The modern landscape of radiotherapy in thyroid malignancies

Thyroid carcinoma is the most common malignancy of the endocrine system and accounts for nearly 1.5% of all new cancer cases in India. The incidence of thyroid cancers is on the rise secondary to multiple factors including the widespread use of radiological imaging. Surgery remains the cornerstone of treatment, and radioactive iodine therapy plays a pivotal role in differentiated thyroid cancer. Radiation therapy appears to be an underutilized treatment modality. In this review, we have summarized the role of radiation in the treatment of thyroid cancer.

Prognostic value of adjuvant external beam radiotherapy for papillary thyroid cancer based on competitive risk model and propensity score matching

This study aimed to assess the impact of adjuvant external beam radiotherapy (EBRT) on the survival of patients with locally invasive papillary thyroid carcinoma. This retrospective study used data from the Surveillance, Epidemiology, and End Results database for the diagnosis of papillary thyroid carcinoma, using Cox models to screen for adverse prognostic factors. The prognostic value of using adjuvant external beam radiotherapy in papillary thyroid carcinoma was further evaluated, based on the competing risk model and propensity score matching. Based on the competitive risk model, the sub-distribution hazard ratio (SHR) of the multivariate analysis of patients receiving EBRT alone versus those receiving radioiodine-131 alone was 9.301 (95% CI 5.99-14.44) (P < 0.001), and the SHR of the univariate analysis was 1.97 (95% CI 1.03-3.78) (P = 0.042). In the propensity score-matched Kaplan-Meier analysis, patients who received EBRT still had worse OS (6-year OS, 59.62% vs 74.6%; P < 0.001) and DSS (6-year DSS, 66.6% vs 78.2%; P < 0.001) than patients who did not receive EBRT. Patients who received EBRT had a higher cumulative risk of death due to thyroid cancer after PSM (P < 0.001). Adjuvant EBRT was not associated with survival benefit in the initial management of locally invasive papillary thyroid cancer.

The role of external beam radiation therapy in the management of thyroid carcinomas: A retrospective study in Iran Cancer Institute

BACKGROUND

Thyroid cancers are histologically classified into three types; differentiated thyroid carcinoma (DTC), medullary thyroid carcinoma (MTC), and anaplastic thyroid carcinoma (ATC). Among the several therapeutic strategies for treatment and management of thyroid cancer, surgical resection in combination with radioactive iodine therapy (RAI) is indicated for moderate to high-risk differentiated thyroid cancer (DTC) patients- according to current guidelines. However, external radiation therapy (EBRT) can be a viable alternative treatment option for these patients and scarce evidence is available regarding the efficacy and effectiveness of EBRT on thyroid cancer.

AIM

This study aims at evaluating the role of EBRT in the management of thyroid carcinomas.

METHODS AND RESULTS

In this retrospective cohort study, the records of 59 patients with thyroid cancer were accessed who were treated by EBRT from 2008 to 2016. The indications for EBRT included unresectable primary (definitive) or loco-regional recurrences (salvage) not suitable for RAI, palliation for local disease or metastatic foci (palliative), and the adjuvant treatment for suspected residual disease following resection. Progression-free survival (PFS) and overall survival (OS) were calculated for different types of cancer. PFS was measured from the start of EBRT to the last uneventful follow-up, recurrence, or death. Kaplan-Meier model was used for the survival analysis. Fifty-nine patients were evaluated. The histopathology of the tumors was differentiated and poorly-differentiated, medullary and anaplastic thyroid carcinomas in 22 and 6, 15 and 16 patients, respectively. Twenty-seven patients received external beam radiotherapy (EBRT) as adjuvant therapy and 18 of the cases as palliative therapy while the remaining received salvage or definitive primary EBRT. The stage of patients' cancer was as follows: stage II in 3 and III in 1, IVA in 18 and IVB in 18 and IVC in 19. Stage-based median overall survival was 26 months for IVA, 44 for IVB, and 29 for IVC. The median PFS was 18, 22 and 21 months for stages IVA, IVB and IVC, respectively.

CONCLUSION

Based on our findings, EBRT may still play a role in the management of patients with thyroid carcinoma and should be considered in the armamentarium against thyroid cancers.

Case of papillary thyroid cancer presenting with an inoperable cervical mass successfully treated with high-dose radiation therapy

External-beam radiation therapy (EBRT) for differentiated thyroid cancer has been controversial. Palliative irradiation is usually recommended for patients with treatment-resistant relapse and/or distant metastases, but high-dose EBRT is not often indicated in this situation. A 50-year-old man had treatment-resistant recurrence of an inoperable cervical mass and multiple lung metastases after total thyroidectomy and neck dissection. Because the patient had good performance status and no other life-threatening metastases, he received high-dose intensity-modulated radiation therapy (IMRT). Remarkably, the tumour shrank during treatment. After 3 months, he had bleeding from the internal carotid artery. The bleeding was outside the high-dose irradiation site and was likely due to infection; emergency interventional radiology was performed. The post-EBRT clinical course was favourable and the cervical mass almost disappeared. The patient remained alive for 3 years post treatment. It is possible to extend the indication of high-dose intensity-IMRT in selected patients with differentiated thyroid cancer.

Analysis of risk factors and prognosis in differentiated thyroid cancer with focus on minimal extrathyroidal extension

AIMS

In contrast to all prior AJCC/TNM classifications for differentiated thyroid cancer (DTC) the 8th edition does not take minimal extrathyroidal extension (M-ETE) into consideration for local tumor staging. We therefore aimed to retrospectively assess the specific impact of M-ETE on the outcome of M-ETE patients treated in our clinic.

METHODS

DTC patients with M-ETE and a follow-up time of ≥ 5 years were included and matched with an identical number of patients without M-ETE, but with equal histopathological tumor subtype and size. The frequency of initially metastatic disease among groups was compared using Fisher's exact test, the recurrence rate by virtue of log-rank test. Fisher's exact test and multivariate analysis were used to account for the presence of confounding risk factors.

