Intraoperative ultrasonography improves identification of recurrent thyroid cancer

Ultrasound-guided hookwire localization of non palpable cervical lymphadenopathy: A case-control study of operative time

OBJECTIVE

We aimed at evaluating the impact of ultrasound-guided (US) hookwire localization of nonpalpable cervical lymphadenopathy on operating time.

DESIGN AND METHODS

Retrospective case control study (January 2017 and May 2021) of 26 patients with lateral nonpalpable cervical lymphadenopathy undergoing surgery with (H+) and without (H-) per operative US-guided hook-wire localization. Operative time (general anesthesiology onset, hookwire placement, end of surgery) and surgery-related adverse events data were collected.

RESULTS

Mean operative time was significantly shorter in H+ group versus H- group (26 ± 16 min vs. 43 ± 22 min) (p = 0.02). Histopathological diagnosis accuracy was 100% versus 94% (H+ vs. H-, p = 0.1). No significant between group difference in surgery-related adverse events was reported (wound healing, p = 0.162; hematomas, p = 0.498; neoplasms removal failure, p = 1).

CONCLUSION

US-guided hookwire localization of lateral nonpalpable cervical lymphadenopathy allowed a significant reduction in operative time, comparable histopathological diagnosis accuracy and adverse events compared with H-.

Imaging of Cervical Lymph Nodes in Thyroid Cancer: Ultrasound and Computed Tomography

Sonographic evaluation of cervical lymph nodes in patients with thyroid malignancy is important both for preoperative staging and for post-treatment surveillance, and contrast-enhanced computed tomography plays a complementary role. Knowledge of anatomy and surgical approaches, combined with an understanding of the various imaging features that distinguish malignant from benign lymph nodes, allows for accurate staging, thereby enabling complete surgical initial resection.

Localización intraoperatoria de las recurrencias en cáncer de tiroides mediante la inyección de azul de metileno guiada por ecografía

Introducción. La cirugía para extirpación de metástasis en un cuello previamente intervenido afronta un reto para lograr una resección exitosa. El presente estudio pretende demostrar la utilidad de la técnica de inyección de azul de metileno, guiada por ecografía, para la localización intraoperatoria de lesiones recurrentes en cáncer de tiroides, para facilitar su resección. Métodos. Se realizó un estudio observacional, descriptivo y retrospectivo, en pacientes reintervenidos por recurrencia de carcinoma diferenciado de tiroides, durante un periodo de dos años y medio. Se utilizó la inyección intratumoral de azul de metileno guiada por ecografía para su identificación intraoperatoria de recurrencia. Se hizo análisis de variables demográficas y clínicas. Resultados. Este estudio incluyó 10 procedimientos en 9 pacientes, 77,8 % mujeres, con una media de edad de 54 años. Todos tenían un nivel de tiroglobulina detectable y elevado antes de la intervención; posteriormente, el 89 % presentó un descenso y el 33 % una adecuada respuesta bioquímica. La técnica agregó 10 minutos al tiempo quirúrgico. En el 100 % se identificaron de manera intraoperatoria los ganglios marcados; el promedio de ganglios resecados fue de 12, de los cuales, 6 fueron positivos, todos con carcinoma papilar de tiroides. Esta técnica se consideró de gran utilidad y de bajo costo en todos los casos. Discusión. Esta técnica se muestra como una estrategia efectiva para la identificación intraoperatoria de las recurrencias locorregionales en carcinoma de tiroides, permitiendo una disección ganglionar exitosa, disminuyendo complicaciones, tiempo quirúrgico y, especialmente, costos frente a otras intervenciones

Magnetic Probe–Guided Excision of Nonpalpable Neck Lesions

Background: Reoperative neck surgery is technically more demanding because of the presence of scar tissue and distorted anatomy. We aimed to investigate the magnetic probe–guided excision of nonpalpable neck lesions in patients with previously operated neck compartments. Methods: This study included 9 patients with recurrent/persistent thyroid carcinoma, recurrent/persistent hyperparathyroidism with previously operated neck compartments. The pathologic lesions were localized by ultrasonography, and magnetic tracer (0.2 mL, iron oxide) was injected directly into the pathologic lesions. Careful dissection was carried out following the area of maximum magnetic activity until the nonpalpable lesions were identified and excised. Result: All neck lesions were removed in 9 patients. The median count from lesion was significantly higher than values from lesion bed (background activity; (9900/5 seconds vs 250/5 seconds, P < .001). During follow-up, all patients had negative ultrasonography. Conclusion: Magnetic probe–guided technique could provide access to nonpalpable lesion localization in centers without readily available access to nuclear medicine facilities.

