Nasopharyngeal carcinoma is one of the most common head and neck tumors. At present, intensity modulated radiation therapy (IMRT) is the main radical treatment. In recent years, adaptive radiation therapy (ART) becomes the focus in the research field of precision radiotherapy. ART can reduce the target conformal and dose changes and increase the dose of exposed organs caused by factors such as weight loss, positioning error, systematic error, and anatomical changes of lesions and organs at risk, thus improving the effectiveness and safety of intensity modulated radiotherapy. This article focuses on and summarizes the recent progress in the application of ART in nasopharyngeal carcinoma, and puts forward the possible research direction in the future.

Objective:To investigate the feasibility of individualized primary clinical target volume (CTV) delineation in intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC).Methods:Clinical data of 87 consecutive patients newly diagnosed with lateralized NPC in Jiangsu Cancer Hospital between October 2016 and February 2018 were retrospectively analyzed. Lateralized NPC is defined as tumor invasion not exceeding the contralateral wall. According to the tumor spread, the primary CTV was optimized as follows: CTV2 only covered the medial part of the contralateral pterygopalatine fossa, whereas the contralateral foramen oval was not included; on the level of parapharyngeal space, the contralateral side of CTV only covered the posterior lateral lymph nodes, whereas the contralateral internal jugular vein was not regularly covered. Failure patterns and 5-year survival [local control rate (LCR), progression-free survival (PFS) and overall survival (OS)] were evaluated by Kaplan-Meier method. Paired t-test and rank-sum test were used to analyze the dose variation in the optimized region and adverse reactions. Results:The median follow-up time was 59.5 months. The 5-year LCR, PFS, and OS were 98.9%, 86.5% and 92.1%, respectively. There was no local recurrence in the optimized area of CTV. Dosimetric comparison results showed that the doses of parotid gland, temporal lobe, cochlea and middle ear on the contralateral side were reduced by 13.45%, 9.14%, 38.83%, and 29.36%, respectively. Four cases (4.6%) developed grade 3 hearing loss, all on the ipsilateral side. The optimized scheme significantly alleviated the hearing loss on the contralateral side compared to that on the ipsilateral side ( P<0.001). Other grade 3 late adverse reactions included cranial nerve injury, subcutaneous fibrosis in the neck and visual impairment, with 1 case each. Conclusion:Individualized primary CTV for lateralized NPC is feasible and safe, with obvious dosimetric advantages and reduced adverse reaction rate, which is worthy of clinical promotion.

Objective:To design a method to introduce random six-dimensional setup error (6D-SE) into the intensity-modulated radiotherapy (IMRT) planning for rectal cancer and evaluate its dosimetric effect.Methods:A total of 21 IMRT plans for patients with rectal cancer were randomly selected as reference plans [2 Gy per fraction for a total of 50 Gy; a 5 mm uniform margin around the clinical target volume (CTV) was taken as the planning target volume (PTV)]. For each fraction of the reference plan, a randomly generated 6D-SE was introduced by adjusting the geometrical parameters of the radiation field, and the dose was recalculated. The overall dose distribution with 6D-SE was obtained by adding up the dose of each fraction. A treatment simulation program that could complete the above workflow was developed using the Varian Eclipse scripting API (ESAPI). 6D-SEs that obey two preset distributions [distribution 1: translational error obey N(0, 4 2), and rotational error obey N(0, 2 2); distribution 2: translational error obey N(0, 2 2), and rotational error obey N(0, 1 2)] were introduced into the reference plans, and the dosimetric effects were assessed. Results:When the reference plans, error distribution 1, and error distribution 2 were applied, the Dmin values of the CTV were (49.4±0.41), (47.56±0.76), and (49.17±0.64) Gy, respectively; the D98% values of the CTV were (50.23±0.07), (49.98±0.10), and (50.27±0.09) Gy, respectively; the D98% values of the primary target area (the kernel part of the target area, excluding the margins) were (50.25±0.08), (50.42±0.13), and (50.33±0.10) Gy, respectively; the D98% values of the marginal area were (50.22±0.10), (49.88±0.11), and (50.26±0.10) Gy, respectively. In addition, compared with the result of the reference plans, the result of errors 1 and 2 showed no significant changes in the mean dose of the bladder and femoral heads ( P>0.05), despite slight decreases in the conformity index of the dose distribution with limited clinical significance. Conclusion:The proposed method and the treatment simulation program developed thereupon can introduce the 6D-SE obeying different distributions into the IMRT plans for rectal cancer on demand and provide overall dosimetric changes.

