Photography as Imaging in Dermato-Oncology Clinical Trials

The health industry has been impacted by numerous technological advances in recent years. Among the most promising innovations are Artificial Intelligence (AI), Intraoperative Imaging, and Virtual Reality. Imaging endpoints have taken center stage in clinical trials for oncology, and there is much conversation around imaging equipment and techniques. In this blog, however, we will look at one of the lesser-known methods for examination in oncology: clinical photography.

Many techniques fall under the general term of “photography.” For example, there is ultraviolet (UV) photography such as that used to record features not visible to the human eye and infrared thermal imaging, which helps researchers to see vessel structure and blood flow. We will focus here on the standard 2D photography techniques.

Photography in Oncology

In oncology clinical trials, serial photography is used to objectively assess the evolution of superficial cutaneous lesions, giving additional information to the physician evaluating tumor response. As per RECIST v1.1, it is preferred to evaluate lesions by CT/MRI, as that method is more objective and can be easily reviewed at the end of the study. Clinical lesions captured by photography are thus usually Non-Target Lesions. However, when only superficial lesions are available and they cannot be documented by CT/MRI, the lesions can be selected as Target Lesions. Callipers and rulers must be used for the measurement of the lesions. To be considered measurable, a lesion must be ≥10mm. 

When central reviews are required, it is critical to acquire images of high-quality so that a calibration process can be carried out after the file’s conversion to a DICOM format. This enables an accurate measurement of the lesion in visualization software. 

Image Capture

Technology for clinical photography is readily available from high-quality digital cameras to basic applications on a smartphone. The range of options can provide for huge variability in image quality across sites worldwide. Members of the International Skin Imaging Collaboration Standards published consensus guidelines in order to achieve universal imaging standards in dermatology. They notably provided statements on lighting, background colours, and fields of view:

For lighting, broad-spectrum is recommended. A neutral, solid background (i.e., no patterns or disruptive surfaces) should be used as a background. Both close-up and global views should be acquired with marked and unmarked shots for each. The center of the lesion of interest should be targeted. Once settings have been checked, a ruler or calliper must be placed in a vertical position as close as possible to the lesion without obscuring any of its edges. 

It is important that the photographer is trained and that the same individual takes all the photographs for a given subject. Photographs must be consistent and repeatable to ensure that any changes recorded reflect treatment results rather than differences in the process (e.g., the image resolution or colour saturation). 

Challenges with Photography

With photography, we must consider some security and privacy issues as eyes, birthmarks, and tattoos may reveal the subject’s identity. Consideration must always be given to protect the patient’s identity within the photograph itself. Therefore, after image upload, imaging core labs like Keosys will mask any identifying details on the photograph via the imaging software.

In order for settings, lighting, and quality to remain consistent at each time point, it is recommended to use the same camera throughout the study, particularly for oncology trials where clinical lesions are potential Target Lesions that need to be measured. In these instances, imaging core labs will usually partner with specialist suppliers who will directly ship equipment (camera, accessories, labels, etc.) to the site and train the photographer on the use of the camera.

Keosys manages several trials in the field of dermato-oncology with indications that include melanoma, cutaneous squamous cell carcinoma, and Merkel Cell Carcinoma. Don’t hesitate to get in touch to learn how we would manage photography in your trial.