Incidental Findings of Intense Radioiodine Uptake in Struma Ovarii and Bilateral Nonlactating Breasts Simultaneously on Postablation <Superscript>131</Superscript>I SPECT/CT for Papillary Thyroid Cancer

A 52-year-old woman diagnosed with papillary thyroid carcinoma was referred for ¹³¹I therapy following total thyroidectomy. She was given 4,810 MBq (130 mCi) of ¹³¹I following 4 weeks of thyroid hormone withdrawal. A posttherapy scan showed intense, focal activity in the pelvis and intense, diffuse activity on both sides of the chest, which was localized to the right ovary and both breasts on SPECT/CT examination. She had bilateral nipple pain and a history of antidopaminergic drugs as combination medication for her rheumatoid arthritis and prokinetics during radioiodine therapy. On a ¹²³I whole-body scan 9 months later after stopping the drugs, bilateral breast uptake was not visible; however, right ovarian focal uptake was still visualized. Bilateral salpingo-oophorectomy was performed, and revealed struma ovarii with substantial internal necrosis due to radioiodine therapy. This case is interesting as two rare entities, ¹³¹I therapy-related struma ovarii and drug-related breast uptake, were simultaneously visualized.     

Airway complication occurring during radioiodine treatment for Graves' disease

Airway complications rarely occur in ¹³¹I radioiodine therapy for Graves' disease. This study presents two cases in which ¹³¹I therapy caused this acute complication. The patients complained of the symptom 6 h and 33 h after administration of ¹³¹I. A histamine H1 receptor antagonist and hydrocortisone rapidly resolved symptoms in both cases. These two cases remind physicians that ¹³¹I therapy for Graves' disease may cause potentially life-threatening complications.     

Nasolacrimal drainage obstruction after radioiodine therapy: case report and a review of the literature

The authors report a 54-year-old woman with papillary thyroid carcinoma (Lindsay type, pT2 N0 M1) with pulmonary metastases. After a total thyroidectomy, a series of 3 radioiodine therapies were performed with a cumulative dose of 700 mCi I-131. After termination of the therapy, the patient was initially without complaints, but approximately 6 months later, epiphora was noted, first only of the right eye and eventually of both eyes. A whole-body I-131 scan performed 1 year after final radioiodine therapy showed atypical tracer accumulation in both medial orbital regions. This finding was new compared with the scan that was done 1 year before. Dacryocystography revealed bilateral occlusion of the lacrimal drainage system. A review of the literature shows that epiphora and lacrimal duct alterations are rarely investigated and potentially underestimated side effects after high-dose radioiodine therapy.     

No evidence of chromosome damage in children and adolescents with differentiated thyroid carcinoma after receiving 131I radiometabolic therapy, as evaluated by micronucleus assay and microarray analysis

Purpose  As ¹³¹I therapy, used to achieve ablation of thyroid gland remnant, can cause chromosome damage in cultured peripheral lymphocytes especially, we investigated whether administration of radioiodine may induce early genome damage in peripheral T lymphocytes of adolescents with differentiated thyroid carcinoma (DTC). Methods  We studied 11 patients, aged 14.8 ± 3.1 years, who assumed ¹³¹I (range: 1.11–4.44 GBq) to ablate thyroid remnant. A blood sample for micronucleus assay and for evaluating expression of some genes involved in the DNA repair or the apoptosis pathways was obtained from each patient 1 h before (T₀) and 24 (T₁) and 48 h (T₂) post-radioiodine administration. Results  Compared to T₀, we did not find any difference in the number of micronucleated cells at both T₁ and T₂ in any subject. Nine out of 11 patients had altered expression levels in a majority of the DNA repair and apoptosis genes at T₁, which decreased at T₂. Conclusions  We demonstrated for the first time that peripheral cells of DTC children and adolescents who received ¹³¹I at a mean dosage of 3.50 ± 0.37 GBq did not show chromosome damage within 48 h from the end of radiometabolic therapy. This may be due to a prompt activation of the cell machinery that maintains the integrity of the genome to prevent harmful double-strand breaks from progressing to chromosome mutations, either by repairing the lesions or by eliminating the most seriously damaged cells via apoptosis. Statement on financial support. The present study did not receive any extramural financial assistance. It was supported exclusively by the Azienda Ospedaliero-Universitaria Pisana.     

