The purpose of this study is to evaluate the usefulness of dual-time-point 18F-FDG PET/CT for discriminating between benign and malignant salivary gland tumors. Dual-time-point FDG PET/CT images of 40 salivary gland tumors (20 benign and 20 malignant) were evaluated retrospectively. The maximum standardized uptake values (SUVmax) in the early and delayed phases and the retention index of each tumor were calculated and compared between benign and malignant tumors by the Mann-Whitney U test. Receiver operating characteristic (ROC) analysis was used to determine the diagnostic accuracy for malignant salivary gland tumors. The correlation between the delayed SUVmax and retention index was analyzed by calculation of the Spearman correlation coefficient. There were no significant differences in the mean early phase SUVmax or mean delayed phase SUVmax between benign and malignant tumors. The mean (±SD) retention index of the malignant tumors was significantly higher than that of the benign tumors (20.1%±10.2% vs 8.5%±12.3%; p=0.006). When the cutoff value of retention index (15.0%) was used, the sensitivity, specificity, and accuracy each was determined to be 75.0%. ROC analysis did not reveal a significant difference in the diagnostic accuracy between the delayed phase SUVmax and retention index (p=0.139). A significant correlation between the delayed phase SUVmax and retention index was observed for the benign salivary gland tumors (r=0.839; p<0.001). Dual-time-point FDG PET/CT is not useful for discriminating between benign and malignant salivary gland tumors, because benign tumors also show high FDG uptake, which increases in the delayed phase.

The concept of cenesthopathy was first introduced by Dupré and Camus in 1907 to describe clinically unexplainable bodily sensations mainly attributed to psychiatric pathology. If it occurs in oral regions, it is termed oral cenesthopathy and it has been of special interest to psychiatrists and dentists. While there is no independently defined criteria for this condition, which is classified as either a delusional or a somatoform disorder, clinical practice and research require a standard scale to measure and rate its symptoms. In this study, we included any types of psychosomatic symptoms in oral regions as oral dysesthesia, and developed an Oral Dysesthesia Rating Scale (Oral DRS) and evaluated its validity and reliability as an assessment tool. The scale was developed based on literature review and extensive clinical experience. Twelve reviewers assessed relevancy of each item to oral dysesthesia symptoms by 1–4 scoring scale and item content validity index was computed. To evaluate the inter-rater reliability of Oral DRS, pairs of raters administered the scale to 40 randomly selected patients with complaints of oral dysesthesia symptoms and Cohen’s weighted kappa coefficient was determined for each item. The scale assesses the severity of feelings of foreign body [A1], exudation [A2], squeezing-pulling [A3], movement [A4], misalignment [A5], pain [A6], and spontaneous thermal sensation or tastes [A7], and the degree of impairment in eating [B1], articulation [B2], work [B3], and social activities [B4] on a scale of 0–5. Items A1, A2, A3, A4, B3, and B4 demonstrated acceptable content validity. Inter-rater reliabilities were good or excellent for all items evaluated. The Oral DRS can help define the nosography of clinically unexplainable oral dysesthesia through further case evaluation and clinical research and facilitate devising of treatment modalities.

To evaluate the usefulness of change in the automated bone scan index (aBSI) value derived from bone scintigraphy findings as an imaging biomarker for the assessment of treatment response and survival prediction in metastatic castration-resistant prostate cancer (mCRPC) patients treated with Ra-223. This study was a retrospective investigation of a Japanese cohort of 205 mCRPC patients who received Ra-223 in 14 hospitals between July 2016 and August 2020 and for whom bone scintigraphy before and after radium-223 treatment was available. Correlations of aBSI change, with changes in the serum markers alkaline phosphatase (ALP) and prostate-specific antigen (PSA) were evaluated. Additionally, the association of those changes with overall survival (OS) was assessed using the Cox proportional-hazards model and Kaplan–Meier curve results. Of the 205 patients enrolled, 165 (80.5%) completed six cycles of Ra-223. Following treatment, ALP decline (%ALP < 0%) was noted in 72.2% (148/205), aBSI decline (%aBSI < 0%) in 52.7% (108/205), and PSA decline (%PSA < 0%) in 27.8% (57/205). Furthermore, a reduction in both aBSI and ALP was seen in 87 (42.4%), a reduction in only ALP was seen in 61 (29.8%), a reduction in only aBSI was seen in 21 (10.2%), and in both aBSI and ALP increasing/stable (≥0%) was seen in 36 (17.6%) patients. Multiparametric analysis showed changes in PSA [hazard ratio (HR) 4.30, 95% confidence interval (CI) 2.32–8.77, p < 0.0001], aBSI (HR 2.22, 95%CI 1.43–3.59, p = 0.0003), and ALP (HR 2.06, 95%CI 1.35–3.14, p = 0.0008) as significant prognostic factors for OS. For mCRPC patients treated with Ra-223, aBSI change is useful as an imaging biomarker for treatment response assessment and survival prediction.