Iodine-131 radio-guided surgery in differentiated thyroid cancer: Outcome on 31 patients and review of the literature

Magseed application for detecting recurrent lymph node metastasis in papillary thyroid cancer: A novel minimally invasive Approach

Papillary thyroid cancer is associated with lymph node metastasis and tumor recurrence that need repeated surgery, entailing surgical challenges with a high risk of complications such as nerve damage and bleeding. Magseed is a metal coil used to detect non-palpable lesions and is an established modality in breast cancer surgery. In this case series, we explore the feasibility of Magseed in metastasis surgery of papillary thyroid cancer. Under the guidance of ultrasonography, Magseed is injected into the target tissue and intraoperatively detected with a handheld magnetometer probe, Sentimag®. Five patients with recurrence of papillary thyroid cancer were operated on with focused Magseed-guided localization. All patients had repeated surgery and radioiodine treatments. Four of the patients had lymph node metastasis hidden in the fibrosis, and one patient had recurrent tumor tissue on the left side of the larynx. Magseed was easy to use, safe, and precise in detecting the target tissue.

Wire-guided localization and surgical resection of non-palpable recurrent of thyroid carcinoma: A STROBE-compliant, retrospective cohort study

BACKGROUND

Information on hook-wire guided (HWG) surgery for non-palpable thyroid carcinoma (TC), locoregional-recurrent disease (LRRD) is scarce. We analyze the results of HWG resection compared with the traditional procedure.

METHODS

Cohort study performed between January 2016 and December 2020. Patients with TC and non-palpable LRRD were included. A "Standard cohort", patients with non-HWG resection and "HWG cohort", with HWG resection of LRRD were defined. Surgical morbidity, re-recurrent/progressive disease (RRD), and re-recurrence-free survival (RRFS) were defined.

RESULTS

43 and 23 patients were assigned to the Standard or HWG cohorts, respectively. Complications occurred in 28 % and 17.3 % of cases, in control or HWG cohorts, respectively. HWG cohort, size of primary TC, 131I dose >150 mCi, and thyroglobulin level >1 ng/ml at detection of LRRD were associated with RRD. HWG cohort, thyroglobulin level at LRRD, 131I treatment, and dose were associated with RRFS.

CONCLUSIONS

HWG surgery of non-palpable TC LRRD had improved results regarding surgical morbidity, RRD, and RRFS.

Radioguided surgery: physical principles and an update on technological developments

Radioguided surgery (RGS) is the use of radiation detection probes and handheld gamma cameras in surgery rooms to identify radioactively labeled lesions inside the body with an aim to improve surgical outcome. In today’s surgery, application of these devices is a well-established practice, which provides surgeons with real-time information to guide them to the site of a lesion. In recent years, there have been several major improvements in the technology and design of gamma probes and handheld gamma cameras, enhancing their applications in surgical practices. Handheld gamma cameras, for example, are now moving from single-modality to dual-modality scanners that add anatomical data to the physiologic data, and with that provide more clinical information of the tissue under study. Also, in the last decade, a radioguided surgical technique based on the Cerenkov radiation was introduced, with more improved sensitivity in identifying radioactively labeled lesions. Additionally, recent advances in hybrid tracers have led to more efficient detection of lesions labeled with these tracers. Besides, it seems that combining medical robotics and augmented reality technology with current radioguided surgical practices potentially will change the delivery and performance of RGS in the near future. The current paper aims to give an overview of the physics of RGS and summarizes recent advances in this field that have a potential to improve the application of radioguided surgical procedures in the management of cancer.

Recurrent Papillary Thyroid Carcinoma to the Cervical Lymph Nodes: Outcomes of Compartment-Oriented Lymph Node Resection

INTRODUCTION

Recurrence of papillary thyroid carcinoma after initial treatment is challenging. Surgical reintervention is recommended, but cure after surgery in uncertain and surgical morbidity may be high. This study evaluates the effect of compartment-oriented lymph node dissection (LND) on clinical and biochemical cure rate as well as the related complications.

