Radiotherapy For Cancer Research Articles

Personalized Deep Learning Model for Clinical Target Volume on Daily Cone-beam Computed Tomography in Breast Cancer Patients

PurposeHerein, we developed a deep learning algorithm to improve the segmentation of the clinical target volume (CTV) on daily cone-beam computed tomography (CBCT) scans in breast cancer radiotherapy. By leveraging the Intentional Deep Overfit Learning (IDOL) framework, we aimed to enhance personalized image-guided radiotherapy (IGRT) based on patient-specific learning. MethodsWe utilized 240 CBCT scans from 100 breast cancer patients and employed a two-stage training approach. The first stage involved training a novel general deep learning model (Swin UNETR, UNET, and SegResNET) on 90 patients. The second stage utilized intentional overfitting on the remaining 10 patients for patient-specific CBCT outputs. Quantitative evaluation was conducted using the Dice Similarity Coefficient (DSC), Hausdorff Distance (HD), mean surface distance (MSD), and independent samples t-test with expert contours on CBCT scans from the 1st to 15th fractions. ResultsIDOL integration significantly improved CTV segmentation, particularly with the Swin UNETR model (p-values <0.05). Using patient-specific data, IDOL enhanced the DSC, HD, and MSD metrics. The average DSC for the 15th fraction improved from 0.9611 to 0.9819, the average HD decreased from 4.0118 mm to 1.3935 mm, and the average MSD decreased from 0.8723 to 0.4603. Incorporating CBCT scans from the initial treatments and 1st to 3rd fractions further improved results, with an average DSC of 0.9850, an average HD of 1.2707 mm, and an average MSD of 0.4076 for the 15th fraction, closely aligned with physician-drawn contours. ConclusionCompared with a general model, our patient-specific deep learning-based training algorithm significantly improved CTV segmentation accuracy of CBCT scans in patients with breast cancer. This approach, coupled with continuous deep learning training using daily CBCT scans, demonstrated enhanced CTV delineation accuracy and efficiency. Future studies should explore the adaptability of the IDOL framework to diverse deep learning models, datasets, and cancer sites.

Internal urethral sphincter reconstruction with anterior bladder neck tube for robotic and laparoscopic radical prostatectomy: improving early return of continence.

In recent years, despite several surgical techniques having been applied, the early incontinence rate after radical prostatectomy (RP) remains high. In this study, we reconstructed an internal urethral sphincter (IUS) with anterior bladder neck tube (ABNT) to improve early return of continence and find a more effective technique for early urinary incontinence after RP. In this study, 96 previous patients who did not receive an ABNT between October 2018 and May 2020 were compared as historical controls (the control group). A total of 210 consecutive patients underwent robotic or laparoscopic RP with ABNT between May 2020 and February 2023 (the ABNT group). The inclusion criteria included Eastern Cooperative Oncology Group (ECOG) score 0-1 and localized prostate cancer (clinical stages cT1-3, cN0, cM0). The exclusion criteria included patients with diabetes, neurologic diseases, previous pelvic operations, symptoms of urinary incontinence, prior radiation, focal therapy, or androgen deprivation therapy for prostate cancer. ABNT was reconducted with a U-shaped flap from the anterior wall of the bladder neck, and was then anastomosed with the urethra. In the control group, the bladder outlet was directly anastomosed with the urethra. Continence, as defined if 0 pads were used per day and International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) score ≤6, was assessed at 1, 4, 8, 12, and 24 weeks after catheter removal. At 2 weeks after catheter removal, urethral pressure profilometry (UPP) and upright urethrography were performed to evaluate the function of ABNT in the ABNT group. More patients in the ABNT group were continent than those in the control group at 1 week (85.2% vs. 22.9%, P<0.001), 4 weeks (91.4% vs. 27.1%, P<0.001), 8 weeks (95.2% vs. 40.6%, P<0.001), 12 weeks (100% vs. 71.9%, P<0.001), and at 24 weeks (100% vs. 87.5%, P<0.001) after catheter removal. Stricture was presented in 5.2% and 2.1% (P=0.34) in the ABNT group and control group, respectively. UPP showed that a functional IUS was reconstructed with ABNT. Upright urethrography showed that the ABNT was filled with contrast medium in the urination period and with no contrast medium during the storage period and interruption of urination. The ABNT technique significantly improved early return of continence in comparison with the no ABNT technique, especially the immediate continence. The ABNT technique reconstructed the functional IUS with acceptable urethral stricture. The limitations of the present study include that the comparison was conducted retrospectively with a historical cohort and lack of randomization, and the single center setting. A prospective, randomized, and multicenter evaluation is expected.