Intraoperative optical coherence tomography for assessing human lymph nodes for metastatic cancer

Background

Evaluation of lymph node (LN) status is an important factor for detecting metastasis and thereby staging breast cancer. Currently utilized clinical techniques involve the surgical disruption and resection of lymphatic structure, whether nodes or axillary contents, for histological examination. While reasonably effective at detection of macrometastasis, the majority of the resected lymph nodes are histologically negative. Improvements need to be made to better detect micrometastasis, minimize or eliminate lymphatic disruption complications, and provide immediate and accurate intraoperative feedback for in vivo cancer staging to better guide surgery.

Methods

We evaluated the use of optical coherence tomography (OCT), a high-resolution, real-time, label-free imaging modality for the intraoperative assessment of human LNs for metastatic disease in patients with breast cancer. We assessed the sensitivity and specificity of double-blinded trained readers who analyzed intraoperative OCT LN images for presence of metastatic disease, using co-registered post-operative histopathology as the gold standard.

Results

Our results suggest that intraoperative OCT examination of LNs is an appropriate real-time, label-free, non-destructive alternative to frozen-section analysis, potentially offering faster interpretation and results to empower superior intraoperative decision-making.

Conclusions

Intraoperative OCT has strong potential to supplement current post-operative histopathology with real-time in situ assessment of LNs to preserve both non-cancerous nodes and their lymphatic vessels, and thus reduce the associated risks and complications from surgical disruption of lymphoid structures following biopsy.

Role of charcoal tattooing in localization of recurred papillary thyroid carcinoma: initial experiences

Purpose

Surgical excision is the definitive treatment for localized recurrence of papillary thyroid carcinoma. Reoperation for recurrence, however, is challenging and associated with increased operative times and complication rates. For safe and effective reoperation, ultrasound-guided charcoal tattooing localization can be used. The aim of this study was to investigate the feasibility and safety of the ultrasound-guided charcoal tattooing localization.

Methods

Between November 2012 and August 2013, ten patients underwent preoperative charcoal tattooing localization for twelve recurrent lesions. Patient demographics, pathologic features, and operation results were reviewed.

Results

The technical success rate of charcoal tattooing was 100%. Eight patients had one recurrent lesion, and two patients had double lesions. Among these 12 recurrent lesions, three (25%) were found in level II, four (33%) in level IV, four (33%) in level VI, and one (8%) was found in the thyroidectomy bed site. The mean size of lesions was 0.87 ± 0.35 cm. Of these 10 patients, eight patients underwent selective lymph node dissection, one patient underwent modified radical neck dissection, and one patient underwent recurrent mass excision. Transient hypocalcemia developed in one patient, and no recurrent laryngeal nerve palsy occurred. There were no major complications related to the injection of the charcoal. The mean follow-up period after reoperation was 8.6 ± 2.7 months; in the follow-up ultrasound, there were no remnant lesions in all patients.

Conclusion

Preoperative ultrasound-guided charcoal tattooing localization for recurrent thyroid cancer appears to be a feasible and safe procedure for reoperation. Further evaluation is warranted in larger patients' cohorts.

Intraoperative ultrasonography is useful in surgical management of neck metastases in differentiated thyroid cancers

Differentiated thyroid carcinomas are the most common malignancies of endocrine organs. Metastases to cervical lymph nodes occur in 20-50% of cases. Recurrence and survival rates are closely related to the type of surgery performed. High-resolution ultrasonography (USG) is a sensitive imaging method used to detect occult lymph node metastases in patients with thyroid cancer. We evaluated how intraoperative USG affected surgical success. This was a retrospective study comparing two groups of patients with thyroid carcinoma who underwent cervical lymph node dissection. A total of 101 patients (33 males and 68 females) were included. Group 1 included 53 patients who underwent surgery with intraoperative USG guidance. Group 2 included 48 patients who underwent surgery without the use of USG. All patients were followed up (mean 23 months; range 5-44 months) with thyroglobulin measurements and USG evaluations. Group 1 (intraoperative USG) had a residual/recurrent tumor rate of 1.9% (1/53 patients). Group 2 had a residual/recurrent tumor rate of 12.5% (6/48 patients). A statistically significant difference appeared between the residual/recurrent tumor rates in Groups 1 and 2 (p<0.05). In addition to its classical use in diagnosis and follow-up, intraoperative use of high-resolution USG can improve surgical success and may decrease the number of residual/recurrent tumors encountered during follow-up.

The rate of operative success achieved with radioguided occult lesion localization and intraoperative ultrasonography in patients with recurrent papillary thyroid cancer

BACKGROUND

To investigate the rate of operative success in excision of nonpalpable lymph nodes with metastatic disease achieved with radioguided occult lesion localization (ROLL) and intraoperative ultrasonography (IOUS) in patients with papillary thyroid cancer (PTC).

