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Purpose: We examined the prognostic significance of early changes in primary tumor SUV measured with Gallium-68-labeled prostate-specific membrane antigen positron emission tomography ([68Ga]Ga-PSMA-11-PET/CT) and serum PSA values after neoadjuvant androgen deprivation treatment (nADT) in high-risk prostate cancer (PCa) patients treated with definitive radiotherapy (RT). Methods: The clinical data and SUV parameters of 71 PCa patients were reviewed retrospectively. The serum PSA and primary tumor SUV values were calculated before and after the start of ADT. Using univariable and multivariable analyses, the prognostic factors predicting biochemical disease free survival (bDFS) and prostate cancer specific survival (PCSS) were investigated. In addition, logistic regression analysis was used to identify predictors of biochemical failure (BF). Results: All but one patient responded with a 98.8% reduction in serum PSA (21.8 ng/mL vs. 0.3 ng/mL; p < 0.001), and 64 patients (91.1%) had a median 66.6% decrease in primary tumor SUV after ADT (13.2 vs. 4.8, p < 0.001). The primary tumor SUV response rate was significantly higher in patients with Gleason score (GS) of 7 than in patients with GS > 7 (59.5% vs. 40.5%; p = 0.04), and it was significantly lower in patients with inadequate treatment response than in those with complete (CR) or partial response (PR) (1.1% vs. 66.1%; p < 0.001). There was a strong and significant correlation (Spearman = 0.41, p < 0.001) and a high concordance (91.5%) between PSA response and SUV response after ADT. With a median follow-up time of 76.1 months, the 5-year bDFS and PCSS rates were 77.2% and 92.2%, respectively. Nineteen patients (26.7%) patients had recurrence at a median of 44.6 months after the completion of RT. In multivariate analysis, lymph node metastasis, GS greater than 7, and SD/PD after nADT were independent predictors of worse bDFS. However, no significant factor for PCSS was identified. In the multivariable logistic regression analysis, advanced age, GS of > 7 disease, lymph node metastasis, and SD or PD after nADT were independent predictors of BF. Conclusion: These results imply that the metabolic response measured with [68Ga]Ga-PSMA-11-PET/CT after nADT could be used to predict progression in high-risk PCa patients treated with definitive RT. [ABSTRACT FROM AUTHOR]

Background: The aim of the study was to perform dosimetric comparisons of helical (H) and TomoDirect (TD) plans for whole-breast irradiation (WBI) with simultaneous integrated boost (SIB) in early-stage breast cancer patients undergoing breast conserving surgery. Materials and methods: Fifty patients, 25 with left-side and 25 with right-side tumors, were determined for a treatment planning system for a total dose of 50.4Gy in 1.8Gy per fraction to WBI, with a SIB of 2.3Gy per fraction delivered to the tumor bed. The planning target volume (PTV) doses and the conformity (CI) and homogeneity indices (HI) for PTVbreast and PTVboost, as well as organ-at-risk (OAR) doses and treatment times, were compared between the H and TD plans. Results: All plans met the PTV coverage criteria for the H plan, except for mean V107 of PTVbreast for TD plan. The H plan yielded better homogeneity and conformity of dose distribution compared to the TD plan. The ipsilateral mean lung doses were not significantly different between the two plans. The TD plans is advantageous for mean doses to the heart, contralateral breast and lung, spinal cord, and esophagus than the H plans. In both the H and TD plans, the right-sided breast patients had lower heart dose parameters than the left-sided breast patients. The TD plan is superior to the H plan in sparing the contralateral breast and lung by decreasing low-dose volumes. Conclusions: While the OAR dose advantages of TD are appealing, shorter treatment times or improved dose homogeneity and conformity for target volume may be advantageous for H plan. [ABSTRACT FROM AUTHOR]

