Washington, DC (UroToday.com) In today’s penile cancer session at the 2015 Society of Urologic Oncology, Dr Vegt Erik from the Netherlands cancer institute gave a very practical lecture on the use of PET CT in penile cancer patients. The use of imaging in penile cancer serves several uses like biopsy, prognosis, staging, measuring response to chemotherapy and radiation and identifying recurrences.
There are different methods for penile cancer nodal staging. First, physical exam is important in most low risk penile cancer patients. If physical exam is felt to be insufficient due to body habitus or In cases when penile preservation is contemplated an US or MRI are the next option. All these modalities have poor sensitivity and specificity (<50%). In contrast, I cases of high risk penile cancer an inuinal lymph node dissection (ILND) or a dynamic sentinel lymph node biopsy should be performed. If the ILND reveals a node positive disease then abdominopelvic and chest imaging are mandated with CT/MRI. The NCCN guidelines list PET FDG as experimental.
So why use PET CT? Dr Vegt starts with an explanation on the technology. PET CT is a hybrid of PET and CT. the patient is injected with a radioactive tracer (e.g. FDG) which is concentrated in the tumoral cells and the radiation is picked by the PET sensors. In addition a CT scan is performed and a fusion of both modalities is obtained thus providing both anatomic and functional imaging.
Next Dr Vogt explained when to use PET-CT:
For clinical N0 there is no advantage for pet over physical examination so there no need to perform this test. In contrast for clinical N+ disease PET CT provides excellent sensitivity and specificity compared with CT alone according to a 2009 trial performed in the Netherlands.
For response to adjuvant treatment and detecting recurrence there is not enough data says Dr Vogt. “It is probably helpful for recurrences because PET is excellent in differentiating fibrosis from viable tumor”.
In conclusion, PET-CT with FDG should be used in clinical N+ disease for the evaluation of pelvic lymph nodes and distant metastases.
Dr Erik Vogt, MD
Netherlands Cancer Institute
Dr. Miki Haifler, MD from the Society of Urologic Oncology Meeting - December 2 - 4, 2015 – Washington, DC.
Fox Chase Cancer Center, Philadelphia, PA.