The Impact of Deep Inspiration Breath Hold (DIBH) Implementation on the Hybrid Technique in Left-Sided Whole Breast Irradiation: A Dosimetric Characteristic Study of 3D-CRT Hybrid VMAT in DIBH and Free Breathing Conditions, and VMAT in Free Breathing Conditions.

Aim: To investigate the impact of DIBH for heart sparing effect on left sided breast postoperative whole breast irradiation by comparing the dosimetric characteristics of 3D-CRT hybrid VMAT and pure VMAT treatment planning under DIBH condition. Materials and Methods: The primary CT data sets from previously treated left sided early breast cancer were used for pure volumetric arc therapy (VMAT) technique re-planning for the dosimetric characteristics comparison. A treatment plan of 3D-CRT hybrid VMAT technique was re-planned on the free breath (FB) condition for the investigation of the dosimetric characteristics comparison on DIBH condition. The prescribed dose for all the treatment plans was 42.5Gy in 16 fractions. All plans were optimized to cover 100% of the PTV by 95% of prescribed dose. The dosimetric differences among the 3 treatment plans for the 20 patients were analyzed using Wilcoxon signed-rank test, with p value<0.05 considered statistically significant. Results: 3D-CRT hybrid VMAT using DIBH technique yielded the best results on the conformity index (CI) and homogeneity index (HI). By comparing this 3D-CRT hybrid VMAT technique using FB and DIBH technique, the mean heart dose (MHD) was reduced from 5.38Gy to 1.65Gy, respectively (p =0.001) and the left anterior descending coronary artery (LAD)0.03cc dose was reduced from 27.87Gy to 9.41Gy, respectively (p =0.001). 3D-CRT hybrid VMAT using DIBH technique significantly reduced the V5, V20 and D mean of the ipsilateral lung and D mean of the contralateral lung. The D5 of right breast was significantly reduced by 3D-CRT hybrid VMAT compared with VMAT using DIBH technique. Conclusion: The incorporation of DIBH into 3D-CRT hybrid VMAT technique provides the best benefits for the heart and the OAR with respect to the radiation dose-sparing effect without compromising the target conformity and homogeneity in the treatment planning.

Preliminary outcomes of accelerated partial breast irradiation by interstitial multicatheter brachytherapy with intraoperative free-hand catheter implantation in early breast cancer.

BACKGROUND: To evaluate the clinical feasibility of interstitial brachytherapy by intraoperative free-hand catheter implantation in the treatment of early breast cancer after breast-conserving surgery (BCS). METHODS: Between January 2018 and December 2019, 44 patients with early breast cancer after BCS who met the inclusion criteria ≥45 years old, invasive carcinoma ≤3 cm or ductal carcinoma in situ <2.5 cm, estrogen receptor positive, lymph node negative, surgical margin negative, no distant metastasis, and an ECOG performance score ≤1 were enrolled in this phase II single-arm study. The postoperative irradiation field includes the tumor bed plus 2-cm margin in all directions, except in the anterior-posterior direction. The total prescribed tumor dose was 3400 cGy delivered in 10 fractions twice daily at 6-hour intervals. The primary endpoints were acute side effects, late treatment-related toxicity, and cosmetic outcome. The secondary endpoints were local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), distant metastasis-free survival (DMFS), and overall survival (OS). RESULTS: The median follow-up time was 33.5 months (mean, 32.9 months; range, 20-43 months). The cosmetic results were good to very good in 92.3% of the questionnaire respondents. The acute toxicities were mild, and no acute grade 3-4 toxicity was noted. Wound infection was noted in two patients (4.5%). There was only one event of regional lymph node recurrence in one patient. The 3-year LRFS, DMFS, and OS were 100%, and RRFS was 94.7%. For two patients who had a positive lymph node based on their final pathology reports, postoperative irradiation, including whole breast and regional lymph nodes, was added. CONCLUSION: Accelerated partial breast irradiation using interstitial brachytherapy with the intraoperative free-hand catheter implantation technique provides an alternative method of postoperative radiotherapy for selected patients with early breast cancer after BCS with acceptable toxicities.

The clinical outcome of postoperative radiotherapy using hybrid planning technique in left breast cancer after breast-conserving surgery.

BACKGROUND: The purpose of this study is to observe the preliminary clinical outcome and acute toxicity of hybrid intensity modulated radiotherapy and volumetric modulated arc therapy planning technique with simultaneous integrated boost (SIB). METHODS: From November 2015 to December 2018, 149 female patients with left-side breast cancer who underwent adjuvant radiotherapy with hybrid IMRT and VMAT planning technique with SIB were reviewed retrospectively. The primary endpoint was acute toxicities and the secondary endpoints were local recurrence-free survival (LRFS), distant metastasis-freesurvival (DMFS), disease-free survival (DFS), and overall survival (OS). RESULTS: The median age was 52 years old and median follow-up was 43.4 months. Eighty-six percent of patients had acute grade 0 to grade1 dermatitis and 14% had grade 2 dermatitis. No acute radiation pneumonitis, esophagitis, or cardiovascular events were recorded during follow-up. The 3-year LRFS, DMFS, DFS, and OS rates were 95.1%, 95.1%, 90.3%, and 97.9%, respectively. The subgroup analysis revealed that patients with lymphovascular invasion had more local recurrence rate and worse DFS rate. Patients with advanced N stage had the trend of worse DMFS. CONCLUSION: In conclusion, the hybrid IMRT and VMAT technique is feasible, safe and has less acute radiation related toxicities in SIB postoperative radiotherapy for left-sided breast cancer.