We aimed to evaluate contralateral breast doses calculated with a Treatment Planning System (TPS) and verified with metal oxide semiconductor field effect transistor (MOSFET) detectors in patients with early-stage breast cancer (BC) who received helical tomotherapy (HT) after breast-conserving surgery. The dosimetric data of 30 patients (15 left-sided and 15 right-sided) with BC treated with 50.4 Gy to the whole breast and 64.4 Gy to the tumor bed in 28 fractions were analyzed. TPS doses were calculated and MOSFET doses were measured in the contralateral breast (CB) at cranial, caudal, and midpoint and 2 cm lateral to the central point. TPS and MOSFET doses were compared in the entire cohort as well as by tumor location (inner vs outer quadrant) and planning target volume of the breast (<1200 cc vs ≥1200 cc). The average doses at superior, inferior, central, and lateral points calculated with the TPS were 0.26 ± 0.15 cGy, 0.21 ± 0.09 cGy, 0.65 ± 0.14 cGy, and 0.50 ± 0.11 cGy, respectively, and were 0.37 ± 0.16 cGy, 0.34 ± 0.12 cGy, 0.60 ± 0.18 cGy, and 0.34 ± 0.15 cGy, respectively in MOSFET readings. Except for the central point, TPS-calculated doses and MOSFET readings were differed. The doses to the CB in patients with inner and outer quadrant tumors were not significantly different. In patients with large breasts, MOSFET doses were higher at superior and lateral points than TPS doses, but TPS doses were greater at inferior points. MOSFET readings were higher than TPS calculated doses in patients with inner or outer quadrant tumors in small or large breast volumes. The dose calculated by the TPS and that measured by MOSFET differed by a very small amount. The maximum dose to the CB administered at the midpoint was 1.8 Gy, as calculated using the TPS and confirmed using MOSFET detectors, in patients with early-stage BC undergoing breast-only radiotherapy with HT. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the prognostic factors and treatment outcomes of cervical esophageal carcinoma (CEC) patients who underwent definitive chemoradiotherapy (CRT). The clinical data of 175 biopsyconfirmed CEC patients treated with definitive CRT between April 2005 and September 2021 were retrospectively analyzed. The prognostic factors predicting overall survival (OS), progression-free survival (PFS), and local recurrence-free survival (LRFS) were assessed in uni- and multivariable analyses. The median age of the entire cohort was 56 years (range: 26-87 years). All patients received definitive radiotherapy with a median total dose of 60 Gy, and 52% of the patients received cisplatin-based concurrent chemotherapy. The 2-year OS, PFS, and LRFS rates were 58.8%, 46.9%, and 52.4%, respectively, with a median follow-up duration of 41.6 months. Patients' performance status, clinical nodal stage, tumor size, and treatment response were significant prognostic factors for OS, PFS, and LRFS in univariate analysis. Non-complete treatment response was an independent predictor for poor OS (HR = 4.41, 95% CI, 2.78-7.00, p < 0.001) and PFS (HR = 4.28, 95% CI, 2.79-6.58, p < 0.001), whereas poor performance score was a predictor for worse LRFS (HR = 1.83, 95% CI, 1.12-2.98, p = 0.02) in multivariable analysis. Fifty-two patients (29.7%) experienced grade II or higher toxicity. In this multicenter study, we demonstrated that definitive CRT is a safe and effective treatment for patients with CEC. Higher radiation doses were found to have no effect on treatment outcomes, but a better response to treatment and a better patient performance status did. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to investigate the clinical outcomes of metastasis-directed therapy (MDT) using stereotactic body radiotherapy (SBRT) in patients with synchronous or metachronous oligometastatic renal cell carcinoma (RCC). Methods: The clinical data of 87 patients with 138 lesions who received MDT between February 2008 and January 2019 were retrospectively analyzed. All patients had ≤5 metastasis at diagnosis (synchronous) or during progression (metachronous) and were treated with SBRT for their metastasis. The primary endpoints were local control (LC) and progression-free survival (PFS). The secondary endpoint was overall survival (OS). Results: Median follow-up was 20.4 months for entire cohort and 27.2 months for survivors. Synchronous oligometastatic disease was observed in 35 patients (40.2%), and 52 patients (59.8%) had metachronous disease. Seventy-two patients (82.8%) received systemic treatment synchronously or after MDT, while 15 patients (17.2%) did not receive any systemic treatment. The 1- and 2-year OS rates were 79.4% and 58.1%, respectively, and