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Abstract In patients with abdominal or pelvic tumors, radiotherapy can result in radiation-induced intestinal injury (RIII), a potentially severe complication for which there are few effective therapeutic options. Sitagliptin (SI) is an oral hypoglycemic drug that exhibits antiapoptotic, antioxidant, and anti-inflammatory activity, but how it influences RIII-associated outcomes has yet to be established. In this study, a pH-responsive metal-organic framework-based nanoparticle platform was developed for the delivery of SI (SI@ZIF-8@MS NP). These NPs incorporated mPEG-b-PLLA (MS) as an agent capable of resisting the effects of gastric acid, and are capable of releasing Zn2+ ions. MS was able to effectively shield these SI@ZIF-8 NPs from rapid degradation when exposed to an acidic environment, enabling the subsequent release of SI and Zn2+ within the intestinal fluid. Notably, SI@ZIF-8@MS treatment was able to mitigate radiation-induced intestinal dysbiosis in these mice. restored radiation-induced changes in bacterial composition. In summary, these data demonstrate the ability of SI@ZIF-8@MS to protect against WAI-induced intestinal damage in mice, suggesting that these NPs represent a multimodal targeted therapy that can effectively be used in the prevention or treatment of RIII.

In patients with abdominal or pelvic tumors, radiotherapy can result in radiation-induced intestinal injury (RIII), a potentially severe complication for which there are few effective therapeutic options. Sitagliptin (SI) is an oral hypoglycemic drug that exhibits antiapoptotic, antioxidant, and anti-inflammatory activity, but how it influences RIII-associated outcomes has yet to be established. In this study, a pH-responsive metal-organic framework-based nanoparticle platform was developed for the delivery of SI (SI@ZIF-8@MS NP). These NPs incorporated mPEG-b-PLLA (MS) as an agent capable of resisting the effects of gastric acid, and are capable of releasing Zn2+ ions. MS was able to effectively shield these SI@ZIF-8 NPs from rapid degradation when exposed to an acidic environment, enabling the subsequent release of SI and Zn2+ within the intestinal fluid. Notably, SI@ZIF-8@MS treatment was able to mitigate radiation-induced intestinal dysbiosis in these mice. restored radiation-induced changes in bacterial composition. In summary, these data demonstrate the ability of SI@ZIF-8@MS to protect against WAI-induced intestinal damage in mice, suggesting that these NPs represent a multimodal targeted therapy that can effectively be used in the prevention or treatment of RIII. [ABSTRACT FROM AUTHOR]

Background: Helical Tomotherapy (HT) has unique capacities for the radiotherapy of large and complicated target volumes. Next generation Dynamic Jaw/Dynamic Couch HT delivery promises faster treatments and reduced exposure of organs at risk due to a reduced dose penumbra. Methods: Three challenging clinical situations were chosen for comparison between Regular HT delivery with a field width of 2.5 cm (Reg 2.5) and 5.0 cm (Reg 5.0) and DJDC delivery with a maximum field width of 5.0 cm (DJDC 5.0): Hemithoracic Irradiation, Whole Abdominal Irradiation (WAI) and Total Marrow Irradiation (TMI). For each setting, five CT data sets were chosen, and target coverage, conformity, integral dose, dose exposure of organs at risk (OAR) and treatment time were calculated. Results: Both Reg 5.0 and DJDC 5.0 achieved a substantial reduction in treatment time while maintaining similar dose coverage. Treatment time could be reduced from 10:57 min to 3:42 min / 5:10 min (Reg 5.0 / DJDC 5.0) for Hemithoracic Irradiation, from 18:03 min to 8:02 min / 8:03 min for WAI and to 18:25 min / 18:03 min for TMI. In Hemithoracic Irradiation, OAR exposure was identical in all modalities. For WAI, Reg 2.5 resulted in lower exposure of liver and bone. DJDC plans showed a small but significant increase of ∼ 1 Gy to the kidneys, the parotid glans and the thyroid gland. While Reg 5.0 and DJDC were identical in terms of OAR exposure, integral dose was substantially lower with DJDC, caused by a smaller dose penumbra. Conclusions: Although not clinically available yet, next generation DJDC HT technique is efficient in improving the treatment time while maintaining comparable plan quality. [ABSTRACT FROM AUTHOR]

