Salivary evaluation in radioactive I131 treated patients with thyroid carcinoma.

BACKGROUND AND OBJECTIVE: radioiodine treatment (I131) used to treat thyroid carcinomas produces side effects (sialadenitis, xerostomia, dysphagia and caries susceptibility) reflecting in a poor patient quality of life. This study aimed to evaluate the effect of I131 on salivary function and possible oral impairment. MATERIAL AND METHODS: Thirty-seven patients undergoing I131 were submitted to oral examination, answer questions regarding xerostomia/hyposalivation and collect saliva at three moments (M1: 30-45 days before I131, M2: 1-2 days after I131 and M3: 7-10 days after treatment). Saliva was assayed for flow rate and calcium/phosphate concentrations. RESULTS AND CONCLUSIONS: significant difference in calcium/phosphate concentration was shown between M1 and M2, with evident decrease at M2. Flow rate reduced right after treatment with 41% of patients returning to previous rate at M3 (no statistical difference). A higher number of patients related xerostomia and difficulty in swallowing food at M2. The results showed that xerostomia/hyposalivation, dysphagia and calcium/phosphate concentration decrease may be considered early radioiodine side effects.

Early and late adverse effects of radioiodine for pediatric differentiated thyroid cancer.

BACKGROUND: Radioiodine-131 (I131) therapy for differentiated thyroid cancer (DTC) is generally a safe and effective treatment, but it has some potential side effects, which have been well described in adults but less analyzed in children. Our aim was to describe early and late adverse events of radioactive I131 in pediatric patients. METHODS: All consecutive patients ≤18 years treated for DTC in the period 1980-2015 were retrospectively analyzed for early and late side effects of radioiodine. Early side effects include nausea/emesis, radiation thyroiditis, sialadenitis, dry mouth, and transient bone marrow (BM) suppression. Late complications include permanent salivary gland dysfunction, permanent BM suppression, pulmonary fibrosis, second cancers, and fertility problems. RESULTS: One hundred five pediatric patients were treated with I131 for DTC in our department for a total amount of 302 radioiodine treatments. In total, 127 early complications were recorded: 44 episodes of nausea/emesis; 30 sialoadenitis, 24 thyroiditis, 18 dry mouth, and 11 transient BM suppression. Early side effects were correlated with the amount of radioactivity administered in any treatment. Twelve children developed ≥1 late complication for a total of 20 complications: two permanent salivary gland dysfunction, four permanent BM suppression, five pulmonary fibrosis, four second malignancies, and five fertility alterations. Late events, except fertility alterations, were correlated with the number of therapies and cumulative activities of I131. CONCLUSIONS: In conclusion, early side effects of I131 are associated with the amount of administrated activities of each treatment, while the late effects are correlated with the number of treatments and cumulative activities of radioiodine, except for fertility problems.

Radiation-induced synchronous mandibular osteosarcoma and papillary thyroid carcinoma: A disguised conundrum.

With substantial improvement in survival in cancer patients, the risk of radiation-induced malignancy in previously irradiated areas is increasingly possible. Both radiation-induced sarcomas and papillary thyroid carcinomas (PTCs) are well documented in literature. However, radiation-induced synchronous malignancies are rare, are often misdiagnosed, and presents with diagnostic and therapeutic challenges due to paucity of literature and lack of available guidelines. Here, we report a case of radiation-induced synchronous mandibular osteosarcoma and PTC in a previously treated carcinoma of base tongue with concurrent chemoradiation. He initially presented with an oral cavity mass, and during the course of the treatment was incidentally diagnosed with a synchronous PTC. It also establishes the indolent course of PTC, which often goes undiagnosed till the presentation with regional nodal metastasis. This report, to the best of our knowledge, is the first reported case of synchronous radiation-induced OSM and PTC.

Lacrimal System Obstruction After Radioiodine Therapy in Differentiated Thyroid Carcinomas: A Prospective Comparative Study.

BACKGROUND: Radioiodine therapy (RIT) is an established treatment for differentiated thyroid carcinomas, and is widely used throughout the world, given the increasing incidence of this malignancy. Although serious adverse effects are infrequent, complications such as dry mouth, sialadenitis, and dysphagia have been described. The involvement of the eyes and accessory visual structures is not commonly discussed, despite dry eye, keratoconjunctivitis, and lacrimal system obstruction (LSO) being reported, especially after high cumulative doses of radiopharmaceuticals. The incidence of LSO is not well established. OBJECTIVES: The aim of this study was to determine the frequency of LSO in patients undergoing RIT at 2, 4, 6, and 12 months after treatment. METHODS: Patients with differentiated thyroid carcinoma undergoing (group 1) and not undergoing (group 2) RIT were evaluated in the preoperative and postoperative periods and 2, 4, 6, and 12 months post surgery or post RIT. Patients underwent tear film evaluation and lacrimal system probing and irrigation. RESULTS: Group 1 (n = 44; 88 eyes) contained three patients (four eyes) with LSO, corresponding to an incidence of 4.55% (four events in 88 eyes) or 6.8% (three cases in 44 patients). Group 2 (n = 43; 86 eyes) did not present any cases of LSO. CONCLUSIONS: In this study, an active prospective investigation allowed LSO detection during the first six months after RIT. This finding demonstrates the importance of making this association clear to patients and health professionals, with a view to early diagnosis, appropriate treatment, and preventing LSO-related complications.