METHODS

Twenty consecutive PTC patients with nonpalpable lymph nodes with metastatic disease localized in previously operated fields were randomized to receive ROLL (n = 11) or IOUS (n = 9). Nodes were excised along with adjacent soft tissue to accomplish a compartment-oriented dissection. The duration of operation, rate of postoperative complications, pre- and postoperative serum thyroglobulin (Tg) levels, and the findings of postoperative neck ultrasonography and postablation scan were recorded in all patients. Measures of operative success included a postoperative Tg level <50% of preoperative Tg level and no abnormal lesions on postoperative imaging.

RESULTS

Histopathologic examination confirmed the excision of all preoperatively identified metastatic nodes. Additional nodes also were excised (2.3 ± 3.3 per specimen in the ROLL group and 1.6 ± 1.8 per specimen in the IOUS group), 23% of which were metastatic. No postoperative complications occurred in either group. The duration of operation was similar in the 2 groups (P = .4). Postoperative imaging confirmed the clearance of suspicious nodes in all patients. The rate of operative success in ROLL and IOUS group were 100% and 89%, respectively.

CONCLUSION

In patients with recurrent PTC, a high rate of operative success in excision of nonpalpable metastatic lymph nodes was achieved by both ROLL and IOUS. We recommend compartment-oriented dissection; this approach may maximize the removal of metastatic nodes not identified by preoperative imaging.

On-site ultrasound-guided localization for impalpable nodal recurrences in papillary thyroid carcinoma patients

Purpose

The cervical lymph nodes are the most common sites of locoregional recurrence in patients with papillary thyroid carcinoma (PTC). Accurate tumor localization is important for the successful removal of impalpable recurrences in the cervical lymph nodes. We evaluated the benefits of ultrasound-guided localization (UGL) performed by a single surgeon on site.

Methods

Of 53 PTC patients who underwent reoperation for impalpable nodal recurrences, 32 (group 1) were assessed only using preoperative imaging, while 21 (group 2) were additionally evaluated by on-site UGL performed by the operating surgeon. Postoperative outcomes were compared between the two groups.

Results

Operation times were significantly shorter (P < 0.001) and the mean size of the resected lymph nodes were smaller (P = 0.013) for group 2 patients. More lymph nodes were identified and resected in group 1 (3.56 vs. 3.19), but the rate of positive lymph nodes was significantly higher in group 2 (P < 0.001). There were no differences between the two groups in terms of resection success rate, complication rate, and postoperative hospital stay. During a mean follow-up period of 27.6 months, 52 patients (98.1%) showed no evidence of recurrence on routine ultrasound, and serum thyroglobulin concentrations remained < 1 ng/mL in 49 patients (92.5%).

Conclusion

On-site UGL performed by the operating surgeon is useful for accurate resection of impalpable nodal recurrences in PTC patients.

Preoperative US-guided hookwire localization for nonpalpable cervical masses

PURPOSE

We investigated whether the preoperative ultrasound (US)-guided hookwire localization for nonpalpable cervical masses allows surgeons to find these masses more easily and more confidently.

METHODS

Eight patients underwent preoperative US-guided hookwire insertion for nonpalpable cervical masses at our institution between January 2008 and January 2011. Cervical masses were detected by US or CT, and seven of the eight patients underwent US-guided fine-needle aspiration. Before surgery, a radiologist inserted a hookwire into the cervical mass, under US guidance.

RESULTS

US-guided hookwire insertion took about 5-10 minutes and was successful in all cases without complications. Final pathologic results were metastatic papillary thyroid cancer (n = 4), no metastasis (n = 1), parathyroid adenoma (n = 1), tuberculosis (n = 1), and Kikuchi's disease (n = 1).

CONCLUSIONS

Preoperative US-guided hookwire insertion in nonpalpable cervical lesions provides surgeons with an effective means of lesion location.

Excision efficiency of radioguided occult lesion localization in reoperative thyroid and parathyroid surgery

BACKGROUND

The purpose of this study was to investigate the efficiency of a radioguided occult lesion localization technique in reoperative thyroid and parathyroid procedures in patients who had undergone previous neck exploration for thyroid or parathyroid disease.

METHODS

Twenty-one consecutive patients who were scheduled for reoperative thyroid or parathyroid surgery were studied. The indication for reoperation was recurrent papillary thyroid cancer (PTC) in eight patients, completion thyroidectomy for PTC in eight patients who had previously undergone a bilateral subtotal thyroidectomy, recurrent goiter in two patients, primary hyperparathyroidism in two patients, and recurrent parathyroid cancer in one patient. Ninety minutes before surgery, 0.1 mL of Technetium-99m (0.2 mCi)-labeled macroaggregated albumin was injected directly into the lesion under ultrasonographic guidance. During surgery, a handheld gamma probe was used to localize and excise the lesions. The background and postexcisional site radioactivities were compared to confirm the completeness of each procedure. The radiation dose in the operating room environment, duration of surgery, and postoperative complication rates were evaluated in all patients. In patients with PTC, the change in serum thyroglobulin (Tg) following surgery was noted.

