Objective:To investigate the clinical characteristics and prognosis of follicular lymphoma (FL) patients with different primary sites using the Surveillance, Epidemiology, and End Results (SEER) database.Methods:Clinical data of 7167 patients with early-stage FL (stage I-II) from the SEER database between 2000 and 2015 were respectively analyzed. Primary sites were divided into intranodal and extranodal types. Intranodal primary sites included supradiaphragmatic lymph nodes (LN), subphrenic lymph nodes and Waldeyer's ring. Extranodal primary sites consisted of skin, gastrointestinal tract, duodenum, head and neck, other sites. Prognostic factors and overall survival (OS) in patients with different primary sites were analyzed. OS rate was evaluated using Kaplan-Meier method and survival difference between primary sites was compared with log-rank test. Inverse probability treatment weighting (IPTW) and multi-variable analysis were applied to adjust for confounding factors. Multivariate Cox regression analysis of influencing factors of OS was performed.Results:The median age was 63 years old, with the median follow-up time of 63 months. There was no difference in prognosis among the intranodal groups or between the intranodal and extranodal groups. The 10-year OS rates of the supradiaphragmatic lymph LN ( n=2146), subdiaphragmatic LN ( n=2811), and the Waldeyer's ring ( n=151) groups were 70.7%, 69.9% and 73.4%, respectively ( P=0.422 for infradiaphragmatic LN vs. supradiaphragmatic LN, P=1.000 for Waldeyer's ring vs. supradiaphragmatic LN), and 70.3% and 68.9% for intranodal ( n=5108) and extranodal ( n=2059), respectively. There was no significant difference in OS between the groups ( P=0.581) after IPTW adjustment. The most common primary sites in extranodal disease were skin, gastrointestinal tract, head and neck, and duodenum. The 10-year OS for skin, gastrointestinal tract, and cutaneous was 74.2%, 74.7%, and 87.3%, respectively, significantly higher than 55.6% for other sites (duodenum vs. others sites, gastrointestinal vs. others sites, skin vs. others sites: all P<0.001). Multivariate Cox regression analysis revealed that difference in OS was not significant among the intranodal groups or between the intranodal and extranodal groups. However, different extranodal primary site was an independent prognostic factor for OS. Conclusions:Early FL patients with supradiaphragmatic LN, subdiaphragmatic LN and Waldeyer's ring, and between the intranodal and extranodal primary sites obtain similar prognosis. However, early-stage FL patients with different extranodal primary sites have prognostic differences. The prognosis of primary skin, gastrointestinal tract and duodenum is significantly better than that of other extranodal primary sites.

Objective:To investigate the long-term efficacy, safety and prognostic factors of intraoperative radiotherapy (IORT) for narrow-margin (resection margin < 1 cm) hepatectomy in patients with hepatocellular carcinoma (HCC) during radical surgery.Methods:A retrospective cohort study was conducted. The data of primary HCC patients undergoing radical surgery and narrow-margin hepatectomy IORT in the Cancer Hospital of the Chinese Academy of Medical Sciences from November 2009 to February 2019 were collected. IORT applied 6 MeV or 9 MeV electron beams and a single irradiation was given to the margin. Kaplan-Meier method was used for the overall survival (OS) and disease-free survival (DFS) analysis; log-rank test was used for survival comparison among subgroups. The recurrence patterns and adverse reactions were recorded. Univariate and multivariate Cox proportional hazards models were used to analyze the factors influencing the OS and DFS.Results:A total of 64 patients were enrolled, with the median age [ M ( Q1, Q3)] of 57 years (49, 63) years. All patients included 55 males (85.9%) and 9 females (14.1%). The median dose of IORT was 15 Gy (range: 12-17 Gy). The median follow-up time was 83.3 (64.4, 91.9) months. The 1-year, 3-year, 5-year, 7-year, 10-year OS rates were 90.4%, 80.6%, 75.5%, 71.4% and 47.6%, respectively; the 1-year, 3-year, 5-year, 7-year,10-year DFS rates were 77.8%, 68.1%, 59.6%, 57.6% and 38.4%, respectively. Univariate Cox regression analysis indicated that preoperative serum alpha-fetoprotein (AFP) > 400 ng/ml was an independent risk factor for poor OS (> 400 ng/ml vs. ≤ 400 ng/ml: HR = 6.57, 95% CI: 2.16-19.96, P < 0.001), while not the independent influencing factor of poor DFS ( HR = 1.71, 95% CI: 0.65-4.52, P = 0.277). The age ≤ 60 years or not, gender, viral