Increase of prostate-specific antigen doubling time predicts survival in metastatic castration-resistant prostate cancer patients undergoing radium therapy.

OBJECTIVE: Radium-223 (Ra-223) is an important treatment modality for bone-dominant metastatic castration-resistant prostate cancer (mCRPC). However, there is currently a lack of effective markers to monitor treatment response during treatment. We aim to investigate the response in prostate-specific antigen doubling time (PSADT) as a potential marker for assessing Ra-223 treatment in mCRPC patients. METHODS: We retrospectively collected data from mCRPC patients who underwent radium treatment at our institution between August 2020 and June 2023. Prostate-specific antigen (PSA) measurements prior to treatment and during treatment were collected. Baseline PSADT was calculated from PSA measurements prior to Ra-223 treatment; interim PSADT was calculated from PSA measurements before Ra-223 treatment and prior to the fourth course injection. Overall survival was calculated from the start of treatment to the date of death. Univariable and multivariable analysis using the Cox proportional hazards model were performed to examine the association of factors with overall survival. RESULTS: We included 35 patients from our institution, with a median overall survival of 13.3 months. Eighteen (51.4%) completed all six courses of treatment. PSA dynamic response (interim PSADT > baseline PSADT or decreased PSA) was observed in 20 patients. Overall survival was associated with a PSA dynamic response (HR = 0.318, 95% CI 0.133-0.762, p = 0.010) when compared to patients without response. CONCLUSIONS: Dynamic changes in PSADT were associated with survival in mCRPC patients receiving radium therapy. Comparing interim and baseline PSADT could serve as a valuable marker for determining treatment benefits.

The role of postoperative radiotherapy or chemoradiation in pT1-2N1M0 oral squamous cell carcinoma.

BACKGROUND: Postoperative radiotherapy (PORT) and concurrent chemoradiation (CCRT) are indicated for patients with advanced oral cancer. However, the benefits for pT1-2N1 disease without adverse pathological features are controversial. METHODS: This retrospective study using the Taiwan Cancer Registry database included patients with pT1-2N1 oral cancer from January 1, 2011, to December 31, 2017. Overall survival was analyzed in patients receiving surgery alone, PORT, or CCRT. RESULTS: Among the 862 patients, the five-year overall survival rate in patients receiving surgery alone, PORT, and CCRT was 62.2%, 58.7%, and 71.1% (P = 0.03), respectively. CCRT was associated with longer survival than PORT (P = 0.008). Survival in patients with pT2 disease was significantly higher with CCRT than PORT (P = 0.001), but no difference was observed in pT1 disease. CONCLUSION: CCRT demonstrated a favorable impact on survival outcomes in patients diagnosed with pT2N1 oral cancer when compared to PORT. However, no significant survival benefits were observed for patients with pT1 disease.

Development and validation of a machine learning model of radiation-induced hypothyroidism with clinical and dose-volume features.

BACKGROUND AND PURPOSE: Radiation-induced hypothyroidism (RIHT) is a common but underestimated late effect in head and neck cancers. However, no consensus exists regarding risk prediction or dose constraints in RIHT. We aimed to develop a machine learning model for the accurate risk prediction of RIHT based on clinical and dose-volume features and to evaluate its performance internally and externally. MATERIALS AND METHODS: We retrospectively searched two institutions for patients aged >20 years treated with definitive radiotherapy for nasopharyngeal or oropharyngeal cancer, and extracted their clinical information and dose-volume features. One was designated the developmental cohort, the other as the external validation cohort. We compared the performances of machine learning models with those of published normal tissue complication probability (NTCP) models. RESULTS: The developmental and external validation cohorts consisted of 378 and 49 patients, respectively. The estimated cumulative incidence rates of grade ≥1 hypothyroidism were 53.5% and 61.3% in the developmental and external validation cohorts, respectively. Machine learning models outperformed traditional NTCP models by having lower Brier scores at every time point and a lower integrated Brier score, while demonstrating a comparable calibration index and mean area under the curve. Even simplified machine learning models using only thyroid features performed better than did traditional NTCP algorithms. The machine learning models showed consistent performance between folds. The performance in a previously unseen external validation cohort was comparable to that of the cross-validation. CONCLUSIONS: Our model outperformed traditional NTCP models, with additional capabilities of predicting the RIHT risk at individual time points. A simplified model using only thyroid dose-volume features still outperforms traditional NTCP models and can be incorporated into future treatment planning systems for biological optimization.

Dual-Time-Point 18 F-FDG PET/CT for Differentiating a Chest Wall Hemangioma From a Malignant Metastasis.

ABSTRACT: Dual-time-point 18 F-flluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) can be used to differentiate benign vascular tumors from other malignant growths. We present the case of a 70-year-old woman with a history of cervical carcinoma who was referred for PET/CT to examine a left chest wall tumor noted on CT, which involved the adjacent rib and pleura, thus raising the suspicion of metastasis. The chest wall tumor demonstrated moderate FDG uptake and further decreased uptake at the delayed-phase scanning, corresponding to biodistribution of FDG in the blood pool. These findings indicated a benign hemangioma rather than a metastasis.

Early post-treatment 18F-FDG PET/CT for predicting radiation-induced hypothyroidism in head and neck cancer.