<Superscript>131</Superscript>I-MIBG Therapy in metastatic phaeochromocytoma and paraganglioma

Purpose ¹³¹Iodine metaiodobenzylguanidine (¹³¹I-MIBG) is a radiopharmaceutical used for scintigraphic localisation of phaeochromocytomas and paragangliomas. The experience with its therapeutic use is limited. We report our experience for the treatment of malignant phaeochromocytoma and paraganglioma. Materials and methods The charts of 19 patients with malignant phaeochromocytoma (n = 12) or paraganglioma (n = 7), who were treated with ¹³¹I-MIBG, were retrospectively reviewed. Four patients (21%) received radiotherapy, three (16%) chemotherapy, and in one patient (5%), both chemotherapy and radiotherapy was given before ¹³¹I-MIBG therapy. Response to ¹³¹I-MIBG treatment was evaluated by objective as tumour response, biochemical and subjective response. Results Of the 19 patients, 13 (68%) were men, 6 (32%) were women. Ages ranged from 22 to 68 years (median, 47). The median initial dose was 7.4 GBq (200 mCi; range, 6.7 GBq–25.9 GBq, 180–700 mCi); median cumulative dose was 22.2 GBq (600 mCi; range, 6.8 GBq–81.4 GBq, 183–2200 mCi). Objective tumour response was achieved in 47% of the patients. Biochemical response rate was 67%, and symptomatic response was seen in 89% of the patients. Overall median follow-up was 29 months, with a range of 3–93 months. Haematologic complications were the most common side effects and were observed in 26% of the patients. Conclusion Our data support that symptomatic and biochemical response can be reached with ¹³¹I-MIBG therapy in patients with metastatic phaeochromocytoma and paraganglioma. Although complete tumour response was not observed, the palliation and control of tumour function by ¹³¹I-MIBG therapy may be valuable for the patients.     

Pulmonary sequestration: a 131I whole body scintigraphy false-positive result

A 35-year-old woman affected by a well-differentiated papillary thyroid carcinoma was referred to our hospital to perform a ¹³¹Iodine (¹³¹I) whole body scintigraphy for restaging purpose. The patient had been previously treated with total thyroidectomy and three subsequent doses of ¹³¹I for the ablation of a remnant jugular tissue and a suspected metastatic focus at the superior left hemi-thorax. In spite of the previous treatments with ¹³¹I, planar and tomographic images showed the persistence of an area of increased uptake at the superior left hemi-thorax. This finding prompted the surgical resection of the lesion. Histological examination of the surgical specimen showed the presence of a pulmonary tissue consistent with pulmonary sequestration. Even though rare, pulmonary sequestration should be included in the potential causes of false-positive results of radioiodine scans.     

Significance of Salivary Gland Radioiodine Retention on Post-ablation 131I Scintigraphy as a Predictor of Salivary Gland Dysfunction in Patients with Differentiated Thyroid Carcinoma

Purpose

We investigated whether ¹³¹I whole-body scintigraphy could predict functional changes in salivary glands after radioiodine therapy.

Methods

We evaluated 90 patients who received initial high-dose (≥3.7 GBq) radioiodine therapy after total thyroidectomy. All patients underwent diagnostic (DWS) and post-ablation (TWS) ¹³¹I whole-body scintigraphy. Visual assessment of salivary radioiodine retention on DWS and TWS was used to divide the patients into two types of groups: a DWS+ or DWS- group and a TWS+ or TWS- group. Salivary gland scintigraphy was also performed before DWS and at the first follow-up visit. Peak uptake and %washout were calculated in ROIs of each gland. Functional changes (Δuptake or Δwashout) of salivary glands after radioiodine therapy were compared between the two groups.

Results

Both peak uptake and the %washout of the parotid glands were significantly lower after radioiodine therapy (all p values <0.001), whereas only the %washout were significantly reduced in the submandibular glands (all p values <0.05). For the parotid glands, the TWS+ group showed larger Δuptake and Δwashout after radioiodine therapy than did the TWS- group (all p values <0.01). In contrast, the Δuptake and Δwashout of the submandibular glands did not significantly differ between the TWS+ and TWS- groups (all p values >0.05). Likewise, no differences in Δuptake or Δwashout were apparent between the DWS+ and DWS- groups in either the parotid or submandibular glands (all p values >0.05).