hepatitis or not, American Joint Committee on Cancer stage, tumor diameter (> 5 cm or not), tumor number, degree of tumor differentiation, microvascular invasion or not, microsatellite nodules or not, anatomical liver resection or not, and the dose of IORT ≤15 Gy or not were not the independent influencing factors of poor OS and DFS (all P > 0.05). Kaplan-Meier method analysis showed that patients with preoperative serum AFP ≤ 400 ng/ml (48 cases) had better OS compared with those with preoperative serum AFP>400 ng/ml (16 cases) (5-year OS rate: 84.8% vs. 44.9%; 7-year OS rate: 79.9% vs.37.4%), and the difference was statistically significant ( P = 0.002). There was no statistically significant difference in the DFS between the 2 groups ( P = 0.134). During the follow-up, 28 patients (43.8%) relapsed, including 17 cases (26.6%) of early recurrence and 11 cases (17.2%) of late recurrence. No marginal recurrence was observed. There were 22 cases (34.4%) of intrahepatic recurrence alone, 2 cases (3.1%) of extrahepatic recurrence and 4 cases (6.3%) of stimutaneous recurrence inside and outside the liver. The 1-, 3-, 5- and 7-year cumulative recurrence rates inside the liver were 19.0%, 27.2%, 37.4% and 39.3% respectively, and the cumulative recurrence rates outside the liver were 6.4%, 8.0%, 9.6% and 9.6% respectively. There were no adverse reactions above grade 3 in the entire group. There were no surgery-related deaths within 30 d after the operation, and no radiation-induced liver disease occurred. Conclusions:Narrow-margin IORT helps HCC patients receiving hepatectomy to achieve favorable long-term survival and adverse reactions are tolerable. It can be used as a safe and effective adjuvant therapy alternative.

Objectives:To explore whether short-course radiotherapy (SCRT)-based total neoadjuvant therapy (TNT) combined with PD-1 inhibitors could further promote tumor regression and improve the prognosis.Methods:This is a prospective, multicenter, two-arm randomized controlled, seamless phase Ⅱ/Ⅲ trial for proficient mismatch repair or microsatellite stable (pMMR/MSS) locally advanced rectal cancer (LARC). Eligible patients were randomly assigned to the iTNT (TNT+PD-1) group or the TNT group. Patients in the TNT group received SCRT (5 Gy×5) followed by 4 cycles of CAPOX or 6 cycles of mFOLFOX chemotherapy, with the iTNT group receiving SCRT followed by the same regime in combination with 4 cycles of Sintilimab. Total mesorectal excision (TME) surgery or watch and wait (W&W) was performed after neoadjuvant therapy and then 2 cycles of same regimen as before were recommended. The primary endpoints are the complete response (CR) rate for phase Ⅱ trial and 3-year disease-free survival (DFS) for phase Ⅲ trial. A total of 588 patients will be enrolled for the phase Ⅱ/Ⅲ trial. Short-term efficacy and safety data from the initial 100 treated patients were analyzed as planned.Results:From 2022-8-31 to 2023-5-24 the initial 100 patients were enrolled from 10 hospitals in China, 76.0%(76/100) patients were male, and the median age was 61 years (21-74 years). More patients had tumors located in the lower rectum (78.0%, 78/100), staged T3-4 (97.0%, 97/100) and N1-2 (93.0%, 93/100), and about half of the tumors invaded the mesorectal fascia (52.0%, 52/100) and with extramural vascular invasion (51.0%, 51/100). Analyses were performed according to the per-protocal (PP) set. All patients in the iTNT group ( n=52) and the TNT group ( n=48) completed SCRT; The 4-cycle chemotherapy±Sintilimab completion rates were 86.5% and 100.0% in the iTNT and TNT groups, respectively. In the iTNT group, 82.7% (43/52), 11.5% (6/52), and 5.8% (3/52) of the patients received 4, 3, and 2 cycles of PD-1 inhibitor. After TNT, 68 patients underwent radical surgery and 15 patients achieved cCR and adopted W&W. The pathological complete response (pCR) rates were 48.5% (16/33) and 17.1% (6/35) in the iTNT and TNT groups, with CR rates of 50.0% (25/50) and 26.1% (12/46), respectively. The incidence of treatment-related grade 3-4 adverse events was 26.9% (14/52, iTNT group) and 18.8% (9/48, TNT group), with thrombocytopenia and leukopenia being the most common. Among patients receiving immunotherapy, grade 3 immunotherapy-related adverse events occurred in 2 (3.8%, 2/52) patients: one case was pancreatitis, another case was hepatitis combined with myositis and myocarditis. Conclusion:The preliminary results show that SCRT-based TNT combined with PD-1 inhibitors could further improve the CR rate for LARC without unexpected serious adverse events.