the 1- and 2-year PFS rates were 58.6% and 15.1%, respectively. The 1- and 2-year LC rates per lesion were 96.6% and 91.4%, respectively. There were no significant differences in survival between patients with synchronous oligometastasis and those with metachronous oligometastasis. All disease progressions were observed at a median time of 31.6 months (range: 1.9–196.9 months) after the completion of SBRT. Patients with solitary oligometastasis had significantly better OS compared to patients with >1 metastasis (p = 0.04). No patients experienced grade 3 or higher acute or late toxicities. Conclusion: SBRT is a successful treatment for oligometastatic RCC patients due to its excellent LC and minimal toxicity profile. There were no statistically significant survival differences between patients with synchronous and metachronous oligometastasis. Patients with solitary oligometastasis outlived their counterparts. [ABSTRACT FROM AUTHOR]

OBJECTIVE Volumetric arc therapy (VMAT) is advantageous for stereotactic body radiotherapy (SBRT) delivery; however, it is still unknown which rotational method is optimal for the treatment of liver metastases. This study aims to compare the dosimetric data of SBRT plans with VMAT techniques and helical tomotherapy (HT) in 18 liver metastasis patients. METHODS Three plans were generated: VMATM was generated with Monaco Treatment Planning System (TPS), VMATE with an Eclipse TPS, and HT plans were generated using a Hi-Art Tomotherapy system. The prescribed dose was 54 Gy delivered in three fractions. The planning target volume (PTV) doses and organs at risk (OAR) doses were compared between three plans. RESULTS All plans met the criteria for PTV coverage. Maximum PTV doses were significantly higher in VMATM plan, and minimum PTV doses were significantly lower in VMATE plan. The dose conformity and homogeneity indices of PTV were better in VMATE plan. Only mean bowel maximum dose was significantly higher in HT plan compared to VMATM plan only. The liver Dmean were significantly higher in PTV larger than 50 cm³. Liver Dmean in PTV >50 cm³ was significantly less in VMATM plan compared to HT (p=0.04) and VMATE plans (p=0.04). CONCLUSION All three plans met the criteria for PTV coverage with no significant difference in OARs doses. VMATE plan yielded better homogeneity and conformity in PTV compared to VMATM and HT, and healthy liver tissue was better spared especially in larger tumors (>50 cm³) with VMATE plans. [ABSTRACT FROM AUTHOR]

Introduction: To assess the rate of disease control and survival after adjuvant treatment in patients with uterine papillary serous (PSC) and clear cell carcinoma (CCC) and compare the results between these two subtypes. Methods: The medical charts of 199 patients with de novo uterine PSC or CCC who underwent radiotherapy (RT) following surgery between 2001 and 2019 in three radiation oncology departments were retrospectively evaluated. Adjuvant treatment was decided by a multidisciplinary tumor board. All patients were planned to undergo adjuvant 4–6 cycles of chemotherapy with external beam RT (EBRT) and/or vaginal brachytherapy (VBT). Results: Median age was 63 years for all, 64 years for PSC, and 59 years for CCC, respectively. Complete surgical staging was applied in 98% of patients. Histopathologic subtype was PSC in 142 (71%) and pure CCC in 57 (29%) patients, respectively. FIGO stage was I in 107 (54%), II in 35 (18%), and III in 57 (28%) patients, respectively. Lympho‐vascular space invasion and positive peritoneal cytology (PPC) were present in 42% and 10% of patients, respectively. All patients but 23 (12%) underwent adjuvant chemotherapy. Median follow‐up was 49.5 months for all patients, 43.9 months for patients with PSC, and 90.4 months for patients with CCC, respectively. During follow‐up, 20 (10%) patients developed pelvic recurrence (PR) and 37 (19%) developed distant metastasis (DM). PSC subtype increased the PR and DM rates, although the latter not statistically significant. The 5‐year overall survival and disease‐free survival rate was 73% and 69% for all patients, 71% and 66% for patients with PSC, and 77% and 75% for patients with CCC, respectively. The difference was more prominent in patients with stage ≥ IB disease. In multivariate analysis, advanced age and PPC significantly decreased all survival rates. Conclusion: PSC has a worse prognosis than CCC with regard to pelvic and distant recurrence with a trend for decreased survival rates. Therefore, a more aggressive therapy is needed for patients with uterine PSC, particularly in patients with stage ≥ IB disease. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The objective of the study was to assess breast cancer (BC) patients' opinion about radiotherapy (RT) with visual analog scale (VAS) and investigate the effect of informative interview by a trained RT technician (RTT). METHODS: Eighty-one female BC patients treated with curative intent were included in the study. To represent both negative and positive views, VAS was modified and visually enhanced. Patients marked their opinion after initial consultation, after informative interview by an RTT, and finally after the completion of RT. We also asked which treatment modality was the easiest and hardest in their experience. Toxicities were reported according to RTOG CTCAE v4.0. VAS score was measured from 0, where minus axis denotes positive and plus denotes negative opinion. Difference between recordings was measured with paired t-test. RESULTS: On the first recording, average opinion was -6.5 mm on VAS. The second recording of -29.4 mm and final recording of -41.1 mm showed positive change. Difference between measurements was significant (p<0.001). About 78.9% thought chemotherapy, whereas 9.9% thought that RT was the hardest. RT was easiest for 74.6% followed by surgery for 9.5%. CONCLUSION: RT is the most elusive treatment modality for patients and non-oncology health professionals. Even though anxiety in BC patients is evaluated extensively, few studies focus on their concerns about RT. Misinformation from unauthorized resources can impair treatment compliance. We demonstrated that informative interview improves all patients' look and alleviates fears about RT, whether they present anxiety or not. RTTs role should extend into pre-treatment communication with patients to detect anxiety, address any existing fears, and provide reliable information. [ABSTRACT FROM AUTHOR]

We sought to analyze the toxicity rates and the treatment outcomes in endometrial cancer (EC) patients treated with postoperative three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT). The clinical data of 646 EC patients treated with postoperative adjuvant 3DCRT (265 patients, 41%) or with IMRT (381 patients, 59%) between April 2007 and August 2019 were retrospectively analyzed. The primary endpoints were treatment-related acute and late gastrointestinal (GI) and genitourinary (GU) toxicities. The secondary endpoints were LC and overall survival (OS) and disease-free survival (DFS). Median follow-up time was 37 months. The rates for acute GI and GU toxicities of any grade for the entire group were 55.6% and 46.8%, respectively. Acute grade ≥2 GI toxicity was significantly less in patients treated with IMRT compared to those treated with 3DCRT (11.0% vs. 19.2%, p=.004). However, no significant difference grade ≥2 GU toxicities was observed between the 3DCRT and IMRT groups (15.1% vs. 11.0%; p=.15). Acute grade ≥2 GI and GU toxicities were higher in patients receiving systemic chemotherapy, while paraaortic field irradiation increases only the risk of acute grade ≥2 GI toxicity. Estimated 3-year late grade ≥3 GI toxicity rates in the 3DCRT- and IMRT-treated patients were 4.6% and 1.9% (p=.03), respectively. The patients treated with adjuvant ChT had higher rates of late serious GI complications than those without adjuvant ChT. No significant difference in terms of survival and disease control was observed between the 3DCRT and IMRT treatment groups. No significant factor for LC was found in the multivariate analysis. In this multicentric study involving one of largest patient population, we found that IMRT-treated EC patients showed comparable clinical outcomes but with a lower incidence of GI toxicities compared with those treated with 3DCRT. