Trends in imaging after diagnosis of thyroid cancer

Physician Confidence in Neck Ultrasonography for Surveillance of Differentiated Thyroid Cancer Recurrence

IMPORTANCE

Neck ultrasonography, a mainstay of long-term surveillance for recurrence of differentiated thyroid cancer (DTC), is routinely used by endocrinologists, general surgeons, and otolaryngologists; however, physician confidence in their ability to use ultrasonography to identify lymph nodes suggestive of cancer recurrence remains unknown.

OBJECTIVE

To evaluate physicians' posttreatment surveillance practices for DTC recurrence, specifically their use of and confidence in ultrasonography.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of 448 physicians in private and academic hospitals who completed a survey on DTC posttreatment practices from October 2018 to August 2019 (response rate, 69%) and self-reported involvement in long-term surveillance for thyroid cancer recurrence. Physicians were identified by patients affiliated with the Surveillance, Epidemiology, and End Results Program registries in Georgia State and Los Angeles County. Of the respondents, 320 physicians who reported involvement with DTC surveillance were included in the analysis.

MAIN OUTCOMES AND MEASURES

Physician-reported long-term surveillance practices for DTC, including frequency of use and level of confidence in ultrasonography for detecting lymph nodes suggestive of cancer recurrence.

RESULTS

In the cohort of 320 physicians who reported involvement with DTC surveillance, 186 (60%) had been in practice for 10 years to less than 30 years; 209 (68%) were White; and 212 (66%) were men. The physicians included 170 (56%) endocrinologists, 67 (21%) general surgeons, and 75 (23%) otolaryngologists. Just 84 (27%) physicians reported personally performing bedside ultrasonography. Only 57 (20%) had high confidence (rated quite or extremely confident) in their ability to use bedside ultrasonography to identify lymph nodes suggestive of recurrence; 94 (33%) did not report high confidence in either their ability or a radiologist's ability to use ultrasonography to detect recurrence. Higher confidence in ultrasonography was associated with the general surgery subspecialty (odds ratio [OR], 5.7; 95% CI, 2.2-14.4; reference endocrinology) and with treating a higher number of patients per year (>50 patients: OR, 14.4; 95% CI, 4.4-47.4; 31-50 patients: OR, 8.4; 95% CI, 2.6-26.7; 11-30 patients: OR, 4.3; 95% CI, 1.5-12.1; reference 0-10 patients).

CONCLUSIONS AND RELEVANCE

Given the importance of neck ultrasonography in long-term surveillance for thyroid cancer, these findings of physicians' low confidence in their own ability and that of radiologists to use ultrasonography to detect recurrence point to a major obstacle to standardizing long-term DTC surveillance practices.

The Utility of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Differentiated Thyroid Cancer Patients with Biochemical Recurrence and Negative Whole-Body Radioiodine Scintigraphy and Evaluation of the Possible Role of a Limited Regional Scan

Purpose of the Study

¹⁸F-Fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) is used in the management of recurrent differentiated thyroid cancer (DTC) patients presented with rising thyroglobulin (Tg) or anti-Tg antibody (Atg) levels and negative whole-body I-131 scan (WBS). We aimed to evaluate the utility of regional or limited PET/CT in a large population preset with variable Tg/(ATg) levels.

Materials and Methods

In a retrospective study, we analyzed 137 PET/CT done on DTC patients presented with raised Tg/Atg and negative WBS. Retrospective evaluation of other available clinical information was done.

Results

One hundred and thirty-seven patients aged 8-72 years (41 ± 17.7 years) were included in the study. Eighty-nine (64.9%) patients had positive findings on ¹⁸F-FDG PET-CT. It included thyroid bed recurrence, cervical, mediastinal lymphadenopathy, lung, and bone lesions. In addition, 36 patients had metabolically inactive lung nodules detected on CT. Serum Tg and female sex were the only predictors for a positive PET scan. In most (97.1%) of the patients, the disease was limited to the neck and thoracic region.

Conclusions

PET/CT is an excellent imaging modality for evaluating DTC patients presented with biochemical recurrence. It not only finds the disease in more than 80% of the patients but also detects distant metastatic disease, which precludes regional therapies. Lesions were noted mostly in the neck and thoracic region with very few distant skeletal metastases (4/137 patients). In most of the patients, routine vertex to mid-thigh imaging could be avoided.

Role of Patient Maximizing-Minimizing Preferences in Thyroid Cancer Surveillance

PURPOSE

To understand the effect of patient preferences on thyroid cancer surveillance intensity.