Objectives:To explore whether short-course radiotherapy (SCRT)-based total neoadjuvant therapy (TNT) combined with PD-1 inhibitors could further promote tumor regression and improve the prognosis.Methods:This is a prospective, multicenter, two-arm randomized controlled, seamless phase Ⅱ/Ⅲ trial for proficient mismatch repair or microsatellite stable (pMMR/MSS) locally advanced rectal cancer (LARC). Eligible patients were randomly assigned to the iTNT (TNT+PD-1) group or the TNT group. Patients in the TNT group received SCRT (5 Gy×5) followed by 4 cycles of CAPOX or 6 cycles of mFOLFOX chemotherapy, with the iTNT group receiving SCRT followed by the same regime in combination with 4 cycles of Sintilimab. Total mesorectal excision (TME) surgery or watch and wait (W&W) was performed after neoadjuvant therapy and then 2 cycles of same regimen as before were recommended. The primary endpoints are the complete response (CR) rate for phase Ⅱ trial and 3-year disease-free survival (DFS) for phase Ⅲ trial. A total of 588 patients will be enrolled for the phase Ⅱ/Ⅲ trial. Short-term efficacy and safety data from the initial 100 treated patients were analyzed as planned.Results:From 2022-8-31 to 2023-5-24 the initial 100 patients were enrolled from 10 hospitals in China, 76.0%(76/100) patients were male, and the median age was 61 years (21-74 years). More patients had tumors located in the lower rectum (78.0%, 78/100), staged T3-4 (97.0%, 97/100) and N1-2 (93.0%, 93/100), and about half of the tumors invaded the mesorectal fascia (52.0%, 52/100) and with extramural vascular invasion (51.0%, 51/100). Analyses were performed according to the per-protocal (PP) set. All patients in the iTNT group ( n=52) and the TNT group ( n=48) completed SCRT; The 4-cycle chemotherapy±Sintilimab completion rates were 86.5% and 100.0% in the iTNT and TNT groups, respectively. In the iTNT group, 82.7% (43/52), 11.5% (6/52), and 5.8% (3/52) of the patients received 4, 3, and 2 cycles of PD-1 inhibitor. After TNT, 68 patients underwent radical surgery and 15 patients achieved cCR and adopted W&W. The pathological complete response (pCR) rates were 48.5% (16/33) and 17.1% (6/35) in the iTNT and TNT groups, with CR rates of 50.0% (25/50) and 26.1% (12/46), respectively. The incidence of treatment-related grade 3-4 adverse events was 26.9% (14/52, iTNT group) and 18.8% (9/48, TNT group), with thrombocytopenia and leukopenia being the most common. Among patients receiving immunotherapy, grade 3 immunotherapy-related adverse events occurred in 2 (3.8%, 2/52) patients: one case was pancreatitis, another case was hepatitis combined with myositis and myocarditis. Conclusion:The preliminary results show that SCRT-based TNT combined with PD-1 inhibitors could further improve the CR rate for LARC without unexpected serious adverse events.

