To address a clinical gap in the management of cutaneous squamous cell carcinoma (CSCC), a multidisciplinary panel has developed consensus-based recommendations for the use of imaging in the staging and surveillance of localized tumors.

Of key messages, imaging for staging was recommended for any CSCC with at least a 15% risk for metastasis while subsequent serial imaging to detect recurrences was recommended for at least 2 years, according to deliberations published online on July 8 in JAMA Dermatology.

Backed by published data, the imaging recommendations were refined for CSCC subtypes using a variety of specific features such as lymphovascular invasion, tumor diameter, subcutaneous fat invasion, and small-caliber perineural invasion. CT was the preferred type of imaging for nodal staging and surveillance in most patients.

A member of the steering committee and the study’s corresponding author, Emily S. Ruiz, MD, MPH, director of the high-risk skin cancer clinic at Dana-Farber Brigham Cancer Center and associate professor of dermatology at Harvard University in Boston, cited prior studies that have shown imaging can change clinical management. In a study of high-risk patients, occult nodal metastases missed with clinical examination were identified with imaging in 19% of patients.

Guidelines Are a Starting Point for Additional Studies

“Our goal was to provide an initial framework and hopefully we will continue to generate data to refine these recommendations,” Ruiz told Medscape Medical News.

Ruiz said that there has not been much guidance about when or how imaging should be employed in the management of CSCC. For example, the National Collaborative Cancer Centers calls for imaging “to be considered” in CSCC but did so without providing specifics.

As a baseline, these newly published recommendations provide standards that can be challenged with new data. “For example, we may move away from imaging if other testing, such as ctDNA, is shown to be helpful,” she said.

The panel consisted of 45 experts representing dermatology, oncology, radiology, and surgery. After a review of published studies, a Delphi consensus was applied to reach recommendations participating in three rounds of deliberation. Consensus was defined by at least an 80% agreement among participants.

To address specific CSCC clinical scenarios, risk factors from both the Brigham and Women’s Hospital (BWH) Tumor Classification System and the American Joint Committee on Cancer (AJCC) Staging Manual were considered.

No Imaging Is Recommended for Low-Risk CSCC

Consensus was reached by the expert panel that no imaging for either staging or surveillance is required in low-risk CSCC, defined as T1 or T2a low risk in the BWH Staging System and T1 or T2 low risk in the AJCC8 Staging System.

There was a near consensus, defined as 70%-79% agreement, to stage and surveil AJCC8 T3 lesions with a diameter of 4 cm or greater or if such lesions had evidence of large-caliber nerve invasion. Imaging staging and surveillance of AJCC8 T3 lesions was also supported in the case of minor or major bone invasion.

For all higher risk lesions, BWH T2b and T3 tumors and AJCC8 4a and 4b tumors, there was consistent consensus for imaging both for staging and for surveillance.

However, other variables affected consensus on staging and surveillance in specific instances. For example, CSCC with poorly differentiated histology also met the consensus criteria for an increased risk for metastasis in cases where the tumor diameter reached 2 cm or larger and there is subcutaneous fat invasion or when lymphovascular invasion and small-caliber perineural invasion is detected.

There were also risk factors outside of the BWH or AJJC8 staging systems that were considered relevant to the decision to image. One is active immunosuppression, which might be relevant to a risk profile that increases risk for metastases, according to the published document.

There was no consensus reached for the value of imaging in patients with CSCC who had received adjuvant radiotherapy or immunotherapy. There was also no consensus on the value of imaging following surgical resection in those without a clear surgical margin. Although nearly half of panelists did consider resection without clear margins to be an indication for surveillance imaging, the available data were inconclusive.

For the same reason, there was no consensus on the value of molecular tools, such as gene expression profiling, in regard to the decision to stage or surveil with imaging.

CT Imaging Preferred for Most but Not All CSCC

Relative to MRI, CT was the preferred imaging modality for most cases because of its efficacy for evaluating nodal metastases as well as bone and structural invasion. It was recognized that PET-CT scan might be better in specific cases, such as those with extensive disease or concomitant hematologic cancers, because this form of imaging has a high relative sensitivity to locoregional and distant metastases.

More than half of the nine radiologists on the panel reported they would be comfortable using ultrasonography for nodal staging at an expert center with experience and training in this modality, but this tool was not a consensus recommendation.

These recommendations are generally consistent with recent review papers evaluating the same body of evidence but without the benefit of a Delphi expert consensus to weigh these data systematically. In a paper, published in July 2025, the authors, led by Sabela Paradela-de la Morena, MD, PhD, a dermatologist affiliated with the University Hospital of La Coruña in La Coruña, Spain, also called for restricting imaging for either staging or surveillance to those at risk for metastasis.

“Routine imaging modalities are not recommended for all patients with cutaneous squamous cell carcinoma, given the generally low risk of metastasis,” reported Paradela-de la Morena and her coinvestigators. But they added, “imaging plays a crucial role in patients with high-risk tumors, recurrences, or clinical findings suggestive of deep invasion or dissemination. ”

They agreed that CT imaging is appropriate for suspected node metastases or bone involvement but consider MRI more sensitive for suspected perineural invasion. She agreed that PET-CT is preferable to look for distant metastases in patients with nodal involvement and that ultrasound is more dependent than other options on experience.

Asked to comment on the guidelines, Kishwer S. Nehal, MD, director of Mohs and Dermatologic Surgery at Memorial Sloan Kettering Cancer Center, New York City, said that the Delphi expert consensus on imaging guidelines for CSCC “will be helpful to clinicians.” Nehal, who was coauthor of a study on surveillance imaging for very high-risk CSCC published earlier this year, was not an author of the guidelines.

“In an area where prospective high-level data is limited and imaging practices have varied considerably, this multidisciplinary consensus provides clinicians with a practical framework for more consistent clinical decision-making,” she said. “It serves as a benchmark for prospective studies to validate, refine, and strengthen evidence-based imaging recommendations for high-risk cutaneous SCC.”

Ruiz reported financial relationships with Almirall, Feldan Therapeutics, Regeneron Pharmaceuticals, RepImmune, and Sun Parma. Paradela-de la Morena reported no potential conflicts of interest. Nehal had no disclosures.

Ted Bosworth, a career medical writer based in New York City, has been covering advances in clinical medicine, including dermatology, for several decades.