Conclusion

Salivary gland radioiodine retention on post-ablation ¹³¹I scintigraphy is a good predictor of functional impairment of the parotid glands after high-dose radioiodine therapy.     

Bilateral Renal Metastasis of Hürthle Cell Thyroid Cancer with Discordant Uptake Between I-131 Sodium Iodide and F-18 FDG

Renal metastasis of thyroid cancer is extremely rare. We report the case of a 62-year-old woman with Hürthle cell thyroid cancer (HCTC) with lungs, bones, and bilateral kidneys metastases. The renal metastatic lesions were clearly demonstrated by ¹³¹I whole body scan (WBS) with SPECT/CT. However, they exhibited false-negative results in ¹⁸F-FDG PET/CT, kidney ultrasonography, and contrast-enhanced CT scan. The findings imply that tumors have low glucose metabolism and are able to accumulate radioiodine, which is not commonly found in the relatively aggressive nature of HCTC. The patient received two sessions of 200 mCi ¹³¹I therapy within 6 months duration. There was complete treatment response as evaluated by the second post-therapeutic ¹³¹I SPECT/CT and serum thyroglobulin. To our knowledge, renal metastasis from HCTC with positive ¹³¹I but negative ¹⁸F-FDG uptake has not been reported in the literature. This case suggests that ¹³¹I SPECT/CT is useful for lesion localization and prediction of ¹³¹I therapy response.     

Radioiodine uptake in a renal cyst mimicking a metastasis in a patient affected by differentiated thyroid cancer: case report and review of the literature

We report a 55-year-old man affected by differentiated thyroid carcinoma with lymph nodes metastases. After conventional levothyroxine withdrawal, the patient underwent thyroid remnant ablation by oral administration of radioiodine-131 ablative activity (3700 MBq). 7 days later, post-therapy whole body scan (pWBS) demonstrated thyroid remnant and showed a large area of abnormal radioiodine uptake located in the posterior left upper abdomen. Ultrasonography of the abdominal region revealed a cyst in left kidney corresponding to the focal radioiodine uptake. On the same day, ¹³¹I static images of the posterior upper abdomen obtained before and after administration of furosemide, showed that radioiodine uptake in the lesion was markedly lower after diuretic administration, indicating that radioiodine accumulation in the renal cyst is linked to an active secretory process by the renal tubule. Due to its non-negligible frequency, renal cyst should be taken into account in DTC patients as a potential pitfall at ¹³¹I pWBS.     

Radioactive contamination of contact lenses during radioiodine therapy

Although the secretion of radioiodine in tears is not unexpected, there are only few investigations in that field. We report the measurement of 131I in disposable contact lenses for daily use during radioiodine treatment. After administration of 740 MBq 131I, all contact lenses of a 59-year-old female used the day before and 5 days after radioiodine therapy were collected and measured in a gamma counter. Activities of 124 Bq (right) and 139 Bq (left) were measured in the contact lenses used during the first day after administration of radioiodine. The activity in the contact lenses of the following days was significantly lower. An initial dose rate of approximately 0.31 microSv x h(-1) was caused by the radioactivity resulting in a total dose of 13 microSv to the patient's eye lens. That dose is negligible compared to the dose caused by the incorporated radioactivity.     

6家医院碘治疗场所工作人员甲状腺131I活度测量

目的调查碘治疗场所工作人员甲状腺131I活度水平及其主要影响因素。方法采用配额抽样的方法, 按照碘治疗场所医院的不同类型, 在山西省和山东省共选择6家开展碘治疗的医院, 采用直接测量法, 对76名碘治疗场所工作人员的甲状腺131I活度进行了测量, 并进行内照射剂量估算。结果共有5家医院的29人甲状腺131I活度高于仪器的探测限, 占全部被检测人员的38.16%, 其中最高值为2 468.45 Bq, 是1名负责手动分装放射性碘的医师。6家医院碘治疗场所工作人员甲状腺131I活度差异无统计学意义(P>0.05), 但手动分装131I的医院测量结果高于自动分装的医院, 差异有统计学意义(Z=1.75, P<0.01), 两家手动分装131I医院的12名碘治疗场所工作人员甲状腺测量结果全部高于探测限, 中位数分别为324.59 Bq和331.98 Bq, 4家使用自动分装仪的医院测量结果的中位数均低于探测限, 甲状腺131I检出率分别为32.61%、25.00%、10.00%和0。对于同一家医院, 参与分装131I的医生和保洁人员甲状腺131I活度高于不参与分装的医生, 差异有统...     