RESULTS

Thirty lesions were marked and excised. The postexcisional bed gamma counts (610 ± 141) were markedly decreased compared with the pre-excisional site counts (21,415.8 ± 4993.4; p = 0.0001). The ratio of the postexcisional and background counts (4.6 ± 4.3) was significantly lower than the ratio of the pre-excisional and background counts (173.7 ± 156.4; p = 0.0001). The mean operation duration was 53.3 ± 7.5 minutes. The dose absorbed by the hands of the surgeon was estimated as 0.07 ± 0.02 and 0.15 ± 0.05 millisievert/h when one or three lesions were marked, respectively. One patient developed postoperative transient hypoparathyroidism. After surgery, serum Tg levels dropped to <2 ng/mL in 86% (6/7) of the patients with PTC whose preoperative serum Tg was elevated.

CONCLUSIONS

The radioguided occult lesion localization technique was efficient in the perioperative identification of thyroid and parathyroid tumors in patients who were undergoing reoperation for PTC and hyperparathyroidism.

Use of ultrasound in the management of thyroid cancer

The use of ultrasound for thyroid cancer has evolved dramatically over the last few decades. Since the late 1960s, ultrasound has become essential in the examination of the thyroid gland with the increased availability of high-frequency linear array transducers and computer-enhanced imaging capabilities of modern day portable ultrasound equipment in a clinic- or office-based setting. As a noninvasive, rapid, and easily reproducible imaging study, ultrasound has been demonstrated to have a broadened utility beyond the simple confirmation of thyroid nodules and their sizes. Recently, office-based ultrasound has become an integral part of clinical practice, where it has demonstrated overwhelming benefits to patients being evaluated and treated for thyroid cancer. Ultrasound has become useful in the qualitative characterization of thyroid nodules based on benign or malignant features. On the basis of such classifications and the relative risk for thyroid malignancy, the need for ultrasound-guided fine-needle aspiration, preoperative and intraoperative staging, lymph node mapping, and the extent of surgery can subsequently be determined. Furthermore, ultrasound has additional value in the surveillance of patients treated for thyroid cancer.

Developments in the use of ultrasound for thyroid cancer

PURPOSE OF REVIEW

This article reviews the recent developments in neck ultrasound for thyroid cancer published in the last 18 months, with emphasis on the emerging role of surgeon-performed ultrasound in clinical endocrine practice.

RECENT FINDINGS

Ultrasound has evolved beyond the simple differentiation of solid and cystic thyroid nodules and their measurement. Although no single ultrasound feature has the highest accuracy in distinguishing between benign and malignant thyroid lesions, the combination of several ultrasound characteristics (e.g. hypoechogenicity, irregular borders and microcalcifications) within such thyroid nodules may have a stronger correlation for thyroid cancer. Based on these ultrasound features and risk for thyroid malignancy, the need for ultrasound-guided fine needle aspiration, preoperative staging, lymph node mapping and extent of surgery can subsequently be determined and performed. Furthermore, ultrasound has an additional value intraoperatively and in the postoperative surveillance of patients treated for thyroid cancer. Surgeon-performed ultrasound has recently become indispensible in clinical practice where endocrine surgeons have integrated this versatile imaging modality in the evaluation and treatment of patients with thyroid cancer.

SUMMARY

Ultrasound is an essential modality in the evaluation of thyroid malignancy. Surgeon-performed ultrasound has proved invaluable in the preoperative, intraoperative and postoperative setting. Future developments in ultrasound may lead to further improvement in the diagnostic accuracy of this modality.

Controversies in the surgical management of newly diagnosed and recurrent/residual thyroid cancer

BACKGROUND

Thyroid surgery is the mainstay of treatment for thyroid cancer, but there are options for the surgical approach. There is a general agreement that the goal of thyroid cancer surgery is to remove evident disease, minimize treatment and disease-related morbidity, minimize the risk of recurrence and metastatic spread, and facilitate long-term follow-up. Within these parameters, however, there are a number of controversies regarding the extent of surgery.

