Background: Lymph Node Metastasis (LNM) is often treated preventively during the initial management of the primary tumor, by chemotherapy-radiotherapy-surgical excision. However, few options exist for the treatment of loco-regional LNM at the time of recurrence.
Objective: This study aims to assess the efficacy, safety, and the loco-regional disease control of Cryoablation (CA) as a removal option for LNM.
Patients/methods: The clinical records of 9 patients, (5 male and 4 female, median age 60), treated by CA at the department of interventional radiology, CHUV, between May 2014 and December 2016 were retrospectively and consecutively reviewed. Permission from the Swiss Ethics Committee was obtained.
Nine patients bearing 17 LNM from various primary tumors were treated by CA. CA was performed by using 2 median freezing cycles, (sd=0), with a median duration of 9 minutes for the first freezing cycle (± 3.3min) and 6 minutes for the second freezing cycle (± 2.7min). The median duration of the total of freezing cycles was 15 minutes (± 5.7min). The number of probes ranged from 1 to 10, (median 2). After CA, the patients were followed up by imagery (PET-CT, CT, MRI) at intervals of 1-3 months, 6 months, 9 months, 12 months, 24 months, etc., for as long as follow-up was available. Both PERCIST and RECIST 1.1 criteria were applied to evaluate the effectiveness of CA, by measuring SUVmax and diameter of lesion respectively.
Results: A total of 13 CA procedures were performed on 17 LNM. All procedures were technically successful resulting in a satisfactory ablation zone. Minor immediate and periprocedural complications were observed (SIR classification). Using PERCIST, out of the 14 hypercaptant target lesions, at the end of the PET-CT follow-up available for each lesion (13.8 months mean), 14% (n=2) had Complete Response, 64% (n=9) had Partial Response, 21% (n=3) were in Stable Disease, and 0% (n=0) showed Progressive Disease. Mean SUVmax decrease was -51%, for a mean follow up time of 13.8 months. Using RECIST 1.1 criteria, out of the 17 target lymph nodes, at the end of the MRI follow-up available for each lesion (15.6 months mean),29% (n= 5) showed CR, 41% (n=7) had PR, 24% (n=4) were in SD, and 6% (n=1) was Not Evaluated. Mean volume decrease was -72% for a mean follow up of 15.6 months. At the end of follow up 44% (p=4) patients showed global disease control for 11.2 months mean, 11% (p=1) had local disease control for 20 months with pre-existing distant tumour deposits at time of CA treatment, and 44% (p=4) patients showed locoregional or distant disease progression at 8.2 months mean.
Conclusion: Our study shows that CA of LNM is a safe and effective method, with minimal complications, and satisfactory locoregional disease control rate. All treated lesions were controlled 15.6 months mean, and 44% of the patients showed global disease control 11.2 months mean.