Simultaneous dacryocystography and dacryoscintigraphy using SPECT/CT in the diagnosis of nasolacrimal duct obstruction

Epiphora, an abnormal overflow of tears, is commonly caused by tear drainage system anomalies including nasolacrimal duct obstruction. To assess morphologic abnormalities, dacryocystography by CT is used when CT contrast material is syringed into the lacrimal drainage system. To evaluate the function of the system, dacryoscintigraphy is the most readily available noninvasive method. In the case presented, a 43-year-old man was referred to our clinic with an 8 months' history of indefinite left side epiphora. After performing dacryoscintigraphy, we acquired SPECT/CT images during dacryocystography by CT to establish the surgical indication.     

Radiotherapy with iodine-131 in recurrent malignant struma ovarii

Malignant struma ovarii is a very rare disease and, therefore, there is neither common agreement on treatment regimens nor sufficient follow-up experience. We present a case of a 49-year-old woman with malignant struma ovarii of the follicular type, who received ablative radioiodine treatment after thyroidectomy and surgical removal of the primary tumour. During followup examinations an increasing thyroglobulin level was found, caused by a tumour relapse with suspected urinary bladder infiltration on CT and proven uptake of radioiodine on whole-body scanning with iodine-131. After administration of 6 GBq¹³¹I, complete tumour regression was achieved with no evidence of a new relapse during a 30-month follow-up period. Correspondingly, repeated thyroglobulin measurements were all negative. This case demonstrates the benefit of combined surgical and radioiodine treatment of malignant struma ovarii for both monitoring and therapy of relapse or metastases; thus, the same therapeutic regimen as is employed in primary differentiated thyroid carcinoma may be recommended.     

Thyroid carcinoma and hot nodule

A 70-year-old woman presented with a nodule in the thyroid gland. ¹³¹I scintigraphy of the gland showed a hot nodule. Histology of the resected thyroid revealed a papillary adenocarcinoma. Although a thyroid carcinoma with a hot nodule seen on the radioiodine isotope scan is a very rare occurrence, it is clinically very important because it may indicate a thyroid malignancy.     

Metastatic phaeochromocytoma with a long-term response after iodine-131 metaiodobenzylguanidine therapy

Iodine-131 metaiodobenzylguanidine ([¹³¹I] MIBG), a radiopharmaceutical agent, is used for treating malignant phaeochromocytoma. [1311]MIBG therapy results in a hormone response rate of approximately 50%, but generally it yields only a partial or no tumour response. We present a case of a 46-year-old woman with a familial history of von Hippel-Lindau disease, who was treated with [1311]MIBG for a metastatic phaeochromocytoma involving the lungs, liver and bones. The patient received a cumulative dose of 33.3 GBq (900 mCi) and a complete hormone response was observed, as evaluated on the basis of catecholamine and metanephrine levels. Conventional radiography, computerized tomography and [1311]MIBG scintigraphy indicated that a near-complete tumour regression was achieved, with no evidence of relapse during a 4-year follow-up period. This case thus demonstrates that treatment with [¹³¹I]MIBG may lead to a dramatic tumour response in malignant phaeochromocytoma presenting both soft tissue and bone metastases.     

False-positive uptake of I-131 in a laryngocele mimicking thyroid remnant after thyroidectomy for papillary thyroid carcinoma

A 66-year-old woman underwent total thyroidectomy for papillary thyroid carcinoma stage pT4 followed by radioiodine therapy with 3.7 GBq (100 mCi) iodine-131. Radioiodine therapy revealed intense radioiodine uptake of the neck, which was interpreted as thyroid remnant tissue. Follow-up whole-body scans with iodine-131 in hypothyroidism 3 months and 1 year after radioiodine therapy revealed focal uptake in the neck. Computed tomography and gadolinium-enhanced MRI of the neck demonstrated an ovoid lesion in the larynx without gadolinium enhancement. Neither thyroid remnant tissue nor enlarged cervical lymph nodes could be demonstrated either on CT or on MRI. Further examination of the patient in the ear, nose and throat department confirmed the finding of a laryngocele and biopsies demonstrated benign tissue. Follow-up whole-body scans with iodine-131 in hypothyroidism 3 years and after injection of rhTSH 5 years after radioiodine therapy reproduced the focal uptake in the neck. After initial radioiodine therapy thyroglobulin levels were never measurable, not at any of the whole-body scans in hypothyroidism, after rhTSH, or at intermediate follow-up examinations under TSH-suppressive levothyroxine therapy. The patient declined definitive operative revision of the laryngocele and is in good health 8 years after the diagnosis of papillary thyroid carcinoma.     