RESULTS

One hundred sixty patients (80 matching pairs) were eligible. With other confounding risk factors being equal, the prevalence of N1-/M1-disease at initial diagnosis was comparable among groups (M-ETE: 42.5 %; no M-ETE: 32.5 %; p = 0.25). No differences with regard to the recurrence rate were shown. However, M-ETE patients were treated with external beam radiation therapy more often (16.3 % vs. 1.3 %; p = 0.004) and received higher median cumulative activities of ¹³¹I (10.0 vs. 8.0 GBq; p < 0.001).

DISCUSSION

Although having played a pivotal role for local tumor staging of DTC for decades M-ETE did not increase the risk for metastases at initial diagnosis and the recurrence rate in our cohort. Patients with M-ETE had undergone intensified treatment, which entails a possible confounding factor that warrants further investigation in randomized controlled trials.

Intensity-modulated radiation therapy and doxorubicin in thyroid cancer: A prospective phase 2 trial

BACKGROUND

The use of external-beam radiotherapy for locally advanced nonanaplastic thyroid cancer remains controversial. This prospective study evaluated the efficacy and tolerability of intensity-modulated radiation therapy (IMRT) with or without concurrent chemotherapy in patients with locally advanced thyroid cancer.

METHODS

The authors conducted a nonrandomized phase 2 trial of IMRT with or without concurrent doxorubicin in patients with gross residual or unresectable nonanaplastic thyroid carcinoma (ClinicalTrials.gov identifier NCT01882816). The primary end point was 2-year locoregional progression-free survival (PFS). Secondary end points included overall survival (OS), safety, patient-reported outcomes, and functional outcomes.

RESULTS

Twenty-seven patients were enrolled: 12 (44.4%) with unresectable disease and 15 (55.6%) with gross residual disease. The median follow-up was 45.6 months (interquartile range, 42.0-51.6 months); the 2-year cumulative incidences of locoregional PFS and OS were 79.7% and 77.3%, respectively. The rate of grade 3 or higher acute and late toxicities was 33.4%. There were no significant functional differences 12 months after treatment (assessed objectively by the modified barium swallow study). Patient-reported quality of life in the experimental group was initially lower but returned to the baseline after 6 months and improved thereafter. In a post hoc analysis, concurrent chemotherapy with intensity-modulated radiation therapy (CC-IMRT) resulted in significantly less locoregional failure at 2 years (no failure vs 50%; P = .001), with higher rates of grade 2 or higher acute dermatitis, mucositis, and dysphagia but no difference in long-term toxicity, functionality, or patient-reported quality of life.

CONCLUSIONS

In light of the excellent locoregional control rates achieved with CC-IMRT and its acceptable toxicity profile as confirmed by functional assessments and patient-reported outcomes, CC-IMRT may be preferred over IMRT alone.

External Beam Radiation Therapy in pT4 Well-Differentiated Thyroid Cancer: A Population-Based Study of 405 Patients

PURPOSE

The benefit of external beam radiation therapy (EBRT) in locally advanced, well- differentiated thyroid cancer (WDTC) is uncertain. The purpose of this study is to evaluate locoregional recurrence (LRR), progression-free survival, and cause-specific survival (CSS) of patients with pT4 well-differentiated thyroid carcinoma.

METHODS AND MATERIALS

A population-based retrospective review was conducted of consecutive patients with pT4 WDTC (per the American Joint Committee on Cancer, 8th edition, criteria) treated provincially between 1985 and 2013. The primary endpoints were cumulative incidence of LRR and CSS. To account for the competing risks of death from other causes, a Fine-Gray's test was used. A Cox-proportional hazards model was used to analyze overall survival (OS). Multivariate models and propensity matching were used to account for the effects of covariates.

RESULTS

A total of 405 patients were identified with a median follow-up time of 14.3 years for a total of 4209 person-years of follow up. The median age at the time of diagnosis was 53 years (range, 20-87). There were 211 patients (52%) who received EBRT. EBRT was associated with age ≥55 years (56% vs 35%; P < .001), airway involvement (42% vs 8%; P < .001), and R1/2 resection (81% vs 51%; P < .001). The 10-year outcomes for the non-EBRT and EBRT groups were 21.6% versus 11.4%, respectively, for LRR, 84.1% versus 93.1%, respectively, for CSS, and 85.7% versus 67.5%, respectively, for OS. On multivariate analysis, EBRT was associated with a lower rate of LRR (hazard ratio [HR]: 0.334; P < .001), but not associated with CSS (HR: 1.56; P = .142) nor OS (HR: 1.216; P = .335). After propensity score matching, the EBRT cohort had lower rates of LRR relative to the non-EBRT cohort (HR: 0.261; P = .0003), but there were no differences in CSS or OS.

CONCLUSIONS

In this large, population-based analysis of patients with pT4 WDTC, EBRT was associated with lower rates of LRR, but no difference in CSS or OS.

Adjuvant radiotherapy and radioiodine treatment for locally advanced differentiated thyroid cancer: systematic review and meta-analysis

BACKGROUND

Treatment for locally advanced differentiated thyroid cancer is surgery followed by radioiodine while the role of adjuvant external beam radiotherapy (EBRT) is debated.

METHODS

The panel of the Italian Association of Radiotherapy and Clinical Oncology developed a clinical recommendation on the addition of EBRT to radioiodine after surgery for locally advanced differentiated thyroid cancer by using the Grades of Recommendation, Assessment, Development, and Evaluation methodology and the Evidence to Decision framework. A systematic review with meta-analysis about this topic was conducted with a focus on outcome of benefits and toxicity.

RESULTS

Locoregional control was improved by EBRT while no considerable toxicity impact was reported.

CONCLUSION

The panel judged uncertain the benefit/harms balance; final recommendation was conditional both for EBRT + radioiodine and radioiodine alone in the adjuvant setting.