PATIENTS AND METHODS

Eligible patients diagnosed with thyroid cancer between January 1, 2014, and December 31, 2015, from the Georgia and Los Angeles County SEER registries were surveyed between February 2017 and October 2018 (N = 2,632; response rate, 63%). Patient reports on health care utilization in the past year and responses to the validated Medical Maximizer-Minimizer Scale were linked to SEER data in the 2,183 disease-free patients. Ordered logistic regression was performed using a cumulative logit with nonproportional odds.

RESULTS

Of disease-free patients, 31.6% were classified as minimizers, 42.5% as moderate maximizers, and 25.9% as strong maximizers. In the past year, 25.2%, 27.3%, and 38.5% of minimizers, moderate maximizers, and strong maximizers, respectively, had ≥ 4 doctor visits, and 18.3%, 24.9%, and 29.5%, respectively, had ≥ 2 neck ultrasounds. When controlling for age, sex, race and ethnicity, comorbidity, stage, and SEER site, strong maximizers (compared with minimizers) were significantly more likely to report ≥ 4 doctor visits (odds ratio [OR], 1.45; 95% CI, 1.10-1.92), ≥ 2 neck ultrasounds (OR, 1.58; 95% CI, 1.17-2.14), ≥ 1 radioactive iodine scan (OR, 1.73; 95% CI, 1.19-2.50), and ≥ 1 additional imaging study (OR, 2.06; 95% CI, 1.56-2.72).

CONCLUSION

Among patients with thyroid cancer who have been declared disease free, preference for a more maximal versus minimal approach to medical care is associated with increased number of physician visits and imaging tests. Because increased surveillance does not clearly correlate with improved outcomes, poses potential risks to patients, and contributes to increased healthcare costs, stronger consideration of the role of patient preferences is necessary when framing discussions on surveillance.

Worry in Thyroid Cancer Survivors with a Favorable Prognosis

Background: Little is known about cancer-related worry in thyroid cancer survivors with favorable prognosis. Methods: A diverse cohort of patients diagnosed with differentiated thyroid cancer in 2014-2015 from the Surveillance, Epidemiology, and End Results (SEER) Program registries of Georgia and Los Angeles County were surveyed two to four years after diagnosis. Main outcomes were any versus no worry about harms from treatments, quality of life, family at risk for thyroid cancer, recurrence, and death. After excluding patients with recurrent, persistent, and distant disease, multivariable logistic regression was used to identify correlates of worry in 2215 disease-free survivors. Results: Overall, 41.0% reported worry about death, 43.5% worry about harms from treatments, 54.7% worry about impaired quality of life, 58.0% worry about family at risk, and 63.2% worry about recurrence. After controlling for disease severity, in multivariable analyses with separate models for each outcome, there was more worry in patients with lower education (e.g., worry about recurrence, high school diploma and below: odds ratio [OR] 1.78, 95% confidence interval [CI 1.36-2.33] compared with college degree and above). Older age and male sex were associated with less worry (e.g., worry about recurrence, age ≥65 years: OR 0.28 [CI 0.21-0.39] compared with age ≤44 years). Worry was associated with being Hispanic or Asian (e.g., worry about death, Hispanic: OR 1.41 [CI 1.09-1.83]; Asian: OR 1.57 [CI 1.13-2.17] compared with whites). Conclusions: Physicians should be aware that worry is a major issue for thyroid cancer survivors with favorable prognosis. Efforts should be undertaken to alleviate worry, especially among vulnerable groups, including female patients, younger patients, those with lower education, and racial/ethnic minorities.

INITIAL ADOPTION OF RECOMBINANT HUMAN THYROID-STIMULATING HORMONE FOLLOWING THYROIDECTOMY IN THE MEDICARE THYROID CANCER PATIENT POPULATION

OBJECTIVE

Recombinant human thyroid-stimulating hormone (rhTSH) has been approved for diagnostic (1998) and therapeutic (2008) indications in conjunction with radioactive iodine (RAI) administration post-thyroidectomy. Potential benefits of rhTSH, including avoidance of hypothyroidism side effects and shorter, less costly hospital stays, have not been assessed at the population level within the United States. In this study we quantify utilization, outcomes, and associated costs of rhTSH within the nationally representative Surveillance, Epidemiology, and End Results (SEER)-Medicare patient population.