PATIENTS AND METHODS

All patients who underwent LND for recurrent papillary thyroid carcinoma between 2000 and 2015 were included. Demography, the extent of the initial surgery, usage of ¹³¹I, the pattern of recurrence, diagnosis, details of the surgical reintervention, histological findings, surgical morbidity, and clinical and biochemical outcomes were analyzed.

RESULTS

There were 11 (12.7%) males and 75 (87.2%) females with a mean age of 42.8 ± 14.6 years. Seventy-seven patients had undergone total thyroidectomy and in 67 (77.9%) some type of LN resection. In 76 (88.3%), ¹³¹I was administered after the initial surgery. We localized suspicious lymph nodes by US in all patients, and metastases were documented before surgery by FNA in 63. Seven (8.13%) patients underwent central LND, 63 (73.2%) lateral LND and 16 (18.6%) both, central and lateral LND. Major complications occurred in 6 patients (6.9%). Sixty-two (72.0%) patients received ¹³¹I after surgery. A second surgical re-exploration was performed in 30 (34.8%) patients, and 7 patients required 3 or more additional LND. In a mean follow-up of 59.4 ± 39 months, 51 (59.3%) patients are clinically, radiologically and biochemically free of disease.

CONCLUSIONS

In this series, compartment-oriented lymph node resection of recurrent papillary thyroid carcinoma leads to a final clinical and biochemical disease-free status of 59.3% with 6.9% of major complications.

Radioguided occult lesion localization in patients with recurrent thyroid cancer

PURPOSE

Well planned re-surgery is critical for recurrent/persistent thyroid cancer (TC). We aimed to investigate the clinical outcome of radioguided-occult lesion localization (ROLL) guided surgery in patients with recurrent/persistent TC.

METHODS

This study includes 29 patients [F/M: 22/7, median age 43 ± 12 years (18-58)] with a diagnosis of TC (22 papillary, 2 follicular and 5 medullary). Before surgery, all patients underwent ultrasonography (USG) guided mapping and intra-lesional radioactivity injection. Surgery was performed based on the excision of radioactivity injected lesions by a gamma probe and non-injected tumor foci via USG-neck map. Researchers determined surgical success by post-operative tumor markers and neck-USG.

RESULTS

Among 29 patients, 60 metastatic lesions were identified by USG [median size 10 ± 6.3 mm (range 5-30)]. Neck-USG performed after surgery provided no evidence of disease (NED) in %97 (28/29) of TC patients. In the follow-up, stimulated thyroglobulin (Tg) levels were less than 1 ng/ml in 79%(19/24) of DTC patients and suppressed Tg < 0.2 ng/ml was noted in 92% (22/24).In patients with DTC with an incomplete structural response, we dramatically changed the American Thyroid Association (ATA) response category and achieved an excellent response in 92% (22/24) of patients. Among patients with MTC, 5/5 patients had normal USG and calcitonin levels were reduced by 60-80% in 4/5 and > 80% in1/5 patients.

CONCLUSIONS

In this study we have shown that, ROLL-guided surgery yielded NED rate of %97 (28/29) and increased excellent response rates according to ATA guidelines. Further studies with larger patient groups and longer follow-up should be performed to confirm the efficacy of this surgery.

Preoperative charcoal suspension tattoo for the detection of differentiated thyroid cancer recurrence