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 compare the dosimetric difference between IMRT and VMAT plans for ovarian protection after cervical cancer ovarian transposition surgery.Methods:Thirty-one patients who had received both cervical cancer resection and ovarian transposition were selected for adjuvant radiotherapy. The 9-field evenly divided IMRT and the dual-arc VMAT technology were performed for the treatment planning. The difference of the ovarian mean dose between the two techniques was explored. The relationship between the position of the ovarian-target interval and the ovarian dose was also analyzed.Results:A total of 54 ovaries in 31 patients were effectively transposed and moved out of the target area. Among them, 9 ovaries were located above the upper boundary of the PTV. For these cases, the ovarian mean dose of IMRT and VMAT were (177.8±90.7) and (166.7±70.6) cGy, respectively, which was not statistically different( P>0.05).45 ovaries were located in the same level with PTV. For these cases, the ovarian mean dose of IMRT and VMAT were (459.1±239.9) and (428.3±238.2) cGy, respectively ( z=3.11, P=0.002). The ovarian mean dose has the highest correlation and negative correlation with the closest lateral distance from the ovarian volume center to the PTV surface (IMRT, r=-0.922, P=0.001; VMAT, r=-0.865, P=0.001). To reduce the ovarian mean dose to 500 cGy, the lateral closest distance between the ovarian volume center and the PTV surface should be 3.6 cm and 3.3 cm for IMRT and VMAT respectively. Conclusions:There is no difference between the two planned ovarian doses when the ovaries were located above the upper boundary of the PTV. When the ovaries were located in the same level with PTV, the VMAT plan is better than IMRT in both ovarian dose and treatment efficiency. The ovarian dose could be predicted by the lateral closest distance from the ovarian volume center to the PTV.

The motion of the tumor limits further improvement in the accuracy of radiotherapy. Real-time monitoring and tracking of tumor location is an emerging technology to improve the accuracy of tumor radiotherapy. According to the adopted methods, it can be broadly divided into non-radiation-based and radiation-based systems. The former system includes ultrasound guidance, nuclear magnetic resonance guidance, electromagnetic tracking, optical image guidance, artificial intelligence-based technologies, and the latter system consists of KV, MV-grade X-ray imaging system and CT-based guidance system. In this review, research progresses on real-time tumor monitoring and tracking technology in radiotherapy, respective advantages and disadvantages and current clinical application were summarized.

Objective:To evaluate the effect of leaf position error of Varian high-definition multi-leaf collimator (HD120) on the dosimetry of stereotactic body radiation therapy (SBRT) for lung tumors.Methods:Nine SBRT plans based on HD120 for lung tumors were selected as the reference plans. The parameters of the plans were modified by the in-house program based on the Varian Eclipse 15.6 scripting application program interface to generate the simulation plans with three types of leaf position errors including the isotropic systematic error, the anisotropic systematic error and the random error, respectively. Then, the dosimetric metric deviation between each simulation plan and the corresponding reference plan was calculated and regression analysis was performed to evaluate the dosimetric effect of three types of leaf position errors of HD120 on SBRT.Results:The planning target volume (PTV) D 99%, D 2cm and V 5Gy of double lungs were decreased quadraticly with the increase of the absolute value of the isotropic systematic error. The first-order sensitivity was -0.06%/mm to -0.26%/mm, and the second-order sensitivity was -0.55%/mm 2 to -1.17%/mm 2 ( R2=0.96-0.99, P<0.01). The maximum change of PTV D 99% was -3.13%. The linear regression analysis of the effects of the anisotropic systematic error and random error showed that the sensitivity of CI was 25.16%/mm ( R2=0.98, P<0.01) and -4.84%/mm( R2=0.99, P<0.01), and the sensitivity of other dosimetric deviations with the anisotropic systematic error was 4.80%/mm to 5.12%/mm ( R2=0.96-0.98, P<0.01), whereas the sensitivity with the random error was -0.47%/mm to -1.01%/mm ( R2=0.96-0.99, P=0-0.02). Conclusions:The dosimetric deviation of SBRT plan based on HD120 for lung cancer is highly sensitive to the anisotropic systematic error of leaf position, but less sensitive to the random error. In addition, the isotropic systematic error of leaf position will lead to the decrease of target coverage to a certain extent. Consequently, it is necessary to strictly control the systematic error of HD120 leaf position in the implementation of SBRT plan in clinical work.