SUMMARY

To minimize the risk of recurrence and to optimize the treatment of patients with thyroid cancer, a total thyroidectomy should be performed as the initial operation if the preoperative diagnosis is consistent with thyroid cancer. Macroscopic lymph node involvement does impact recurrence and may influence survival. Therefore, a preoperative ultrasound evaluation of the neck is essential before operative intervention. If pathologic nodes are identified in either the central or lateral neck they should be removed at the initial operation. The role of prophylactic central neck dissection remains controversial, and the risks of this procedure may outweigh the benefits. Therefore, we do not recommend the routine performance of a central neck dissection. Similar to the recent American Thyroid Association guidelines, we agree that their may be a subset of high-risk patients who may benefit from a prophylactic central neck dissection, but that population has yet to be defined. The extent of lateral dissection that is required is also debated as levels 1 and 5 lymph node involvement is uncommon with thyroid cancer. Recurrent disease can be challenging to remove, but several adjuncts are available to maximize the safety and efficacy of reoperation, making it the best option for patients with localized recurrences.

CONCLUSIONS

Total thyroidectomy and neck dissection are very safe procedures when performed by experienced surgeons and can play an essential role in the management of patients with thyroid cancer.

Outcomes in reoperative thyroid cancer

The recommended initial treatment for locoregional recurrence of thyroid cancer is surgery. Of most value to the surgeon considering reoperation for thyroid cancer is the impact that such procedures have on patient survival; the data in this regard are limited. Also of great interest to the surgeon is morbidity associated with reoperation. Because these patients have already had a total or near total thyroidectomy, reoperation requires a surgical revisiting of an already operated bed; intuitively, one might predict a higher rate of complications owing to scar tissue. This article reviews the evidence regarding rates of various complications.

Surgical management of recurrent thyroid cancer

While well-differentiated thyroid cancer is generally thought to be a treatable cancer with excellent outcomes, some patients suffer from recurrent disease. Risk factors for recurrent disease include primary disease greater than 4 cm, incomplete resection, multiple positive lymph nodes in the central compartment, and lateral neck disease with multiple positive lymph nodes in multiple levels or pathologic extracapsular extension. These factors can help stratify the thyroid cancer population in to low-, medium-, and high-risk patients. Low-risk patients can generally be followed with thyroglogulin levels and routine ultrasounds to the head and neck. High-risk patients are best monitored with stimulated thyroglobulin, ultrasound of the head and neck, and low-dose iodine 131 uptake scans at the 6- to 12-month mark. The treatment of locoregional recurrent thyroid cancer is surgical resection with the overall goal of complete tumor removal while maintaining function and decreasing risks. The use of adjuvant therapy is dependent on the presence / absence of high risk pathologic features.

F-18 FDG PET/CT in the management of thyroid cancer

PURPOSE

There are approximately 32,000 new cases of thyroid carcinoma annually in the United States. F-18 FDG PET/CT has an established role in cancer management, including thyroid cancer, usually in patients who are thyroglobulin (Tg) positive/iodine negative. We reviewed our experience with F-18 FDG PET/CT in thyroid cancer, with an emphasis on correlation with Tg, and maximum standardized uptake values (SUV). We also analyzed the role of thyroid stimulating hormone (TSH) on PET/CT results.

MATERIALS AND METHODS

This is a retrospective study (January 2003 to December 2006) of 76 patients with differentiated thyroid cancer, who had F-18 FDG PET/CT scans. There were 44 women and 32 men, with age range of 20 to 81 years (average, 51.1 +/- 18.1). The administered doses of F-18 FDG ranged from 396 to 717 MBq (15.8-19.4 mCi) (average, 566 +/- 74.8) (15.3 +/- 2). Reinterpretation of the imaging studies for accuracy and data analysis from medical records were performed.

RESULTS

A total of 98 PET/CT scans were analyzed (59 patients had 1 scan, 12 patients had 2, and 5 patients had 3). PET/CT was 88.6% sensitive (95% CI: 78.-94.3) and 89.3% specific (95% CI: 71.9-97.1). Mean Tg level was 1203 ng/mL (range, 0.5-28,357) in patients with positive PET/CT and 9.72 ng/mL (range, 0.5-123.0) in patients with negative PET/CT scans (P = 0.0389). Mean SUV max was 10.8 (range, 2.5-32) in the thyroid bed recurrence/residual disease and 7.53 (range, 2.5-26.2) in metastatic lesions (P = 0.0114). Mean SUV max in recurrent/residual disease in patients with TSH </=30 mIU/L was 9.3 (range, 2.5-34.1) and in patients with TSH >30 mIU/L was 8.1 (range, 2.6-32) (P = 0.2994).

CONCLUSION

F-18 FDG PET/CT had excellent sensitivity (88.6%) and specificity (89.3%) in this patient population. Metastatic lesions were reliably identified, but were less F-18 FDG avid than recurrence/residual disease in the thyroid bed. TSH levels at the time of PET/CT did not appear to impact the FDG uptake in the lesions or the ability to detect disease. In the setting of high or rising levels of Tg, our study confirms that it is indicated to include PET/CT in the management of patients with differentiated thyroid cancer.

