The incidence of testicular recurrence of childhood acute leukemia after total body irradiation (TBI) in conjunction with stem cell transplantation (SCT) has been reported to be as high as 24%. The authors studied the incidence of testicular failure in a large series of male patients who underwent SCT using either TBI and a testicular irradiation boost or chemotherapy alone.

One hundred thirty-one boys with either acute myeloid leukemia (AML) or acute lymphocytic leukemia (ALL) were treated with SCT with either TBI with testicular boost (n = 94 patients), TBI without testicular boost (n = 1 patient), or chemotherapy alone (n = 36 patients) between 1991 and 1999.

The median follow-up was 26.5 months (range, 0.6-99.5 months) from the date of bone marrow infusion. Two patients in the study had a primary testicular failure after TBI with testicular boost followed by an umbilical cord blood transplantation. The first patient had ALL, did not engraft, and was rescued with autologous cells. He developed disease in the testicle 15 months afterward and subsequently died. The second patient had Philadelphia chromosome-positive ALL and developed a testicular recurrence 26 months after SCT. He was treated with orchiectomy, further testicular irradiation, and chemotherapy and remained in complete remission > 3 year after his failure. The incidence of testicular failure in boys who received TBI and testicular irradiation who survived > or = 1 year was 4.2%. There were no primary testicular failures reported in boys who received chemotherapy alone.

Boys with AML or ALL had a low incidence of primary testicular failure when they were treated with TBI plus a testicular boost or with chemotherapy alone.