Transvaginal Photobiomodulation for the Treatment of Chronic Pelvic Pain: A Pilot Study

Abstract

Background: Chronic pelvic pain (CPP) is a common and debilitating condition that affects millions of U.S. women. Most treatments are ineffective and innovative new therapies are desperately needed. Large, controlled studies show that photobiomodulation (PBM) can reduce pain in patients with other chronic pain conditions, such as low back pain, neck pain, and fibromyalgia. The objective of this pilot study was to determine if transvaginal PBM (TV-PBM) can reduce pain in women with CPP. Methods: We conducted a before and after, observational, pilot study. Patients completed the Short Form-McGill Pain Questionnaire (SF-MPQ) at baseline, 1 week, 3 months, and 6 months after nine treatments of TV-PBM. Clinicians completed the Clinical Global Impression Scale (CGI) assessing patient illness severity at the same time. Wilcoxon rank-sum t-tests and effect size using Cohen's d coefficient (low effect size if d < 0.2, medium if 0.2 < d > 8, and high if d > 0.8) was used to measure degree of pain improvement, which was also considered clinically significant if pain reduction was >30%. Results: Thirteen women completed 9 treatments, and 10 women were successfully followed to 6 months. At baseline, the mean SF-MPQ score was 19.7 (standard deviation [SD] ± 5.9). Compared with baseline, 60% improved; the mean SF-MPQ score decreased to 10.0 (SD ±7.5, p = 0.004, d = 1.6) at 1 week after treatment, to 9.7 (SD ±7.9, p = 0.005, d = 1.7) at 3 months, and 8.2 (SD ±8.1, p = 0.002, d = 1.9) at 6 months. Conclusion: Transvaginal PBM provided significant and sustained pain relief to women with CPP up to 6 months. Further controlled studies are needed to confirm these findings, however, in this initial pilot, TV-PBM shows promise.

Keywords: chronic pelvic pain; low-level laser therapy; photobiomodulation.

FIG. 1.

Photobiomodulation device with transvaginal probe.

FIG. 2.

Percent of patients in each severity of illness category on the Clinical Global Impression (CGI) scale before and after treatment. CGI, Clinical Global Impression scale.

FIG. 3.

Mean severity of illness scores on the Clinical Global Impression scale before and after treatment.

FIG. 4.

Changes in global improvement scores from pre- to post-treatment.

FIG. 5.

Mean therapeutic effect scores (efficacy) comparing baseline to after treatment.

FIG. 6.

Change in SF-MPQ Mean Score for Each Pain Descriptor Across Time. SF-MPQ, Short Form-McGill Pain Questionnaire.