Y(OTf)3-catalyzed phosphorylation of 2H-chromene hemiacetals with P(O)-H compounds to 2-phosphorylated 2H-chromenes.

A facile synthesis of 2-phosphorylated 2H-chromenes has been accomplished herein via a Y(OTf)3-catalyzed dehydrative coupling of 2H-chromene hemiacetals with P(O)-H compounds. This protocol features low catalyst loading, mild reaction conditions, broad substrate scope and easy elaboration of the products.

Dosimetric characteristics of accelerated partial breast irradiation by interstitial multicatheter brachytherapy with intraoperative free-hand implantation in the treatment of early breast cancer.

INTRODUCTION: The aim of this study is to evaluate the characteristics of the dosimetry and the skin dose of interstitial brachytherapy by the use of the free-hand implantation technique toward the treatment of early breast cancer. MATERIALS & METHODS: Seventeen patients diagnosed with early breast cancer were selected for the study. The implantation of the catheters for postoperative interstitial brachytherapy was performed using the free-hand technique. The total tumor dose to the tumor cavity plus 2 cm margin was 3400 cGy, twice daily for 10 fractions in 5 days. The dosage to the target and the organ at risk (OAR) were recorded for analysis. The skin dose of the patient and the phantom were measured with Gafchromic film (EBT3) and the results were compared with the skin dose calculated by the brachytherapy treatment planning system. RESULTS: The median conformal index is 94% (range 89%-99%), and the median homogeneity index is 71%. The median skin dose measured from the skin of the patients was 20.1% lower than the skin dose calculated from the treatment planning system and consistent with the phantom surface measurement experiment. There were no grade 3 or above acute toxicity recorded. CONCLUSIONS: Interstitial brachytherapy by the use of the free-hand implantation technique for early breast cancer is feasible and avoids the need for a second surgical intervention. The calculated skin dose was overestimated by at least 20%. The results of this study may help in building a modification model for the prediction of skin toxicity in any future study.

Adjuvant whole breast radiotherapy with simultaneous integrated boost to tumor bed with intensity modulated radiotherapy technique in elderly breast cancer patients.

BACKGROUND: Adjuvant whole breast radiotherapy is the standard of care for breast cancer patients after partial mastectomy. Intensity-modulated radiation therapy (IMRT) has been reported to reduce acute toxicities compared to conventional radiotherapy. IMRT with simultaneous integrated boost (SIB) technique can deliver higher doses to tumor bed and irradiate whole breast with a lower dose level to shorten overall treatment duration. This study presents the long-term results of adjuvant IMRT with SIB in elderly breast cancer patients who received partial mastectomy. METHODS: From January 2007 to January 2018, 93 elder breast cancer patients (≥65-year-old) who received IMRT with SIB technique after partial mastectomy were reviewed retrospectively. The axillary areas were managed with either sentinel lymph node biopsies or axillary lymph node dissection. The dose to whole breast was 50.4 Gy in 28 fractions in all patients and the dose to tumor bed was 61.6 to 66.4 Gy in 28 fractions. The primary end point is locoregional control. Secondary end points include: overall survival, breast cancer-specific survival, distant-metastases-free survival, disease-free survival, and acute and chronic toxicities. RESULTS: The median follow-up was 56.1 months. One patient had ipsilateral breast tumor recurrence, 3 patients had regional lymph node recurrence, and 9 patients had distant metastases. Death occurred in 5 patients, including 3 patients died of breast cancer progression. Five-year overall survival is 96.3% and 5-year locoregional recurrence-free survival is 96.4%. The 5-year breast cancer specific survival and 5-year distant metastases-free survival is 97.5% and 87.2%, respectively. Seven patients developed second primary cancer after RT. Eighty-one point seven percent patients had acute grade 1 dermatitis while 18.3% suffered from grade 2 dermatitis. The incidence of grade 1 pneumonitis and grade 1 stomatitis was 4.3% and 8.6%, respectively. CONCLUSIONS: Adjuvant IMRT with SIB technique is a safe and effective treatment strategy for elderly breast cancer patients after partial mastectomy.

Synthesis of photo-excited Chlorin e6 conjugated silica nanoparticles for enhanced anti-bacterial efficiency to overcome methicillin-resistant Staphylococcus aureus.

Multidrug resistant bacterial infection remains a significant public concern. In this report, photosensitizer Chlorin e6 doped silica was synthesized. This hybrid structure exhibits enhanced photostability and high antibacterial efficiency towards Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA). In summary, this work demonstrates an effective platform to improve the efficiency of antibiotics for better treatment of wound infections.

Dosimetric comparison of hybrid volumetric-modulated arc therapy, volumetric-modulated arc therapy, and intensity-modulated radiation therapy for left-sided early breast cancer.