The impact of baseline health factors on second primary cancer risk after radiotherapy for prostate cancer.

In evaluating second primary cancers (SPCs) following External Beam Radiotherapy (EBRT), the role of lifestyle factors is frequently not considered due to data limitations. We investigated the association between smoking, comorbidities, and SPC risks within EBRT-treated patients for localized prostate cancer (PCa). The study included 1,883 PCa survivors aged 50-79, treated between 2006 and 2013, with intensity-modulated radiotherapy (IMRT) or three-dimensional conformal radiotherapy (3D-CRT). Clinical data were combined with SPC and survival data from the Netherlands Cancer Registry with a 12-month latency period. Standardized Incidence Ratios (SIRs) were calculated comparing the EBRT cohort with the general Dutch population. To explore the effect of patient and treatment characteristics on SPCs we conducted a Cox regression analysis. Lastly, we estimated cumulative incidences of developing solid SPC, pelvis SPC, and non-pelvis SPC using a competing risk analysis. Significantly increased SIRs were observed for all SPC (SIR = 1.21, 95% confidence interval [CI]: 1.08-1.34), pelvis SPC (SIR = 1.46, 95% CI: 1.18-1.78), and non-pelvis SPC (SIR = 1.18, 95% CI [1.04-1.34]). Smoking status was significantly associated with pelvic and non-pelvic SPCs. Charlson comorbidity index (CCI) ≥ 1 (Hazard Ratio [HR] = 1.45, 95% CI: 1.10-1.91), cardiovascular disease (HR = 1.41, 95% CI: 1.05-1.88), and chronic obstructive pulmonary disease (COPD) (HR = 1.91, 95% CI: 1.30-2.79) were significantly associated with non-pelvis SPC. The proportion of active smoking numbers in the cohort was similar to the general population. We conclude that the presence of comorbidities in the EBRT population might be a relevant factor in observed excess non-pelvis SPC risk, but not for excess pelvis SPC risk.

CHILDREN AND ADOLESCENTS WITH CANCER UNDERGOING RADIOTHERAPY: WHAT IS THE IMPACT ON SCHOOLING?

Introduction and Aim of the Study:When a child or adolescent is diagnosed with cancer, it represents a challenging ordeal that often brings significant changes to their daily life. School is an important concern for young patients, but a cancer diagnosis usually leads to school disruptions. The aim of our study is to evaluate the impact of radiotherapy treatment on the schooling of children and adolescents affected by cancer. Materials and Methods:This is a prospective study conducted in the Radiotherapy Department of the National Institute of Oncology in Rabat from January 2022 to December 2022, including 40 children and adolescents aged between 6 and 16 years undergoing radiotherapy or concurrent radiochemotherapy treatment for cancer. Results:The median age of our patients was 10 years, with a predominance of males (sex ratio = 2). The most common neoplasms were malignant hemopathies (35%), nasopharyngeal carcinoma (20%), soft tissue sarcoma (17.5%), brain neoplasms (15%), and others (nephroblastoma , neuroblastoma 12.5%).42.5% of the patients had previously received chemotherapy alone, 30% had chemotherapy plus surgery, and 27.5% had surgery alone.During our study, all patients received either radiotherapy alone (80%) or concurrent radiochemotherapy (20%). The average number of sessions was 22, held daily from Monday to Friday.All our patients were attending school before their diagnosis. However, 96% discontinued school at the start of their treatment, with only 4% continuing to attend school. The heaviness of the treatments received and their side effects are the main cause of school discontinuation. The distance between the treatment location and the patients home was also factor for patients undergoing radiotherapy. Conclusion:The discontinuation of schooling for children and adolescents represents a significant disruption in their daily lives, potentially impacting their psychological well-being. Furthermore, feeling different from other children their age can be challenging for them. Therefore, it is important to offer an adaptation of their schooling with specialized education to enable their social development and well-being.

