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

Hope for motherhood: pregnancy after allogeneic hematopoietic cell transplantation (a national multicenter study)

ABSTRACT

Improved long-term survival rates after allogeneic hematopoietic cell transplantation (alloHCT) make family planning for young adult cancer survivors an important topic. However, treatment-related infertility risk poses challenges. To assess pregnancy and birth rates in a contemporary cohort, we conducted a national multicenter study using data from the German Transplant Registry, focusing on adult women aged 18 to 40 years who underwent alloHCT between 2003 and 2018. Of 2654 women who underwent transplantation, 50 women experienced 74 pregnancies, occurring at a median of 4.7 years after transplant. Fifty-seven of these resulted in live births (77%). The annual first birth rate among HCT recipients was 0.45%, which is >6 times lower than in the general population. The probability of a live birth 10 years after HCT was 3.4%. Factors associated with an increased likelihood of pregnancy were younger age at alloHCT, nonmalignant transplant indications, no total body irradiation or a cumulative dose of <8 Gy, and nonmyeloablative/reduced-intensity conditioning. Notably, 72% of pregnancies occurred spontaneously, with assisted reproductive technologies used in the remaining cases. Preterm delivery and low birth weight were more common than in the general population. This study represents the largest data set reporting pregnancies in a cohort of adult female alloHCT recipients. Our findings underscore a meaningful chance of pregnancy in alloHCT recipients. Assisted reproductive technologies techniques are important and funding should be made available. However, the potential for spontaneous pregnancies should not be underestimated, and patients should be informed of the possibility of unexpected pregnancy despite reduced fertility. Further research is warranted to understand the impact of conditioning decisions on fertility preservation.

Effects of Radiation Therapy on the Female Reproductive Tract in Childhood Cancer Survivors: A PENTEC Comprehensive Review

PURPOSE

The PENTEC (Pediatric Normal Tissue Effects in the Clinic) task force aimed to quantify effects of radiation therapy (RT) dose to the female reproductive organs after treatment for childhood cancer.

METHODS AND MATERIALS

Relevant studies published 1970 to 2017 were identified systematically through PubMed, Medline, and Cochrane databases with additional articles before 2021 identified by the group. Two large studies reported sufficient data to allow modeling of acute ovarian failure (AOF; loss of function ≤5 year from diagnosis) and premature ovarian insufficiency (POI; loss of function at attained age <40 years) based on maximum dose to least affected ovary. Although normal tissue complication probability modeling was not feasible for the uterus due to limited data, the relationship between ultrasound-measured uterine volume and estimated amount of RT was plotted. Limited data regarding vaginal toxicity were available.

RESULTS

The risk of AOF increases with RT dose to least affected ovary, alkylating agent cumulative dose (cyclophosphamide equivalent dose [CED] in g/m2), age at RT, and stem cell transplantation: Two Gy to the least affected ovary resulted in AOF risk of 1% to 5% (CED = 0, risk increasing with age), 4% to 7% (CED = 10 g/m2, risk increasing with age), and 6% to 13% (CED = 30 g/m2, risk increasing with age). For patients aged 1 and 20 years at time of RT, AOF risk was ≥50% at doses of 24 Gy and 20 Gy with no alkylating chemotherapy, 22.5 Gy and 17 Gy with intermediate alkylator dose (10 g/m2), and 17 Gy and 13 Gy with high alkylator dose (30 g/m2). Risk of POI increases with survivor (attained) age (rather than age at time of RT), radiation dose to least affected ovary, and alkylator dose. Data review suggested that higher radiation doses to the uterus are associated with uterine toxicity, with uterine size considerably restricted after 12 Gy. Vaginal radiation in children is associated with high toxicity risk, although dose-volume data are not available for quantification.

CONCLUSIONS

Risk of AOF increases with age at RT, CED exposure, and RT dose; risk of POI likewise increases with RT dose, CED exposure, and survivor age. Both AOF and POI are expected to affect fertility and estrogen production. Data suggest that RT uterine dose >12 Gy may be associated with uterine size restriction. Adult literature suggests that maintaining vaginal dose <5 Gy may limit toxicity. Treatment of life-threatening malignancy remains a priority over reproductive preservation; however, when possible, radiation and surgical techniques should be considered to minimize dose to least affected ovary, uterus, and vagina. Survivors should receive endocrine and gynecologic support; those desiring pregnancy should be counseled early to maximize reproductive options.

Prospective study of a modified posttransplant cyclophosphamide regimen for severe aplastic anemia patients with HLA-haploidentical transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative modality for severe aplastic anemia (SAA). The availability of haploidentical donors has expanded valid choices for SAA. However, previous posttransplantation cyclophosphamide (PTCy)-based protocols for HLA-haploidentical HSCT in SAA patients are associated with relatively delayed neutrophil and platelet engraftment. We prospectively studied HLA-haploidentical HSCT using bone marrow combined with peripheral blood stem cells as grafts and a modified PTCy regimen for treating SAA; we evaluated the efficacy and safety of this regimen, which had an increased dose (from 4.5 mg/kg to 6.0 mg/kg) and backward adjusted timing (from day -9 to -7 to day -5 to -3) of antithymocyte globulin (ATG) compared with previous PTCy protocols. Seventy-one eligible patients were included in this prospective study between July 2019 and June 2022. The median time to and cumulative incidence (CI) of neutrophil and platelet engraftment were 13 days (range, 11-19) and 97.2±2.2% and 12 days (range, 7-62) and 94.4 ± 2.9%, respectively. Five patients experienced graft failure (GF), including 2 with primary GF and 3 with secondary GF. The CI of GF was 7.0±3.1%. The interval between diagnosis and transplantation (≥1 year) was a risk factor for GF development (HR 8.40, 95% confidence interval (1.40-50.47), p=0.02). No patients developed grade IV acute graft-versus-host disease (aGVHD) or severe chronic GVHD (cGVHD). The 100-day CI of grade II-IV aGVHD and 2-year cGVHD were 13.4±4.2% and 5.9±2.9%, respectively. With a median follow-up of 580 days (range, 108-1014) for 63 survivors, the estimated 2-year overall survival (OS) and 2-year GVHD-free and failure-free survival (GFFS) were 87.3% (95% confidence interval, 79.4-96.0) and 83.8% (95% confidence interval, 74.9-93.7), respectively. In conclusion, the PTCy regimen with an increased dose and backward adjusted timing of ATG is an effective and feasible choice for treatment with HLA-haploidentical HSCT using BM combined with PBSCs as grafts, with a high rate of and faster engraftment, a low rate and intensity of aGVHD and cGVHD, and prolonged OS and GFFS.

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.