Advances in metabolic imaging for surgical oncology

This review focuses on several aspects of molecular imaging. First, current positron emission tomography (PET)/CT scanner technology and several novel imaging techniques that are being developed are briefly discussed. Next, current clinical indications for (18)F FDG PET and PET/CT that are relevant to the surgical oncologist are discussed. Finally, advances in molecular imaging that may herald the next generation of PET radiotracers beyond (18)F FDG are reviewed.

Radio-guided nonpalpable metastatic lymph node localization in patients with recurrent thyroid cancer

The detection of nonpalpable recurrent thyroid carcinoma has increased due to the use of imaging techniques in time. This report is to investigate whether preoperative injection of a radiotracer under ultrasound guidance is useful in nonpalpable recurrent thyroid carcinoma. The neck of two patients with recurrent thyroid carcinoma was scanned with the probe to localize the area of maximal radioactivity allowing appropriate location of the incision over the lesion. After the lymph nodes were removed, radioactivity was measured in the lesion bed to confirm the success of the dissection. In conclusion, the radio-guided nonpalpable lesion localization technique can be performed safely for the detection and excision of metastatic foci.

Hook needle-guided excision of recurrent differentiated thyroid cancer in previously operated neck compartments: a safe technique for small, nonpalpable recurrent disease

CONTEXT

As a result of more sensitive techniques to detect recurrent thyroid cancer, the number of patients presenting with small, nonpalpable recurrent thyroid cancer in cervical lymph nodes is increasing. Surgical excision of nonpalpable recurrent thyroid cancer can be difficult, particularly in a previously operated area.

OBJECTIVE

The objective of this study was to investigate whether preoperative insertion of a hook needle under ultrasound guidance is useful in neck reoperations for recurrent thyroid cancer.

PATIENTS

Ten consecutive patients presenting over a 4-month period with nonpalpable, ultrasound-visible, fine needle biopsy-proven recurrent thyroid cancer in previously operated neck compartment(s) were studied.

MAIN OUTCOME MEASURES

We measured whether it was technically possible to insert a hook needle preoperatively, rate of negative neck exploration, and complication rate.

RESULTS

The hook needle was inserted in seven patients. In three patients, the hook needle was not inserted; one patient had palpable disease 4 months after the preoperative clinic visit, one patient had a tumor too close to the carotid artery, and one patient had multiple bilateral foci of recurrent disease in the central neck. One patient had bleeding after insertion of the needle due to a penetration of an anterior jugular vein that was easily managed at neck reexploration. No other complication occurred during the hook needle insertion, and the only surgical complication was a transient recurrent nerve palsy. All pathology reports showed malignant disease.

CONCLUSION

Hook needle-guided excision of recurrent thyroid cancer is feasible and appears to be a promising tool for safe and successful reoperation of patients with small recurrent thyroid cancer in cervical lymph nodes.

Comparison of ultrasonographic characteristics of the thyroid gland in healthy small-, medium-, and large-breed dogs

OBJECTIVE

To determine ultrasonographic characteristics of the thyroid gland in healthy small-, medium-, and large-breed dogs and evaluate the relationships of thyroid gland size and volume with body weight and body surface area (BSA).

ANIMALS

72 dogs of small (6 Toy and 6 Miniature Poodles), medium (12 Beagles), and large breeds (12 Akitas and 36 Golden Retrievers).

PROCEDURE

Each dog's thyroid gland was examined ultrasonographically with a 10- to 5-MHz multifrequency linear-array transducer. Size, shape, echogenicity, and homogeneity of thyroid lobes were evaluated on longitudinal and transverse images. Thyroid lobe volume was estimated by use of the equation for an ellipsoid (pi/6 [length x height x width]).

RESULTS

Thyroid lobes appeared fusiform or elliptical on longitudinal images and triangular or round to oval on transverse images. In most dogs, thyroid lobes were hyperechoic or isoechoic, compared with surrounding musculature, and had a homogeneous echogenic pattern. Mean length, width, height, and volume of thyroid lobes were significantly greater in Akitas and Golden Retrievers, compared with findings in Beagles or Poodles; mean length, width, and height were significantly greater in Beagles, compared with findings in Poodles. Total thyroid gland volume correlated with body weight (r = 0.73) and BSA (r = 0.74).

CONCLUSIONS AND CLINICAL RELEVANCE

Among the dog breeds examined ultrasonographically, thyroid lobe size and volume were more variable than shape, echogenicity, and homogeneity. The correlation of thyroid gland volume with BSA suggests that size of the dog, rather than breed, should be considered when assessing thyroid glands ultrasonographically.