Recurrent differentiated thyroid carcinoma can easily be detected by means of ultrasound (US) and thyroglobulin, and often requires further surgical intervention. Revision surgery is often a technical challenge with significant risk of complications, considering the altered anatomy, with a possibility of leaving behind residual neoplasm. Preoperative US-guided tattooing localization has been introduced to reduce and prevent these potential problems during revision surgery. Encouraging results have been reported in the literature. Under US guidance, the lesion is identified and 0.5-2 ml of colloidal charcoal is injected in its proximity using a 23 gauge needle. The extraction is accompanied by injection at constant pressure of charcoal in order to leave a trace of pigment along the path of the needle till the skin. From April 2008 to January 2016 we performed revision surgery in 27 patients for lymph-nodes metastasis in differentiated thyroid cancer, using the technique of preoperative charcoal tattoo localization. Our previous study on the first group of 13 patients published in 2012, reported the preliminary results in terms of success rate and complications. The tolerance of charcoal injection was good for all patients and the procedure was demonstrated to be useful, contributing to the removal of metastatic lesion in 93% of procedures. We have registered minor surgical complications during revision in the central compartment of the neck: Transitory hypoparathyroidism in 2 cases (11%) and transitory vocal cord paresis in 3 cases (16%). Based on these results, preoperative charcoal tattoo localization in revision surgery of the neck for differentiated thyroid cancer recurrence can be considered a safe technique, easy to perform, with low-costs and useful during surgical procedures, providing a significant reduction of iatrogenic damage and risks.

Management and outcome of clinically evident neck recurrence in patients with papillary thyroid cancer

BACKGROUND

The aim of this study was to report our incidence of clinically evident neck recurrence, salvage neck management and subsequent outcomes in patients with papillary thyroid cancer. This is important to know so that patients with thyroid cancer can be properly counselled about the implications of recurrent disease and subsequent outcome.

METHODS

An institutional database of 3664 patients with thyroid cancer operated between 1986 and 2010 was reviewed. Patients with nonpapillary histology and gross residual disease and those with distant metastases at presentation or distant metastases prior to nodal recurrence were excluded from the study. Of these, 99 (3.0%) patients developed clinically evident nodal recurrence. Details of recurrence and subsequent therapy were recorded for each patient. Subsequent disease-specific survival (sDSS), distant recurrence-free survival (sDRFS) and nodal recurrence-free survival (sNRFS) were determined from the date of first nodal recurrence using the Kaplan-Meier method.

RESULTS

Of the 99 patients, 59% were female and 41% male. The median age was 41 years (range 5-91). The majority of patients had pT3/4 primary tumours (63%) and were pN+ (78%) at initial presentation. The median time to clinically evident nodal recurrence was 28 months (range: 3-264). Nodal recurrence occurred in the central neck in 15 (15%) patients, lateral neck in 74 (75%) patients and both in 10 (10%) patients. After salvage treatment, the 5-year sDSS was 97.4% from time of nodal recurrence. The 5-year sDRFS and sNRFS were 89.2% and 93.7%, respectively.

CONCLUSION

In our series, isolated clinically evident nodal recurrence occurred in 3.0% of patients. Such patients are successfully salvaged with surgery and adjuvant therapy with sDSS of 97.4% at 5 years.

Impact of Radioguided Occult Lesion Localization (ROLL) in the management of cervical recurrences from differentiated thyroid cancer

BACKGROUND

Surgery is the elective treatment for cervical relapse from differentiated thyroid cancer (DTC) but it is technically challenging, with risk of failure and morbidity. We explored the feasibility and the efficacy of Radioguided Occult Lesion Localization (ROLL) with intratumoral 99mTc radiolabeled human albumin macroaggregates ([99mTc]MAA) injection in this setting.

METHODS

Fifteen patients who underwent ROLL by ultrasonography (US)-guided intratumoral injection of [99mTc]MAA between December 2013 and October 2016 for DTC recurrence were considered for this study. An hand-held gamma-probe was employed for intrasurgical lesion detection. Mini-invasive ROLL-guided excision for soft tissue recurrence and ROLL-assisted modified radical neck dissection for lymph-node metastases were performed respectively.

RESULTS

DTC recurrence was located in loco-regional lymph-nodes (n=8 patients) and in thyroid bed (n=7 patients). A total of 27 lesions was identified and injected before surgery. On a total of 124 lesions resected, histology showed 38 DTC metastases. In particular, 26 out of 27 lesions injected with [99mTc]MAA were correctly detected intra-operatively and resected without surgical complications. Ten patients received subsequent radioactive iodine (RAI) treatment to verify the complete recurrence resection. At a median follow-up of 16 months patients were classified in complete response (n=4), biochemical incomplete response (n=3), indeterminate response (n=1) with no evidence of structural disease. The remaining 7 patients were classified as structural incomplete response for cervical persistent disease (n=2), for cervical recurrence (n=2) and for both cervical and lung metastases progression (n=3).