Treatment of recurrent nasolacrimal duct obstructions with balloon-expandable metallic stents: results of early experience.

PURPOSETo evaluate the efficacy of Palmaz balloon-expandable metallic stents for the maintenance of luminal patency in the treatment of recurrent nasolacrimal duct, obstructions after failed transluminal balloon dilatation.METHODSMetallic stents were implanted in the nasolacrimal duct of four patients with recurrent epiphora. All the patients had already undergone transluminal balloon dilatation of the nasolacrimal duct with no or only temporary improvement. In two eyes, 9.5-mm-long Palmaz stents were used; in the other two eyes, 20-mm-long articulated-design Palmaz stents were placed under digital fluoroscopic monitoring. In each case, the upper tip protruded slightly into the lacrimal sac and the lower end was positioned inside the nasolacrimal duct.RESULTSThe stents were placed accurately in all cases, and no complications were observed. After stent placement, all patients had complete resolution of epiphora. During the follow-up period of 10 months, although complete obstruction did not occur in any case, complete resolution of epiphora was maintained only in one of four eyes. In two eyes, improvement was remarkable. In one eye with partial improvement, intrastent balloon dilatation was performed.CONCLUSIONTreatment of recurrent nasolacrimal duct obstructions with balloon-expandable metallic stents is a noninvasive, efficient, and safe outpatient procedure that may be an alternative to surgery as a means for managing epiphora.     

Relationship between cumulative radiation dose and salivary gland uptake associated with radioiodine therapy of thyroid cancer

AIM: To estimate the individual absorbed dose to the parotid and submandibular salivary glands in radioiodine therapy and its dependence from the previous cumulative therapy. METHODS: Fifty-five patients with differentiated thyroid carcinoma after thyroidectomy received 1-21 GBq (131)I using single activities of 1-6 GBq. The patients were stratified according to the cumulative activities into low-activity (1-2 GBq), middle-activity (3-7 GBq), and high-activity groups (9-21 GBq). The time-activity curves over the respective salivary glands were derived from multiple static calibrated images measured for each patient up to 48 h after ingestion of the radioiodine therapy capsule with a gamma camera. Manually drawn regions of interests were used to determine the background activities and the activities arising from the salivary glands. The gland volumes were determined by ultrasonography using appropriate volume models. RESULTS: The median absorbed dose per administered activity of each single parotid and submandibular gland was about 0.15 Gy.GBq (range, 0.1-0.3 Gy.GBq(-1)) and 0.48 Gy.GBq(-1) (range, 0.2-1.2 Gy.GBq(-1)), respectively. The maximum uptake of both gland types was significantly lower for the high-activity than for the low-activity groups and correlated with the mean cumulative administered activity of the activity groups. CONCLUSION: The iodine uptake of salivary glands is significantly reduced, whereas the absorbed dose per administered (131)I activity was not significantly decreased during the course of therapy. Comparing the well-known dose-effect relationships in external radiation therapy, the absorbed dose per administered (131)I activity is too low to induce comparable radiation damage, suggesting an inhomogeneous distribution of (131)I in human salivary glands.     

<Superscript>124</Superscript>I-L19-SIP for immuno-PET imaging of tumour vasculature and guidance of <Superscript>131</Superscript>I-L19-SIP radioimmunotherapy