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the prognostic value of the lymph node ratio (LNR) and other clinicopathological factors in patients with stage IIIC endometrial cancer. Methods: Factors affecting overall survival (OS) and progression-free survival (PFS) were assessed in 397 patients with stage IIIC endometrial cancer treated with postoperative radiotherapy. Patients undergoing the removal of at least ten lymph nodes were included in the study. Results: The 5-year OS and PFS rates were 58% and 52%, respectively, with a median follow-up time of 35.7 months. The LNR cutoff value was 9.6%. In the multivariate analysis, advanced age (≥60 years), grade III tumor, presence of cervical stromal invasion, higher LNR and lack of adjuvant chemotherapy were independent predictors for worse OS and PFS. Conclusion: The LNR is an independent predictor for OS and PFS in patients with stage IIIC endometrial cancer treated with postoperative radiotherapy. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study is to investigate the correlation between the intensity of prostate-specific membrane antigen (PSMA) uptake in primary tumor and clinico-pathological characteristics of non-metastatic prostate cancer patients treated with definitive radiotherapy (RT).Methods: Using the clinical data of 201 prostate cancer patients who were referred for 68 Ga-PSMA-positron emission tomography (PET/CT) for staging and RT planning, we analyzed the correlations among intermediate- or high-risk disease based on Gleason score (GS), prostate-specific antigen (PSA) level, D'Amico risk group classification, and maximum standardized uptake (SUVmax) of primary tumor.Results: Primary tumor was visualized via 68 Ga-PSMA-PET/CT scan in 192 patients (95.5%). The median SUVmax of primary tumor and metastatic lymph node were 13.2 (range 3.3-83.7) and 11.4 (range 3.6-64.5), respectively. A significant moderate correlation was observed between PSA level and median tumor SUVmax as measured by 68 Ga-PSMA-PET/CT (Spearman = 0.425; p < 0.001). Patients with serum PSA > 10 ng/mL, GS > 7, D'Amico high-risk group classification, and pelvic lymph node metastasis had significantly higher tracer uptake in primary tumor than their counterparts. The median SUVmax of primary tumor was highest in patients with GS 9. The primary tumor detection rates of 68 Ga-PSMA-PET/CT were 83%, 92%, and 99% for patients with serum PSA ≤ 5.0 ng/mL (14 patients, 7%), PSA 5.1-10.0 ng/mL (45 patients, 22%), and PSA > 10 ng/mL (142 patients, 71%), respectively.Conclusions: We demonstrated a correlation between prostate tumor characteristics and PSMA tracer uptake. Patients with serum PSA > 10 ng/mL, GS > 7, D'Amico high-risk group classification, and pelvic lymph node metastasis had significantly higher SUV than their counterparts. In addition, the primary tumor detection rate was higher in patients with serum PSA > 10 ng/mL and GS > 7. [ABSTRACT FROM AUTHOR]

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The most common malignancy of the eye is metastatic tumors, with choroidal metastases being the majority of them. In women, breast cancer is the most common cause of orbital metastases, and in men, it is lung cancer. Despite the fact that there are efficient treatment options for orbital metastases, the benefit of procedures to detect choroidal metastases is debatable due to the quick progression and poor prognosis of lung cancer. In choroidal metastases resulting from lung cancer, patients are usually presented with decreased sight. Defects in the field of vision, flashes of light and floating bodies generally follow. Treatment options of choroidal metastases include many methods including laser photocoagulation, cryotherapy, chemotherapy, radiotherapy, surgical resection, enucleation and photodynamic therapy. There are reports emphasizing radiotherapy as the most efficient treatment option. In this case report, we sum up the case of a male patient presenting with blurry vision in both eyes, who was subsequently detected to have bilateral choroidal metastatic tumor and was diagnosed with primary lung adenocarcinoma. [ABSTRACT FROM AUTHOR]

