Canterbury DHB



The term "reduced intensity" conditioning (RIC) is used to describe regimens which are less myelotoxic than conventional intensity myeloablative conditioning, usually result in reversible myelosuppression within 28 days without stem cell support, result in mixed chimerism in a proportion of patients at first assessment and have lower rates of non-haematological toxicity.

A second definition used by the CIBMTR in retrospective analyses defines RIC as a regimen containing <500 cGy single dose or <800 cGy fractionated TBI, <9 mg/kg oral busulphan (or IV equivalent), <140 mg/m2 melphalan, <10 mg/kg thiotepa, and the BEAM regimen (Giralt, Ballen et al. 2009).

Confusion over terminology sometimes arises because most RIC regimens still produce significant myelosuppression but there are some which result in no or very little myelosuppression. Both can be referred to as "reduced intensity" but the latter are more accurately described as "non-myeloablative".

There is general agreement that a RIC allograft does have a lower treatment related mortality (TRM) compared to standard allograft. However this is to some extent balanced by a lower anti tumour effect from the less intensive conditioning. Infection and GvHD remain significant risks to the patient, but there is evidence that any anti tumour effect is closely linked to the presence of chronic GvHD.

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About this Canterbury DHB document (8885):

Document Owner:

Andrew Butler (see Who's Who)

Last Reviewed:

December 2016

Next Review:

December 2018


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Topic Code: 8885