: PurposeTo evaluate the role of high-dose whole abdominal and pelvic irradiation (WART) in the treatment of epithelial ovarian carcinoma.: Methods and materialsA retrospective review was performed on 71 patients with Stage I–III ovarian carcinoma who were treated with WART using an open field technique after total abdominal hysterectomy and bilateral oophorectomy with or without omentectomy. Whole abdominal doses greater than typically recommended were used in a series of patients to enhance local control and to decrease abdominal recurrence. None of the patients had received chemotherapy before RT. Thirty-one patients received Alkeran or cyclophosphamide and two received cisplatin-based chemotherapy after WART. The median whole abdominal dose was 36 Gy (range 9–45.5), delivered in a median of 30 fractions (range 8–46). A pelvic boost was delivered using AP–PA fields during whole abdominal RT to a total midline pelvic dose of 200 cGy/d. The median pelvic dose was 51 Gy (range 16–59). The right lobe and a portion of the left lobe of the liver were shielded with custom blocks at a median dose of 25 Gy (range 9–41). The kidneys were shielded either AP–PA or PA from the first day of RT. The median dose to the kidneys was 19 Gy (range 4–30).: ResultsThe 5-year overall survival rate was 93%, 48%, and 29% for Stage I, II, and III patients, respectively. On multivariate analysis, stage and the extent of residual disease were independent prognostic factors. The 5- and 10-year overall survival rate for the 46 patients in the intermediate-risk group was 61% and 54%, respectively. For this group, a total abdominal dose of ≥36 Gy was associated with a longer overall survival independent of stage, grade, and the amount of residual disease. This was most likely due to a significant reduction in the incidence of abdominal recurrence in patients receiving >36 Gy to the whole abdomen (18% vs. 49%, p = 0.006). Multivariate analysis revealed that grade (p = 0.023) and abdominal dose (p = 0.018) were independent factors influencing the rate of abdominal recurrence. Pelvic recurrence was rare as a first site of failure (6%). Twenty-one percent (n = 15) of the patients developed Grade 3 or 4 (Radiation Therapy Oncology Group [RTOG] criteria) chronic small or large bowel toxicity. Eleven percent of all patients had a small bowel obstruction requiring surgery. A whole abdominal dose >30 Gy and a pelvic dose >50 Gy were associated with a significant increase in small bowel obstruction (p = 0.01) independent of other factors. Chronic Grade 3 or 4 (Common Toxicity Criteria) anemia, thrombocytopenia, and leukopenia were seen in 7%, 1%, and 4% of the patients, respectively. Transient liver enzyme elevation was common (62%). Two patients had Grade 3 (RTOG) hepatic toxicity. Grade 3 or 4 renal toxicity (RTOG) was observed in 4%, and 2 patients (3%) were diagnosed with pelvic insufficiency fractures that were managed conservatively.: ConclusionSurvival after RT for ovarian carcinoma rivals that achieved with systemic chemotherapy. The results of this study suggest a possible dose–control relationship between the whole abdominal dose and the risk of abdominal recurrence; however, a higher rate of small bowel obstruction was observed when greater abdominal doses and greater pelvic doses were combined. Careful attention to balancing toxicity and efficacy is imperative if RT is to have a future role in the treatment of this disease. [Copyright &y& Elsevier]

Purpose: To reexamine the use of adjuvant radiotherapy in optimally debulked patients.Methods and Materials: Between January 1985 and April 1998, 60 patients were treated with adjuvant whole abdominal radiotherapy (A-WART). The stage distribution was Stage IC in 17 patients, Stage II in 9, and Stage III in 34. The grade distribution was Grade 1 in 9 patients, Grade 2 in 27, and Grade 3 in 24; thus, 60% of the patients had Stage III disease and 40% had Grade 3 tumors. After surgery, no residuum was left in 42 (70%), ≤2 cm in 13 (22%), and >2 cm in 5 (8%) of 60 patients. Of the 60 patients, 19 also received platinum-based chemotherapy; in 12 of the 19, the chemotherapy was before A-WART. Thirty-seven of the patients had undergone previous abdominal procedures and a second-look operation was performed in 25% of them. A-WART consisted of 22 Gy in 22 fractions, at 5 fractions weekly in 90% of the patients. The remaining 10% received 25 Gy in 25 fractions within 5 weeks. The A-WART was delivered using a 4-MV linear accelerator. After abdominal irradiation, a boost to the pelvis was given to reach 45 Gy at 1.8 cGy/fraction, using a 4–15-MV linear accelerator.Results: Treatment was delivered in a median of 50 days (range 48–70). In 12 (20%) of the 60 patients, a transient treatment interruption occurred because of acute toxicity, mainly vomiting and diarrhea. The overall survival rate was 55% at 5 years (median follow-up 96.5 months). Patients with low-histologic grade tumors (Grade 1-2) had a better 5-year survival rate (66%) than those with Grade 3 tumors (35%; p <0.03). A tendency for better survival was found for those with Stage I-II than for those with Stage III (69% vs. 43%). Nonetheless, this difference did not reach statistical significance (p = 0.17). For patients receiving chemotherapy, the 5-year survival rate was 51%, not statistically different from the 58% 5-year survival rate observed among those patients without adjuvant chemotherapy (p = 0.9). The abdominal control rate was 83%. Thirty-five percent of the patients sustained acute Grade 2-3 complications. Late complications were observed in 6 of 60 patients, 4 had Grade 3 (7%) and 2 had Grade 4 (3%). Two patients died of intestinal occlusion, both had undergone previous abdominal procedures and in 1, no tumor was found in the abdomen at the postmortem examination.Conclusion: A-WART achieves a quite favorable 5-year survival rate with a low complication rate in properly selected patients. A-WART should be included in the elective postoperative treatment of ovarian cancer patients who are at risk of abdominal failure, and this should be explored in a randomized trial. [Copyright &y& Elsevier]