The Role of Radioactive Iodine in the Treatment of Well-differentiated Thyroid Cancer

The prognosis in differentiated thyroid cancer is excellent. The completeness of thyroidectomy and removal of involved regional metastases are the most important elements of management. Iodine 131 has a role in ablating residual thyroid and treating regional and distant metastases. The effectiveness of the treatment is confirmed by negative follow-up scans and low or undetectable Tg. This therapy is relatively specific, but other tissues can receive meaningful doses of radiation and acute and long-term complications can occur. Therefore, whether the patient will have a better prognosis after treatment with 131I and whether the benefits of treatment are greater than the side effects must be determined for every patient.

Feasibility and benefit of fluorine 18–fluoro-2-deoxyglucose–guided surgery in the management of radioiodine-negative differentiated thyroid carcinoma metastases

BACKGROUND

Fluorine 18-fluoro-2-deoxyglucose (FDG) positron emission tomography ((18)F-FDG PET) can be used to visualize metastases in patients with differentiated thyroid carcinoma that does not take up radioiodine ((131)I). This study was aimed at evaluating the feasibility of (18)F-FDG radio-guided surgery in patients with radioiodine-negative differentiated thyroid cancer.

METHODS

Ten patients received a mean activity of 265 MBq of (18)F-FDG 30 minutes before operation. Radioactivity uptake (counts per second [cps], with a pretime of 10 seconds) in tumor and normal tissues was measured before and after resection.

RESULTS

Patients with 1 to 5 foci detected by FDG-PET were included in the study. Six of these patients were injected with recombinant human thyroid-stimulating hormone (TSH) preoperatively. Abnormal findings detected by preoperative (18)F-FDG PET were also detected with the gamma probe in all patients. The mean tumor activity in vivo was 3,272 cps, and tumor-to-neck and tumor-to-shoulder ratios were, respectively, 1.40 and 1.73. Tumor resection was incomplete in 3 patients. When resection was complete, mean radioactivity at the tumor site was decreased by 22%. The ex vivo mean tumor-to-normal tissue ratio was 2.4. All positive tissues detected with the probe were confirmed histologically to be differentiated thyroid cancer. The surgeon's hands were exposed to 90 to 270 microSv.

CONCLUSIONS

These results show the feasibility and benefit of (18)F-FDG radio-guided surgery with a gamma probe in the management of differentiated thyroid cancer patients with radioiodine-negative recurrence.

Long-term course and predictive factors of elevated serum thyroglobulin and negative diagnostic radioiodine whole body scan in differentiated thyroid cancer

Following the initial management, some patients with differentiated thyroid cancer (DTC) develop a state of high thyroglobulin (Tg) and negative diagnostic radioactive iodine (RAI) whole body scan (DxWBS). The predisposing factors and outcome of this condition are unclear. In this study, our objectives were to determine the predictive factors for the development of high Tg and negative DxWBS (Tg+/scan-) and to study the long-term course of the disease in patients with this condition.

METHODS

We, retrospectively, reviewed the medical records of a cohort of 105 non-selected DTC patients (26 males and 79 females; median age 37.7 yr, range 7-72). None of these patients had positive Tg antibodies or distant metastases. All Tg levels were obtained off thyroid hormone therapy. At the first follow-up visit after RAI ablation (13 +/- 7.6 months), patients were classified into those with low Tg (<2 ng/ml off L-T4) and negative DxWBS (control group) and those with high Tg ( > or = 22 ng/ ml off L-T4) and negative DxWBS (Tg+/scan- group). Using univariate and multivariate logistic regression analyses, we evaluated a number of parameters (see results) for their association with the development of Tg+/scan-. In addition, the long-term course of the disease in Tg+/scan- group was analyzed.

RESULTS

In univariate analysis, the following factors were found to be significantly associated with Tg+/scan-: perithyroidal tumor extension (p=0.025), soft tissue invasion (p=0.001), cervical lymph node metastases (p=0.014) and Tg level before RAI ablation (p=0.015). In multivariate analysis, only soft tissue invasion remained significantly associated with Tg+/scan- [p 0.001, odds ratio, 15.6 (95% Cl, 2.96-82.06)]. Age, sex, duration of goiter before surgery, pressure symptoms, tumor size, tumor multifocality, lymph nodedissection at initial surgery, tumor-node-metastasis (TNM) stage, and RAI ablative dose were not associated with Tg+/ scan-. In 53 patients with Tg+/scan-, 42 cases were followed without any therapeutic intervention; over a median follow-up of 71.6 months (range, 13-144.7), 31 cases had a spontaneous remission and 11 cases continued to have a persistent disease (Tg > or = 2 ng/ml, negative DxWBS, and no palpable disease or distant metastases); Tg declined from 9.32 +/- 9.91 ng/ml at first visit after RAI ablation to 1.59 +/- 5.39 ng/ml at last visit (p<0.0001). In the other 11 cases of Tg+/scan- group, one or more therapeutic interventions (RAI, surgery, or external radiotherapy) were undertaken. Over a median follow-up of 98.4 months (range, 6-147), Tg decreased from 110.2 +/- 147.5 to 23.5 +/- 41.2 ng/ml (p 0.026); 4 cases achieved remission, 5 cases continued to have persistent disease, and 2 cases had progression of their disease, which led to their death.

