OBJECTIVETo investigate the feasibility of 9Tc(m)-HL91 imaging in prediction of 34 radiotherapy sensitivity of naqsopharyngeal cancer( NPC) and its relationship with prognosis.

METHODSpatients with NPC confirmed by pathology, staging from II-IVa, underwent 99Tc(m)-HL91 SPECT imaging one week before radiotherapy. 18 of them received adjuvant chemotherapy. The hypoxia in primary nasopharyngeal lesions and cervical lymph node metastases were calculated semi-quantitatively, and compared with clinical findings in medium-term therapy at 4 months and 1 year post therapy.

RESULTS(1) There was no significant relationship between the total preliminary curative effect of adjuvant chemotherapy and the degree of nasopharyngeal lesion hypoxia (T/Mu, gamma = -0.394, P = 0.145; T/ Ce gamma = -0.510, P = 0.052). But there was a significant difference between the partial curative effect group and significant curative effect group. (2) The degree of NPC regression in the medium-term radiotherapy group was negatively correlated with the degree of hypoxia (T/Mu, gamma = -0.602; T/Ce, gamma = -0.643, P < 0.01). (3) 23 patients had good local control except one case with lung and bone metastasis 4 months post-therapy. The lesions disappeared or not developed in 6 patients (T/Mu 1.30 +/- 0.23, T/Ce 3.61 +/- 0.84). Two patients at stage III and IVa relapsed (T/Mu were 1.40 and 1.27, respectively; T/Ce were 4.10 and 3.85, respectively), there was no significant difference. (4) The degree of lymph node hypoxia had no correlation with the curative effect on medium-term radiotherapy.

CONCLUSION99 Tc(m)-HL91 hypoxia imaging may predict sensitivity to radiotherapy in patients with NPC, with a potential help to carry out individual therapy. However, further investigation is needed to ascertain whether it could predict the long-time curative effect on NPC radiotherapy.