Radiotherapy for parotid cancer: 10 years of experience in a single center

&lt;b&gt;&lt;br&gt;Introduction:&lt;/b&gt; We report our experience in the treatment of parotid cancers by radiotherapy delivered with curative intent over a period of 10 years.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Aim:&lt;/b&gt; The aim of this study was to evaluate the therapeutic results and prognostic factors.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Materials and methods:&lt;/b&gt; This is a retrospective study of patients with parotid cancer treated with radiotherapy between 2008 and 2017 at the National Institute of Oncology in Rabat. Patients who received adjuvant or exclusive radiotherapy were included in this study. We performed a multivariate analysis for the factors related to locoregional control and overall survival.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Results:&lt;/b&gt; Initially, 74 patients (45 men and 29 women), at a median age of 57 years. were identified. At the time of diagnosis, 10 (13.6%), 36 (48.6%), and 28 (37.8%) patients were in stage II, III, and IVab, respectively. Sixty patients received adjuvant radiotherapy after parotidectomy and 14 patients received exclusive radiotherapy for an unresectable tumor. At 5 years, the rate of locoregional control and overall survival were 68.2% and 53.7%, respectively. Surgical resection and negative margins were significantly correlated with locoregional control. Lymph node involvement, unresectable tumors, high-grade histological types, and cystic adenoid carcinoma were significantly correlated with poor overall survival.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Conclusions:&lt;/b&gt; Acceptable long-term results are obtained with surgery combined with radiotherapy. Surgical resection remains essential for parotid cancer, given the disappointing results of treatment with radiotherapy alone.&lt;/br&gt;

Constipation - A Disregarded Symptom in Patients Undergoing Radiotherapy for Head and Neck Cancer – A Clinical Audit on Management

Background: In clinical practice, constipation in patients undergoing Radiotherapy (RT) for head and neck cancer is not only very common, but many a times left unattended. Unrelieved constipation results in patient distress and poor compliance to treatment. Most of the patients are empirically treated with poor symptom control. The aim of this audit was to find out the burden of constipation and to treat them effectively. Methods: Standard based clinical audit was undertaken in the department of Radiation Oncology from July 2021 to January 2022, in patients with complaints of constipation who are undergoing RT for head and neck cancers. The intervention planned (criteria) was to follow the European Society for Medical Oncology (ESMO) 2018 flowchart for the management of constipation, which were divided into 4 checkpoints for the ease of quantification – 1. history taken, 2. documentation of type of laxative used, 3. review for symptom relief and 4. maintenance therapy prescription. The standard set was 65%. Results: A total of 48 patients in the initial assessment (retrospective) and 44 patients in the re-assessment (prospective) were evaluated. The mean age in both the audit was 54 years, 32 (66.6%) patients in the initial assessment and 26 (60%) patients in the re-assessment reported constipation during RT. Comparing the pre intervention and post intervention, the 4 checkpoints of the ESMO flowchart were never addressed (0%) as compared to 92%, 92%, 77% and 77% respectively. The mean number of days for complete symptom relief were 7 v/s 2 days respectively. Mean number of days to report constipation was 5 days v/s 3 days respectively. The mean number of active reviews till complete symptom relief was 0 v/s 2 times. Conclusion: Empirical management of constipation occurring during RT for head and neck cancers gives poor results. Guideline based treatment help manage the constipation better thus enhancing the patient care.

Incidence, Characteristics and Survival Rates of Bladder Cancer after Rectosigmoid Cancer Radiation.

Historical external beam radiation therapy (EBRT) for rectosigmoid cancer (RCa) predisposed patients to an increased risk of secondary bladder cancer (BCa). However, no contemporary radiotherapy studies are available. We addressed this knowledge gap. Within the Surveillance, Epidemiology, and End Results database (2000-2020), we identified non-metastatic RCa patients who either underwent radiotherapy (EBRT+) or did not (EBRT-). Cumulative incidence plots and multivariable competing risk regression models (CRR) were fitted to address rates of BCa after RCa. In the subgroup of BCa patients, the same methodology addressed BCa-specific mortality (BCSM) according to EBRT exposure status. Of the 188,658 non-metastatic RCa patients, 54,562 (29%) were EBRT+ vs. 134,096 (73%) who were EBRT-. In the cumulative incidence plots, the ten-year BCa rates were 0.7% in EBRT+ vs. 0.7% in EBRT- patients (p = 0.8). In the CRR, EBRT+ status was unrelated to BCa rates (multivariable HR: 1.1, p = 0.8). In the subgroup of 1416 patients with BCa after RCa, 443 (31%) were EBRT+ vs. 973 (69%) who were EBRT-. In the cumulative incidence plots, the ten-year BCSM rates were 10.6% in EBRT+ vs. 12.1% in EBRT- patients (p = 0.7). In the CRR, EBRT+ status was unrelated to subsequent BCSM rates (multivariable HR: 0.9, p = 0.9). Although historical EBRT for RCa predisposed patients to higher BCa rates, contemporary EBRT for RCa is not associated with increased subsequent BCa risk. Moreover, in patients with BCa after RCa, exposure to EBRT does not affect BCSM.

The Current Position of Postoperative Radiotherapy for Salivary Gland Cancer: A Systematic Review and Meta-Analysis.

