Locoregional recurrence or persistence of papillary carcinoma: radioiodine treatment Michele Klain, Marco Salvatore Department of Functional and Biomorphological Science University of Naples "Federico II" Rome 18th-June-09
Differentiated thyroid cancer (DTC) 1% of malignancies incidence 0.5-10 per 100,000 per year DTC is the most frequent endocrine neoplasia significant social-health impact prevalence similar to myeloma, the LH and Ca esophagus or larynx
Differentiated thyroid cancer (DTC) 1948 First treatment with 131-I of the DTC (JCEM 8: 423, 1948) Since then, more knowledge on biophysical properties and intracellular biokinetic of 131I have partially changed the method of treatment and applications
When therapy with 131 I is indicated post-surgical ablation of thyroid remnants loco-regional recurrence distant metastases Tg high levels and negative 131 I WBS
Ablation of thyroid remnants - Definition: "Destruction of normal residual thyroid tissue after thyroidectomy" - Purpose: Eradicate postoperative microscopic residual DTC Increase WBS post-teraphy sensitivity. Decrease recurrence and mortality rates. Facilitate early detection of recurrences by serum Tg measurement.
Radioactive Iodine Ablation (SIE-AIMN-AIFM ) NO YES low-risk patients: unifocal papillary tumours without lymph-node or distant metastases (pt1an0m0) medium high-risk patients: with all CTD staging more than pt1an0m0, the follicular carcinomas, aggressive variants of papillary carcinoma and poorly differentiated tumors at all stages.
Mazzaferri, JCEM 86:1447, 2001
Post-surgical thyroid ablation Total Thyroidectomy No teraphy Lt4 3-4 weeks low iodine diet TSH > 30 mu/l Study: RAI 131 I ABLATIVE TERAPHY NO 131 I WBS PRE-TERAPHY (Stunning and reduced sensibility) Yes 131 I WBS POST-TERAPHY
WBS I-131 131 I pre-terapy (diagnostic) 131 I post-terapy (therapeutic) Sensitivity : 56% Sensitivity: 79%
Recombinant Human TSH (rh-tsh) in DTC rhtsh for diagnostic and therapeutic purposes in post-surgical thyroid ablation. rhtsh in metastases should be limited to certain special populations. Schlumberger M. et al, Eur J Med Mol Imaging 36:329-330; 2009
0.9 mg rhtsh 0.9 mg rhtsh 131-I W.B.S. Post teraphy 0 1 2 3 4 5 6 TBS post-rhtsh TSH 140 Tg 1
131 I in local- regional recurrences (15%-20% of cases) SURGERY Followed by 131 I (3.7 GBq) Surgery non indicated 131 I (3.7-5.5 GBq)
131 I teraphy of loco-regional recurrences Palpation, Ultasonography, MRI and thyroglobulin. Iodine-131 treatment effective mainly in small lesions (<1cm). Surgery is always the main treatment. FDG-PET before surgery can show small mediastinal lesions. Probe in patients with local and regional recurrences is decesive and useful and permits a complete resection of funtional neoplastic foci (gamma-probe) (^). (^) Travagli JP et al, J Clin Endocrinol Metab 1998; 83:598-605.
Imaging of local and regional recurrences Ultrasonography 7.4 GBq I-131
MRI in the thyroid carcinoma Diagnosis pre surgery of thyroid nodules Valutation of retrosternal extentions Identification of limpho-node involved Invaded structures (muscles, trachea, esofagus, vein, tissues)
MRI advantages in diagnosis local-regional limphnodes in DTC Trachea Esofagus
MRI advantages in diagnosis mediastinal limphnodes in DTC lfd lfd
Positron emission tomography (PET) PET is not indicated in initial stadium, especially when local regional recurrences. PET can be useful in patients with high thyroglobulin level and/or 131I-WBS negativ. PET can be useful in patients with poorly differentiated thyroid carcinoma.
Comparison of PET with ultrasonography of patients with DTC 100% 80% 60% 40% 20% 0% PET US Sensibilità Grant et al, World J Surg, epub 2008
High Tg but negative post-therapeutic I-131 scanning WBS PET US
High Tg but negative post-therapeutic I-131 scanning Papillary thyroid Cancer
High Tg but negative post-therapeutic I-131 scanning PET/TC Follicular Carcinoma
Imaging: PET-TC TC PET PET-TC
PET: Follow-up (12months) 100% 77% Tg norm Tg no norm 81% 80% 60% 40% 20% 0% PET- 13% 19% PET+ Salvatore et al. Q J Nucl Med Mol Imm. 2008 Jun;52(1):2-8.
Sensibility PET basal vs PET rhtsh * * 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Lesion Organi Patients Pet Basale PET rhtsh Schlumberger et al J Clin Endocrinolol Metab 2009
The diagnostic value of 124I-PET in patients with differentiated thyroid cancer 124I-PET 131I/TBS diagnostic 131I/TBS therapeutic Ha et al Eur J Nucl Mol Imaging 2007
The diagnostic value of 124I-PET in patients with differentiated thyroid cancer 124I-PET FDG-PET Ha et al Eur J Nucl Mol Imaging 2007
Recurrent/metastatic thyroid carcinomas false negative for serum thyroglobulin but positive by posttheraphy I- 131 whole body scans Thyroglobulin: 52 patients with negative serum Tg and positive post I-131 therapy metastatic sites were found predominantly in the cervical region and mediastinal lymph nodes Thyroglobulin: 128 patients with positive Tg and positive post I-131 therapy metastatic sites were found predominantly We recomned the complementary use of post-therapy I-131 Park et al, Eur J Nucl Med Mol Imaging 2009, 36:172-179
Recurrent/metastatic thyroid carcinomas false negative for serum thyroglobulin but positive by posttheraphy I- 131 whole body scans Follow-up. F a 50-year-old Papillary thyroid carcinoma Total thyroidectomy After serial I-131 treatment, thyroid remnant activity and functioning metastases to cervical and mediastinal lymph nodes disappeared At initial ablation therapy, her serum Tg level was 3.3 ng/ml, which converted to a negative finding over the I-131 treatment course Park et al, Eur J Nucl Med Mol Imaging (2009) 36:172 179
CONCLUSION Iodine 131 ablation may decrease the recurrence and mortality rates by eradicating microscopic residual postperative tumor foci. Iodine 131 ablation facilitates the early detection of recurrences by serum thyroglobulin and WBS-I131. Cancer-related deaths are less frequent when recurrences are discovered on WBS-I131 than at clinical examination. This suggest that their early discovery may improve their outcome.