Objective:To investigate the clinical characteristics and prognosis of follicular lymphoma (FL) patients with different primary sites using the Surveillance, Epidemiology, and End Results (SEER) database.Methods:Clinical data of 7167 patients with early-stage FL (stage I-II) from the SEER database between 2000 and 2015 were respectively analyzed. Primary sites were divided into intranodal and extranodal types. Intranodal primary sites included supradiaphragmatic lymph nodes (LN), subphrenic lymph nodes and Waldeyer's ring. Extranodal primary sites consisted of skin, gastrointestinal tract, duodenum, head and neck, other sites. Prognostic factors and overall survival (OS) in patients with different primary sites were analyzed. OS rate was evaluated using Kaplan-Meier method and survival difference between primary sites was compared with log-rank test. Inverse probability treatment weighting (IPTW) and multi-variable analysis were applied to adjust for confounding factors. Multivariate Cox regression analysis of influencing factors of OS was performed.Results:The median age was 63 years old, with the median follow-up time of 63 months. There was no difference in prognosis among the intranodal groups or between the intranodal and extranodal groups. The 10-year OS rates of the supradiaphragmatic lymph LN ( n=2146), subdiaphragmatic LN ( n=2811), and the Waldeyer's ring ( n=151) groups were 70.7%, 69.9% and 73.4%, respectively ( P=0.422 for infradiaphragmatic LN vs. supradiaphragmatic LN, P=1.000 for Waldeyer's ring vs. supradiaphragmatic LN), and 70.3% and 68.9% for intranodal ( n=5108) and extranodal ( n=2059), respectively. There was no significant difference in OS between the groups ( P=0.581) after IPTW adjustment. The most common primary sites in extranodal disease were skin, gastrointestinal tract, head and neck, and duodenum. The 10-year OS for skin, gastrointestinal tract, and cutaneous was 74.2%, 74.7%, and 87.3%, respectively, significantly higher than 55.6% for other sites (duodenum vs. others sites, gastrointestinal vs. others sites, skin vs. others sites: all P<0.001). Multivariate Cox regression analysis revealed that difference in OS was not significant among the intranodal groups or between the intranodal and extranodal groups. However, different extranodal primary site was an independent prognostic factor for OS. Conclusions:Early FL patients with supradiaphragmatic LN, subdiaphragmatic LN and Waldeyer's ring, and between the intranodal and extranodal primary sites obtain similar prognosis. However, early-stage FL patients with different extranodal primary sites have prognostic differences. The prognosis of primary skin, gastrointestinal tract and duodenum is significantly better than that of other extranodal primary sites.

Objective:To investigate the long-term efficacy, safety and prognostic factors of intraoperative radiotherapy (IORT) for narrow-margin (resection margin < 1 cm) hepatectomy in patients with hepatocellular carcinoma (HCC) during radical surgery.Methods:A retrospective cohort study was conducted. The data of primary HCC patients undergoing radical surgery and narrow-margin hepatectomy IORT in the Cancer Hospital of the Chinese Academy of Medical Sciences from November 2009 to February 2019 were collected. IORT applied 6 MeV or 9 MeV electron beams and a single irradiation was given to the margin. Kaplan-Meier method was used for the overall survival (OS) and disease-free survival (DFS) analysis; log-rank test was used for survival comparison among subgroups. The recurrence patterns and adverse reactions were recorded. Univariate and multivariate Cox proportional hazards models were used to analyze the factors influencing the OS and DFS.Results:A total of 64 patients were enrolled, with the median age [ M ( Q1, Q3)] of 57 years (49, 63) years. All patients included 55 males (85.9%) and 9 females (14.1%). The median dose of IORT was 15 Gy (range: 12-17 Gy). The median follow-up time was 83.3 (64.4, 91.9) months. The 1-year, 3-year, 5-year, 7-year, 10-year OS rates were 90.4%, 80.6%, 75.5%, 71.4% and 47.6%, respectively; the 1-year, 3-year, 5-year, 7-year,10-year DFS rates were 77.8%, 68.1%, 59.6%, 57.6% and 38.4%, respectively. Univariate Cox regression analysis indicated that preoperative serum alpha-fetoprotein (AFP) > 400 ng/ml was an independent risk factor for poor OS (> 400 ng/ml vs. ≤ 400 ng/ml: HR = 6.57, 95% CI: 2.16-19.96, P < 0.001), while not the independent influencing factor of poor DFS ( HR = 1.71, 95% CI: 0.65-4.52, P = 0.277). The age ≤ 60 years or not, gender, viral hepatitis or not, American Joint Committee on Cancer stage, tumor diameter (> 5 cm or not), tumor number, degree of tumor differentiation, microvascular invasion or not, microsatellite nodules or not, anatomical liver resection or not, and the dose of IORT ≤15 Gy or not were not the independent influencing factors of poor OS and DFS (all P > 0.05). Kaplan-Meier method analysis showed that patients with preoperative serum AFP ≤ 400 ng/ml (48 cases) had better OS compared with those with preoperative serum AFP>400 ng/ml (16 cases) (5-year OS rate: 84.8% vs. 44.9%; 7-year OS rate: 79.9% vs.37.4%), and the difference was statistically significant ( P = 0.002). There was no statistically significant difference in the DFS between the 2 groups ( P = 0.134). During the follow-up, 28 patients (43.8%) relapsed, including 17 cases (26.6%) of early recurrence and 11 cases (17.2%) of late recurrence. No marginal recurrence was observed. There were 22 cases (34.4%) of intrahepatic recurrence alone, 2 cases (3.1%) of extrahepatic recurrence and 4 cases (6.3%) of stimutaneous recurrence inside and outside the liver. The 1-, 3-, 5- and 7-year cumulative recurrence rates inside the liver were 19.0%, 27.2%, 37.4% and 39.3% respectively, and the cumulative recurrence rates outside the liver were 6.4%, 8.0%, 9.6% and 9.6% respectively. There were no adverse reactions above grade 3 in the entire group. There were no surgery-related deaths within 30 d after the operation, and no radiation-induced liver disease occurred. Conclusions:Narrow-margin IORT helps HCC patients receiving hepatectomy to achieve favorable long-term survival and adverse reactions are tolerable. It can be used as a safe and effective adjuvant therapy alternative.

