Background: Pulsed radiofrequency (PRF) treatment of the dorsal root ganglia (DRG) has recently been used as an important option for postherpetic neuralgia (PHN) patients who do not respond well to drugs. This procedure is commonly guided by computed tomography (CT) or fluoroscopy, but they cannot be performed in real time and are associated with radiation exposure. Ultrasound (US) is a potential alternative option, but no reliable method of US-guided DRG PRF treatment has been reported.
Objectives: The goal of this study was to propose a method for performing US-guided transforaminal PRF on cervical DRG. By comparing the results with those of CT guidance, we also sought to assess the accuracy, safety, and efficacy of this new approach in the treatment of PHN.
Study design: A retrospective cohort study.
Setting: The study took place at the department of pain management of a single academic medical center.
Methods: The data of 73 PHN patients receiving 2 sessions of US-guided (US group, n = 26) or CT-guided (CT group, n = 47) cervical DRG PRF were reviewed. US-guided DRG PRF was performed using our proposed protocol. The one-time success rate was used to assess accuracy. The average radiation dose, the number of scans per operation, and the rate of complications were recorded for safety assessment. For the evaluation of pain amelioration, a Numeric Rating Scale (NRS-11), the daily sleep interference score (SIS), and oral medication (i.e., anticonvulsants and analgesics) usage 2 weeks, 4 weeks, 12 weeks, and 24 weeks after treatment were compared to the baseline values and between groups.
Results: The one-time success rate in the US group was significantly higher than that in the CT group (P < 0.05). Compared those of the CT group, the mean radiation dose and number of scans per operation were both obviously lower in the US group (P < 0.05). The average operation time was also shorter in the US group (P < 0.05). No obvious serious complications occurred in either group. No obvious between-group difference was found in the NRS-11 score, daily SIS, or rate of oral medications at any of the time points (P > 0.05). The NRS-11 score and SIS significantly decreased after treatment at each follow-up time point (P < 0.05) in both groups. Compared with those at baseline, the use rate of anticonvulsants and analgesics obviously decreased 4 weeks, 12 weeks, and 24 weeks after treatment (P < 0.05).
Limitations: This study was limited by its nonrandomized and retrospective design.
Conclusions: US-guided transforaminal DRG PRF is a safe and effective method for the treatment of cervical PHN. It is a reliable alternative option to the CT-guided procedure, demonstrating great advantages in reducing radiation exposure and the operation time.
Keywords: dorsal root ganglion; postherpetic neuralgia; pulsed radiofrequency; transforaminal; Ultrasound.