Assessment of response to treatment in Hodgkin’s lymphoma with 99mTc-HYNIC-TATE

Objectives Hodgkin’s lymphoma is a lymphatic system malignancy with good response to treatment and is consideredcurable. Selection of proper treatment has a significant effect on the patient’s outcome. Staging of the disease, response to treatment and relapse rates are all crucial for management. Anatomic imaging is the basis of patient management but it cannot distinguish residual tumor mass from necrotic or fibrotic tissueafter treatment. This failure in therapy assessment induces tendency to functional imaging. This study is an attempt to show the efficiency of scanning with 99mTc-HYNIC -TATE in assessment of the response of Hodgkin’s disease to treatment.

Methods 30 patients with histological confirmation of Hodgkin’s lymphoma,who had been assessed with conventional imaging,underwent 99mTc-HYNIC-TATE(Octreotate) scan. 99mTc-Octreotate scintigraphy and conventional imaging for assessment of response to therapy were done for all of the patients before and after completion of the treatment course. Planar and SPECT images were taken 4 h after injection of 20 mCi of 99mTc-HYNIC TATE and the images were interpreted by two nuclear medicine specialists. Areas of abnormal uptake were also quantitatively compared to their counterparts. The results were compared with the results of the CT scan in both phases. The Results of CT findings and scintigraphy changes after treatment were used to determine the response to treatment

Results 30 Patients (17 males and 13 females with a mean age of 29 years) were included in this study. All patients had abnormal 99mTc-octreotate uptake in the involved areas. Sensitivity and specificity of the Octreotate scan in detection of response to treatment were 92%and 75% respectively. 14 patients had negative Octreotate scan after treatment. 13 patients of this group, did not undergo further treatment andshowed no evidence of residual tumor or relapse in 1 year follow-up. One patient with negative scan but positive CT findings got the second line of therapy.16 patients who had positive scintigraphy and CT findingsafter treatment (remnant tumor in 9 patients, no response in 6 patients and progression in 1 patient) got the second line of therapy

Conclusions Like previous studies, the findings of this study indicate that99mTc-HYNIC-TATE scintigraphy along with conventional CT are cost effectiveness methods for assessment of response to treatment of patients with Hodgkin’s Lymphoma especially in assessment of residual mass in the supradiaphragmatic regions. Considering these radiopharmaceutical characteristics and the availability and production of its kit in many countries, which do not have easy access to PET/CT scan, the authors recommend the application of 99mTc-HYNIC-TATE scintigraphyto assess the response of Hodgkin’s Lymphoma to treatment.