diagnosis still relies on a physical exam, which is variable in its accuracy,” said Associate Professor Linda Martin, head of dermatology at the Melanoma Institute Australia.
“Total body photography is considered to be a potentially useful tool because it allows you to objectively identify things that are changing, which is hoped will improve the accuracy of standard care.”
Researchers at the University of Queensland randomised over 300 patients at high risk of developing melanoma to receive either four sessions of 3D total body photography with sequential digital dermatology imaging using the VECTRA WB360 or usual care (including regular skin checks) over a two-year period to determine whether the use of total body photography imaging improved the early detection and cost-effectiveness of melanoma and other skin cancers.
But the clinical and cost-effectiveness analyses of the trial testing the total body photography technology, conducted at the Princess Alexandria Hospital in Brisbane, yielded mixed results.
Over 1500 excisions were conducted, with the average number of lesions excised per person higher in the intervention arm (5.7) compared to the control arm (4.0). However, only 4% of the 1500-plus excisions were later confirmed to be melanoma, with a greater number of melanomas excised from participants who received usual care (29) compared to participants who received total body photography (19).
The cost-effectiveness analysis, which was based on participant surveys and administrative health care datasets (i.e., the Medicare Benefits Scheme) revealed that the average per person costs to the government were similar for the intervention ($555) and control ($617) arms. Participants in each group also paid similar out of pocket costs ($333 for the intervention arm, $352 for the control arm).
After accounting for the effects of sex, insurance status, annual household income and comorbidities, the total costs were 2.8 times higher for the 3D total body photography group compared to the usual care group ($1708 versus $763).
There was no difference in the quality-adjusted life years (QALYs) gained between the two groups over the two-year study period.
The researchers highlighted two potential reasons as to why their findings were contrary to expectations.
“Skin checks were performed by junior clinicians, who subsequently presented the identified suspicious lesions to a teledermatologist for final assessment. As a result, the accuracy of the diagnostics was constrained by the skill levels and experience of the junior clinicians,” they wrote.
“[Furthermore,] Queensland clinicians may be more cautious by excising more tumours that are suggestive of melanoma, particularly in high-risk melanoma cohorts. Fear of medical malpractice litigation resulting from missed melanomas, as well as patient pressure and anxiety, may contribute to an increased likelihood of excising a suspicious tumour.”
Professor Martin agreed that the design of the study was a limiting factor.
“The interpretation of the images was done by an experienced clinician, but completely out of context of the patient, said the staff specialist dermatologist at the Sydney Children’s Hospital.
“The way this was implemented, [being] removed from patient centric care, is the problem. Choosing which image to lesion is, in my opinion, the most important and most difficult part [of the process]. You need to work out which lesions are worth imaging and to interpret those lesions in the context of the patient.”
Writing in an accompanying editorial, Professor Laura Ferris and Assistant Professor Adewole Adamson – two US-based dermatologists who were not involved in the current research – emphasised the need to consider the results in a balanced manner.
“Although these findings may temper enthusiasm for these powerful technologies, this study provides an opportunity to think critically about how this and future imaging technologies should be studied, and ultimately, incorporated into practice.
“The authors should be commended for conducting a prospective randomised study focusing on measuring biopsies and detection rates because a rigorous approach is rarely applied to skin cancer screening research.
“Nevertheless, it is a reminder that demonstrating the benefits of cancer screening is difficult.”
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The editorial authors also addressed some of the potential limitations of the current study, including how the authors approached the subjective and non-standardised decision-making process around whether to biopsy a potential melanoma.
“The inclusion of multiple clinicians choosing, reviewing and making the recommendations regarding the biopsy of lesions imposed a degree of diagnostic scrutiny that would seemingly lead to more biopsies and may not simulate true practice patterns,” they wrote.
The non-use of AI in the study was another point of discussion, even though there was a perfectly valid reason why it could not be used.
“The … device used in the intervention arm … has artificial intelligence capacity to detect lesion change in serial images of a patient. This capability was not used due to Australian regulations requiring a higher level of approval before an AI-enabled tool can be used in patient care.
“It is plausible that the use of these AI capabilities could have affected study outcomes, although it is unclear how. While AI can make the diagnosis of pigmented lesions faster and more consistent, it also runs the risk of exacerbating overdiagnosis.”
Professor Martin felt there was still a potential role for total body photography in melanoma detection, citing other studies that report the addition of photography increases rates of diagnosis and reduces unnecessary biopsy, but emphasised that the research and implementation needs to be done in a more patient-centric way that aligns what happens in the clinic.
Professor Martin also felt that using AI to support clinician decision making may be beneficial, particularly in the context of supporting junior doctors in identifying which featureless melanomas need to be examined further.