METHODS

We conducted a retrospective analysis of beneficiaries aged >65 years diagnosed within the SEER-Medicare data with differentiated thyroid cancer. Endpoints examined included ( 1) rhTSH utilization in the 2 years post-thyroidectomy (patients diagnosed 1996-2011 [utilization cohort]) and ( 2) comparison of resource utilization and costs as a function of rhTSH receipt in the 30 days prior to and 1 year following therapeutic RAI administration (patients diagnosed 2008-2011 [resource use cohort]). All costs were adjusted to reflect 2013 dollars.

RESULTS

A total of 6,482 patients met inclusion criteria, of which, 1,363 (21.0%) received rhTSH. Receipt varied by region and was higher in the South (18%), Northeast (28%), and West (44%) compared to the Midwest (10%), and lower in census tracts in the bottom quartile of high school education rates (odds ratio 0.68, 95% confidence interval [CI] 0.55-0.83). rhTSH receipt was not associated with patient sex, age, comorbidities, or stage. Post-therapeutic RAI, 1,444 patients were assessed for resource utilization (2008-2011). The average cost of rhTSH was $905 per patient, with $2,483 being spent on average among patients who received rhTSH in association with therapeutic RAI. rhTSH receipt was not significantly associated with total inpatient days or number of outpatient and emergency department visits. Multivariable analyses showed similar overall costs among patients who did versus did not receive rhTSH (cost ratio [CR] 0.96, 95% CI 0.86-1.09), partially due to increased mean outpatient costs ($5,213 vs. $4,190) being offset by lower inpatient costs ($3,493 vs. $6,143). Overall costs were significantly higher in multivariable analyses among patients with distant metastatic disease (CR 1.92, 95% CI 1.58-2.32) and multiple comorbidities (CR 2.15, 95% CI 1.83-2.53).

CONCLUSION

rhTSH recipients had higher outpatient, lower inpatient, and similar total Medicare payments as those not receiving rhTSH in conjunction with RAI, lending support to the use of rhTSH as a cost-neutral treatment option from the payer perspective.

ABBREVIATIONS

CI = confidence interval; CMS = Centers for Medicare & Medicaid Services; CR = cost ratio; HCPCS = Healthcare Common Procedure Coding System; IQR = interquartile range; mCi = millicurie; OR = odds ratio; PET = positron emission tomography; RAI = radioactive iodine; rhTSH = recombinant human thyroid-stimulating hormone; RR = risk ratio; SEER = Surveillance, Epidemiology, and End Results.

Ions doped melanin nanoparticle as a multiple imaging agent

Background

Multimodal nanomaterials are useful for providing enhanced diagnostic information simultaneously for a variety of in vivo imaging methods. According to our research findings, these multimodal nanomaterials offer promising applications for cancer therapy.

Results

Melanin nanoparticles can be used as a platform imaging material and they can be simply produced by complexation with various imaging active ions. They are capable of specifically targeting epidermal growth factor receptor (EGFR)-expressing cancer cells by being anchored with a specific antibody. Ion-doped melanin nanoparticles were found to have high bioavailability with long-term stability in solution, without any cytotoxicity in both in vitro and in vivo systems.

Conclusion

By combining different imaging modalities with melanin particles, we can use the complexes to obtain faster diagnoses by computed tomography deep-body imaging and greater detailed pathological diagnostic information by magnetic resonance imaging. The ion-doped melanin nanoparticles also have applications for radio-diagnostic treatment and radio imaging-guided surgery, warranting further proof of concept experimental.

Electronic supplementary material

The online version of this article (doi:10.1186/s12951-017-0304-3) contains supplementary material, which is available to authorized users.

Impact of combined FDG-PET/CT and MRI on the detection of local recurrence and nodal metastases in thyroid cancer

Background

Suspected recurrence of thyroid carcinoma is a diagnostic challenge when findings of both a radio iodine whole body scan and ultrasound are negative. PET/CT and MRI have shown to be feasible for detection of recurrent disease. However, the added value of a consensus reading by the radiologist and the nuclear medicine physician, which has been deemed to be helpful in clinical routines, has not been investigated. This study aimed to investigate the impact of combined FDG-PET/ldCT and MRI on detection of locally recurrent TC and nodal metastases in high-risk patients with special focus on the value of the multidisciplinary consensus reading.

Materials and methods

Forty-six patients with suspected locally recurrent thyroid cancer or nodal metastases after thyroidectomy and radio-iodine therapy were retrospectively selected for analysis. Inclusion criteria comprised elevated thyroglobulin blood levels, a negative ultrasound, negative iodine whole body scan, as well as combined FDG-PET/ldCT and MRI examinations.