Treatment of Unresectable Differentiated Thyroid Carcinoma With Upfront External Radiotherapy and Salvage Surgery: A STROBE-Compliant Retrospective Cohort Study

INTRODUCTION

In patients with unresectable Differentiated thyroid cancer (DTC), the use of external beam radiation therapy (EBRT), leads mostly to palliation. Our aim is to define the role of upfront EBRT, followed or not by salvage surgery, on Progression-free survival (PFS) or Overall survival (OS) in patients with DTC.

METHODS

This is a cohort study of patients with initially unresectable DTC who received EBRT. Cohort A received EBRT followed by rescue surgery and cohort B, EBRT only. The Kaplan-Meier method and Cox model were employed for survival analysis.

RESULTS

Thirty-three patients were included; 69.6% females and 30.3% males. Mean age was 60.6 and mean tumor diameter was 10.4 cm; 17 and 16 patients were included in cohorts A and B, respectively. Belonging to cohort A (Hazard ratio [HR] 0.177, 95% CI 0.05-0.7) and use of intensity modulated radiotherapy (HR 0.177, 95% CI 0.03-1.08) were associated to better PFS, while high-risk histopathology (HR 6.6, 95% CI 0.9-50) and EBRT dose (HR 1.05, 95% CI 1.01-1.08) were independently associated with lower PFS. Patients from cohort A (HR 0.061, 95% CI 0.01-0.3) had improved OS, while high-risk histopathology (HR 5.7, 95% CI 1.1-28.6) and EBRT dose (HR 1.05, 95% CI 1.01-1.09) were independently associated to worse OS.

CONCLUSION

EBRT, and when feasible, salvage surgery, should be an integral part of the therapeutic strategy in initially unresectable DTC.

Prognostic Impact of Histologic Grade for Papillary Thyroid Carcinoma

BACKGROUND

While numerous factors affect prognosis in papillary thyroid carcinoma (PTC), the comparative impact of histologic grade has not been well described. Moreover, indications for external beam radiation therapy (EBRT) remain imprecise. We evaluate clinicopathologic characteristics and outcomes for PTC stratified by grade.

METHODS

We profiled histologic grade for PTC (well differentiated, moderately differentiated, poorly differentiated) via hospital (National Cancer Database) and population-based (Surveillance, Epidemiology, and End Results) registries. Cox regression was used to adjust for clinicopathologic covariates. Statistical interactions between subtypes and the effect of EBRT on survival were assessed.

RESULTS

Collectively, worsening clinicopathologic factors (age, tumor size, extrathyroidal extension, nodal spread, M1 disease) and outcomes (disease-free survival, overall survival) correlated with less differentiated state, across all histologic grades (p < 0.001). Multivariable analysis showed escalating hazard with loss of differentiation relative to well-differentiated PTC (moderately differentiated hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.04-1.41, p = 0.02; poorly differentiated HR 2.62, 95% CI 2.23-3.08, p < 0.001). Correspondingly, greater survival benefit was associated with EBRT for poorly differentiated cases (HR 0.36, 95% CI 0.18-0.72, p = 0.004). This finding was upheld after landmark analysis to address potential immortal time bias (HR 0.37, 95% CI 0.17-0.80, p = 0.01).

CONCLUSIONS

Worsening histologic grade in PTC is independently associated with parallel escalation in mortality risk, on a scale approximating or surpassing established thyroid cancer risk factors. On preliminary analysis, EBRT was associated with improved survival in the most aggressive or least differentiated subvariants. Further investigation is warranted to examine the efficacy of EBRT for select poorly differentiated thyroid carcinomas.

The revised clinical practice guidelines on the management of thyroid tumors by the Japan Associations of Endocrine Surgeons: Core questions and recommendations for treatments of thyroid cancer

The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Practice Guidelines for Thyroid Tumors. This article describes the guidelines translated into English for the 35 clinical questions relevant to the therapeutic management of thyroid cancers. The objective of the guidelines is to improve health-related outcomes in patients with thyroid tumors by enabling users to make their practice evidence-based and by minimizing any variations in clinical practice due to gaps in evidential knowledge among physicians. The guidelines give representative flow-charts on the management of papillary, follicular, medullary, and anaplastic thyroid carcinoma, along with recommendations for clinical questions by presenting evidence on the relevant outcomes including benefits, risks, and health conditions from patients' perspective. Therapeutic actions were recommended or not recommended either strongly (◎◎◎ or XXX) based on good evidence (😊)/good expert consensus (+++), or weakly (◎, ◎◎ or X, XX) based on poor evidence (😣)/poor expert consensus (+ or ++). Only 10 of the 51 recommendations given in the guidelines were supported by good evidence, whereas 35 were supported by good expert consensus. While implementing the current guidelines would be of help to achieve the objective, we need further clinical research to make our shared decision making to be more evidence-based.

The Role of postoperative external beam radiotherapy for differentiated thyroid carcinoma: A Systematic review and meta-analysis

The indications for external beam radiotherapy (RT) in differentiated thyroid carcinomas (DTC) are still undefined. The objective of this study was to synthesize current evidence defining the role of postoperative RT in patients with DTC. A systematic review and meta-analysis were done. Included studies compared oncologic outcomes and toxicity of RT vs no RT in patients with DTC. Nine studies were included, two prospective and seven retrospective cohorts. RT improved 5-year locoregional recurrence-free survival but not overall survival and distant metastasis failure-free survival. The locoregional control benefit was seen in patients at increased risk for recurrence, including those with advanced age, locoregionally advanced disease, gross or microscopic residual tumor, and structural invasion. Serious RT-related acute and late toxicities were rare. Available evidence suggests that postoperative RT can improve locoregional control in high-risk DTC with acceptable toxicity. Further prospective studies are warranted.

