Journal: American Journal of Obstetrics and Gynecology (in press, available now on-line for subscribers)

Authors: William Parker

From: UCLA School of Medicine, Los Angeles, CA.

Problem: Fibroids can usually be diagnosed by pelvic examination and ultrasound, but neither gives us exact information about the sizes, number, and positions of all fibroids present. Excellent studies show that MRI is the most accurate way to get all this information, but most gynecologists do not order MRIs or know how to interpret them.

Clinical Opinion: This article describes how MRI works, illustrates normal pelvic anatomy and the appearance of fibroids (and adenomyosis) on MRI and discusses the ways to limit the number of images and, therefore, the cost of an MRI. Three actual cases from my practice are presented to show how MRI can change the treatment options available to women with fibroids.

Authors’ (Dr. Parker’s) Conclusions: If your gynecologist is able to perform only a hysterectomy, then precise imaging of fibroids is not necessary since they will all be removed with the uterus. However, with many other treatment options now available, magnetic resonance imaging (MRI) can help tell us which options may be best. If your gynecologist does not offer the available, often less invasive, treatment options, accurate information allows you to find a gynecologist who has the skills to take care of you.

Journal: Procedings of the National Acadamy of Science U S A. 2008 Dec 16;105(50):19887-92.

Authors: Peddada SD, Laughlin SK, Miner K, Guyon JP, Haneke K, Vahdat HL, Semelka RC, Kowalik A, Armao D, Davis B, Baird DD.

Study from: National Institute of Environmental Health Sciences, NC

Problem: Fibroids are the leading cause of hysterectomy in the United States. Black women have a greater fibroid burden than whites, yet no study has systematically evaluated the growth of fibroids in blacks and whites.

Study: The authors tracked growth of 262 fibroids (size range: 1-13 cm in diameter) from 72 premenopausal participants (38 black and 34 white women). Fibroid volume was measured by computerized analysis of up to four MRI scans over 12 months.

Results: The average growth rate over 12 months was 9%, but the difference among women was very large: from -89% to +138%.  Seven percent of fibroids got smaller (>20% shrinkage). Fibroids from the same woman grew at different rates.

Black and white women younger than 35 had similar fibroid growth rates. However, growth rates declined with age for white, but not for black women.  Growth rates were not dependant on initial fibroid size, location in the uterus, women’s weight, or number of children.

Most fibroids did not grow (0% change), but other fibroids either grew or got smaller.

Authors’ Conclusions: 1) fibroids can get smaller; 2) fibroids from the same woman grow at different rates, despite exposure to the same hormones in the blood; 3) initial fibroid size does not predict its growth rate; 4) as black women age, they do not experience slower fibroid growth which may explain why black women have more fibroid-related symptoms.

Dr. Parker’s Comments: This is the first study to accurately track fibroid growth, both in different women and different fibroids in the same woman. I (and other gynecologists) have been telling women for 30 years that fibroids do not get smaller until after menopause – this study proves that idea wrong.  I have also been telling women that fibroid growth is unpredictable, some fibroids grow slowly, others fast and others go through growth spurts and then slow down (see next study below).  This idea turns out to be correct.  We do not understand what makes fibroids grow (or shrink), but it is clearly NOT estrogen excess.  If this were the case, as specifically addressed in this article, all fibroids in the same women, and thus exposed to the same hormone levels, would either grow or not grow.  And, that clearly does not happen.  Unfortunately, we still have a lot to learn about fibroid growth.

Short-term change in growth of uterine leiomyoma: tumor growth spurts.

Journal: Fertility & Sterility. 2011 Jan;95(1):242-6.

Authors: Baird DD, Garrett TA, Laughlin SK, Davis B, Semelka RC, Peddada SD.

Study from: National Institute of Environmental Health Sciences, North Carolina

Problem: No one has ever followed fibroid growth closely enough to see what happens over 3 month periods.

Study: 18 black and 18 white premenopausal women had 101 fibroids measured with MRI at the study beginning and again at 3, 6, and 12 months. Growth spurts were defined by growth rates greater than 30% in 3 months.

Results: Growth spurts were seen in 37 of the 101 fibroids. Fibroids from the same woman did not have similar growth, nor were age, race/ethnicity, number of children or a woman’s weight related to growth spurts.  However,fibroids smaller than 5 cm went through growth spurts more often than larger fibroids.

Authors’ Conclusions: Short spurts of growth are common for fibroids.

Dr. Parker’s Comments: As noted above, we do not understand what causes fibroids to grow, but these two studies show that fibroid growth is unpredictable and that small fibroids are likely to grow more quickly than larger (>5 cm) fibroids.

Magnetic resonance imaging (MRI) and transvaginal ultrasound for determining fibroid burden: implications for research and clinical care.

Authors: Levens ED, Wesley R, Premkumar A, Blocker W, Nieman LK.

Journal: Am J Obstet Gynecol. 2009 May;200(5):537.e1-7. Epub 2009 Mar 9.

Study performed by: Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.

Problem: The authors want to determine whether MRI or Ultrasound is better at finding fibroids.

Study: 18 women had both an MRI and an ultrasound before they had a hysterectomy. The uterus was then inspected by the pathologist to determine how many fibroids were present and these results were compared to what the MRI and ultrasounds had predicted.

Results: MRI found 80% of the fibroids, while ultrasound found only 40% of the fibroids.

Conclusions: MRI was superior to ultrasound for fibroid assessment.

Dr. Parker’s Comment: This study confirms what other studies have previously shown – that MRI is the best way to “see” fibroids before choosing a treatment or surgery. I find MRI particularly helpful if a patient wants a laparoscopic or robotic myomectomy. By looking at the MRI images myself, I know exactly where all the fibroids are, and whether they can all be removed during surgery. I have also had a number of women who were discovered to have fibroids inside the uterine cavity that were not seen with ultrasound. These women had all been told they needed an abdominal myomectomy or a hysterectomy, but were able to have a hysteroscopic myomectomy, the least invasive procedure with the fastest recovery.

MRI is not always necessary, though. If many fibroids are found with ultrasound and the uterus is very large, usually abdominal myomectomy is going to be the only successful way to take all the fibroids out. So, MRI will add nothing useful because I will be able to feel all the fibroids during surgery and know where they are. Also, if a woman wants to have a laparoscopic hysterectomy, then it is not necessary to know where the individual fibroids are since they will all be removed with the uterus.