Scrambler Therapy for Patients with Cancer Pain - Case Series -
A 55-year-old female patient with a height of 151 cm and a weight of 55 kg was referred from the hematooncology clinic for left buttock pain caused by right infiltrative ductal breast cancer with left pelvic bone metastasis. The degree of pain on the 1-10 numeric rating scale (NRS) was 8, and it was characterized as a spontaneous tingling and ripping pain. She had received breast conserving surgery for right breast cancer 2 years before, but metastasis to the left pelvic bone had been discovered in an MRI one year before. Chemotherapy with adriamycin, cyclophosphamide, and taxol had been performed 6 times, and radiation therapy had been performed 8 times, but there had been no reduction in tumor size. Metastasis had occurred in the right acetabulum. Hence, palliative chemotherapy of Gemzar and Navelbine had been performed 6 times, and radiation therapy had been performed 6 times. At the time of referral, the patient was only scheduled for palliative care. The patient was having difficulty walking due to the pain in the pelvic area. In the MRI and bone scan of the pelvic area performed before referral, bone metastasis was observed in the left ilium, left ischium, and right acetabulum, in addition to a pathologic fracture in the left iliac wing (). At the time of referral, the patient was administered with fentanyl patch 100 µg/hr, oxycodone IR 10 mg bid, gabapentin 200 mg tid, and carbamazepine 200 mg bid for pain control; however, she was continuously complaining of severe pain (NRS 8/10) that worsened when walking. During hospitalization, fluoroscopically guided caudal epidural injection of 0.125% Chirocaine™ (levobupivacaine hydrochloride, Abbott Korea, Korea) 10 ml and Triam™ (triamcinolone acetonide, Shin Poong Pharm, Korea) 20 mg was performed twice with a one-week interval. However, the pain alleviation effect did not continue for more than one day after the procedure. Hence, scrambler therapy (MC5-A Calmare®) was planned. Because the patient's pain was located at the S1-2 dermatome of the left buttocks, the scrambler electrodes were attached at 4 normal sensory areas above and below the painful area of the S1-2 dermatome for treatment. During the scrambler treatment, the NRS score decreased to 0. The NRS score was maintained at 3 in the ward on the day of treatment. The patient was discharged after 10 sessions of scrambler therapy. During the 10 sessions, the dermatome location of pain did not change, but the area of pain slowly contracted; hence, the painful area of the patient was consulted daily before attaching the electrodes. Pain medications were continually administered without a change in dosage during the scrambler therapy. The pain alleviation effect through scrambler therapy continued for 2 months; on the third month, the pain recurred in the same area. The patient was re-hospitalized, and a second round of scrambler therapy was started. During treatment, the NRS score decreased from 7/10 to 0/10 on the first day, and this was maintained for 3-4 hours after treatment. Subsequently, the NRS score remained at 3.5/10 for 2 months, and pain medication was consistently given without a change in dosage during this period.