Because of the rarity, heterogeneous histology, and diverse anatomical sites of salivary gland cancer (SGC), there are a limited number of clinical studies on its management. This study reports the cumulative evidence of postoperative radiotherapy (PORT) for SGC of the head and neck. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched the PubMed, Embase, Cochrane Library, and Web of Science databases between 7th and 10th November 2023. A total of 2962 patients from 26 studies between 2007 and 2023 were included in this meta-analysis. The median RT dose was 64 Gy (range: 56-66 Gy). The median proportions of high-grade, pathological tumor stage 3 or 4 and pathological lymph node involvement were 42% (0-100%), 40% (0-77%), and 31% (0-75%). The pooled locoregional control rates at 3, 5, and 10 years were 92% (95% confidence interval [CI], 89-94%), 89% (95% CI, 86-93%), and 84% (95% CI, 73-92%), respectively. The pooled disease-free survival (DFS) rates at 3, 5, and 10 years were 77% (95% CI, 70-83%), 67% (95% CI, 60-74%), and 61% (95% CI, 55-67%), respectively. The pooled overall survival rates at 3, 5, and 10 years were 84% (95% CI, 79-88%), 75% (95% CI, 72-79%), and 68% (95% CI, 62-74%), respectively. Severe late toxicity ≥ grade 3 occurred in 7% (95% CI, 3-14%). PORT showed favorable long-term efficacy and safety in SGC, especially for patients with high-grade histology. Considering that DFS continued to decrease, further clinical trials exploring treatment intensification are warranted.

Comparative outcomes between adjuvant and salvage radiotherapy in prostate cancer after minimally invasive radical prostatectomy

Objective: Radical prostatectomy (RP) is the standard treatment in clinically localized prostate cancer. However, the timing of postoperative radiotherapy (RT) in patients with adverse pathologic features or PSA persistence remains controversial. The objective of this study is to compare the survival outcomes and treatment complications between adjuvant radiotherapy (aRT) and salvage radiotherapy (sRT) in patients after minimally invasive RP. Materials and Methods: This retrospective study reviewed the clinical data in patients who underwent minimally invasive RP in our institution between January 2012 and April 2021. The patients were divided into three groups: no RT, aRT, and sRT. Patient demographic data, pathological reports, RTOG/EORTC toxicity scores, functional outcomes, and survival outcomes were compared between aRT and sRT groups. Results: A total of 487 patients were included in the study. One-hundred and thirty-three patients (27.3%) received postoperative RT. The pathological stage and positive margin rate were significantly higher in the aRT group. Five-year ADT-free survival (78.8% vs 80%, p = 0.68), 5-year metastasis-free survival (80.2% vs 92.2%, p = 0.38), and 5-year overall survival (97.1% vs 100%, p = 0.68) were no different between groups. There were no significant differences in continence, potency, genitourinary or gastrointestinal toxicities between groups. Conclusions: Timing of postoperative RT does not affect survival. Functional outcomes and radiation toxicity were comparable between patients undergoing aRT and sRT.

Tumor recurrence and survival prognosis in patients with advanced gastric cancer after radical resection with radiotherapy and chemotherapy.

Advanced gastric cancer is a common malignancy that is often diagnosed at an advanced stage and is still at risk of recurrence after radical surgical treatment. Chemoradiotherapy, as one of the important treatment methods for gastric cancer, is of great significance for improving the survival rate of patients. However, the tumor recurrence and survival prognosis of gastric cancer patients after radiotherapy and chemotherapy are still uncertain. To analyze the tumor recurrence after radical radiotherapy and chemotherapy for advanced gastric cancer and provide more in-depth guidance for clinicians. A retrospective analysis was performed on 171 patients with gastric cancer who received postoperative adjuvant radiotherapy and chemotherapy in our hospital from 2021 to 2023. The Kaplan-Meier method was used to calculate the recurrence rate and survival rate; the log-rank method was used to analyze the single-factor prognosis; and the Cox model was used to analyze the prognosis associated with multiple factors. The median follow-up time of the whole group was 63 months, and the follow-up rate was 93.6%. Stage II and III patients accounted for 31.0% and 66.7%, respectively. The incidences of Grade 3 and above acute gastrointestinal reactions and hematological adverse reactions were 8.8% and 9.9%, respectively. A total of 166 patients completed the entire chemoradiotherapy regimen, during which no adverse reaction-related deaths occurred. In terms of the recurrence pattern, 17 patients had local recurrence, 29 patients had distant metastasis, and 12 patients had peritoneal implantation metastasis. The 1-year, 3-year, and 5-year overall survival (OS) rates were 83.7%, 66.3%, and 60.0%, respectively. The 1-year, 3-year, and 5-year disease-free survival rates were 75.5%, 62.7%, and 56.5%, respectively. Multivariate analysis revealed that T stage, peripheral nerve invasion, and the lymph node metastasis rate (LNR) were independent prognostic factors for OS. Postoperative intensity-modulated radiotherapy combined with chemotherapy for gastric cancer treatment is well tolerated and has acceptable adverse effects, which is beneficial for local tumor control and can improve the long-term survival of patients. The LNR was an independent prognostic factor for OS. For patients with a high risk of local recurrence, postoperative adjuvant chemoradiation should be considered.