Purpose  The human monoclonal antibody (MAb) fragment L19-SIP is directed against extra domain B (ED-B) of fibronectin, a marker of tumour angiogenesis. A clinical radioimmunotherapy (RIT) trial with ¹³¹I-L19-SIP was recently started. In the present study, after GMP production of ¹²⁴I and efficient production of ¹²⁴I-L19-SIP, we aimed to demonstrate the suitability of ¹²⁴I-L19-SIP immuno-PET for imaging of angiogenesis at early-stage tumour development and as a scouting procedure prior to clinical ¹³¹I-L19-SIP RIT. Methods   ¹²⁴I was produced in a GMP compliant way via ¹²⁴Te(p,n)¹²⁴I reaction and using a TERIMO™ module for radioiodine separation. L19-SIP was radioiodinated by using a modified version of the IODO-GEN method. The biodistribution of coinjected ¹²⁴I- and ¹³¹I-L19-SIP was compared in FaDu xenograft-bearing nude mice, while ¹²⁴I PET images were obtained from mice with tumours of <50 to ∼700 mm³. Results   ¹²⁴I was produced highly pure with an average yield of 15.4 ± 0.5 MBq/μAh, while separation yield was ∼90% efficient with <0.5% loss of TeO₂. Overall labelling efficiency, radiochemical purity and immunoreactive fraction were for ¹²⁴I-L19-SIP: ∼80 , 99.9 and >90%, respectively. Tumour uptake was 7.3 ± 2.1, 10.8 ± 1.5, 7.8 ± 1.4, 5.3 ± 0.6 and 3.1 ± 0.4%ID/g at 3, 6, 24, 48 and 72 h p.i., resulting in increased tumour to blood ratios ranging from 6.0 at 24 h to 45.9 at 72 h p.i.. Fully concordant labelling and biodistribution results were obtained with ¹²⁴I- and ¹³¹I-L19-SIP. Immuno-PET with ¹²⁴I-L19-SIP using a high-resolution research tomograph PET scanner revealed clear delineation of the tumours as small as 50 mm³ and no adverse uptake in other organs. Conclusions   ¹²⁴I-MAb conjugates for clinical immuno-PET can be efficiently produced. Immuno-PET with ¹²⁴I-L19-SIP appeared qualified for sensitive imaging of tumour neovasculature and for predicting ¹³¹I-L19-SIP biodistribution. Bernard M. Tijink and Lars R. Perk contributed equally to this article.     

Pre-therapeutic blood dosimetry in patients with differentiated thyroid carcinoma using 124-iodine: predicted blood doses correlate with changes in blood cell counts after radioiodine therapy and depend on modes of TSH stimulation and number of preceding radioiodine therapies

Objective

Pre-therapeutic blood dosimetry prior to a high-dose radioiodine therapy (RAIT) is recommended and a blood dose of 2?Gy is considered to be safe. In this study, changes in the blood cell count after radioiodine therapy of high risk differentiated thyroid carcinoma (DTC) were analyzed and compared with the results of the pre-therapeutic blood dosimetry using ¹²⁴I. Moreover, the influence of different modes of TSH stimulation and the number of preceding radioiodine therapies on the blood dose were assessed.

Methods

198 patients with locally advanced or metastasized DTC received a pre-therapeutic blood dosimetry using ¹²⁴I. To analyze the influence of the modes of TSH stimulation and the number of preceding RAITs on blood dose subgroups were built as follows: patients with endogenous TSH stimulation versus patients with exogenous TSH stimulation and patients with no preceding RAIT versus patients with at least one preceding RAIT. In 124/198 patients subsequent RAIT was performed. In 73/124 patients, hemograms were performed from day 2 to 12?month after RAIT.

Results

There was no high-grade bone marrow toxicity (i.e. ??grade 3) in patients receiving less than 2?Gy blood dose??independent of the therapeutic history. Within the first month after radioiodine therapy, there was an overall decrease in the white blood cell and platelet counts. The erythrocyte count was essentially stable. There was a correlation between cell count decrease and predicted blood doses (Spearman??s correlation coefficient >?0.6 each) for the white cell line and the platelets. With regard to the subgroups, the blood dose per administered ¹³¹I activity (BDpA) was significantly higher in patients with endogenous TSH stimulation (median 0.08?Gy/GBq) than in patients with exogenous TSH stimulation (0.06?Gy/GBq) and in patients with no previous RAIT (0.08?Gy/GBq) compared to patients who had previously undergone at least one RAIT (0.07?Gy/GBq).

Conclusions

The range of BDpA among DTC patients is rather wide. Our results suggest that lower blood doses can be expected when using exogenous TSH stimulation and blood doses are generally higher at first RAIT compared to subsequent RAITs. Thus, we advise to make blood dosimetry standard praxis prior to a high-activity RAIT.