10-Year Locoregional Control with Postoperative External Beam Radiotherapy in Patients with Locally Advanced High-Risk Non-Anaplastic Thyroid Carcinoma De Novo or at Relapse, a Propensity Score Analysis

(1) Background: To assess the role of postoperative external beam radiotherapy (pEBRT) on locoregional failure (LRF) for patients with locally advanced high-risk non-anaplastic thyroid carcinoma (naTC) at primary event or relapse. (2) Methods: Between 1995 and 2015, postoperative naTC patients with a theoretical indication for EBRT were included based on criteria that were common to American-British-French current guidelines, i.e., pT3-4, pN+, gross or microscopic residual disease. Inverse probability of treatment weighting (IPTW) after multiple imputation was used to reduce selection biases. (3) Results: Of 254 naTC patients, 216 patients underwent pEBRT (106 de novo, 110 at relapse, median dose 60 Gy) and 38 underwent surgery only. pEBRT patients had more gross residual disease, a major prognostic factor (p = 0.027) but less perineural invasion (p = 0.008) or lymphovascular emboli (p = 0.009). pEBRT patients more frequently underwent radioiodine therapy (p = 0.026). The 10-year cumulative incidence of LRF was 56% (95% CI, 32–74%) in operated patients, and 23% (95% CI, 17–30%) in pEBRT patients. After IPTW method, pEBRT reduced the risk of LRF (hazard ratio 0.30; 95% CI [0.18–0.49], p < 0.001), but had no impact on OS. In the pEBRT group, non-Intensity Modulated RadioTherapy (IMRT) plans and interruption of the radiotherapy were associated with poorer survival, while extended versus limited field strategy and dose were not. (4) Conclusions: In naTC patients who have pT3-4, pN+ disease or R1-2 resection, pEBRT improved LRF. Limited-field IMRT is preferred.

Locoregional disease control after external beam radiotherapy in 91 patients with differentiated thyroid carcinoma and pT4 tumor stage - a single institution experience

Background Locoregional recurrence is common in patients with locally advanced differentiated thyroid carcinoma (DTC). Our aim was to find out the rate of locoregional control of the disease after external beam radiotherapy (EBRT) of the neck and mediastinum in patients with DTC and pT4 tumor. Patients and methods Altogether 91 patients (47 males, 44 females, median age 61 years) with DTC had EBRT of the neck and mediastinum as part of the multimodal treatment of pT4 tumor (63 cases pT4a, 28 cases pT4b) from the year 1973 to 2015. Data on clinical factors, histopathology and recurrence were collected. Disease-free, disease-specific and overall survival was calculated. Results Median tumor size was 5 cm (range 1-30 cm). Out of 91 patients, 23 had distant and 38 regional metastases. A total or near-total thyroidectomy, lobectomy, subtotal thyroidectomy and lymph node dissection was performed in 70%, 14%, 2% and 30% of cases, respectively. Thirteen percent of patients were not treated with surgery. All patients had EBRT and 39 had chemotherapy. Radioiodine (RAI) ablation of thyroid remnant and RAI therapy was applied in 90% and 40% of cases, respectively. Recurrence was diagnosed in 29/64 patients without a persistent disease: locoregional and distant in 16 and 13 cases, respectively. Five-year and ten-year disease-free survival rate was 64% and 48%, respectively. Conclusions The majority of patients with DTC and pT4 tumors who were treated with EBRT of the neck and mediastinum region as part of multimodal treatment have long-lasting locoregional control of the disease.

Analysis of postoperative ultrasonography surveillance after total thyroidectomy in patients with papillary thyroid carcinoma: a multicenter study

Background In papillary thyroid carcinoma (PTC) patients, postoperative ultrasonography (US) surveillance is recommended at intervals of six or 12 months even though evidence is weak. Purpose To determine the optimal interval of postoperative US surveillance in patients after total thyroidectomy for the treatment of PTC using multicenter data. Material and Methods A total of 1400 patients from seven tertiary hospitals who underwent total thyroidectomy for treatment of PTC were included. Based on a retrospective review of clinical and pathologic results, multiple factors were analyzed according to recurrence/persistence or no recurrence/persistence. In recurrence/persistence group, the interval and number of follow-up US sessions in the initial detection of recurrence/persistence were investigated. Results Of the 1400 patients, 115 (8.2%) showed tumor recurrence/persistence on follow-up US. Of 115 recurrence/persistence cases, 89 (77.4%) were initially detected on US: nodal recurrence/persistence (n = 92), non-nodal recurrence/persistence (n = 22), and both (n = 1). Among the clinical and pathologic factors, only tumor size and N stage were significant predictors for recurrence/persistence. In the recurrence/persistence group, the mean interval and number of follow-up US sessions in the initial detection of recurrence/persistence was 22.3 ± 16.8 months and 2.2 ± 1.9, respectively. Approximately two-thirds of recurrence/persistence cases (76/115, 66.1%) were detected in follow-up US within two years after total thyroidectomy. Conclusion In PTC patients after total thyroidectomy, the optimal interval of the first US follow-up may be one to two years after thyroid surgery, and the appropriate number of postoperative US surveillance sessions within the first five years may be only one or two.

