Table 2 Parameters of pulsed radiofrequency treatment of dorsal root ganglion

Holanda 2016 [14]

PRF treatment and lidocaine injection vs. laser irradiation

Pulse width: 20 ms with wash-out period of 480 ms;

Frequency: 50 Hz;

Amplitude: 45 V;

Duration: 5 min (with wash out periods of 300 ms);

Temperature: 42 °C

150 mm RF probe with 5 mm active tip (company is not specified); COSMAN G4 pulse generator (Cosman Medical, Burlington, MA, USA).

L2

Lee 2018 [15]

Diagnostic block + PRF

Amplitude: 100 V;

Duration: 240 s;

Temperature: 40–42 °C

20-gauge cannula and Cosman

Four-Electrode Radiofrequency Generator (G4) (Cosman Medical, Burlington, MA, USA).

L2 - L5 and S1

Yang 2010 [16]

2 implantation techniques

No stimulation parameters given

22-gauge, SMK-C10 (Radionics Inc., Burlington, MA, USA). RF generator not specified.

L4

Hsu 2017 [17]

No comparator

Frequency: 2 Hz;

Amplitude: 45 V;

Duration: 120 s;

Temperature: 42 °C

10-cm 22-gauge sliced-tip cannula with 1 cm active tip (company is not specified); RF generator (Baylis Medical Company, Montreal, Canada).

L2

Tsou 2010 [18]

No comparator

Frequency: 2 Hz;

Amplitude: 45 V;

Duration: 120 s;

Temperature: 42 °C

10-cm, 22-gauge, curved-tip cannula with a 1 cm active tip electrode (company not specified); RF generator (Baylis Medical Co., Montreal, Canada).

L2-L5 and S1

Albayrak 2017 [19]

TENS + exercise vs. TENS + exercise + PRF

Pulse width: 20 ms active and 480 ms silent periods;

Frequency: 2 Hz;

Amplitude: 45 V;

Duration: 120 s;

Temperature: 42 °C

22-gauge cannula (OWL RF cannula 100 mm) with 5 mm active tip electrode (Diros Technology Inc., Canada); NeuroTherm 1100 RF generator (NeuroTherm, Wilmington, MA, USA).

L4

Cohen 2006 [20]

Intercostal nerve stimulation and medical management

Pulse width: 20 ms in 1 s cycle;

Frequency: 2 Hz;

Amplitude: 45 V;

Duration: 120 s;

Temperature: 42 °C.

The procedure was repeated 4 times, for a total duration of 8 min.

10 cm electrode with a 5 mm active tip (PMC22–100-5, Baylis Medical, Montreal, Quebec, Canada); PMG-115-TD, V2.0A RF generator (Baylis Medical Company, Montreal, Canada).

Exact DRGs are not specified

Fam 2018 [21]

No comparator

Duration: 120 s;

Temperature: 42 °C

2 cycles performed

22-gauge, 10 cm, curved cannula with 10 mm active tip (Baylis Medical Company, Montreal, Canada). RF generator used not reported.

T2 and T3

Kim 2017 [6]

Continuous epidural block (ropivacaine)

Pulse width: 20 ms;

Frequency: 2 Hz;

Amplitude: 45 V;

Duration: 360 s;

Temperature: 42 °C

22-gauge 10 cm electrode with 10 mm active tip (Radionics Inc., Burlington, MA, USA); RF generator not specified.

Cervical, thoracic, lumbosacral (exact DRGs not specified)

van Zundert 2003 [22]

No comparator

Pulse width: 20 ms;

Amplitude: 45 V;

Duration: 120 s (20 ms current and 480 ms without current);

Temperature: 42 °C

54 mm, 22-gauge SMK Pole needle with 4 mm active tip (Cotop International BV, Amsterdam, Netherlands); RFG 3C Plus RF generator (Radionics Inc. Burlington, MA, USA).

Cervical DRG

Zhang 2011 [23]

No comparator

Duration: 360 s;

Temperature: 42 °C

Information not given.

C2

Albayrak 2016 [24]

No comparator

Pulse width: 20 ms active and 480 ms silent periods;

Frequency: 2 Hz;

Amplitude: 40 V;

Duration: 120 s;

Temperature: 42 °C

22-gauge cannula (OWL RF cannula 54 mm) with 4 mm active tip electrode (Diros Technology Inc., Canada); NeuroTherm 1100 RF generator (NeuroTherm, Wilmington, MA, USA).

C5 and C6

Apiliogullari 2015 [25]

No comparator

Pulse width: 20 ms active and 480 ms silent periods;

Frequency: 2 Hz;

Amplitude: 45 V;

Duration: 120 s;

Temperature: 42 °C

22-gauge cannula (OWL RF cannula 54 mm) with 4 mm active tip electrode (Diros Technology Inc., Canada); NeuroTherm 1100 RF generator (NeuroTherm, Wilmington, MA, USA).

L4 and L5

Arai 2015 [26]

No comparator

Pulse width: 20 ms active and 480 ms silent periods;

Frequency: 2 Hz;

Amplitude: 40 V;

Duration: 120 s;

Temperature: 42 °C

5 mm active tip KT, guiding needle (Hakko Co. Ltd., Tokyo, Japan); RF generator JK-3 NeuroTherm (Morgan Automation Ltd., Liss, UK).

On each metastatic vertebral body, L1–5 and Th 7, 9–12

Hofmeester 2013 [27]

No comparator

Pulse width: 8 ms;

Frequency: 2 Hz;

Amplitude: 45 V;

Duration: 480 s;

Temperature: 42 °C

Information not given.

T12, L1 and L2

Lee 2015 [28]

No comparator

Duration: 120 s, three cycles performed;

Temperature: 42 °C

21-gauge 10 cm insulated needle (company is not specified); RF generator not specified.

C2

Li 2018 [29]

No comparator

Pulse width: 20 ms;

Frequency: 2 Hz;

Amplitude: 45 V;

Duration: 900 s;

Temperature: 42 °C

22-gauge needle, RF generator G4 (Cosman Medical, Burlington, MA, USA).

C2