To compare the dosimetric performance of 3 different treatment techniques: hybrid volumetric-modulated arc therapy (hybrid-VMAT), pure-VMAT, and fixed-field intensity-modulated radiation therapy (F-IMRT) for whole-breast irradiation of left-sided early breast cancer. The hybrid-VMAT treatment technique and 2 other treatment techniques­pure-VMAT and F-IMRT­were compared retrospectively in 10 patients with left-sided early breast cancer. The treatment plans of these patients were replanned using the same contours based on the original computed tomography (CT) data sets. Dosimetric parameters were calculated to evaluate plan quality. Total monitor units (MUs) and delivery time were also recorded and evaluated. The hybrid-VMAT plan generated the best results in dose coverage of the target and the dose uniformity inside the target (p < 0.0001 for conformal index [CI]; p = 0.0002 for homogeneity index [HI] of planning target volume [PTV](50.4 Gy) and p < 0.0001 for HI of PTV(62 Gy)). Volumes of ipsilateral lung irradiated to doses of 20 Gy (V(20 Gy)) and 5 Gy (V(5 Gy)) by the hybrid-VMAT plan were significantly less than those of the F-IMRT and the pure-VMAT plans. The volume of ipsilateral lung irradiated to a dose of 5 Gy was significantly less using the hybrid-VMAT plan than that using the F-IMRT or the pure-VMAT plan. The total mean MUs for the hybrid-VMAT plan were significantly less than those for the F-IMRT or the pure-VMAT plan. The mean machine delivery time was 3.23 ± 0.29 minutes for the hybrid-VMAT plans, which is longer than that for the pure-VMAT plans but shorter than that for the F-IMRT plans. The hybrid-VMAT plan is feasible for whole-breast irradiation of left-sided early breast cancer.

Preoperative chemoradiotherapy with oxaliplatin and tegafur-uracil in locally advanced rectal cancer: pathologic complete response rate and preliminary results of overall and disease-free survival in a single institute in Taiwan.

BACKGROUND: We conducted a Phase II study of biweekly oxaliplatin plus oral tegafur-uracil in the preoperative chemoradiotherapy (CRT) for locally advanced resectable mid-to-lower rectal cancer in our hospital, to evaluate the feasibility of this drug combination in tumor pathologic response, acute toxicity, local control, disease-free survival (DFS), overall survival (OS), and time to distant metastasis in an Asian cohort. METHODS: Twenty patients with histopathologically confirmed rectal cancer (Stage II-III) were enrolled in the study. Radiotherapy of 50 Gy was delivered in 25 fractions of 2 Gy, one fraction/day, five fractions/week, for 5 weeks. Oxaliplatin 55 mg/m(2) was administered intravenously for 60 minutes on Day 1 every 2 weeks, and tegafur-uracil 350 mg/m(2) was given orally everyday during the whole radiotherapy course, including holidays. Surgery was scheduled 6 weeks after completion of the preoperative chemoradiotherapy. The primary endpoint was to determine the pathologic complete response (pCR) rate after this neoadjuvant chemoradiotherapy. The secondary endpoint was to determine the treatment-related toxicity profile, local control, DFS, OS, and time to metastasis. RESULTS: All patients underwent a complete course of preoperative chemoradiotherapy. There was no local recurrence during the study period. The complete resection rate was 20/20 (100%) and the close resection margin rate was 3/20 (15%). The pCR rate was 8/20 (40%). During chemoradiotherapy, the most frequent toxicity was diarrhea 9/20 (45% of patients, grade 2 in 3/20, 15%). There were no grade 3 or higher hematologic or non-hematologic events or treatment-related deaths. The 3-year OS and DFS rates were 94.1% and 78.6%, respectively. CONCLUSION: Preoperative chemoradiotherapy with oxaliplatin and tegafur-uracil was well-tolerated and achieved an excellent pCR in our patients with locally advanced mid-to-lower rectal cancer.

Total body irradiation with step translation and dynamic field matching.

The purpose of this study is to develop a total body irradiation technique that does not require additional devices or sophisticated processes to overcome the space limitation of a small treatment room. The technique aims to deliver a uniform dose to the entire body while keeping the lung dose within the tolerance level. The technique treats the patient lying on the floor anteriorly and posteriorly. For each AP/PA treatment, two complementary fields with dynamic field edges are matched over an overlapped region defined by the marks on the body surface. A compensator, a spoiler, and lung shielding blocks were used during the treatment. Moreover, electron beams were used to further boost the chest wall around the lungs. The technique was validated in a RANDO phantom using GAFCHROMIC films. Dose ratios at different body sites along the midline ranged from 0.945 to 1.076. The dose variation in the AP direction ranged from 96.0% to 104.6%. The dose distribution in the overlapped region ranged from 98.5% to 102.8%. Lateral dose profiles at abdomen and head revealed 109.8% and 111.7% high doses, respectively, at the body edges. The results confirmed that the technique is capable of delivering a uniform dose distribution to the midline of the body in a small treatment room while keeping the lung dose within the tolerance level.