Diagnostic value and therapeutic impact of 18F-FDG-PET/CT in differentiated thyroid cancer

The clinical significance of 18F-FDG-PET/CT in the follow-up of patients with differentiated thyroid carcinoma was evaluated and the results were compared with those of 18F-FDGPET, 131I-whole-body scintigraphy including SPECT/CT (WBS) and ultrasound. In addition, it was the aim to investigate the impact of 18F-FDG-PET/CT on the therapeutic management. Patients, methods: 327 patients (209 women, 118 men; mean age 53 ± 18 years) with differentiated thyroid cancer (242 papillary, 75 follicular, 6 mixed, 1 Hürthle cell and 3 poorly differentiated tumours) were analyzed retrospectively at four tertiary referral centres. 289 18F-FDG-PET/CT and 118 18F-FDG-PET studies were performed in these patients between 2007 and 2010. In addition, an overall clinical evaluation was performed, including cytology, histology, thyroglobulin level, ultrasound, WBS, and subsequent clinical course in order to compare the molecular imaging results. Finally, the change in therapeutic management due to findings of 18F-FDG-PET/CT was investigated. Results: The sensitivity of 18F-FDG-PET/CT was 92%, the specificity was 95%. Sensitivity and specificity of 18F-FDG-PET alone were 67% and 93%, respectively. WBS showed a sensitivity of 65% and a specificity of 94%. The corresponding values of ultrasound were 37% and 94%, respectively. The sensitivity of 18F-FDG-PET/CT in the group of patients with a negative WBS (n=194) amounted to 96%. When 18F-FDG-PET/CT and WBS were considered in combination, tumour tissue was missed in only 2 out of 133 patients; when 18F-FDG-PET and WBS were combined, tumour tissue was missed in 1 out of 24 patients. 18F-FDG-PET/CT resulted in management change in 43% (n=57/133) with a decision on surgical approach in 20% (n=27/133). Conclusions: 18F-FDG-PET/CT is superior to 18F-FDG-PET alone in patients with differentiated thyroid cancer and has a direct impact on the therapeutic management of patients with suspected local recurrence or metastases, particularly in those with negative WBS.

Comparison of Survival Outcomes Following Postsurgical Radioactive Iodine Versus External Beam Radiation in Stage IV Differentiated Thyroid Carcinoma

BACKGROUND

There is a lack of well-powered data regarding outcomes in stage IV differentiated thyroid carcinoma (DTC) treated with postsurgical radiation. The objective of this study was to examine survival in patients with stage IV papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC) who received radioactive iodine (RAI), external beam radiation therapy (EBRT), or neither following surgery.

METHODS

In this retrospective cohort study, data collected from the National Cancer Data Base (NCDB) yielded 11,832 patients with stage IV DTC who underwent primary surgical treatment between 2002 and 2012. Patients were stratified by histology and sub-stage. Fully parametric, multilevel survival-time models were used to evaluate survival outcomes in three adjuvant treatment groups: RAI, EBRT, or no adjuvant radiation. Hazard ratios (HR) and time ratios (TR) were calculated against patients who did not receive radiation. All models were adjusted for demographic and clinical factors.

RESULTS

The mean age of all patients was 61.6 years (SD = 11.6), and 57.5% were female. Patients who received EBRT had significantly higher 5- and 10-year hazards of death in several PTC sub-stages (10-year HR_{PTC Stage IV-A} = 2.12 [confidence interval (CI) 1.79-2.52]; HR_{PTC Stage IV-B} = 2.03 [CI 1.33-3.10]). For stage IV-B PTC requiring EBRT, lifespan after diagnosis was shortened by a factor of 3 when compared to patients who did not receive radiation (TR_{PTC Stage IV-B} = 0.32 [CI 0.16-0.62]). In contrast, RAI was significantly associated with improved 5- and 10-year survival in both PTC and FTC patients regardless of pathological sub-stage. Large reductions in mortality were observed in patients with FTC who were treated with RAI (HR_{FTC Stage IV-C} = 0.19 [CI 0.06-0.65]). When patients with stage IV-C FTC were treated with RAI, life-span after diagnosis doubled (TR_{FTC Stage IV-C} = 1.98 [CI 1.31-3.00]).

CONCLUSIONS

Through the NCDB, this study sought to describe prognosis and survival for adjuvant radiation in stage IV DTC. RAI was associated with improved survival for stage IV DTC. Despite treatment benefits conferred by adjuvant EBRT, indications to treat with EBRT were associated with poorer survival outcomes in patients with advanced-stage DTC, particularly PTC.

The role of adjuvant external beam radiation therapy for papillary thyroid carcinoma invading the trachea

PURPOSE

To evaluate the effect of adjuvant external beam radiation therapy (EBRT) on local failure-free survival rate (LFFS) for papillary thyroid cancer (PTC) invading the trachea.

MATERIALS AND METHODS

Fifty-six patients with locally advanced PTC invading the trachea were treated with surgical resection. After surgery, 21 patients received adjuvant EBRT and radioactive iodine therapy (EBRT group) and 35 patients were treated with radioactive iodine therapy (control group).

RESULTS

The age range was 26-87 years (median, 56 years). The median follow-up period was 43 months (range, 4 to 145 months). EBRT doses ranged from 50.4 to 66 Gy (median, 60 Gy). Esophagus invasion and gross residual disease was more frequent in the EBRT group. In the control group, local recurrence developed in 9 (9/35, 26%) and new distant metastasis in 2 (2/35, 6%) patients, occurring 4 to 68 months (median, 37 months) and 53 to 68 months (median, 60 months) after surgery, respectively. Two patients had simultaneous local recurrence and new distant metastasis. There was one local failure in the EBRT group at 18 months after surgery (1/21, 5%). The 5-year LFFS was 95% in the EBRT group and 63% in the control group (p = 0.103). In the EBRT group, one late grade 2 xerostomia was developed.

CONCLUSION

Although, EBRT group had a higher incidence of esophagus invasion and gross residual disease, EBRT group showed a better 5-year LFFS. Adjuvant EBRT may have contributed to the better LFFS in these patients.

F18-FDG-PET for recurrent differentiated thyroid cancer: a systematic meta-analysis

Background

Positron emission tomography (PET) with fluor-18-deoxy-glucose (FDG) is widely used for diagnosing recurrent or metastatic disease in patients with differentiated thyroid cancer (DTC).

Purpose

To assess the diagnostic accuracy of FDG-PET for DTC in patients after ablative therapy.

Material and Methods

A systematic search was conducted in Medline/PubMed, EMBASE, Cochrane Library, Web of Science, and Open Grey looking for all English-language original articles on the performance of FDG-PET in series of at least 20 patients with DTC having undergone ablative therapy including total thyroidectomy. Diagnostic performance measures were pooled using Reitsma’s bivariate model.