Neck compartments in FDG-PET/ldCT and MRI examinations were independently analyzed by two blinded observers for local recurrence and nodal metastases of thyroid cancer. Consecutively, the scans were read in consensus. To explore a possible synergistic effect, FDG-PET/ldCT and MRI results were combined. Histopathology or long-term follow-up served as a gold standard.

For method comparison, sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated.

Results

FDG-PET/ldCT was substantially more sensitive and more specific than MRI in detection of both local recurrence and nodal metastases. Inter-observer agreement was substantial both for local recurrence (κ = 0.71) and nodal metastasis (κ = 0.63) detection in FDG-PET/ldCT. For MRI, inter-observer agreement was substantial for local recurrence (κ = 0.69) and moderate for nodal metastasis (κ = 0.55) detection. In contrast, FDG-PET/ldCT and MRI showed only slight agreement (κ = 0.21). However, both imaging modalities identified different true positive results. Thus, the combination created a synergistic effect. The multidisciplinary consensus reading further increased sensitivity, specificity, and diagnostic accuracy.

Conclusions

FDG-PET/ldCT and MRI are complementary imaging modalities and should be combined to improve detection of local recurrence and nodal metastases of thyroid cancer in high-risk patients. The multidisciplinary consensus reading is a key element in the diagnostic approach.

Electronic supplementary material

The online version of this article (doi:10.1186/s40644-016-0096-y) contains supplementary material, which is available to authorized users.

ENDOCRINE TUMOURS: Imaging in the follow-up of differentiated thyroid cancer: current evidence and future perspectives for a risk-adapted approach

The clinical and epidemiological profiles of differentiated thyroid cancers (DTCs) have changed in the last three decades. Today's DTCs are more likely to be small, localized, asymptomatic papillary forms. Current practice is, though, moving toward more conservative approaches (e.g. lobectomy instead of total thyroidectomy, selective use of radioiodine). This evolution has been paralleled and partly driven by rapid technological advances in the field of diagnostic imaging. The challenge of contemporary DTCs follow-up is to tailor a risk-of-recurrence-based management, taking into account the dynamic nature of these risks, which evolve over time, spontaneously and in response to treatments. This review provides a closer look at the evolving evidence-based views on the use and utility of imaging technology in the post-treatment staging and the short- and long-term surveillance of patients with DTCs. The studies considered range from cervical US with Doppler flow analysis to an expanding palette of increasingly sophisticated second-line studies (cross-sectional, functional, combined-modality approaches), which can be used to detect disease that has spread beyond the neck and, in some cases, shed light on its probable outcome.

Use of imaging tests after primary treatment of thyroid cancer in the United States: population based retrospective cohort study evaluating death and recurrence

OBJECTIVE

 To determine whether the use of imaging tests after primary treatment of differentiated thyroid cancer is associated with more treatment for recurrence and fewer deaths from the disease.

DESIGN

 Population based retrospective cohort study.

SETTING

 Surveillance Epidemiology and End Results-Medicare database in the United States.

PARTICIPANTS

 28 220 patients diagnosed with differentiated thyroid cancer between 1998 and 2011. The study cohort was followed up to 2013, with a median follow-up of 69 months.

MAIN OUTCOME MEASURES

 Treatment for recurrence of differentiated thyroid cancer (additional neck surgery, additional radioactive iodine treatment, or radiotherapy), and deaths due to differentiated thyroid cancer. We conducted propensity score analyses to assess the relation between imaging (neck ultrasound, radioiodine scanning, or positron emission tomography (PET) scanning) and treatment for recurrence (logistic model) and death (Cox proportional hazards model).

RESULTS

 From 1998 until 2011, we saw an increase in incident cancer (rate ratio 1.05, 95% confidence interval 1.05 to 1.06), imaging (1.13, 1.12 to 1.13), and treatment for recurrence (1.01, 1.01 to 1.02); the change in death rate was not significant. In multivariable analysis, use of neck ultrasounds increased the likelihood of additional surgery (odds ratio 2.30, 95% confidence interval 2.05 to 2.58) and additional radioactive iodine treatment (1.45, 1.26 to 1.69). Radioiodine scans were associated with additional surgery (odds ratio 3.39, 95% confidence interval 3.06 to 3.76), additional radioactive iodine treatment (17.83, 14.49 to 22.16), and radiotherapy (1.89, 1.71 to 2.10). Use of PET scans was associated with additional surgery (odds ratio 2.31, 95% confidence interval 2.09 to 2.55), additional radioactive iodine treatment (2.13, 1.89 to 2.40), and radiotherapy (4.98, 4.52 to 5.49). Use of neck ultrasounds or PET scans did not significantly affect disease specific survival (hazard ratio 1.14, 95% confidence interval 0.98 to 1.27, and 0.91, 0.77 to 1.07, respectively). However, radioiodine scans were associated with an improved disease specific survival (hazard ratio 0.70, 95% confidence interval 0.60 to 0.82).