Prophylactic Effect of Clarithromycin on Radiation Pneumonitis in IMRT for Lung Cancer.

To evaluate the association between prophylactic administration of clarithromycin (CAM) and the development of radiation pneumonitis (RP) in patients treated with intensity modulated radiation therapy (IMRT) for lung cancer. A total of 89 patients who underwent definitive or salvage IMRT for lung cancer were retrospectively evaluated. The median total and daily doses were 60 Gy and 2 Gy, respectively. A total of 39 patients (44%) received CAM for a median of three months after the start of IMRT. The relationship between the development of RP and certain clinical factors was analyzed. RP of Grade ≥2 was recognized in 10 (11%) patients; Grade 2 in six patients and Grade 3 in four patients. The incidence of Grade ≥2 RP was 3% (1/39) in patients treated with CAM, which was significantly lower than that of 18% (9/50) in patients without CAM. The median lung V20 and V5 in the 10 patients with RP Grade ≥2 were 24% and 46%, respectively, compared with 18% and 37% in the 79 patients with RP Grade 0-1, and the differences were significant. Durvalumab administration after IMRT was also a significant factor for RP Grade ≥2. Prophylactic administration of CAM may reduce Grade ≥2 RP in patients treated with IMRT for lung cancer. Therefore, further clinical trials are warranted.

Evaluation of dose delivery based on deformed CT using a commercial software for lung cancer

This study employed a commercial software velocity to perform deformable registration and dose calculation on deformed CT images, aiming to assess the accuracy of dose delivery during the radiotherapy for lung cancers. A total of 20 patients with lung cancer were enrolled in this study. Adaptive CT (ACT) was generated by deformed the planning CT (pCT) to the CBCT of initial radiotherapy fraction, followed by contour propagation and dose recalculation. There was not significant difference between volumes of GTV and CTV calculated from the ACT and pCT. However, significant differences in dice similarity coefficient (DSC) and coverage ratio (CR) between GTV and CTV were observed, with lower values for GTV volumes below 15 cc. The mean differences in dose corresponding to 95% of the GTV, GTV-P, CTV, and CTV-P between ACT and pCT were − 0.32%, 4.52%, 2.17%, and 4.71%, respectively. For the dose corresponding to 99%, the discrepancies were − 0.18%, 8.35%, 1.92%, and 24.96%, respectively. These differences in dose primarily appeared at the edges of the target areas. Notably, a significant enhancement of dose corresponding to 1 cc for spinal cord was observed in ACT, compared with pCT. There was no statistical difference in the mean dose of lungs and heart. In general, for lung cancer patients, anatomical motion may result in both CTV and GTV moving outside the original irradiation region. The dose difference within the original target area was small, but the difference in the planning target area was considerable.

Treatment Outcomes of Stereotactic Body Radiotherapy for Early-stage Non-small Cell Lung Cancer and Lung Metastasis

Background and rationale: Stereotactic body radiotherapy (SBRT) is a highly precise localized high-dose per fraction radiation treatment used mainly in lung cancer. Despite SBRT's increasing use, no clear predictive factors of outcome exist. Objectives: To report local control rates, patterns of failure, and incidence of treatment-related toxicity, and to determine factors predicting SBRT outcomes for primary and secondary lung tumors at Ramathibodi Hospital using competing risk analysis. Materials and methods: This retrospective study included all patients diagnosed with primary early non-small cell lung cancer (NSCLC) and lung metastasis in our radiosurgery and radiotherapy database registry between January 2009 and September 2018. Results: Fifty-nine patients (98 lung tumors) were studied; primary NSCLC and lung metastasis were 15.3% and 84.7%, respectively. Median follow-up was 16.8 months. The overall 1-year local control rate was 90.8%. The most common pattern of failure was distant failure (46.9%). The incidence of radiation pneumonitis (RP) grade ≥2 was 9.2%, and one of four patients with an ultra-central tumor developed grade 5 pulmonary toxicity. The predictive factor for local failure was the mean biological equivalent dose (BED) of the planning target volume (PTV), and for RP grade ≥2, the tumor's maximal diameter. BED PTV mean &lt;100 Gy had higher local failure than BED PTV mean ≥100 Gy (adjusted subdistribution hazard ratio 8.26; 95% confidence interval (CI) 1.76–38.68, p=0.007). Patients with tumors with maximal diameters ≥5 cm compared with those with maximal diameters &lt;5 cm had more RP grade ≥2 (adjusted subdistribution hazard ratio 5.34; 95% CI 1.52–18.69, p=0.009). The overall 1-year survival rate was 73.5%. Conclusions: Local control of lung tumors using SBRT was high with acceptable toxicity. BED PTV mean was a local control predictor. Large tumors correlated with symptomatic RP grade ≥2. SBRT should be used judiciously for ultra-central lung tumors.