We analyzed the correlation of 18F-fluorodeoxyglucose (FDG) uptake into primary tumors using the maximum standardized uptake value (SUVmax) and clinicopathological factors of disease. The impact of the pretreatment SUVmax of the primary tumor on survival was investigated.The records of 149 patients with biopsy-proven cervical cancer treated with definitive chemoradiotherapy (ChRT) were reviewed. All patients underwent pretreatment FDG positron emission tomography with computed tomography, and posttherapy FDG positron emission tomography with computed tomography was performed within a median interval of 4.2 months (range, 3.0-11.2 months) after the completion of chemoradiotherapy.The mean SUVmax in patients with lymph node metastasis was significantly higher than that in patients without metastasis (19.7 ± 8.2 vs 16.4 ± 8.2, respectively; P = 0.01). A significant difference existed between tumor size (<4 vs ≥4 cm) and the primary tumor SUVmax (14.7 ± 6.6 vs 18.7 ± 8.5, respectively; P = 0.02). The primary tumor pretreatment SUVmax for patients with complete remission was significantly lower than that of patients with partial response or progressive disease (15.6 ± 5.7 vs 28.0 ± 9.9, respectively; P < 0.001). The relationship between primary tumor FDG uptake and survival was evaluated by the cutoff value determined by receiver operating characteristic curve analysis. The area under the curve was 0.901 (P < 0.001; 95% confidence interval, 0.848-0.954), and 15.6 was determined as the SUVmax cutoff value. The 4-year actuarial overall survival (OS) and disease-free survival for SUVmax of less than 15.6 compared with SUVmax of 15.6 or greater were 85% vs 34% (P < 0.001) and 80% vs 29%, respectively (P < 0.001). In multivariate analysis, age, SUVmax of 15.6 or greater, and lymph node metastasis were independent prognostic factors of OS, and International Federation of Gynecology and Obstetrics stage IIB or higher, SUVmax of 15.6 or greater, and lymph node metastasis were significant factors for disease-free survival.The primary tumor pretreatment SUVmax is correlated with increased tumor size and lymph node involvement at diagnosis, how well the primary tumor responds to treatment, the likelihood of disease recurrence, and OS. [ABSTRACT FROM AUTHOR]

• Serum PSA value may be of limited value in determining the true treatment response after RT. • An early PSA response at 4 months in low/intermediate disease risk may not be indicative of treatment response. • The role of ADC value in treatment response evaluation after definitive RT is not well known. • A total of 229 low- and intermediate-risk PC patients treated with RT were analyzed. • Post-treatment mean ADC values were lower in patients with recurrence than in those without recurrence. We assessed early changes in apparent diffusion coefficient (ADC) and serum prostate specific antigen (PSA) values after definitive radiotherapy (RT) without androgen deprivation treatment in low- and intermediate-risk prostate cancer (PC) patients. The clinical data and ADC parameters of 229 PC patients were retrospectively evaluated. Pre-treatment and post-treatment serum PSA and primary tumor ADC values were calculated. Post-treatment DW-MRI was performed median 4.1 months after completion of definitive RT. The prognostic factors predicting freedom from biochemical failure (FFBF) and progression-free survival (PFS) were analyzed using univariable and multivariable analyses. With a median follow-up time of 80.8 months, the 5-year FFBF and PFS rates were 95.9% and 89.3%, respectively. Eleven patients (4.8%) had PSA relapse, with a median of 34.4 months after the completion of RT. A statistically significant difference in post-treatment ADC values was noted between patients with and without recurrence (0.94 ± 0.07 vs. 1.10 ± 0.20 × 10-3 mm2/sec; p< 0.001). Patients with a Gleason score (GS) of 6 and low-risk disease had significantly higher post-treatment tumor ADC and PSA levels than patients with a GS of 7 and intermediate-risk disease. The 5-year FFBF rate in patients with tumor ADC ≤ 0.96 × 10-3 mm2/sec was significantly lower than patients with tumor ADC > 0.96 × 10-3 mm2/sec (85.5% vs. 100; p< 0.001). In the multivariable analysis, a lower ADC value, GS 4 + 3 and intermediate-risk disease were independent predictors of worse FFBF. In the multivariate analysis, a lower post-treatment ADC value and a GS of 4 + 3 were significant prognostic factors for a lower PFS. These findings suggest that the post-treatment tumor ADC value could be used for early treatment response evaluation after definitive RT in PC patients. [ABSTRACT FROM AUTHOR]