Results

Thirty-four publications between 1996 and 2014 met the inclusion criteria. Pooled sensitivity and specificity were 79.4% (95% confidence interval [CI], 73.9–84.1) and 79.4% (95% CI, 71.2–85.4), respectively, with an area under the curve of 0.858.

Conclusion

F18-FDG-PET is a useful method for detecting recurrent DTC in patients having undergone ablative therapy.

External beam radiotherapy in thyroid carcinoma: clinical review and recommendations of the AIRO "Radioterapia Metabolica" Group

The therapeutic approach to thyroid carcinoma usually involves surgery as initial treatment. The use of external beam radiotherapy (EBRT) is limited to high-risk patients and depends on clinical stage and histologic type. Different behavior patterns and degrees of aggressiveness of thyroid carcinomas require different management for differentiated, medullary, and anaplastic carcinoma. However, the role of EBRT is an issue of debate. Most clinical studies are retrospective and based on single-institution experiences. In this article, we review the main literature and give recommendations for the use of EBRT in thyroid carcinoma on behalf of the "Radioterapia Metabolica" Group of the Italian Radiation Oncology Association.

Intensity-modulated radiation therapy use for the localized treatment of thyroid cancer: Nationwide practice patterns and outcomes

In the absence of randomized data, the optimal approach to adjuvant radiation therapy in locally advanced thyroid cancer remains unclear. We employed a large retrospective analysis to assess the best available evidence of a potential beneficial impact of intensity-modulated versus 3D-conformal radiotherapy (IMRT vs. 3D-CT). Retrospective analysis of adult thyroid cancer diagnosed between 2004 and 2011 within the National Cancer Database. Among patients treated with radiation therapy (N = 855), the use of IMRT (N = 437) increased among both comprehensive and academic centers (both p < 0.001), but not community hospitals (p = 0.43). Receipt of IMRT was associated with adverse clinical factors in multivariable analysis, including positive surgical margins, non-DTC histologies, and nodal metastases (all p < 0.001). IMRT use was associated with a significantly higher dose of radiation (60.7 vs. 52.4 Gy, p < 0.001). In multivariable analyses, receipt of IMRT demonstrated a trend toward improved overall survival (HR, 0.67; 95 % CI, 0.40-1.10; p = 0.115). This study presents the largest cohort to date examining receipt of IMRT in patients with locally advanced thyroid cancer and demonstrates an association between IMRT, treatment at a tertiary care center, higher total dose, and comparable or superior outcomes compared to patients treated with 3D conformal techniques despite more adverse disease features. In the absence of adequately powered prospective randomized trials, our retrospective analysis provides empirical evidence to support the use in these patients of dose escalation and IMRT, particularly at tertiary care centers.

Management of Invasive Differentiated Thyroid Cancer

BACKGROUND

Invasive disease is a poor prognostic factor for patients with differentiated thyroid cancer (DTC). Uncontrolled central neck disease is a common cause of distressing death for patients presenting in this manner. Advances in assessment and management of such cases have led to significant improvements in outcome for this patient group. This article reviews the patterns of invasion and a contemporary approach to investigation and treatment of patients with invasive DTC.

SUMMARY

Aerodigestive tract invasion is reported in around 10% of case series of DTC. Assessment should include not only clinical history and physical examination with endoscopy as indicated, but ultrasound and contrast-enhanced cross-sectional imaging. Further studies including positron emission tomography should be considered, particularly in recurrent cases that are radioactive iodine (RAI) resistant. Both the patient and the extent of disease should be carefully assessed prior to embarking on surgery. The aim of surgery is to resect all gross disease. When minimal visceral invasion is encountered early, "shave" procedures are recommended. In the setting of transmural invasion of the airway or esophagus, however, full thickness excision is required. For intermediate cases in which invasion of the viscera has penetrated the superficial layers but is not evident in the submucosa, opinion is divided. Early reports recommended an aggressive approach. More recently authors have tended to recommend less aggressive resections with postoperative adjuvant therapies. The role of external beam radiotherapy continues to evolve in DTC with support for its use in patients considered to have RAI-resistant tumors.

CONCLUSIONS

Patients with invasive DTC require a multidisciplinary approach to investigation and treatment. With detailed assessment, appropriate surgery, and adjuvant therapy when indicated, this patient group can expect durable control of central neck disease, despite the aggressive nature of their primary tumors.

[Postoperative external beam radiotherapy for medullary thyroid carcinoma with high risk of locoregional relapse]

PURPOSE

To assess the outcome of locally advanced medullary thyroid carcinoma treated with surgery and adjuvant external beam radiotherapy.

PATIENTS AND METHODS

Twenty-nine consecutive patients with non-metastatic medullary thyroid carcinoma treated in our institution between January 1995 and December 2012 were retrospectively evaluated. All underwent curative-intended optimal surgery, followed by external beam radiotherapy because of high risk of locoregional relapse. Twelve patients were stage III, 16 IVa and 1 IVb. Positive surgical margins were present in 11 cases (10 R1 and 1 R2). Median and average preradiotherapy serum calcitonin were 141pg/mL and 699pg/mL, respectively. Fourteen patients received 3D-conformal radiotherapy and 15 received intensity-modulated radiotherapy. Median prescribed dose was 63Gy to the high-risk volumes and 54Gy to the low-risk volumes. Treatment was delivered in 30 fractions. The median gap between surgery and radiotherapy was 1.9months. Median follow-up was 76.4months.