Treatment Outcomes of Stereotactic Body Radiotherapy for Early-stage Non-small Cell Lung Cancer and Lung Metastasis

Background and rationale: Stereotactic body radiotherapy (SBRT) is a highly precise localized high-dose per fraction radiation treatment used mainly in lung cancer. Despite SBRT's increasing use, no clear predictive factors of outcome exist. Objectives: To report local control rates, patterns of failure, and incidence of treatment-related toxicity, and to determine factors predicting SBRT outcomes for primary and secondary lung tumors at Ramathibodi Hospital using competing risk analysis. Materials and methods: This retrospective study included all patients diagnosed with primary early non-small cell lung cancer (NSCLC) and lung metastasis in our radiosurgery and radiotherapy database registry between January 2009 and September 2018. Results: Fifty-nine patients (98 lung tumors) were studied; primary NSCLC and lung metastasis were 15.3% and 84.7%, respectively. Median follow-up was 16.8 months. The overall 1-year local control rate was 90.8%. The most common pattern of failure was distant failure (46.9%). The incidence of radiation pneumonitis (RP) grade ≥2 was 9.2%, and one of four patients with an ultra-central tumor developed grade 5 pulmonary toxicity. The predictive factor for local failure was the mean biological equivalent dose (BED) of the planning target volume (PTV), and for RP grade ≥2, the tumor's maximal diameter. BED PTV mean &lt;100 Gy had higher local failure than BED PTV mean ≥100 Gy (adjusted subdistribution hazard ratio 8.26; 95% confidence interval (CI) 1.76–38.68, p=0.007). Patients with tumors with maximal diameters ≥5 cm compared with those with maximal diameters &lt;5 cm had more RP grade ≥2 (adjusted subdistribution hazard ratio 5.34; 95% CI 1.52–18.69, p=0.009). The overall 1-year survival rate was 73.5%. Conclusions: Local control of lung tumors using SBRT was high with acceptable toxicity. BED PTV mean was a local control predictor. Large tumors correlated with symptomatic RP grade ≥2. SBRT should be used judiciously for ultra-central lung tumors.

Evolving Prostate Cancer Radiotherapy: Exploring Gonadal Doses in 3DCRT and IMRT with Testicular Shielding

Objective: To compare the dosimetry of IMRT versus 3DCRT in prostate cancer, with a focus on testicular dose using lead testicular shielding. Materials and Methods: From January 2021 to January 2022, twenty patients with localized prostate cancer underwent IMRT treatment. Plans for 3DCRT were generated for each patient. Comparison was made between 3D-CRT and IMRT regarding target volume dose uniformity, sparing of critical organs, and testicular doses. Results: Significant differences were observed in dose uniformity and sparing of critical organs between the two modalities (p&lt;0.005), demonstrating the superiority of IMRT over 3DCRT. However, with lead testicular shielding, comparable testicular doses were achieved with both techniques. Conclusion: IMRT offers superior dosimetric advantages compared to 3DCRT. Nevertheless, the testicular dose remains nearly equivalent between the two techniques when utilizing lead testicular shielding.