BACKGROUND: Radiation-induced hypothyroidism (RIHT) is a common, but underestimated, late adverse effect in head and neck cancer. We investigated the value of early post-treatment 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for predicting RIHT. METHODS: We searched our institutional database for patients aged ≥ 20 years who had undergone definitive radiotherapy for nasopharyngeal or oropharyngeal cancer between 2005 and 2017, followed by 18F-FDG PET/CT within 180 days of radiotherapy completion. We visually assessed and compared PET/CT and baseline characteristics in patients with and without RIHT using the chi-square test for categorical variables and the t-test for continuous variables. Variable predictive ability was evaluated by measuring the area under receiver operating characteristic curves. RESULTS: Fifty-two patients were included; 22 (42%) developed RIHT and 30 (58%) did not. Two patients presented with diffuse thyroid uptake on PET/CT via visual assessment, and both developed RIHT later. Among the PET/CT variables, thyroid functioning volume was significantly higher in patients without RIHT than in patients with RIHT (16.30 ± 6.03 cm3 vs. 10.61 ± 3.81 cm3, p < 0.001). The maximum standard uptake values of the thyroid and pituitary glands did not differ significantly between the groups. Two patient characteristics, pretreatment thyroid volume and mean radiotherapy dose to the thyroid, also showed significant differences between the groups. An algorithmic approach combining visual grading of thyroid 18F-FDG uptake and thyroid functioning volume cutoff of 14.01 yielded an area under curve of 0.89 (95% confidence interval, 0.80-0.98); the sensitivity, specificity, positive predictive value, and negative predictive value were 87.0%, 82.3%, 80.0%, and 88.9%, respectively. CONCLUSION: Early post-treatment PET/CT-derived thyroid functioning volume was a good predictor of RIHT development. Diffusely increased thyroid 18F-FDG uptake on PET/CT may indicate impending RIHT. Routine surveillance of thyroid function is warranted in patients at high risk of developing RIHT.

Improved overall survival is associated with adjuvant chemotherapy after definitive concurrent chemoradiotherapy for N3 nasopharyngeal cancer.

Concurrent chemoradiotherapy is the established treatment for locally advanced nasopharyngeal carcinoma (NPC). However, there is no evidence supporting routine adjuvant chemotherapy. We aimed to demonstrate the effect of adjuvant chemotherapy on survival and distant metastasis in high-risk N3 NPC patients. We linked the Taiwan Cancer Registry and Cause of Death database to obtain data. Clinical N3 NPC patients were divided as those receiving definitive concurrent chemoradiotherapy (CCRT) with adjuvant 5-fluorouracil and platinum (PF) chemotherapy and those receiving no chemotherapy after CCRT. Patients receiving neoadjuvant chemotherapy were excluded. We compared overall survival, disease-free survival, local control, and distant metastasis in both groups using Cox proportional hazards regression analysis. Propensity-score matching was also performed to evaluate the independent effect of adjuvant PF in a matched cohort with similar baseline characteristics. We included 431 patients (152 and 279 patients in the adjuvant PF and observation groups, respectively). Median follow-up was 4.3 years. The 5-year overall survival were 69.1% and 57.4% in the adjuvant PF chemotherapy and observation groups, respectively (p = 0.02). Adjuvant PF chemotherapy was associated with a lower risk of death (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.43-0.84; p = 0.003), even after adjusting for baseline prognostic factors (HR 0.61, 95% CI 0.43-0.86; p = 0.005). Distant metastasis-free survival at 12 months was higher in the adjuvant PF chemotherapy group than in the observation group (98% vs 84.8%; p < 0.001). After adjusting for baseline prognostic factors, adjuvant PF chemotherapy was associated with freedom from distant metastasis (HR 0.11, 95% CI 0.02-0.46; p = 0.003). Adjuvant chemotherapy was also associated with a decreased risk of death (HR 0.59, 95% CI 0.41-0.85, p = 0.004) in a propensity score-matched cohort. Prospective evaluation of adjuvant PF chemotherapy in N3 NPC patients treated with definitive CCRT is warranted because adjuvant PF chemotherapy was associated with improved overall survival and decreased risk of distant metastasis.

Prognostic Significance of Pretreatment Staging With 18F-FDG PET in Esophageal Cancer: A Nationwide Population-Based Study.

PURPOSE OF THE REPORT: Without the routine use of 18F-FDG PET for initial staging of esophageal cancer, it may lead to inaccurate staging and suboptimal treatment. The purpose of this study was to evaluate the prognostic significance of pretreatment 18F-FDG PET in nonmetastatic esophageal cancer by comparing the survival between patients with and without pretreatment PET. MATERIALS AND METHODS: We selected newly diagnosed esophageal cancer patients without metastasis between 2009 and 2015 from Taiwan Cancer Registry and National Health Insurance Research Database. Pretreatment 18F-FDG PET staging was determined according to the implementation of PET within 90 days before starting treatment. Overall survival was calculated from the day of treatment initiation to the death from any cause. Survival curves were compared between patients with and without PET staging using the log-rank test. RESULTS: Of the 9078 patients included, 1765 (19.4%) and 7313 (80.6%) patients were staged with and without pretreatment PET, respectively. The median follow-up time for all patients and survivors was 1.29 years and 5.46 years, respectively. The pretreatment PET group had a lower risk of death than the no pretreatment PET group (hazards ratio, 0.74; 95% confidence interval, 0.70-0.79; P < 0.001). After adjusting for age, stage, histology, and tumor location, pretreatment PET remained significantly correlated with a lower risk of death (hazards ratio, 0.78; 95% confidence interval, 0.73-0.83; P < 0.001). CONCLUSIONS: The utilization of pretreatment 18F-FDG PET for staging in nonmetastatic esophageal malignancy is associated with a lower risk of death even after adjusting for age, stage, histology, and tumor location.