Dosimetric Evaluation of the Uterus in Patients Receiving Total Body Irradiation with Ovarian Shielding.

Infertility is a well-known late complication in patients receiving hematopoietic stem cell transplantation (HSCT). We previously reported that total body irradiation (TBI) with ovarian shielding reduces the radiation dose to the ovaries to 2.4 Gy - one-fifth of the dose compared to conventional TBI - and preserves fertility without increasing the risk of relapse. Exposure to the uterus and ovaries can reportedly affect pregnancy and childbirth. However, the dose constraint of the uterus that causes infertility remains unknown. Herein, we report the pregnancy and birth outcomes of 2 patients who gave birth following TBI with ovarian shielding and evaluated the dose to the uterus using a dose-volume histogram. Case 1 involved a 30-year-old woman with acute myeloid leukemia who underwent HSCT at 21 years of age with a uterus mean dose (D mean) of 7.0 Gy. She had a natural pregnancy and elective cesarean section at 38 weeks of gestation due to hypertensive disorders of pregnancy. She gave birth to a normal-birthweight infant. Case 2 involved a 32-year-old woman with T-cell acute lymphoblastic leukemia who underwent HSCT at 30 years of age with a uterus D mean of 7.6 Gy. Her baby was delivered at full term with normal birthweight. These results indicate that a uterus D mean between 7.0 and 7.6 Gy does not have a significant impact on pregnancy and delivery with the ovarian function being preserved for patients who received TBI with ovarian shielding after puberty.

Dosimetric evaluation of ovaries and pelvic bones associated with clinical outcomes in patients receiving total body irradiation with ovarian shielding.

Total body irradiation (TBI) with ovarian shielding is expected to preserve fertility among hematopoietic stem cell transplant (HSCT) patients with myeloablative TBI-based regimens. However, the radiation dose to the ovaries that preserves ovarian function in TBI remains poorly understood. Furthermore, it is uncertain whether the dose to the shielded organs is associated with relapse risk. Here, we retrospectively evaluated the relationship between fertility and the dose to the ovaries, and between relapse risk and the dose to the pelvic bones. A total of 20 patients (median age, 23 years) with standard-risk hematologic diseases were included. Median follow-up duration was 31.9 months. The TBI prescribed dose was 12 Gy in six fractions for three days. Patients' ovaries were shielded with cylinder-type lead blocks. The dose-volume parameters (D98% and Dmean) in the ovaries and the pelvic bones were extracted from the dose-volume histogram (DVH). The mean ovary Dmean for all patients was 2.4 Gy, and 18 patients recovered menstruation (90%). The mean ovary Dmean for patients with menstrual recovery and without recovery were 2.4 Gy and 2.4 Gy, respectively, with no significant difference (P = 0.998). Hematological relapse was observed in five patients. The mean pelvis Dmean and pelvis D98% for relapse and non-relapse patients were 11.6 Gy and 11.7 Gy and 5.6 Gy and 5.3 Gy, respectively. Both parameters showed no significant difference (P = 0.827, 0.807). In conclusion, TBI with ovarian shielding reduced the radiation dose to the ovaries to 2.4 Gy, and preserved fertility without increasing the risk of relapse.

Updated Clinical Outcomes of Hematopoietic Stem Cell Transplantation Using Myeloablative Total Body Irradiation with Ovarian Shielding to Preserve Fertility.

Myeloablative conditioning regimens are associated with severe gonadal toxicity. To preserve ovarian function, we have been investigating ovarian shielding during total body irradiation (TBI) with a myeloablative dose. In this report, we update the clinical outcomes. Female patients with standard-risk hematologic diseases, aged 40 years or younger, who desired to have children, were included (n = 19). The conditioning regimen consisted of TBI at 12 Gy with ovarian shielding and cyclophosphamide (120 mg/kg) or cytarabine (24 g/m2). Ovarian shielding reduced the actual irradiation dose applied to the ovaries from 12 Gy to 2 to 3 Gy. The median age at hematopoietic stem cell transplantation (HSCT) was 24 years (range, 19 to 33 years). With a median follow-up period of 1449 days (range, 64 to 3694) after HSCT, 5-year overall survival and 1- and 5-year relapse rates were 67%, 17%, and 31%, respectively. Only 2 of 14 patients with acute myeloid or lymphoid leukemia in remission have relapsed thus far. The 6-month and 1-year cumulative rates of menstrual recovery were 42% and 78%, respectively. In all patients with menstrual recovery, menstruation recovered within 1 year. The serum anti-Müllerian hormone (AMH) level tended to gradually increase after menstrual recovery. Three patients with extensive chronic graft-versus-host disease experienced delayed recovery of menstruation and serum AMH. Five pregnancies in 3 patients resulted in normal delivery in 1, selective cesarean operation in 1, current pregnancy in 1, and natural abortion in 2. These results suggest that a myeloablative TBI regimen with ovarian shielding could preserve fertility after HSCT without an apparent increase in relapse in standard-risk patients. Because serum AMH recovered gradually over time, the AMH level during the early phase after HSCT may have little value as a marker of ovarian reserve.

Assessment of the ovarian reserve with anti-Müllerian hormone in women who underwent allogeneic hematopoietic stem cell transplantation using reduced-intensity conditioning regimens or myeloablative regimens with ovarian shielding.

Conditioning regimens that include cyclophosphamide (CY) and total body irradiation (TBI) induce severe gonadal toxicity and permanent infertility in approximately 90 % of female patients who undergo hematopoietic stem cell transplantation (HSCT). However, the use of ovarian shielding or non-myeloablative regimens may preserve ovarian function. To evaluate the ovarian reserve, serum anti-Müllerian hormone (AMH) levels were retrospectively measured in 11 female HSCT recipients aged less than 40 years, including seven with acute leukemia (AL) and four with aplastic anemia (AA), who received a myeloablative conditioning regimen with ovarian shielding or a reduced-intensity conditioning regimen. In most patients, menstruation had stopped and AMH level had decreased to an undetectable level (<0.1 ng/ml) after HSCT. Most patients showed a recovery of regular menstruation, but AMH levels did not increase immediately after the resumption of menstruation. However, in three AL patients and two AA patients who were evaluable for long-term recovery, AMH level increased gradually beyond 1 year after HSCT. In conclusion, recovery of the serum AMH level may be delayed after HSCT, and the AMH level early after HSCT may not accurately reflect ovarian reserve. A prospective study is required to address the usefulness of measuring the AMH level in HSCT recipients.