Proton radiotherapy for rectal cancer

AIM: to assess the effectiveness of proton radiotherapy as part of a combined approach to the treatment of rectal malignancies and to assess acute radiation toxicity, which directly affects patients’ quality of life.PATIENTS AND METHODS: between 2020 and 2023, a study included 74 patients with rectal cancer. The mean age of the patients was 65 ± 9.9 years, 44 (60%) males. Stage I occurred in 8 (10.8%) patients, stage II — in 14 (18.9%) patients, stage III — in 52 (70.3%) patients. At the first stage, all patients completed proton radiation therapy in the classical fractionation mode.RESULTS: of the adverse events, 49 (66%) patients had grade 1–2 radiation reactions in the form of proctitis and cystitis. There were no local radiation reactions of grade 3 or higher. Systemic complications of grade 3 were noted in 2 (2%) patients in the form of hematological toxicity — anemia (1%), afebrile neutropenia (2%). Of the 62 operated patients, 12 (19.3%) people showed complete therapeutic pathomorphosis. With a median follow-up of 23 months (13;35), 1 (1.35%) patient showed continued tumor growth 28 months after completed radiotherapy, 2 (2.7%) patients had local recurrence 3 and 18 months after treatment. Distant metastases to the lungs, liver, or bones were detected in 9 (12.2%) patients, median — 12 months (6;23). Mortality during the entire observation period was 9 (12.2%) patients. Sixty-two (83.8%) patients showed no signs of relapse or progression of the disease, of which 9 (14.5%) patients did not receive any treatment after chemoradiotherapy and are in the process of active follow-up.CONCLUSION: proton radiation therapy in patients with rectal cancer in two-year overall survival (90.5%) and progression-free survival (88.9%) are comparable with the literature data of recent studies, but are superior in overall survival pathological response (19.3%).

Stereotactic Body Radiation Therapy (SBRT) for Non-Small Cell Lung Cancer (NSCLC) Therapy

For patients with early-stage non-small cell lung cancer (NSCLC) who cannot undergo surgery, stereotactic body radiotherapy (SBRT), also known as stereotactic ablative radiotherapy (SABR), usually achieves good therapeutic effects. This new treatment method has the characteristics of low toxicity and high efficacy for peripheral lung cancer. However, in central type lung cancer, especially in lesions near structures such as bronchial trees or mediastinum, there is an increased risk of severity. This review summarizes the following areas: (1) the methods and indications of using SBRT to treat NSCLC patients in different areas; (2) the principle and advantages and disadvantages of targeted MRI linear accelerators; (3) the diagnostic and evaluation process of targeted MRI linear accelerator therapy for lung cancer; (4) the clinical process of targeted MRI linear accelerator treatment for lung cancer; (5) tracking and monitoring of targeted MRI linear accelerator therapy for lung cancer; (6) pulmonary MRI disorders may include the following situations; (7) how to evaluate stage I-IV non-small cell lung cancer with targeted MRI linear accelerator; (8) how to locate central and peripheral lung cancer using targeted MRI linear accelerators; (9) increase safety of SBRT in central locations.

The role of a radiopaque peri-rectal hydrogel spacer in aiding accurate daily image-guidance for prostate stereotactic radiotherapy.

Precise patient positioning with image guidance (IGRT) is essential for safe prostate radiotherapy. We present the first report of utilizing a CT-visible hydrogel spacer, used to decrease rectal radiation dose, as a surrogate fiducial marker to aid in daily IGRT with cone-beam CT (CBCT) in stereotactic radiotherapy (SABR) for prostate cancer. Prior to CT simulation, patients underwent placement of three intraprostatic gold fiducial markers and radiopaque hydrogel spacer per standard practice. At treatment, after initial setup, a CBCT was acquired and fused to the planning CT based on 3-dimensional matching of the spacer. A second alignment was then performed based on the fiducial markers. The six directional shifts (three linear and three rotational) were recorded, and the differences compared. 140 individual fractions across 41 consecutive patients were evaluated. Mean/median differences between hydrogel spacer-based and fiducial-based alignment in linear (vertical, longitudinal, lateral) and rotational (rotation, pitch, roll) shifts were 0.9/0.6mm, 0.8/0.5mm, and 0.6/0.4mm, and 0.38/0, 0.62/0, and 0.35/0 degrees, respectively. No difference was observed in 9.9%, 22.9%, and 22.14% of linear shifts, and 65.7%, 65%, and 66.4% rotational shifts, respectively. Significantly smaller differences were observed in the latter 70 fractions vs. the former, and results were consistent across evaluators. For precise daily IGRT with CBCT for prostate SABR, alignment using a radiopaque hydrogel spacer was highly comparable to intraprostatic fiducial markers. This represents the first report supporting an additional indication of IGRT for a CT-visible hydrogel spacer, to further enhance treatment accuracy and potentially obviate the need for the additional fiducial marker procedure.

