Objective:To investigate the dosimetric advantages of deep inspiration breath-hold (DIBH) technique in postoperative radiotherapy for left-sided breast cancer.Methods:A prospective study was conducted on patients requiring adjuvant radiotherapy after left-sided breast cancer surgery at Jiangsu Cancer Hospital from January 2018 to May 2023. CT simulation images were acquired under both free breathing (FB) and DIBH respiratory modes. Planning target volumes (PTV) and organs at risk (OAR) were delineated, and dosimetric parameters were compared between the two respiratory modes. Additionally, patients were grouped into subgroups [internal mammary lymph node irradiation (IMNI) vs. non-IMNI, breast-conserving surgery (BCS) followed by radiotherapy vs. modified radical mastectomy (MRM) followed by radiotherapy], and dosimetric differences among subgroups for both breathing modes were compared. The Velocity system was used to measure the minimum distances from the heart and left anterior descending coronary artery (LAD) to the PTV surface on CT images. These distances were defined as the heart-to-PTV and LAD-to-PTV distances. Pearson correlation analysis was performed to assess the relationships between heart D max and LAD D max, heart-to-PTV distance and heart D mean, and LAD-to-PTV distance and LAD D max under both respiratory modes. Results:A total of 132 patients were included. Compared to the FB, DIBH showed no significant difference in target dose distribution, but significantly reduced dose to OAR. Specifically, the heart D mean and D max decreased by 1.8 Gy and 8.1 Gy, respectively, and the LAD D max decreased by 7.9 Gy, and the affected lung V 5 Gy and V 20 Gy were reduced by 6.4% and 2.5%, respectively (all P<0.05). All subgroups benefited from DIBH, with greater decrease of dose to OAR in the IMNI subgroup (compared with the non-IMNI subgroup) and the subgroup of MRM followed by radiotherapy (compared with the BCS followed by radiotherapy group). Under both FB and DIBH modes, heart D max and LAD D max showed linear correlations ( r=0.62 and 0.84, respectively; both P<0.001), heart-to-PTV distance correlated with heart D mean ( r=-0.61 and -0.67, respectively; both P<0.001), and LAD-to-PTV distance correlated with LAD D max ( r=-0.58 and -0.63, respectively; both P<0.001). Conclusions:The DIBH technique can significantly reduce dose to the heart, LAD, and lungs in patients undergoing postoperative radiotherapy for left-sided breast cancer without compromising target dose. Patients receiving IMNI after left-sided breast cancer surgery benefit more from the DIBH technique.

Objective:To investigate the dosimetric advantages of deep inspiration breath-hold (DIBH) technique in postoperative radiotherapy for left-sided breast cancer.Methods:A prospective study was conducted on patients requiring adjuvant radiotherapy after left-sided breast cancer surgery at Jiangsu Cancer Hospital from January 2018 to May 2023. CT simulation images were acquired under both free breathing (FB) and DIBH respiratory modes. Planning target volumes (PTV) and organs at risk (OAR) were delineated, and dosimetric parameters were compared between the two respiratory modes. Additionally, patients were grouped into subgroups [internal mammary lymph node irradiation (IMNI) vs. non-IMNI, breast-conserving surgery (BCS) followed by radiotherapy vs. modified radical mastectomy (MRM) followed by radiotherapy], and dosimetric differences among subgroups for both breathing modes were compared. The Velocity system was used to measure the minimum distances from the heart and left anterior descending coronary artery (LAD) to the PTV surface on CT images. These distances were defined as the heart-to-PTV and LAD-to-PTV distances. Pearson correlation analysis was performed to assess the relationships between heart D max and LAD D max, heart-to-PTV distance and heart D mean, and LAD-to-PTV distance and LAD D max under both respiratory modes. Results:A total of 132 patients were included. Compared to the FB, DIBH showed no significant difference in target dose distribution, but significantly reduced dose to OAR. Specifically, the heart D mean and D max decreased by 1.8 Gy and 8.1 Gy, respectively, and the LAD D max decreased by 7.9 Gy, and the affected lung V 5 Gy and V 20 Gy were reduced by 6.4% and 2.5%, respectively (all P<0.05). All subgroups benefited from DIBH, with greater decrease of dose to OAR in the IMNI subgroup (compared with the non-IMNI subgroup) and the subgroup of MRM followed by radiotherapy (compared with the BCS followed by radiotherapy group). Under both FB and DIBH modes, heart D max and LAD D max showed linear correlations ( r=0.62 and 0.84, respectively; both P<0.001), heart-to-PTV distance correlated with heart D mean ( r=-0.61 and -0.67, respectively; both P<0.001), and LAD-to-PTV distance correlated with LAD D max ( r=-0.58 and -0.63, respectively; both P<0.001). Conclusions:The DIBH technique can significantly reduce dose to the heart, LAD, and lungs in patients undergoing postoperative radiotherapy for left-sided breast cancer without compromising target dose. Patients receiving IMNI after left-sided breast cancer surgery benefit more from the DIBH technique.