RESULTS

Kaplan-Meier estimates of 5-year locoregional relapse-free survival and overall survival were 79 and 96 %, respectively. Among the five locoregional relapses, two were related to a macroscopic metastatic cervical lymph node that was unfortunately not removed during the lymphadenectomy. Eight of ten patients with microscopic positive margins (R1) were controlled regarding the thyroidectomy bed. Eight patients had normal serum calcitonin after external beam radiotherapy, of whom only one developed a locoregional relapse during follow-up. Regarding the 21 patients with persistent positive serum calcitonin after treatment, only ten developed a macroscopic locoregional or distant relapse. One grade III and no grade IV acute morbidity were reported. Fifteen patients reported grade II chronic morbidity and no grade III/IV.

CONCLUSION

Maximal surgery followed by adjuvant external beam radiotherapy as a treatment for locally advanced medullary thyroid carcinoma provides a high rate of long-term locoregional control and overall survival with limited toxicity. Postoperative external beam radiotherapy should be considered when patients present features indicating a high risk of locoregional relapse.

External-beam radiotherapy for differentiated thyroid cancer locoregional control: A statement of the American Head and Neck Society

The use of external-beam radiotherapy (EBRT) in differentiated thyroid cancer (DTC) is debated because of a lack of prospective clinical data, but recent retrospective studies have reported benefits in selected patients. The Endocrine Surgery Committee of the American Head and Neck Society provides 4 recommendations regarding EBRT for locoregional control in DTC, based on review of literature and expert opinion of the authors. (1) EBRT is recommended for patients with gross residual or unresectable locoregional disease, except for patients <45 years old with limited gross disease that is radioactive iodine (RAI)-avid. (2) EBRT should not be routinely used as adjuvant therapy after complete resection of gross disease. (3) After complete resection, EBRT may be considered in select patients >45 years old with high likelihood of microscopic residual disease and low likelihood of responding to RAI. (4) Cervical lymph node involvement alone should not be an indication for adjuvant EBRT.

Radiotherapy in well-differentiated thyroid cancer: is it underutilized?

BACKGROUND

The usual management of thyroid cancer is surgery and radioactive iodine. The role of external beam radiotherapy (EBRT) in well-differentiated thyroid carcinoma remains controversial. Indications for the use of EBRT, contained within both the American and British Thyroid Association published guidelines, include unresectable or non-iodine avid disease, extra-thyroidal extension or distant metastatic disease.

METHODS

A retrospective review of prospectively collected data from a single Australian institution was conducted, analysing patients referred and treated with EBRT for well-differentiated thyroid carcinoma between November 1992 and July 2013.

RESULTS

Of 36 patients referred, 32 were treated with EBRT. Sixteen patients in total received locoregional treatment (six radical, 10 palliative), of whom 81% (13/16) had gross disease and 88% (14/16) had recurrent disease (eight with multiple recurrences). Additionally, 63% (10/16) had multiple surgical resections and 50% (8/16) had previously received multiple courses of radioactive iodine. Overall, 67% (4/6) of patients treated with radical intent had no locoregional recurrence or progression. Thirteen of the 16 patients who received locoregional EBRT remained asymptomatic from their locoregional disease at the time of last follow-up or death. The most commonly treated distant metastatic disease site was bone, with a total of 45 sites irradiated. Of these patients, 93% and 78% were symptom-free at two and four years, respectively.

CONCLUSION

Our study suggests that in a select group of patients with well-differentiated thyroid carcinoma, EBRT treatment appears to provide durable tumour and symptom control.

Post-PET ultrasound improves specificity of 18F-FDG-PET for recurrent differentiated thyroid cancer while maintaining sensitivity

Background

Positron emission tomography (PET) using fluor-18-deoxyglucose (18F-FDG) with or without computed tomography (CT) is generally accepted as the most sensitive imaging modality for diagnosing recurrent differentiated thyroid cancer (DTC) in patients with negative whole body scintigraphy with iodine-131 (I-131).

Purpose

To assess the potential incremental value of ultrasound (US) over 18F-FDG-PET-CT.

Material and Methods

Fifty-one consecutive patients with suspected recurrent DTC were prospectively evaluated using the following multimodal imaging protocol: (i) US before PET (pre-US) with or without fine needle biopsy (FNB) of suspicious lesions; (ii) single photon emission computed tomography (≥3 GBq I-131) with co-registered CT (SPECT-CT); (iii) 18F-FDG-PET with co-registered contrast-enhanced CT of the neck; (iv) US in correlation with the other imaging modalities (post-US). Postoperative histology, FNB, and long-term follow-up (median, 2.8 years) were taken as composite gold standard.

Results

Fifty-eight malignant lesions were identified in 34 patients. Forty lesions were located in the neck or upper mediastinum. On receiver operating characteristics (ROC) analysis, 18F-FDG-PET had a limited lesion-based specificity of 59% at a set sensitivity of 90%. Pre-US had poor sensitivity and specificity of 52% and 53%, respectively, increasing to 85% and 94% on post-US, with knowledge of the PET/CT findings (P < 0.05 vs. PET and pre-US). Multimodal imaging changed therapy in 15 out of 51 patients (30%).

Conclusion

In patients with suspected recurrent DTC, supplemental targeted US in addition to 18F-FDG-PET-CT increases specificity while maintainin sensitivity, as non-malignant FDG uptake in cervical lesions can be confirmed.

External beam radiotherapy in differentiated thyroid carcinoma: A systematic review

External beam radiotherapy (EBRT) is not a first line treatment in differentiated thyroid carcinoma (DTC), but is recommended as an adjuvant treatment in certain cases. The evidence for EBRT in DTC is limited. A comprehensive literature search was performed. Data on patient demographics, disease stage, treatment characteristics, and outcomes were collected from included articles after quality appraisal. Sixteen articles met the inclusion criteria, with a pooled population of 5114. Only 1 study was prospective and there were no randomized controlled trials. Most of the evidence suggests that EBRT improves locoregional control in patients at high risk of locoregional recurrence. This was corroborated by analysis of pooled patient data. Available evidence suggests an improvement in locoregional control when EBRT is used in patients over the age of 45 at high risk for locoregional recurrence. However, there is a need for long-term prospective multicenter research on the subject. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2297-E2305, 2016.

