April Alexander Bailey MD, Presenter: Nothing to Disclose

Lindsay Hwang BS, Abstract Co-Author: Nothing to Disclose

Yin Xi, Abstract Co-Author: Nothing to Disclose

Matthew McKeever BS, Abstract Co-Author: Nothing to Disclose

Kevin V. Albuquerque MD, Abstract Co-Author: Nothing to Disclose

Geographically map lymph node metastases, using CT in advanced cervical cancer patients, and correlate with standard conformal radiation planning techniques.

IRB-approved study of imaging, demographic and treatment data for patients with advanced cervical cancer referred for definitive radiation therapy between 2006-2013. Pelvic (PLN) and paraaortic (PALN) lymph nodes were mapped on baseline CT examinations. PLN >8 mm and PALN >10 mm were considered abnormally enlarged and a surrogate for nodal metastatic disease. The anatomic location was recorded for PLN (common, internal, external iliac) and PALN (left paraaortic LPA, aortocaval AC, right paracaval RPC). Craniocaudal position and location with relation to the adjacent vertebral body for all PALN was recorded to create nodal maps. PET/CT was also obtained in 71.4% of this population; FDG-avid nodes were compared to the results of CT after primary analysis.

There were 77 patients included. PLN were identified in 74 of which 23 also had PALN. There were 3 additional patients with isolated PALN. Distribution of nodal disease in the pelvis was predominantly external iliac. The mean age of patients with and without PALN was different (55 v. 46.5 years, p=0.002). Higher FIGO stage (III or IV) also had a higher likelihood of PALN (p=0.0371). The most common PALN distribution was LPA (82.6%). No isolated RPC nodes were identified. Nearly all PALN (95.6%) were below the renal arteries. There was no correlation with type of PLN or presence of lower PALN to predict upper PALN indicating necessity to treat the entire infra-renal PALN chain with the presence of a single PALN. For the subset of patients with PET/CT evaluation, when a size threshold of >8 mm was used in the pelvis, no FDG-avid nodes were below detection, but if >10 mm was used in the pelvis, 13 out of 58 patients had metabolically active lymph nodes that would not have been identified.

Short axis PLN size of 8 mm on CT was a good surrogate for PET avidity which will assist resource poor locations. Geographic mapping of nodal size and patterns aid CRT planning by directing radiation port size and extent.

Advanced cervical cancer treatment can be tailored by reviewing the common distribution patterns of pelvic and paraaortic lymphadenopathy on CT in an indigent US population.

Bailey, A, Hwang, L, Xi, Y, McKeever, M, Albuquerque, K, CT Mapping of Metastatic Nodal Disease in Patients with Advanced Cervical Cancer in an Indigent US Population: Implications for Resource Utilization and Conformal Radiation (CRT) Planning.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013248.html