CONCLUSION

Soft tissue invasion on original surgery strongly predicts the development of Tg+/scan- in DTC patients. The long-term course of the disease is mostly favorable especially when the Tg level is only modestly elevated.

Preoperative neck ultrasonographic mapping for persistent/recurrent papillary thyroid cancer

Surgical resection of persistent/recurrent (P/R) papillary thyroid cancer (PTC), when localized to the neck, is generally recommended; however, its impact on the course of the disease is not clear. We introduced a new technique in the form of preoperative neck ultrasonographic mapping (US-M) to improve the outcome of the surgical resection of P/R PTC. A total of 19 patients had undergone regional (central, lateral, or both) neck dissection before introducing the current technique (group 1, or G1), and 26 patients (group 2, or G2) had limited lymph node resection guided by US-M with findings accurately plotted on a standard diagram. All of the operations were performed by a single surgeon. The surgical outcomes of the two groups were compared. The resected lesions were positive for PTC in 17 patients (89.5%) in G1 and in 25 patients (96.2%) in G2. In G2, the intraoperative findings exactly matched the US-M in 23 patients (88.5%). Postoperatively, neck US became negative in 50% in G1 and in 83.3% in G2 (p = 0.02). Thyroglobulin (Tg) became undetectable in 37.5% in G1 and 52.3% in G2 (p = 0.37). Whole-body iodine scans (WBS) became negative in one of six patients (16.7%) in G1, and in three of four patients (75%) in G2, (p = 0.06). After a mean follow-up of 23.8+/-7.1 months in G1 and 9.8+/-4.7 months in G2, 6 patients (31.6%) in G1 and 15 patients (62.5%) in G2 were in remission (p = 0.04), whereas the disease persisted in 13 cases (68.4%) in G1 and 9 (37.5%) in G2 (p = 0.04). In conclusion, US-M improved the surgical outcome, as evidenced by the postoperative US, Tg, and WBS findings and the higher remission rate for the G2 patients than for the G1 patients.

Intraoperative ultrasound

Intraoperative ultrasound (IOUS) can provide various diagnostic information that is otherwise not available, and can guide or assist various surgical procedures in real time. With refinement of equipment, IOUS is currently used in a wide variety of surgical operations,such as hepatobiliary, pancreatic, endocrine, cardiovascular,and neurologic surgery. Our overview of IOUS, including instrumentation,techniques, indications, advantages, disadvantages,and future perspective, is described in this article. Being safe, quick, accurate, and versatile intraoperatively, IOUS is a valuable technique that surgeons are recommended to master to improve intraoperative decision making and surgical procedures.

[Surgical treatment of recurrent thyroid carcinoma]

Recurrent thyroid tumors are much less frequent but more aggressive than primary tumors. The aim is to find out their characteristics, aggressiveness and the possibility of radical surgical excision as well as the frequency of complications.

METHOD AND MATERIAL

Retrospective study on 69 patients operated for recurrent thyroid tumors.

RESULTS

Recurrent tumors were found in 42 patients with papillary, 11 with follicular (8 with Hurthle), 9 with medullary and 7 with anaplastic thyroid tumors. Relapse in thyroid bed on dominant side had 41 patients (59.4%), relapse on the opposite side we found in 19 patients (27.5%) and relapse in lymph nodes outside of thyroid bed in 37 patients (53.6%). In 33/69 patients, the first procedure was incomplete (reduction in 5, partial resection in 19, hemithyroidectomy in 9). The second procedure was incomplete in 14, near total thyroidectomy in 2, total thyroidectomy in 33 and dissection of lymph nodes in 33, among them in 20 with the operation in thyroid bed. Pre-operative recurrent nerve palsy had 2 patients and transitional recurrent nerve palsy occurred after second procedure in 2 patients. Among 33 patients after thyroidectomy for recurrent tumor, postoperative hypoparathyroidism occurred in 8 (24.2%), of whom in 2 permanent (6%). In the group of 54 patients with recurrent differentiated thyroid cancer, radioiodine therapy after first operation had received only 7 patients (13%).

CONCLUSION

The main causes of thyroid cancer relapse are incomplete first procedure and aggressiveness of cancer. It is not always possible to excise the complete recurrent tumor. After surgery for papillary cancer, radioiodine therapy is seldom used.