CONCLUSIONS

 The marked rise in use of imaging tests after primary treatment of differentiated thyroid cancer has been associated with an increased treatment for recurrence. However, with the exception of radioiodine scans in presumed iodine avid disease, this association has shown no clear improvement in disease specific survival. These findings emphasize the importance of curbing unnecessary imaging and tailoring imaging after primary treatment to patient risk.

Evaluating Positron Emission Tomography Use in Differentiated Thyroid Cancer

BACKGROUND

Using the Surveillance, Epidemiology, and End Results-Medicare database, a substantial increase was found in the use of positron emission tomography (PET) scans after 2004 in differentiated thyroid cancer (DTC) patients. The reason for the increased utilization of the PET scan was not clear based on available the data. Therefore, the indications for and outcomes of PET scans performed at an academic institution were evaluated.

METHODS

A retrospective cohort study was performed of DTC patients who underwent surgery at the University of Michigan Health System from 2006 to 2011. After identifying patients who underwent a PET scan, indications, rate of positive PET scans, and impact on management were evaluated. For positive scans, the location of disease was characterized, and presence of disease on other imaging was determined.

RESULTS

Of the 585 patients in the cohort, 111 (19%) patients had 200 PET scans performed for evaluation of DTC. Indications for PET scan included: elevated thyroglobulin and negative radioiodine scan in 52 scans (26.0%), thyroglobulin antibodies in 13 scans (6.5%), rising thyroglobulin in 18 scans (9.0%), evaluation of abnormality on other imaging in 22 scans (11.0%), evaluation of extent of disease in 33 scans (16.5%), follow-up of previous scan in 57 scans (28.5%), other indications in two scans (1.0%), and unclear indications in three scans (1.5%). The PET scan was positive in 124 studies (62.0%); positivity was identified in the thyroid bed on 25 scans, cervical or mediastinal lymph nodes on 105 scans, lung on 28 scans, bone on four scans, and other areas on 14 scans. Therapy following PET scan was surgery in 66 cases (33.0%), chemotherapy or radiation in 23 cases (11.5%), observation in 110 cases (55.0%), and palliative care in one case (0.5%). Disease was identifiable on other imaging in 66% of cases. PET scan results changed management in 59 cases (29.5%).

CONCLUSIONS

In this academic medical center, the PET scan was utilized in 19% of patients. Indications for the PET scan included conventional indications, such as elevated thyroglobulin with noniodine avid disease, and more controversial uses, such as evaluation of extent of disease or abnormalities on other imaging tests. PET scan results changed management in about 30% of cases.

Cost-effectiveness analysis of papillary thyroid cancer surveillance

BACKGROUND

The recent overdiagnosis of subclinical, low-risk papillary thyroid cancer (PTC) coincides with a growing national interest in cost-effective health care practices. The aim of this study was to measure the relative cost-effectiveness of disease surveillance of low-risk PTC patients versus intermediate- and high-risk patients in accordance with American Thyroid Association risk categories.

METHODS

Two thousand nine hundred thirty-two patients who underwent thyroidectomy for differentiated thyroid cancer between 2000 and 2010 were identified from the institutional database; 1845 patients were excluded because they had non-PTC cancer, underwent less than total thyroidectomy, had a secondary cancer, or had <36 months of follow-up. In total, 1087 were included for analysis. The numbers of postoperative blood tests, imaging scans and biopsies, clinician office visits, and recurrence events were recorded for the first 36 months of follow-up. Costs of surveillance were determined with the Physician Fee Schedule and Clinical Lab Fee Schedule of the Centers for Medicare and Medicaid Services.

RESULTS

The median age was 44 years (range, 7-83 years). In the first 36 months after thyroidectomy, there were 3, 44, and 22 recurrences (0.8%, 7.8%, and 13.4%) in the low-, intermediate-, and high-risk categories, respectively. The cost of surveillance for each recurrence detected was US $147,819, US $22,434, and US $20,680, respectively.

CONCLUSIONS

The cost to detect a recurrence in a low-risk patient is more than 6 and 7 times greater than the cost for intermediate- and high-risk PTC patients. It is difficult to justify this allocation of resources to the surveillance of low-risk patients. Surveillance strategies for the low-risk group should, therefore, be restructured.