Research progress on automatic treatment planning methods for radiotherapy / 中华放射肿瘤学杂志

The design of a conventional radiotherapy plan is a time-consuming and labor-intensive process, and relevant parameters need to be continuously adjusted in the plan optimization to identify the optimal plan. In addition, experience differences between planners, time invested in plan design, and institutional standards all affect the quality of the plan, which in turn influences clinical outcomes and patient prognosis. In recent years, automatic planning has developed rapidly, which can improve the efficiency of planning design while ensuring the quality of the plan. At present, there are several methods dedicated to the automation of radiotherapy planning design, such as the Rapid Plan and Auto-Planning functions in Eclipse and Pinnacle commercial treatment planning systems, and there are also studies applying artificial intelligence technology in dose prediction to achieve automatic planning. In this article, the research progress on automatic radiotherapy planning was reviewed, and the realization principles, clinical efficacy and existing problems of various automatic planning methods were illustrated.

The feasibility study of generalization of knowledge-based planning for cervical cancer / 中华放射医学与防护杂志

Objective:To design a knowledge-based cervical cancer planning model and apply it to cases of endometrial cancer and rectal cancer in order to explore the generalization of the model.Methods:A total of 179 cases of pelvic regions with different prescribed doses of dual-arc volumetric modulated arc therapy clinical plans were collected, of which 99 cases of cervical cancer clinical plans with a prescribed dose of 50.4 Gy were used as the training set to establish the RapidPlan model, and the remaining clinical plans were divided into 4 validation groups with 20 cases in each group. The clinical plans for cervical cancer and endometrial cancer with a prescription dose of 50.4 Gy were named groups A and B, while the clinical plan for endometrial cancer and rectal cancer with a prescription dose of 45 Gy were named groups C and D. The model was used to redesign the clinical plans in the 4 groups and the automatic plans were obtained. The planning target volume (PTV) and organ at risk (OAR) dosimetry parameters were compared between automatic plans and clinical plans.Results:The conformity index (CI) of the automatic plans in the A, B, C, and D groups were equivalent to that of the clinical plans ( P>0.05). The homogeneity index (HI) and D2% of the automatic plans in groups A, B, and C were all lower than those in clinical plans(HI, Z=-3.248, -3.360, -2.329, P<0.05; D2%, Z=-2.987, -3.397, -2.442, P<0.05). The HI and D2% of the automatic plans in group D were similar those in the clinical plans ( P>0.05). While ensuring the PTV coverage, the average value of OAR dosimetry parameters in all automatic plans groups were lower than that of the clinical plans. Conclusions:The RapidPlan model established by the cervical cancer clinical plans can complete the automatic plan design for endometrial cancer and rectal cancer under different prescription doses, which preliminarily proves the possibility of the generalization of the RapidPlan model.

Application of Vacuum sealing drainage in full-thickness skin grafts / 中国组织工程研究

BACKGROUND: Full-thickness skin graft was a base for bum and plastic surgery, while uniform pressure and regional brake were key factors to ensure skin graft survival and avoid from necrosis. Traditionally, package and pressurized fixation were performed after skin transplantation; however, it induced residual dead space and unclear skin graft fixation, as well as suturing scar.OBJECTIVE: To study the effect of vacuum sealing drainage applied to full-thickness skin graft.METHODS: A total of 8 New Zealand rabbits were used to establish full-thickness skin graft models in three regions of bilateral spine. Vacuum sealing drainage, traditional pressurized suture and common wrapping were performed in the three regions, respectively. The skin graft survival was observed, and survival rate was calculated at 14 and 21 days. On the 3rd, 7th, and 14th days, samples were selected from skin graft and stained. The morphology was observed under light microscope and transmission electron microscope. The time to remove the drain vessel was that when the fluid was not increased or the fluid was clear.RESULTS AND CONCLUSION: The survival rate of vacuum sealing drainage group was significantly higher than that in other two group (P < 0.05), while the survival rate of traditional pressurized suture group was significantly higher than that in the common wrapping group (P< 0.05). Morphology examination demonstrated that regional cuticular layer was necrotic in the vacuum sealing drainage group after early skin transplantation, while inflammatory cell infiltration, fibroblast degeneration, and mitochondrial swelling were also observed. At later skin transplantation, fibroblast and basal cell were proliferated, and function of mitochondria and plasmid was active. This suggested that vacuum sealing drainage promoted survival rate of skin graft.

Expanded prefabricated flaps of femoral artery and vein: an experimental study / 中华医学美学美容杂志

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.

Plastic surgery of neurofibroma / 中华医学美学美容杂志

Objective To study the reconstructive treatment of the different types of neurofibroma and neurofibromatosis in different locations. Methods 37 patients with neurobibroma or neurofibromatosis were reviewed, including 8 cases with simple suture after excision, 9 cases with skin grafting in situ, 12 cases with skin flap grafting. The main points of the treating methods for different types of neurofibroma and neurofibromatosis were discussed, and the chief clinical manifestations, therapeutic principle and notices of the operation were then summarized.Results These 37 patients, including 25 cases of neurofibroma, 11 cases of neurofibromatosis typeⅠ and 1 case of neurofibromatosis type Ⅱ, were satisfied with the results after reconstructive operation. Conclusion The methods of reconstructive operation of neurofibroma and neurofibromatosis, such as simple suture after excision, skin grafting in situ, skin flap grafting, the use of skin soft tissue expansion, microskin grafting and so on, must be selected according to the different type and location of the neurofibroma and neurofibromatosis. The reconstructive operation must guarantee the best recovery of the visage and the function on the basis of the most degree of tumor excision.