Radiotherapy planning techniques for thyroid cancer.

External beam radiotherapy has a role in each histological type of thyroid cancer. For treatment confined to the thyroid bed, an antero--oblique wedged pair of beams is simple to apply. More frequently, however, the volume needs to include both sides of the neck and adequate dose must be given down to the level of the suprasternal notch, precluding use of lateral fields. Thus, anterior and posterior fields are usually necessary, extending from the tips of the mastoid processes or hyoid down to the carina and laterally to include both sides of the neck and supraclavicular fossae. The mandible and infraclavicular portions of both lungs are shielded, but there is no midline lead in the phase one volume. A mid-plane dose of 46 Gy given in 23 daily fractions results in an acceptable early radiation reaction and will avoid late damage to the spinal cord. Because of considerable variation of interplanar distance along the length of the volume, a lateral simulator film should be taken to determine the maximum cord dose. For most patients, a three-dimensional CT planned phase two volume will be required and should be determined prior to completing phase one. The optimum beam arrangement, usually incorporating conformal beam shaping assisted by use of a multileaf collimator, should avoid further dose to the cord. If there is additional dose to the spinal cord, this phase can be introduced before 46 Gy is reached.

Radioiodine uptake in the head and neck.

OBJECTIVE: To report two cases of sinusitis-associated radioiodine uptake in patients with thyroid cancer and to review the reported causes of false-positive radioiodine uptake in the head and neck area. METHODS: We present the radiologic findings in two patients who had undergone treatment for papillary thyroid cancer and discuss other settings in which radioiodine uptake suggested the presence of metastatic disease. RESULTS: Radioiodine whole-body scans of two patients who had had thyroid cancer demonstrated uptake in the sphenoid and maxillary sinuses, respectively, mimicking bone or brain metastatic involvement. The thyroglobulin levels were low. Computed tomographic (CT) scanning disclosed mucosal swelling in the sinuses, consistent with sinusitis. The radioiodine uptake cleared on a follow-up scan in one case and was more localized than the CT findings in the other. Eighteen causes of false-positive radioiodine uptake in the head and neck area have been reported. On the basis of the mechanism of uptake, they can be classified into four categories: (1) physiologic uptake (ectopic thyroid tissue), (2) nonthyroidal pathologic conditions (dacryocystitis, sinusitis, sinus mucocele, sialadenitis, folliculitis, Warthin's tumor, parotid cyst, porencephaly, posttraumatic cerebromalacia, and inflammation due to dental disease or a nose ring), (3) internal retention (ectasia of the carotid artery and an artificial eye), and (4) external contamination by body secretions (sweat and nasal, tracheobronchial, lacrimal, and salivary secretions). The estimated prevalence of external contamination in the head and neck area on whole-body radioiodine scans is 0.3%. CONCLUSION: Physicians should rule out the presence of radioiodine uptake by inflamed mucosa of the paranasal sinuses, as well as various other causes of false-positive radioiodine uptake, before metastatic thyroid cancer in the head and neck area is diagnosed.

Effect of reserpine on salivary gland radioiodine uptake in thyroid cancer.

Nine patients with thyroid cancer were treated with reserpine in an attempt to reduce radiation exposure to the salivary glands from 100-150 mCi doses of I-131 therapy to thyroid remnants or metastases. Three control patients were not treated with reserpine but did receive 100-150 mCi of I-131. Parotid/background ratios of activity after radioablative doses of I-131 in patients not treated with reserpine were significantly higher than the patients treated with reserpine, and this was also true seven days after the radioablative dose. Combined therapy with reserpine, chewing gum, lemon candies, and hydration is suggested for the prevention of sialadenitis and xerostomia due to large doses of radioiodine.

Interstitial radioactive implants for oral and oropharyngeal cancer: dentistry's role.

Five patients with oral or oropharyngeal cancer were treated with external beam radiation therapy and interstitial radioactive implants as part of their tumor management. The radiation oncologists used various radioisotopes and techniques for placement. Local anesthesia, and in most cases conscious sedation, were used instead of general anesthesia to insert the implants. The dental team, working in conjunction with the radiation oncologists, was able to provide this service which resulted in safe, cost-effective care for the patients.

Verrucous carcinoma--changing concepts in management.

Verrucous carcinoma is an unusual, non-metastasizing, distinct variant of a well differentiated squamous cell carcinoma. Multiple biopsies are frequently necessary to establish its diagnosis. Seven of 10 patients treated with irradiation showed no evidence of anaplastic transformation. A high recurrence rate in tumors of the oral cavity treated with either irradiation or surgery alone is noted. Extensive lesions in this area may benefit from combined therapy. A good response to radiotherapy with a low recurrence rate in small laryngeal lesions is recognized. Irradiation should be considered in the management of this tumor without undue concern for change in its biologic behavior.