Objective To construct a Type 1 diabetes model in miniature pigs and explore postoperative care strategies for effectively prolonging the survival time of the model pigs.Methods Seven Banna miniature pigs were selected for pancreatectomy.Glucose,vitamins,and antibiotics were administered for 3-5 days after surgery to aid recovery.Blood glucose and urine glucose levels were measured twice a day in the morning and evening to adjust insulin supplementation accordingly.The model pigs were observed daily and records were kept,including orexis,psychosis,weakness,skin ulcer,and feces and urine.Body weight was measured weekly until the death of the model animals.Based on the model pigs'condition,glucose injection and Ringer's lactate solution were administered to supplement nutrition and correct electrolyte imbalances.Results All seven Banna miniature pigs showed typical symptoms of diabetes:random blood glucose levels higher than 11.1 mmol/L after pancreatectomy,far exceeding the average blood glucose level of 6.0 mmol/L in normal pigs;positive urine glucose;and progressive weight loss.These features indicated the successful construction of Type 1 diabetes model.Additionally,Type 1 diabetic pigs that survived more than 8 weeks showed progressive hair loss and skin ulceration.Euthanasia was performed on model pigs when they were unable to stand or even eat independently,and pathological examination and HE staining were conducted on tissues collected from affected organs such as the liver,kidneys,and skin.Pathological sections revealed liver congestion,massive glycogen accumulation,ballooning degeneration of hepatocytes,and progressive liver fibrosis,along with glomerular congestion,vacuolar degeneration in renal tubular epithelial cells,proteinuria,dermal congestion,thinning of vascular walls,and varying degrees of parakeratosis and dyskeratosis in the liver,kidneys,and skin tissues due to prolonged hyperglycemia.The average survival time of the constructed Banna miniature pig diabetes model was 44 d,with a maximum survival time of 121 d.Conclusion Type 1 diabetes model can be constructed successfully in Banna miniature pigs through pancreatectomy.With meticulous postoperative care,a long-term Type 1 diabetes model with significant complications can be achieved,providing a stable large-animal model for Type 1 diabetes treatment strategies.

Objective:To explore the quality of working life and its related factors in patients with breast canc-er returned to work after surgery.Methods:A total of 316 patients with breast cancer who had returned to work af-ter surgery were selected,and they were investigated with the General information questionnaire,Quality of Working Life Questionnaire for Cancer Survivors(QWLQ-CS),Breast Cancer Survivors Resilience Scale(BCRS)and Strat-egies Used by People to Promote Health(SUPPH).Multivariate linear regression analysis was used to analyze the related factors of quality of working life.Results:Multiple linear regression analysis showed that the QWLQ-CS score was positively correlated with education level,per capita monthly income of family,work pattern,return to work time,personal protection and social protection score of BCRS,and positive attitude scores of SUPPH(β=1.05,1.23,2.26,0.69,0.95,1.00,0.13),while negatively correlated with the complications(β=-3.83).Con-clusion:The quality of working life for patients with breast cancer after surgery needs to be improved after they re-turn to work,psychological resilience and self-efficacy are positively correlated with quality of working life.

Objective:The respiratory waveform of lung cancer patients based on 4D-CT respiratory gating was analyzed to evaluate the accuracy of gating during radiotherapy, and to explore the off-target in the 4D-CT respiratory gating radiotherapy.Methods:Clinical data of 18 patients with lung cancer admitted to Radiotherapy Department of Jiangsu Cancer Hospital were collected to obtain the respiratory waveform data during 4D-CT respiratory gating radiotherapy. The waveform in each treatment working cycle was compared with the waveform in 4D-CT scan to study whether there was a possibility of the off-target in the treatment of lung cancer patients.Results:There were 154 treatment sessions and 20,790 treatment breathing cycles in 18 patients, among which the threshold of gated opening beam miss amplitude (Δm-en) was greater than 0 in 95 treatment breathing cycles in 7 patients, accounting for 0.46% of all breathing cycles, and the threshold of gated closing beam miss amplitude (Δm-dis) was greater than 0 in 1419 treatment breathing cycles in 13 patients, accounting for 6.83% of all cycles. Among the 13 patients withΔm-dis greater than 0, actual tumor range of motion (R G) was greater than the sum of the value of target margin (M) and the value of plan tumor range of motion (R T) in 7 patients, R G was more than 1.5 times of M+R T in 7 patients, and there were also 7 patients in the phase of rapid rise and fall of respiratory curve. The correlation efficients between R G-M-R T and the percentage of beam on miss phase (T en%) and the percentage of beam closing off phase (T dis%) were 0.41 and 0.57, respectively. Conclusion:When R G is more than 1.5 times of M+R T value and the gating beam on phase contains the phases in the rapid rise and fall of the respiratory curve, the possibility of the off-target during radiotherapy is significantly increased.

Objective To evaluate the application of the placement of titanium clips in the upper and lower tumor margins in precision radiotherapy for early esophageal cancer. Methods:Seventeen patients with early esophageal cancer underwent endoscopy-guided implantation of titanium clips to mark the upper and lower tumor margins. CT-based simulation was performed to delineate the gross tumor volume ( GTV) . The application value of this technology in precision radiotherapy was evaluated. Results:For all patients (including 13 cases with initial treatment and 4 patients requiring radiotherapy after endoscopic resection), the esophageal tumors were not explicitly displayed on CT and barium meal images and the GTV range could not be accurately determined. The esophageal tumors were marked by successful placement of at least one titanium clip in the upper and lower tumor margins. Subsequently, the esophageal tumors were successfully displayed on CT simulation and the target area was accurately delineated. No grade 3-4 adverse events, such as bleeding and perforation occurred. Conclusion Endoscopy-guided titanium clip placement is convenient and feasible for early esophageal cancer, which is of clinical significance for determining the target area of radiotherapy.