CONCLUSIONS

ROLL is a simple and safe procedure in the surgical management of DTC loco-regional relapse.

Quantitative Comparison of 124I PET/CT and 131I SPECT/CT Detectability

Radioiodine therapy with (131)I is used for treatment of suspected recurrence of differentiated thyroid carcinoma. Pretherapeutic (124)I PET/CT with a low activity (~1% of (131)I activity) can be performed to determine whether uptake of (131)I, and thereby the desired therapeutic effect, may be expected. However, false-negative (124)I PET/CT results as compared with posttherapeutic (131)I SPECT/CT have been reported by several groups. The purpose of this study was to investigate whether the reported discrepancies may be ascribed to a difference in lesion detectability between (124)I PET/CT and (131)I SPECT/CT and, hence, whether the administered (124)I activity is sufficient to achieve equal detectability.

METHODS

Phantom measurements were performed using the National Electrical Manufacturers Association 2007 image-quality phantom. As a measure of detectability, the contrast-to-noise ratio was calculated. The (124)I activity was expressed as the percentage of (131)I activity required to achieve the same contrast-to-noise ratio. This metric was defined as the detectability equivalence percentage (DEP).

RESULTS

Because lower DEPs were obtained for smaller spheres, a relatively low (124)I activity was sufficient to achieve similar lesion detectability between (124)I PET/CT and (131)I SPECT/CT. DEP was 1.5%, 1.9%, 1.9%, 4.4%, 9.0%, and 16.2% for spheres with diameters of 10, 13, 17, 18, 25, and 37 mm, respectively, for attenuation- and scatter-corrected SPECT versus point-spread function (PSF) model-based and time-of-flight (TOF) PET. For no-PSF no-TOF PET, DEP was 3.6%, 2.1%, 3.5%, 7.8%, 15.1%, and 23.3%, respectively.

CONCLUSION

A relatively low (124)I activity of 74 MBq (~1% of (131)I activity) is sufficient to achieve similar lesion detectability between (124)I PSF TOF PET/CT and (131)I SPECT/CT for small spheres (≤10 mm), since the reported DEPs are close to 1%. False-negative (124)I PET/CT results as compared with posttherapeutic (131)I SPECT/CT may be ascribed to differences in detectability for large lesions (>10 mm) and for no-PSF no-TOF PET, since DEPs are greater than 1%. On the basis of DEPs of 3.5% for lesion diameters of up to 17 mm on no-PSF no-TOF PET, (124)I activities as high as 170 MBq may be warranted to obtain equal detectability.

Preoperative localization of neck recurrences from thyroid cancer: charcoal tattooing under ultrasound guidance

BACKGROUND

Reoperation for thyroid cancer recurrence is a surgical challenge in previously dissected necks, and there is a need for a reliable procedure for surgeon guidance. In this study, the usefulness of preoperative charcoal tattooing for surgical guidance was evaluated.

METHODS

From July 2007 to May 2010, 53 patients (40 females; Mage=44 years, range 19-76 years) were prospectively included for preoperative localization of neck recurrences from differentiated (n=46) or medullary thyroid cancer (n=7). Preoperative cytological assessment was performed for at least one lesion in each patient. Ultrasound (US) imaging was performed with high-frequency probes (8-14 Mhz). Micronized peat charcoal (0.5-3 mL) was injected under US guidance using a 25 gauge needle, 0-15 days preoperatively.

RESULTS

A total of 106 lesions were selected for charcoal tattooing. Of these, 101 had been tattooed, and 102 were removed (85 metastases, 17 benign on pathology). The tolerance of charcoal injection was good in all but three patients. A mean volume of 1 mL of charcoal was injected with a mean of two targets per patient. Charcoal labeling facilitated intraoperative detection in 56 "difficult" lesions (i.e., small size, dense fibrosis, anatomical pitfalls), and charcoal trace facilitated intraoperative guidance in 17 lesions. Feasibility and usefulness rates were 83% and 70.7% respectively.