Indications for the use of external beam radiation in thyroid cancer

PURPOSE OF REVIEW

The role of external beam radiation therapy (EBRT) in the management of thyroid cancer is not clearly defined. In the absence of randomized studies, the review aims to identify any recent literature that helps define the role.

RECENT FINDINGS

In differentiated thyroid cancer, single institutional studies report durable locoregional disease control in patients considered to be at high risk of local relapse after EBRT and recent guidelines are consistent in their recommendations. In medullary thyroid cancer, the evidence is more limited but again there is benefit in selected cases. In anaplastic thyroid cancer, multimodality therapy is superior to surgery alone in achieving local control and possibly survival but the benefit must be weighed against the toxicity. Newer radiation techniques may help reduce toxicity.

SUMMARY

Although surgery is the main treatment for thyroid carcinoma, EBRT has a role in the adjuvant setting following surgery in high-risk patients and in unresectable cancer. Advances in the delivery of external beam radiotherapy, including intensity-modulated radiotherapy reduces toxicity.

A simple versatile solution for collecting multidimensional clinical data based on the CakePHP web application framework

Clinical trials aiming for regulatory approval of a therapeutic agent must be conducted according to Good Clinical Practice (GCP). Clinical Data Management Systems (CDMS) are specialized software solutions geared toward GCP-trials. They are however less suited for data management in small non-GCP research projects. For use in researcher-initiated non-GCP studies, we developed a client-server database application based on the public domain CakePHP framework. The underlying MySQL database uses a simple data model based on only five data tables. The graphical user interface can be run in any web browser inside the hospital network. Data are validated upon entry. Data contained in external database systems can be imported interactively. Data are automatically anonymized on import, and the key lists identifying the subjects being logged to a restricted part of the database. Data analysis is performed by separate statistics and analysis software connecting to the database via a generic Open Database Connectivity (ODBC) interface. Since its first pilot implementation in 2011, the solution has been applied to seven different clinical research projects covering different clinical problems in different organ systems such as cancer of the thyroid and the prostate glands. This paper shows how the adoption of a generic web application framework is a feasible, flexible, low-cost, and user-friendly way of managing multidimensional research data in researcher-initiated non-GCP clinical projects.

Successful Treatment of Tracheal Invasion Caused by Thyroid Cancer Using Endotracheal Tube Balloon Inflation under Flexible Bronchoscopic Guidance

Tracheal invasion is an uncommon complication of thyroid cancer, but it can cause respiratory failure. A rigid bronchoscope may be used to help relieve airway obstruction, but general anesthesia is usually required. Tracheal balloon dilatation and stent insertion can be performed without general anesthesia, but complete airway obstruction during balloon inflation may be dangerous in some patients. Additionally, placement of the stent adjacent to the vocal cords can be technically challenging. An 86-year-old female patient with tracheal invasion resulting from thyroid cancer was admitted to our hospital because of worsening dyspnea. Due to the patient's refusal of general anesthesia and the interventional radiologist's difficulty in completing endotracheal stenting, we performed endotracheal tube balloon dilatation and argon plasma coagulation. We have successfully treated tracheal obstruction in the patient with thyroid cancer by using endotracheal tube balloon inflation and a flexible bronchoscope without general anesthesia or airway obstruction during balloon inflation.

Update on external beam radiation therapy in thyroid cancer

Surgery is the mainstay of treatment for thyroid cancer. The role for external beam radiotherapy (EBRT) as an adjuvant to surgery or as the primary therapy is established in anaplastic thyroid cancer but is controversial in differentiated thyroid cancer and uncertain in medullary thyroid cancer. This update reviews the recent reported success of combining EBRT with taxanes in anaplastic thyroid cancer. Also discussed are the recent reports from large single institutions that support the recommendations of the American and British Thyroid Associations on the use of EBRT in high-risk differentiated thyroid cancer. Further evidence on the role of EBRT in MTC is discussed. The important advances in the delivery of EBRT using intensity-modulated radiation and image-guided radiation that result in more accurate and potentially more effective radiation therapy with less toxicity are also discussed.

Primary tumour size is a prognostic parameter in patients suffering from differentiated thyroid carcinoma with extrathyroidal growth: results of the MSDS trial

OBJECTIVE

The Multicentre Study Differentiated Thyroid Cancer (MSDS) collective represents a well-defined group of patients with thyroid carcinomas with extrathyroidal extension. The aim of the present study was to evaluate the relationship of the primary tumour size with clinicopathological features as well as the outcome of patients with minimum and extensive extrathyroidal growth (pT3b- and pT4a-tumours; UICC 2002/2003, 6th ed).

METHODS

The tumour diameter was available in 324 out of 351 MSDS patients (244 females, 80 males). Mean age of patients was 47.7±12.0 years (range, 20.1-69.8 years), and the median follow-up was 6.2 years. The relationship between primary tumour size and the following clinicopathological data was investigated: age, gender, histological tumour type (papillary thyroid carcinomas (PTC) versus follicular thyroid carcinomas (FTC)) and UICC/AJCC TNM classification. In addition, the correlation between primary tumour size and event-free and overall survival was assessed.

RESULTS

The FTC of our series were significantly larger than PTC (3.46 vs 1.84 cm; P<0.001). Patients suffering from pT3b-tumours presented with significantly smaller tumour size than those with extensive extrathyroidal growth (pT4a-tumours) (1.9 vs 3.0 cm; P<0.01). All patients with distant metastases suffered from tumours >2 cm. Furthermore, event-free and overall survival were significantly correlated with increasing tumour size (P<0.05). Using multivariate analysis, a pT4a-category and a tumour diameter >2 cm remained independent predictors of survival.

CONCLUSIONS

In patients suffering from differentiated thyroid carcinoma with extrathyroidal growth (pT3b and pT4a), the tumour size is an independent predictor of event-free and overall survival.