Skip the main content if you do not want to read it as the next section.
Skip the location trail if you do not want to read it as the next section.
Location trail
HEALTH PROFESSIONALS > DISCUSSION TOPICS > FERTILITY & CANCER TREATMENT > RADIOTHERAPYFertility and radiotherapy treatment
Effect of radiotherapy on the ovaries
The degree of damage caused by radiotherapy to the ovary depends on the person’s age, the field of radiation, the total dose and the number of fractions needed to deliver the dose. Fractionated radiation is less likely to cause injury than a single fraction of equivalent dose. Younger women appear to be able to tolerate higher doses. Women who are in their late reproductive years would probably require only a dose of 4Gy to induce a menopause, whereas this dose would probably not influence ovarian function in an adolescent. Doses in excess of 10Gy will cause ovarian failure in the majority of adult women.(20) It has recently been reported that a dose as low as 2Gy may be sufficient to reduce the number of remaining eggs by 50%.(26)
The ovaries will be directly affected when radiotherapy is given to the abdomen or during TBI. They may also receive scatter during lower-spinal irradiation. The effects of radiotherapy will be potentiated if gonadotoxic chemotherapy has also been given. Age can be significant when it comes to the possibility of recovery from these effects, with children treated at a younger age having the greater likelihood of recovery.
Uterine radiation in childhood increases the incidence of nulliparity, miscarriage and small-for-dates infants.(27)
Girls who have received low-dose cranial irradiation prophylaxis for ALL may experience an early puberty. It has also been reported that cranial radiation given to children with ALL can potentially reduce fertility, depending on the age at which the child was treated.(28)
Effect of radiotherapy on the testes
G.C.W. Howard cites a study (reported by Rowley in 1974) in which the testes of male volunteers were exposed to incremental doses of X-rays. From this study, according to Howard, it is apparent that the germinal epithelium is more sensitive to radiation than the supporting Leydig cells.(29)
Spermatogonia (early progenitor sperm cells) can be affected by very small doses of radiotherapy resulting in either azoospermia or oligospermia.8 The effects of radiation on the testes are dependent on how it is given. Doses given in fractions over a number of weeks cause more damage than single doses. There may be a period of delay (6–22 weeks) before a reduction in the sperm count is seen. Recovery of sperm production can take months or years depending on the dose of radiation the testes have received.
Doses given as part of TBI conditioning for stem cell or bone marrow transplantation will generally produce permanent azoospermia, although sperm production does recover in a small number of cases.(24)
Direct irradiation of the testes impairs testosterone production in most boys.(30) The total dose and fractionation schedule of testicular irradiation determines the degree of damage. The risk of Leydig cell damage associated with radiation is directly related to the dose delivered and inversely related to age at treatment. Doses above 20Gy cause Leydig cell failure in most pre-pubertal boys but doses above 30Gy are required in adolescent boys and young adults. Permanent azoospermia is likely to occur following doses of more than 40Gy.(26) These boys will require androgen replacement therapy.
Content last reviewed: 01 February 2007
Page last modified: 22 February 2007
Page last modified: 22 February 2007