CONCLUSION

These findings suggest that charcoal tattooing under US guidance is an easy to implement, safe, and useful procedure for surgeon guidance in neck reoperation for thyroid cancer.

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.

Management of recurrent/persistent nodal disease in patients with differentiated thyroid cancer: a critical review of the risks and benefits of surgical intervention versus active surveillance

BACKGROUND

The primary goals of this interdisciplinary consensus statement are to define the eligibility criteria for management of recurrent and persistent cervical nodal disease in patients with differentiated thyroid cancer (DTC) and to review the risks and benefits of surgical intervention versus active surveillance.

METHODS

A writing group was convened by the Surgical Affairs Committee of the American Thyroid Association and was tasked with identifying the important clinical elements to consider when managing recurrent/persistent nodal disease in patients with DTC based on the available evidence in the literature and the group's collective experience.

SUMMARY

The decision on how best to manage individual patients with suspected recurrent/persistent nodal disease is challenging and requires the consideration of a significant number of variables outlined by the members of the interdisciplinary team. Here we report on the consensus opinions that were reached by the writing group regarding the technical and clinical issues encountered in this patient population.

CONCLUSIONS

Identification of recurrent/persistent disease requires a team decision-making process that includes the patient and physicians as to what, if any, intervention should be performed to best control the disease while minimizing morbidity. Several management principles and variables involved in the decision making for surgery versus active surveillance were developed that should be taken into account when deciding how best to manage a patient with DTC and suspected recurrent or persistent cervical nodal disease.

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.

Characterization of an asymmetric add-on collimator used with a hand-held gamma probe for radioguided surgery and sentinel node detection: a demonstration of an alternative collimation method

OBJECTIVE

The aim of the study was to investigate a new principle for collimation of gamma probes for radioguided surgery and sentinel node detection: the use of asymmetric lateral shielding. The intension was to maintain the sensitivity in the lateral and forward directions on the unshielded side while at the same time to shield the probe against high activity sources that could mask the signal from the object to be detected.

METHODS

The device was constructed to shield only against photons that come from a region in space that spans approximately 180° sideways and forwards relative to the detector. The intension of the study was to demonstrate the principle rather than to document its use in the clinic. Sensitivity profiles were derived from measurements obtained while stepwise moving the probe relatively to a point source of known activity surrounded by water. The measurements were taken in the symmetry plane of the collimator where the shielding effects were expected to be most pronounced.

RESULTS

The asymmetric collimator led to nearly unchanged sensitivity in the lateral and forward directions. At the same time, the field of view was effectively shrunk on the shielded side. Contributions from sources lateral and close to the shield were reduced by factors up to 45.

CONCLUSION

By rotating the probe around its longitudinal axis, an asymmetric add-on shield collimator could potentially make it easier to detect a sentinel node when this is located close to a neighbouring high activity region like the urinary bladder or the injection site.

Update in utility of secondary node dissection for papillary thyroid cancer

BACKGROUND

Detection of recurrent/persistent thyroid cancer has improved significantly in the past decade. Disease is detected earlier in recently treated patients and localized in patients long out from initial treatment. This update reviews recent literature regarding the utility of secondary node dissection for papillary thyroid carcinoma. Outcomes include disease-free status measured biochemically and clinically.

RESULTS

The utility of secondary node dissection as measured by clinically detectable disease exceeds 70% for all series and 90% for most. The utility as measured biochemically is more modest, with rates of biochemical cure ranging from 27-81% depending upon strictness of definition and patient selection. In predominately radioiodine scan-negative patients, using the strictest definition of biochemical cure, undetectable stimulated thyroglobulin (Tg) of less than 0.5 ng/ml, a rate of 27% is reported. Biochemical cure rates are reportedly 30-51% for stimulated Tg of less than 2 ng/ml and 56-71% for basal Tg of less than 2 ng/ml, with higher preoperative Tg levels less likely to achieve biochemical cure. Radioiodine-avid disease appears more amenable to cure, with 81% of patients achieving negative stimulated Tg after repeat I131 treatment and radio-assisted surgery. Complication rates of secondary nodal surgery appear similar to initial surgery in experienced hands; however, bilateral reoperative central neck dissection is associated with significantly higher complication rates than unilateral.

