Combining Serial and Parallel Functionality in Functional Lung Avoidance Radiation Therapy.

PURPOSE: Functional lung avoidance (FLA) radiation therapy (RT) aims to minimize post-RT pulmonary toxicity by preferentially avoiding dose to high-functioning lung (HFL) regions. A common limitation is that FLA approaches do not consider the conducting architecture for gas exchange. We previously proposed the functionally weighted airway sparing (FWAS) method to spare airways connected to HFL regions, showing that it is possible to substantially reduce risk of radiation-induced airway injury. Here, we compare the performance of FLA and FWAS and propose a novel method combining both approaches. METHODS: We used breath-hold computed tomography (BHCT) and simulation 4-dimensional computed tomography (4DCT) from 12 lung stereotactic ablative radiation therapy patients. Four planning strategies were examined: (1) Conventional: no sparing other than clinical dose-volume constraints; (2) FLA: using a 4DCT-based ventilation map to delineate the HFL, plans were optimized to reduce mean dose and V13.50 in HFL; (3) FWAS: we autosegemented 11 to 13 generations of individual airways from each patient's BHCT and assigned priorities based on the relative contribution of each airway to total ventilation. We used these priorities in the optimization along with airway dose constraints, estimated as a function of airway diameter and 5% probability of collapse; and (4) FLA + FWAS: we combined information from the 2 strategies. We prioritized clinical dose constraints for organs at risk and planning target volume in all plans. We performed the evaluation in terms of ventilation preservation accounting for radiation-induced damage to both lung parenchyma and airways. RESULTS: We observed average ventilation preservation for FLA, FWAS, and FLA + FWAS as 3%, 8.5%, and 14.5% higher, respectively, than for Conventional plans for patients with ventilation preservation in Conventional plans <90%. Generalized estimated equations showed that all improvements were statistically significant (P ≤ .036). We observed no clinically relevant improvements in outcomes of the sparing techniques in patients with ventilation preservation in Conventional plans ≥90%. CONCLUSIONS: These initial results suggest that it is crucial to consider the parallel and the serial nature of the lung to improve post-radiation therapy lung function and, consequently, quality of life for patients.

Differentiation of Thyroid Nodules Difficult to Diagnose With Contrast-Enhanced Ultrasonography and Real-Time Elastography.

According to the 2015 American Thyroid Association (ATA), referred risk stratification and thyroid nodules with intermediate- and low-suspicion patterns are difficult to diagnose. The objective of this study is to evaluate the diagnostic performance of contrast-enhanced ultrasonography (CEUS) and elastosonography (ES) for the differentiation of these thyroid nodules. From November 2011 to June 2016, a total of 163 thyroid nodules with intermediate- and low-suspicion patterns in 150 consecutive patients at our hospital were studied before surgery. With surgical pathology as the standard, the diagnostic value of CEUS and ES was analyzed. There were 29 (17.8%) malignant lesions and 134 (82.2%) benign lesions. The enhancement patterns of CEUS, the echogenicity, and the elastography were significantly different between malignant and benign lesions (P < 0.05). Heterogenous enhancement was more common in malignant nodules, and the sensitivity, specificity, positive predictive value, negative predictive value, and odds ratio were 51.7, 88.1, 48.4, 89.4, and 10.1%, respectively. The diagnostic accuracy of CEUS was better than the conventional ultrasound [area under the curve (AUC), 0.729 vs. 0.616, P = 0.021]. The enhancement patterns of CEUS were helpful in the differential diagnosis of thyroid nodules with intermediate and low suspicion.

Comparison of Ultrasound Features of Primary Metastatic Papillary Thyroid Carcinoma and Recurrent/Persistent Metastatic Cervical Lymph Nodes.

Objective To explore the ultrasound features and levels of cervical lymph node metastases in primary and recurrent/persistent papillary thyroid cancer (PTC).Methods We retrospectively analyzed the clinical data of 2181 patients who underwent cervical lymph nodes dissection for PTC from January 1st 2015 to January 1st 2016.Totally 418 PTC patients (with 622 lymph nodes) who met the inclusion criteria entered the final analysis.Patients who had not received any prior thyroid treatment (surgery with or without radioactive iodine) were categorized as the primary group (352 patients with 527 metastatic lymph nodes),and patients who had received prior treatment (thyroidectomy with or without radioactive iodine) for PTC were categorized as recurrent/persistent group (66 patients with 95 metastatic lymph nodes).Pathological results from lymph node dissections were used as the gold standards by means of level-to-level analysis.Results The mean of the minimum axis diameter of the lymph nodes in the primary group was (6.7±3.6)mm,and that of the recurrent/persistent group was (6.6±3.1)mm (U=0.180,P=0.857).The proportion of metastasis in the central area of primary group was 40.0%,which was significantly higher than that in the recurrent/persistent group (12.6%);the proportion of metastasis in the lateral area was 60.6% in the primary group,which was significantly lower than that in the recurrent/persistent group (87.4%)(χ2=26.288,P<0.001).In lateral metastatic lymph nodes,Ⅲ level was the most common place in both groups.Level Ⅴ metastatic lymph was rare in both primary group and recurrent/persistent group.Calcifications (63.1% vs. 48.2%;χ2=7.207,P=0.007) and peripheral vascularity (81.1% vs. 59.4%;χ2= 16.147, P<0.001) were more common in the recurrent/persistent group.The round shape,absence of an echogenic hilum,hyperechogenicity,and cystic aspects were not significantly different between these two groups (all P>0.05).Conclusions Primary metastatic lymph nodes often occur in the central area of lymph nodes,while lateral metastatic lymph nodes are more common in recurrent/persistent PTC.For metastatic lymph nodes,calcifications and peripheral vascularity are more common in recurrent/persistent PTC.

Cervical soft tissue recurrence of differentiated thyroid carcinoma after thyroidectomy indicates a poor prognosis.

BACKGROUND: We investigated cervical soft tissue recurrence of differentiated thyroid carcinoma (DTC) after thyroidectomy, and these lesions exhibited no evidence that they were lymph nodes (LNs). METHODS: Between January 2012 and April 2016, consecutive 6308 patients underwent thyroid surgery for DTC at our center. Among them, we encountered 21 patients with recurrent cervical soft tissue lesions, none of whom had previously undergone fine needle aspiration biopsy (FNAB). RESULTS: The 21 patients accounted for 0.33% of all 6308 patients, including twenty cases of papillary thyroid carcinoma and one case of follicular thyroid cancer. Approximately half (52.3%) of the recurrence were first detected by ultrasound (US). Eighteen lesions underwent complete preoperative US, but 6 lesions were misdiagnosed as metastatic LNs by US. Therefore, 54 age- and gender-matched recurrent or persistent LNs derived from DTC were randomly selected from the same database. The soft tissue lesions (mean size, 2.30 cm) were larger than the LNs. Fewer hyperechogenic hila and punctuations were found in the group of soft tissue recurrence (P < 0.05). During follow-up, distant metastasis was detected in 38.1% of patients in the soft tissue recurrence group. The distant metastasis rates showed that local soft tissue recurrence led to a poorer prognosis than cervical LN persistence or recurrence (P = 0.00). CONCLUSIONS: Although the incidence of DTC recurrence in cervical soft tissue was low, it may be a predictor for distant recurrence. To minimize the risk, a long-term postoperative evaluation, preferably with US, should be performed.