Mild Decreases in White Blood Cell and Platelet Counts Are Present One Year After Radioactive Iodine Remnant Ablation
ABSTRACT Bone marrow suppression after multiple, high-dose radioactive iodine (RAI) therapies is well described. However, changes in the peripheral complete blood count (CBC) that may occur after a single treatment of RAI such as that commonly used for routine remnant ablation is much less well studied. In this retrospective trial, we examined the rate of persistent anemia, leukopenia, and thrombocytopenia 1 year after a single RAI administration.
Peripheral blood counts at baseline were compared to those obtained 1 year after RAI remnant ablation in 206 consecutive thyroid cancer patients. Analyses were performed to determine the potential impact of both the method of preparation (recombinant human thyroid stimulating hormone [rhTSH] vs. thyroid hormone withdrawal) and administered activity of (131)I on hemoglobin, white blood cell (WBC), and platelet counts.
Comparison of the baseline CBC before RAI ablation (median administered activity of approximately 3700 MBq or 100 mCi) with the follow-up CBC done 1 year later demonstrated a statistically significant decline in total WBC (6.7 +/- 2.1 x 10(9) vs. 6.0 +/- 1.8 x 10(9)/L, p < 0.001; 9.7% below the reference range at 1-year follow-up) and platelet (272 +/- 67 vs. 250 +/- 65 x 10(9)/L, p < 0.001; 5.8% below the reference range at 1-year follow-up) with no significant change in hemoglobin (1.40 +/- 0.14 vs. 1.40 +/- 0.14 g/L or 14.0 +/- 1.4 vs. 14.0 +/- 1.4 g/dL; 1.5% below the reference range at 1-year follow-up). There were no significant clinical complications observed during the 1-year follow-up period. The changes in total WBC and platelets were not related to the method of preparation or the administered activity of RAI.
A single RAI treatment of approximately 3700 MBq (100 mCi) after thyroidectomy is associated with a statistically significant, mild decline in WBC and platelet counts that persists for at least 1 year after ablation. Given the small magnitude of the changes and the lack of clinically significant adverse events, these observations should not decrease the use of RAI ablation in moderate to high-risk patients in whom the benefits of ablation are likely to outweigh these minor risks.
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ABSTRACT: Risk assessment is the cornerstone of contemporary management of thyroid cancer. Following thyroid surgery, an initial risk assessment of recurrence and disease-specific mortality is made using important intra-operative findings, histologic characteristics of the tumor, molecular profile of the tumor, post-operative serum thyroglobulin and any available cross-sectional imaging studies. This initial risk assessment is used to guide recommendations regarding the need for remnant ablation, external beam irradiation, systemic therapy, degree of TSH suppression, and follow-up disease detection strategy over the first 2 years after initial therapy. While this initial risk stratification provides valuable information, it is a static representation of the patient in the first few weeks post-operatively that does not change over time. Depending on how the patient responds to our initial therapies, the risk of recurrence and death may change significantly during follow-up. In order to account for differences in response to therapy in individual patients and to incorporate the impact of treatment on our initial risk estimates, we recommend a re-stratification of risk at the 2-year point of follow-up. This re-stratification provides an updated risk estimate that can be used to guide ongoing management recommendations including the frequency and intensity of follow-up, degree of ongoing TSH suppression, and need for additional therapies. Ongoing management recommendations must be tailored to realistic, evolving risk estimates that are actively updated during follow-up. By individualizing therapy on the basis of initial and ongoing risk assessments, we can maximize the beneficial effects of aggressive therapy in patients with thyroid cancer who are likely to benefit from it, while minimizing potential complications and side effects in low-risk patients destined to have a full healthy and productive life after minimal therapeutic intervention.Clinical Oncology 08/2010; 22(6):419-29. DOI:10.1016/j.clon.2010.04.005 · 2.83 Impact Factor
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ABSTRACT: Objective: The aim of this study was to evaluate the effect of radioactive iodine (RAI) ablation therapy on the complete blood count (CBC) in thyroid cancer patients. Materials and Methods: One hundred sixty four patients undergoing RAI ablation therapy after total thyroidectomy were included. CBC results were available from the patients’ medical records at the time of ablation and at the 1st, 6th, and 12th months after RAI therapy.Results: Hemoglobin (Hb), white blood cell (WBC) and platelet (Plt) values were significantly lower than baseline at 1 month after treatment (p<0.0001). Hb and WBC values were increased at the 6th month and at the 1st year. Plt values increased at the 6th month but had decreased again at the 1st year. The values were usually in normal ranges except in the patients with low pretreatment Hb and WBC values.Conclusion: RAI ablation therapy in thyroid cancer patients is a safe treatment modality without any serious or persistent hematological side effects.Turkish Journal of Haematology 12/2010; 27(4). DOI:10.5152/tjh.2010.40 · 0.34 Impact Factor
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ABSTRACT: Both radioactive iodine (RAI) and external beam radiation therapy (EBRT) offer important clinical benefits in properly selected patients with differentiated thyroid cancer. With the increased emphasis on a risk-adapted model for the management of thyroid cancer, it is important to identify which patients are most likely to benefit from radiation therapies given in the adjuvant setting and as treatment of gross residual disease. This review compares the authors' current management practices with the recommendations of published guidelines from both the National Comprehensive Cancer Network and the American Thyroid Association. Because of the lack of prospective randomized studies on either RAI or EBRT in differentiated thyroid cancer, recommendations must be based on retrospective cohort studies that vary in selection criteria, histologies, sample size, inclusion criteria, and follow-up. RAI has an important adjuvant therapy and treatment function in properly selected patients. Likewise, EBRT is associated with increased locoregional control and palliative therapeutic effects in high-risk patients.Cancer control: journal of the Moffitt Cancer Center 04/2011; 18(2):89-95. · 2.66 Impact Factor