SUMMARY

Surgical resolution of clinically detectable disease is likely. Biochemical cure rates are more modest, with the greatest likelihood of biochemical cure occurring in patients with radioiodine-avid disease. In radioiodine-negative patients, there may be a higher likelihood of biochemical cure for those with lower preoperative detectable Tg levels.

18F-fluorodeoxyglucose and 131I radioguided surgical management of thyroid cancer

OBJECTIVE

To describe a technique that assists in the surgical management of recurrent local regional well-differentiated thyroid cancer (WDTC).

STUDY DESIGN

Case series with chart review.

SETTING

Two academic health centers from 2001 to 2009.

SUBJECTS AND METHODS

Patients operated upon by the senior surgeon (BCS) for recurrent WDTC.

RESULTS

Thirteen patients with recurrent WDTC were operated upon with radioguided surgical (RGS) technique to indentify recurrence for excision. Eight patients had iodine avid disease and were candidates for RGS with (131)I. The remaining 5 patients had cancer with a proven loss of iodine avidity and were, therefore, operated upon with a fluorodeoxygluocose (FDG) RGS technique.

CONCLUSION

RGS is a feasible approach to identify recurrent disease in an operated field and ensure its successful excision. Although focal disease may be identified with this technique, this is not a tool for limited excisions ("berry picking").

[Differentiated thyroid cancer -- 2009]

Three years ago continental guidelines were published referring management and follow-up of low risk thyroid cancer patients. The aim of this paper is to summarize the changes and new directions in this field. High risk patients require another protocol. Neck ultrasound plays important role in differential diagnosis and in detecting recurrences. Some new ultrasound techniques are discussed, too. FDG-PET can help to solve the problem of patients having negative scan and increased thyroglobulin level. In recent years there was an expansion of our knowledge about the pathomechanism of thyroid cancer. It appears that genetic alterations frequently play a key role in carcinogenesis. There are molecular methods that allow the detection of these genetic events in thyroid fine needle aspirations samples providing important information for diagnosis, management and prognosis. Instead of diagnostic whole body scanning the posttherapeutic scan became preferable but in high risk cases the diagnostic whole body scintigrams serve useful data. Primary therapy of thyroid cancer is an adequate surgery: total thyreoidectomy and, if necessary, lymph node dissection or limited surgery in selected cases. Nowadays radioguided surgery can help to improve the results. Radioiodine therapy (e.g. rest ablation) proved to be a safe and effective method to complete surgery. It can prevent relapses and results in longer survival. Thyroid hormone withdrawal or recombinant human thyrotropin stimulation can increase thyrotropin level before radioiodine treatment. These two methods have similar success rate of rest ablation but irradiation burden of blood is lower in the case of exogenous stimulation which avoids hypothyroid state and preserves quality of life. Since tumor cells fail to maintain the ability to perform physiological functions they undergo dedifferentiation. Therefore, an important aim is to reactivate some function of differentiated cells, e.g. iodine uptake, production of thyroperoxydase and thyroglobulin. Opportunities for this therapeutic effort are also mentioned. Restoration of iodine uptake enables radioisotope treatment. Until now there has been little interest in the development of new drugs for the treatment of thyroid cancer. However, advances in our understanding of tumor cell biology will lead to a paradigm shift in the therapy that is likely to benefit patients who have high risk disease and who do not almost have any therapeutic option. There are new drugs in clinical trials that appear to be more effective than earlier cytotoxic agents. Probably modern chemotherapy of advanced thyroid cancer will have significant results in the near future.

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.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.