Observation of Millimeter Wave Therapy for Cancer Pain in 30 Cases

　　Materials and Methods

　　Our hospital has treated 30 cancer pain patients using millimeter wave therapy, including 19 males and 11 females; their ages ranged from 20 to 73 years, with an average age of 52. Among them, 9 had lung cancer, 7 had gastrointestinal tumors, 4 had urological tumors, 3 each had esophageal cancer and breast cancer, 2 had soft tissue sarcomas, and 1 each had nasopharyngeal carcinoma and malignant schwannoma. Of these patients, 9 were classified as Stage III according to the TNM staging system, while 21 were classified as Stage IV. Eighteen patients had previously undergone surgical treatment. All 30 patients met the following criteria: ① pain caused by cancer; ② generally good general condition, without cachexia; ③ a Karnofsky Performance Status score of 70 or higher. In 9 cases, the pain was due to local invasion by the primary tumor; in 19 cases, it was caused by metastatic lesions; and in 2 cases, it was post‑operative incisional pain. The pain was localized to the chest wall in 8 cases, the thoracolumbar spine in 9 cases, the abdominal cavity in 5 cases, the pelvis in 5 cases, the skull in 2 cases, and the right upper limb in 1 case. Pain was assessed using a 4‑level pain scale: Level 0 indicated no significant pain, with no impact on sleep, free movement, and no facial expression of pain; Level I indicated mild pain that was tolerable, with slight disruption to sleep, free movement, and no obvious facial expression of pain; Level II indicated moderate pain that was still bearable, with greater interference to sleep, slightly restricted movement, and a noticeable facial expression of pain; Level III indicated severe pain that was difficult to tolerate, with severe disruption to sleep, limited mobility, forced positioning, and intense…

　　A painful expression, with incessant moans. Among this group of cases, 14 patients experienced Grade II pain, and 16 patients experienced Grade III pain.

　　A millimeter-wave therapeutic device operating at a frequency of 42.5 GHz and a wavelength of 7.1 mm is used, with an output power density ranging from 8 to 15 mW/cm². The radiation head is placed directly on the skin over the acupoint, administered once daily for 30 minutes, five times per week, for a total of 4–20 treatment sessions, with an average of 10.4 sessions. Acupoint selection follows a combined approach, incorporating points along the meridians, syndrome‑specific points, and local tender points (Ashi points). Typically, back Shu points are paired with Hegu or Zusanli, along with Ashi points. Patients who were taking analgesic medications prior to treatment should continue at their original dosage; once the millimeter‑wave therapy begins to effectively relieve pain, the dosage should be gradually reduced until the medication can be completely discontinued.

　　Pain relief is graded on a 5‑point scale: Grade 0 indicates no relief, Grade I indicates mild relief and is classified as ineffective; Grade II indicates moderate relief and is classified as effective; Grade III indicates marked relief; and Grade IV indicates complete relief, with the treatment considered highly effective.

　　Results and Discussion

　　The total effective rate for pain relief in 30 cases was 63%, with 7 cases showing marked improvement, 12 cases showing improvement, and 11 cases showing no improvement. Pain relief was observed after just one treatment.

　　Two cases showed initial relief, while 19 cases achieved relief within 10 treatment sessions, with an average of 4 sessions required for the first response. After symptom improvement, the dosage of analgesics was gradually reduced; among those who showed marked efficacy, analgesics were completely discontinued after an average of 9 treatment sessions. In the 12 cases that responded effectively, both the potency of analgesics was lowered and the dosage was reduced following treatment. These results indicate that millimeter wave therapy is highly effective in managing cancer pain, and no significant toxic or adverse reactions were observed in this group of patients during treatment.

　　Millimeter waves are electromagnetic waves with wavelengths ranging from 1 to 10 mm, corresponding to a frequency band of 30–300 GHz—representing the highest end of the microwave spectrum and closely matching the intrinsic resonance frequency of mammalian tissues at approximately 50 GHz. In recent years, the biological properties of millimeter waves have been increasingly elucidated, particularly with the gradual expansion of applications in medicine for non‑thermal biological effects and long‑range effects. These effects have demonstrated promising therapeutic outcomes in the treatment of various diseases, as well as in promoting wound healing and burn recovery [1]. In cancer therapy, millimeter waves also play a unique role: they not only help manage pain in patients with advanced cancer but can also inhibit the growth of cancer cells [2], modulate the body’s immune function [1], improve peripheral blood counts [3], alleviate the toxic side effects of radiotherapy and chemotherapy [3], and enhance the quality of life for cancer patients.

　　All patients in this group experienced Grade II and Grade III pain. After an average of 10 treatments with millimeter wave therapy, the effective rate was 63%, with 23% of patients achieving complete remission. The mechanism by which millimeter waves relieve pain remains unclear to this day. From the perspective of traditional Chinese medicine, the acupoint selection principles employed during millimeter wave therapy are consistent with meridian theory. Millimeter waves are introduced into the body via resonance, triggering energy conversion that closely parallels the analgesic effects of acupuncture. By following the pathways of the meridians, millimeter waves regulate the patient’s neuroendocrine system and activate the body’s endogenous pain modulation system, thereby producing a pain‑relieving effect. Modern medical research has demonstrated that millimeter waves exert inhibitory and cytotoxic effects on cancer cells [2], reducing tumor burden and alleviating pain. Millimeter waves can also alter the rheological properties of blood, enhance local tissue metabolism, promote inflammation resolution, reduce swelling, and relieve pain [4]. At the same time, they facilitate the excretion of pathological and metabolic byproducts, accelerating the elimination of local pain‑producing substances and providing relief from pain [1]. In summary, millimeter wave therapy for cancer pain is highly effective, though its underlying mechanisms require further investigation. As an important modality in palliative care for advanced cancer, millimeter wave therapy deserves widespread promotion.

　　References (omitted)