Dosimetric risk factors for radiation esophagitis in patients with breast cancer following regional nodal radiation

BACKGROUND Radiation esophagitis (RE) is one of the most common clinical symptoms of regi-onal lymph node radiotherapy for breast cancer. However, there are fewer studies focusing on RE caused by hypofractionated radiotherapy (HFRT). AIM To analyze the clinical and dosimetric factors that contribute to the development of RE in patients with breast cancer treated with HFRT of regional lymph nodes. METHODS Between January and December 2022, we retrospectively analysed 64 patients with breast cancer who met our inclusion criteria underwent regional nodal intensity-modulated radiotherapy at a radiotherapy dose of 43.5 Gy/15F. RESULTS Of the 64 patients in this study, 24 (37.5%) did not develop RE, 29 (45.3%) developed grade 1 RE (G1RE), 11 (17.2%) developed grade 2 RE (G2RE), and none developed grade 3 RE or higher. Our univariable logistic regression analysis found G2RE to be significantly correlated with the maximum dose, mean dose, relative volume 20-40, and absolute volume (AV) 20-40. Our stepwise linear regression analyses found AV30 and AV35 to be significantly associated with G2RE (P &lt; 0.001). The optimal threshold for AV30 was 2.39 mL [area under the curve (AUC): 0.996; sensitivity: 90.9%; specificity: 91.1%]. The optimal threshold for AV35 was 0.71 mL (AUC: 0.932; sensitivity: 90.9%; specificity: 83.9%). CONCLUSION AV30 and AV35 were significantly associated with G2RE. The thresholds for AV30 and AV35 should be limited to 2.39 mL and 0.71 mL, respectively.

Total neoadjuvant treatment with long-course radiotherapy versus concurrent chemoradiotherapy in local advanced rectal cancer with high risk factors (TNTCRT): A multicenter, randomized, open-label, phase 3 trial.

LBA3511 Background: Distant metastases remain a common problem in locally advanced rectal cancer (LARC) patients who received neoadjuvant chemoradiotherapy (NCRT) and surgery. Previous researchers have demonstrated the survival benefits of total neoadjuvant treatment (TNT) using short-course radiotherapy with CAPOX and long-course radiotherapy (LCRT) with mFOLFIRINOX. This study aimed to explore the efficacy of TNT using long-course radiotherapy (LCRT) combined with CAPOX. Methods: In this phase 3, open-label, multicenter, randomized trial, eligible pts were diagnosed as stage II/III and had at least one high risk factor: cT4a-b (resectable), cT3c-d with extramural venous invasion, cN2; involved mesorectal fascia, or enlarged lateral lymph nodes. Pts were randomly assigned to either Arm A to receive TNT (LCRT with six cycles of neoadjuvant CAPOX (one cycle of induction CAPOX, two cycles of concurrent CAPOX, and three cycles of consolidation CAPOX) followed by total mesorectal excision (TME)) or Arm B to receive NCRT (LCRT with concomitant capecitabine, followed by TME and adjuvant CAPOX). Radiotherapy in both groups was administered at 50-50.4 Gy in 25-28 fractions. The primary endpoint was disease free survival (DFS). The secondary endpoints were pathological response complete (pCR) rate, overall survival (OS), metastasis-free survival (MFS) and postoperative 30-day morbidity. Results: (ITT) Between June 6, 2017, and Mar 5, 2024, 458 pts were randomly assigned to two Arms (232 in Arm A, and 226 in Arm B). At a median follow-up of 44 months (IQR, 24-57.25), the 3-yr DFS was significantly increased in Arm A (77.0% vs 67.9% in Arm A/B respectively, HR 0.623, 95% CI 0.435-0.892, p = 0.009). 3-yr MFS was also significantly higher in arm A: 83.0% vs 74.2% in arm B (HR 0.595, 95% CI 0.392-0.903, p= 0.013). A total of 56 OS events was reported, and the 3-yr OS was 90.3% vs 87.9% (HR 0.747, 95% CI 0.441-1.266, p = 0.276) in arm A/B, respectively. TNT and NCRT in both arms were well tolerated. Thrombocytopenia was the most frequent grade 3-4 hematological adverse event in Arm A, occurring in 24 (10.3%) of 232 pts. Until now, 27.5% of pts achieved pCR in Arm A, compared to only 9.9% in Arm B. (OR 3.436, [1.1.941-6.084], p= 0.0001). In Arm A and B, 13 and 2 pts achieved clinical complete response (cCR) and received watch-and-wait strategy, respectively. No significant difference in severe morbidity within 30 days post-operation were found between the two arms. Conclusions: TNT with LCRT combined with CAPOX significantly improve DFS, MFS and pCR compared to standard concurrent neoadjuvant chemoradiotherapy in LARC patients with high risk factors, with acceptable toxicities. Clinical trial information: NCT03177382 .