Transgluteal biopsy and drainage is one of the least common routes undertaken in image guided biopsy. It virtually always requires CT for image guidance.
Good anesthesia is important to ascertain patient cooperation at the tract crosses the large sensitive gluteal muscles.
It is typically uses for accessing pelvic tumors or recurrence for biopsy and the drainage of colorectal or gynecological related collections.
In this case the nodule of presume local recurrence was accessed for biopsy to guide ongoing oncological management.