Background::Magnetic resonance (MR)-guided ultra-hypofractionated radiotherapy with whole-pelvic irradiation (UHF-WPRT) is a novel approach to radiotherapy for patients with high-risk (HR) and very high-risk (VHR) prostate cancer (PCa). However, the inherent complexity of adaptive UHF-WPRT might inevitably result in longer on-couch time. We aimed to estimate the delivered dose, study the feasibility and safety of adaptive UHF-WPRT on a 1.5-Tesla MR-Linac.Methods::Ten patients with clinical stage T3a-4N0-1M0-1c PCa, who consecutively received UHF-WPRT, were enrolled prospectively. The contours of the target and organ-at-risks on the position verification-MR (PV-MR), beam-on 3D-MR(Bn-MR), and post-MR (after radiotherapy delivery) were derived from the pre-MR data by deformable image registration. The physician then manually adjusted them, and dose recalculation was performed accordingly. GraphPad Prism 9 (GraphPad Prism Software Inc.) was utilized for conducting statistical analyses.Results::In total, we collected 188 MR scans (50 pre-MR, 50 PV-MR, 44 Bn-MR, and 44 post-MR scans). With median 59 min, the mean prostate clinical target volume (CTV)-V 100% was 98.59% ± 2.74%, and the mean pelvic CTVp-V 100% relative percentages of all scans was 99.60% ± 1.18%. The median V 29 Gy change in the rectal wall was -2% (-18% to 20%). With a median follow-up of 9 months, no patient had acute Common Terminology Criteria for Adverse Events (CTCAE) grade 2 or more severe genitourinary (GU) or gastrointestinal (GI) toxicities (0%). Conclusion::UHF-RT to the prostate and the whole pelvis with concomitant boost to positive nodes using an Adapt-To-Shape (ATS) workflow was technically feasible for patients with HR and VHR PCa, presenting only mild GU and GI toxicities. The estimated target dose during the beam-on phase was clinically acceptable based on the 3D-MR–based dosimetry analysis.Clinical trial registration::Chinese Clinical Trial Registry ChiCTR2000033382.

Objective:To explore the patterns of failure after postoperative intensity-modulated radiotherapy for gastric cancer.Methods:Clinical data of patients diagnosed with gastric cancer or gastroesophageal junction carcinoma with pathological stages T 3-4N 0 or T xN 1-3 admitted to Cancer Hospital of Chinese Academy of Medical Sciences from May 2009 to December 2018 were retrospectively analyzed. All patients received postoperative radiotherapy. During the follow-up, tumor recurrence was confirmed by imaging or endoscopic or pathological data, etc. According to the location of tumor recurrence, recurrence patterns were divided into local, regional and distant recurrence. Differences in recurrence patterns among different groups were compared using t-test and Chi-square test. Patient survival was assessed through Kaplan-Meier method. Results:A total of 76 patients were enrolled, with a median age of 49 years old (27-67 years old), 34 cases (45%) were classified as T 3 stage, 40 cases (53%) of T 4 stage, and 75 cases (99%) of N 1-3 stage, respectively. Seventy-three patients (92%) were classified as stage Ⅲ, and 38 patients (50%) underwent D2 dissection. The median follow-up time was 32.8 months (7.1-138.5 months). The median time of recurrence was 17.6 months (2.9-113.6 months). The median survival time after recurrence was 8.19 months (0.6-91.9 months). There were 13 cases (17%) of local recurrence, 6 cases (8%) of regional recurrence, and 72 cases (95%) of distant metastasis in patients. Peritoneal metastasis (33 cases, 43%) and distant lymph node metastasis (12 cases, 16%) were the main patterns of distant recurrence. Conclusions:By intensity-modulated radiotherapy technology, adjuvant radiotherapy yields favorable local and regional control for gastric cancer. Distant metastasis is still the main pattern of recurrence.

