Journal of Clinical and Scientific Research (Jan 2020)

Incremental value of post-high dose therapy I-131 scan over pre.therapy diagnostic I-131 scan in patients with differentiated thyroid cancer: Experience from a tertiary care centre in South India

  • Chandra Teja Reddy Singareddy,
  • Ranadheer Gupta Manthri,
  • V S Krishnamohan,
  • K B Sricharan,
  • Tekchand Kalawat,
  • Narendra Hulikal

DOI
https://doi.org/10.4103/JCSR.JCSR_122_19
Journal volume & issue
Vol. 9, no. 4
pp. 206 – 212

Abstract

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Objective: Objective of this study is to establish the incremental value of post-high dose therapy I-131 whole body scintigraphy (WBS) over diagnostic pre-therapy I-131 WBS in the detection of radioiodine avid foci, staging and change in the management in patients with differentiated thyroid carcinoma post-total thyroidectomy. Methods: We retrospectively studied 93 post-total thyroidectomy patients with well differentiated thyroid cancer (mean age 47 [range 18–78] years; 72 females) who underwent diagnostic dose pre-therapy? I-131 WBS and post-high dose therapy? I-131 WBS from January 2017 to June 2018 were included. Discordance rate of pre-therapy? I-131 WBS findings with post-therapy? I-131 WBS was calculated. Results: Post-therapy I-131 WBS revealed additional radioiodine avid foci not detected on pre-therapy? I-131 WBS in 16 (17.2%) patients. Upstaging was more common in patients =55 years (8 of 23, 34.8%) when compared to patients <55 years (1 of 70, 0.014%). In 13/93 patients (13.9%) who were considered as low risk on pre-therapy? I-131 WBS, 10 patients (10.7%) were found to be intermediate risk and 3 patients as high risk on post-therapy I-131 WBS. Conclusion: Post-therapy? I-131 WBS revealed new foci in 17.2% patients and clinical upstaging occurred in 9.6% of patients compared to pre-therapy I-131 WBS. There is a significant improvement in the detection of radioiodine avid foci overall and also metastatic lymph nodes by doing post-therapy? I-131 WBS. We suggest that post-therapy? I-131 WBS should be routinely done as it had an incremental role over pre-therapy? I-131 WBS in establishing the true extent of tumour burden, in upstaging the disease and thereby planning adequate hormone suppression to attain target thyroid stimulating hormone levels.

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