• Comprehensive evaluation of the entire prostate is required prior to performing definitive RT. • It is unknown whether pretreatment ADC can be used to predict outcomes following definitive RT. • A total of 503 prostate cancer patients treated with definitive RT were analyzed. • Lower tumor ADC values were found in patients with high-risk characteristics. • Lower ADC values and higher ISUP grades were associated with increased risk of BF and progression. To assess the correlation between initial tumor apparent diffusion coefficient (ADC) values and clinicopathological parameters in prostate cancer (PCa) patients treated with definitive radiotherapy (RT). Additionally, the prognostic factors for freedom from biochemical failure (FFBF) and progression-free survival (PFS) in this patient cohort were analyzed. The clinical data of 503 patients with biopsy-confirmed PCa were evaluated retrospectively. All patients had clearly evident tumors on diffusion-weighted magnetic resonance imaging (DW-MRI) for ADC values. Univariable and multivariable analyses were used to determine prognostic factors for FFBF and PFS. The median follow-up was 72.9 months. The 5-year FFBF and PFS rates were 93.2% and 86.2%, respectively. Significantly lower ADC values were found in patients with a high PSA level; advanced clinical stage; higher ISUP score, and higher risk group than their counterparts. Receiver operating characteristic (ROC) curve analysis revealed an ADC cut-off value of 0.737 × 10−3 mm2/sec for tumor recurrence. Patients who progressed had a lower mean ADC value than those who did not (0.712 ± 0.158 vs. 1.365 ± 0.227 × 10−3 mm2/sec; p < 0.001). There was a significant difference in 5-year FFBF (96.3% vs. 90%; p < 0.001) and PFS rates (83.8% vs. 73.5%; p = 0.002) between patients with higher and lower mean ADC values. The FFBF and PFS were found to be correlated with tumor ADC value and ISUP grades in multivariable analysis. Additionally, older age was found to be a significant predictor of worse PFS. Lower ADC values were found in patients with high-risk characteristics such as a high serum PSA level, stage or grade of tumor, or high-risk disease, implying that ADC values could be used to predict prognosis. Lower ADC values and higher ISUP grades were associated with an increased risk of BF and progression, implying that treatment intensification may be required in these patients. [ABSTRACT FROM AUTHOR]

• There is a debate in pelvic nodal irradiation for patients with high-risk feature of LN metastasis. • 68Ga-PSMA-PET/CT is used for detecting lesions in PC patients treated with RT. • A total of 441 PSMA-PET-positive LN metastases in 134 PC patients were analyzed. • The current guidelines are insufficient for covering all PSMA-positive LNs. • The LN coverage in predefined pelvic fields were 51.7%, 61 and 83.1%, respectively. • Inadequate LN coverage is relatively higher in patients with higher metastatic LNs. To evaluate the distribution of metastatic lymph nodes (LN) detected on 68Ga-PSMA-positron emission tomography/computed tomography (PET/CT) in treatment-naïve prostate cancer (PC) patients and to analyze the LN coverage rates of the pelvic fields defined in the GETUG trial and RTOG guidelines and a pelvic field extending superiorly from the L4/L5 interspace. 68Ga-PSMA-PET/CT images obtained at diagnosis of 138 PC patients were retrospectively analyzed. The number and locations of 68Ga-PSMA-positive LNs were co-registered with one single-planning CT. The numbers, locations, and sizes of LNs located outside the three pelvic volumes were investigated for the entire cohort and for patients with LN metastasis in the pelvic area only. A total of 441 PSMA-PET-positive LN metastases were identified. The most frequent metastatic LNs were internal iliac LNs (25.2%). Para-aortic and presacral LNs outside the three pelvic fields were present in 20 (14.5%) and 22 patients (15.9%), respectively. The LN coverage rates according to the GETUG trial, the RTOG guidelines, and the pelvic field extending superiorly from L4/L5 were 44.2%, 52.2%, and 71, respectively, in the entire cohort and 51.7%, 61 and 83.1%, respectively, in patients with only pelvic LN metastasis. The number of metastatic LNs was a predictive factor for LNs located outside the three pelvic fields. Extending the cranial margin of the pelvic field from L5/S1 to L4/L5 increases the accuracy of pelvic field irradiation in approximately 20% of patients, highlighting the importance of proximal common iliac irradiation, particularly in patients with multiple LN metastasis. [ABSTRACT FROM AUTHOR]