Objective:To analyze clinical efficacy of intensity-modulated chemoradiotherapy for patients with anal squamous cell carcinoma and identify prognostic factors.Methods:Clinical data of patients with anal squamous cell carcinoma who received intensity-modulated chemoradiotherapy in the Cancer Hospital of Chinese Academy of Medical Sciences from January 1, 2010 to January 1, 2022 were retrospectively analyzed. Regular follow-up was carried out. The main indexes included disease-free survival (DFS), locoregional failure-free survival (LRFFS) and overall survival (OS), and adverse reactions were recorded. The survival curve was delineated by Kaplan-Meier method and the influencing factors of survival were analyzed by Cox regression models.Results:A total of 65 patients were enrolled with 19 (29%) males and 46 (71%) females. According to the American Joint Committee on Cancer (AJCC) 7 th edition staging, there were 7 (11%), 28 (43%), 10 (15%), and 20 (31%) patients with stage I, II, IIIa, and IIIb, respectively. Before the chemoradiotherapy, 2 (3%) patients received chemotherapy and 12 (18%) patients received local resection. The median dose of radiotherapy was 54 Gy (range: 45-64 Gy) and the main concurrent chemotherapy regimen was capecitabine combined with cisplatin ( n=34, 52%). The completion rate of radiotherapy during concurrent chemoradiotherapy was 100%, and the chemotherapy completion rate was 88%. During the therapy, 5 patients (8%) were interrupted but completed concurrent chemoradiotherapy in full dose, and 8 patients (12%) reduced the dose of concurrent chemotherapy due to the toxicities. During the chemoradiotherapy, 15 cases (23%) experienced grade 3-4 leukopenia, and 17 cases (26%) experienced grade 3-4 radiation dermatitis. No treatment-related death occurred during the treatment. The median follow-up time was 50.4 months (range: 4.4-142.2 months), local recurrence occurred in 7 cases (11%), distant metastasis occurred in 3 cases (5%), and the 5-year DFS, LRFFS and OS rates were 78.8%, 86.5% and 85.1%, respectively. Cox univariate analysis indicated that T stage was significantly associated with DFS ( P=0.006), and tended to be associated with OS ( P=0.054). Conclusions:Intensity-modulated radiotherapy combined with concurrent chemotherapy is an effective treatment for anal squamous cell carcinoma, with tolerable acute toxicities. T stage is an influencing factor of DFS in anal squamous cell carcinoma patients.

Background::Magnetic resonance (MR)-guided ultra-hypofractionated radiotherapy with whole-pelvic irradiation (UHF-WPRT) is a novel approach to radiotherapy for patients with high-risk (HR) and very high-risk (VHR) prostate cancer (PCa). However, the inherent complexity of adaptive UHF-WPRT might inevitably result in longer on-couch time. We aimed to estimate the delivered dose, study the feasibility and safety of adaptive UHF-WPRT on a 1.5-Tesla MR-Linac.Methods::Ten patients with clinical stage T3a-4N0-1M0-1c PCa, who consecutively received UHF-WPRT, were enrolled prospectively. The contours of the target and organ-at-risks on the position verification-MR (PV-MR), beam-on 3D-MR(Bn-MR), and post-MR (after radiotherapy delivery) were derived from the pre-MR data by deformable image registration. The physician then manually adjusted them, and dose recalculation was performed accordingly. GraphPad Prism 9 (GraphPad Prism Software Inc.) was utilized for conducting statistical analyses.Results::In total, we collected 188 MR scans (50 pre-MR, 50 PV-MR, 44 Bn-MR, and 44 post-MR scans). With median 59 min, the mean prostate clinical target volume (CTV)-V 100% was 98.59% ± 2.74%, and the mean pelvic CTVp-V 100% relative percentages of all scans was 99.60% ± 1.18%. The median V 29 Gy change in the rectal wall was -2% (-18% to 20%). With a median follow-up of 9 months, no patient had acute Common Terminology Criteria for Adverse Events (CTCAE) grade 2 or more severe genitourinary (GU) or gastrointestinal (GI) toxicities (0%). Conclusion::UHF-RT to the prostate and the whole pelvis with concomitant boost to positive nodes using an Adapt-To-Shape (ATS) workflow was technically feasible for patients with HR and VHR PCa, presenting only mild GU and GI toxicities. The estimated target dose during the beam-on phase was clinically acceptable based on the 3D-MR–based dosimetry analysis.Clinical trial registration::Chinese Clinical Trial Registry ChiCTR2000033382.