Objective:To investigate the effect and reasonable strategy of shuffling fat in the treatment of eyelid stick-bone scar cicatricial depression and atrophy.Methods:A retrospective analysis consisted of patients admitted in Plastic Surgery Hospital, CAMS from March 2017 to May 2019, and the inclusion criteria was depressive and atrophic deformities caused by eyelid stick-bone scar. By performing subcutaneous liposuction on the abdomen, the harvested fat was further mechanically refined into shuffling fat. Single serialized shuffling fat injection with a 3-month interval was performed in the orbital region. Approximately 3 months after fat transplantation, symptomatic treatment was performed due to complications of upper eyelid ptosis or ectopic, and fat injection combined with the orbicularis oculi muscle flap was carried out to repair the lower eyelid atrophic deformity. Follow up regularly after the operation to observe the occurrence of complications. Six months after the end of treatment, the patient and observer scar assessment scale (POSAS) was used to assess scars, and the doctor-patient comprehensive score was used to assess patient satisfaction.Results:A total of 6 patients with stick-bone scar in the eyelid area were enrolled including 4 males and 2 females, aged 24-53 years old, with an average of 37 years old. The causes of defects included 4 cases of trauma, 2 cases after maxillary osteomyelitis treatment. Duration of disease ranged 1.5-50.0 years, average 14.2 years. Scars were located in the regions of upper eyelid in 4 cases and lower eyelid in 2 cases. Area of depressed region ranged 0.5 cm×2.0 cm-1.5 cm×3.0 cm. After mechanical refinement, the fat texture was more delicate and even. Injection of shuffling fat with the single volume of 0.6 to 1.3 ml was performed 3 to 4 times (average 3.25 times) on the upper eyelid and average 2 times on the lower eyelid, respectively. During the post-operative 6 months, the appearance of all patients was significantly improved, the volume of soft tissues of the eyelid was significantly increased, the pliability and elasticity of the scar tissue was ameliorated, and no complications occurred. The scores of patient scar assessment scale (PSAS) and observer scar assessment scale (OSAS) were (7.0±1.0) and (6.7±1.1), respectively, and the doctor-patient comprehensive score was 4-5 (average 4.5).Conclusions:For upper eyelid, shuffling fat injection has a good therapeutic effect on depressive and atrophic deformity caused by the stick-bone scar by increasing the tissue volume; for lower eyelid, it is necessary to combine the orbicularis oculi myocutaneous flap on the basis of shuffling fat transplantation to further increase the support structure for better appearance.

Objective:To investigate the effect and reasonable strategy of shuffling fat in the treatment of eyelid stick-bone scar cicatricial depression and atrophy.Methods:A retrospective analysis consisted of patients admitted in Plastic Surgery Hospital, CAMS from March 2017 to May 2019, and the inclusion criteria was depressive and atrophic deformities caused by eyelid stick-bone scar. By performing subcutaneous liposuction on the abdomen, the harvested fat was further mechanically refined into shuffling fat. Single serialized shuffling fat injection with a 3-month interval was performed in the orbital region. Approximately 3 months after fat transplantation, symptomatic treatment was performed due to complications of upper eyelid ptosis or ectopic, and fat injection combined with the orbicularis oculi muscle flap was carried out to repair the lower eyelid atrophic deformity. Follow up regularly after the operation to observe the occurrence of complications. Six months after the end of treatment, the patient and observer scar assessment scale (POSAS) was used to assess scars, and the doctor-patient comprehensive score was used to assess patient satisfaction.Results:A total of 6 patients with stick-bone scar in the eyelid area were enrolled including 4 males and 2 females, aged 24-53 years old, with an average of 37 years old. The causes of defects included 4 cases of trauma, 2 cases after maxillary osteomyelitis treatment. Duration of disease ranged 1.5-50.0 years, average 14.2 years. Scars were located in the regions of upper eyelid in 4 cases and lower eyelid in 2 cases. Area of depressed region ranged 0.5 cm×2.0 cm-1.5 cm×3.0 cm. After mechanical refinement, the fat texture was more delicate and even. Injection of shuffling fat with the single volume of 0.6 to 1.3 ml was performed 3 to 4 times (average 3.25 times) on the upper eyelid and average 2 times on the lower eyelid, respectively. During the post-operative 6 months, the appearance of all patients was significantly improved, the volume of soft tissues of the eyelid was significantly increased, the pliability and elasticity of the scar tissue was ameliorated, and no complications occurred. The scores of patient scar assessment scale (PSAS) and observer scar assessment scale (OSAS) were (7.0±1.0) and (6.7±1.1), respectively, and the doctor-patient comprehensive score was 4-5 (average 4.5).Conclusions:For upper eyelid, shuffling fat injection has a good therapeutic effect on depressive and atrophic deformity caused by the stick-bone scar by increasing the tissue volume; for lower eyelid, it is necessary to combine the orbicularis oculi myocutaneous flap on the basis of shuffling fat transplantation to further increase the support structure for better appearance.

Objective:To analyze the effect and safety of levonorgestrel-releasing intrauterine system(LNG-IUS) for the premenopausal patients with breast cancer who took tamoxifen as adjuvant therapy.Methods:From June 2014 to June 2016, 84 patients with breast cancer who met the inclusion criteria in the First People′s Hospital of Xiaoshan District were randomly divided into two groups according to the digital table.The treatment group (39 cases) underwent LNG-IUS insertion, while the control group (45 cases) received no LNG-IUS insertion.The general condition of patients before the use of tamoxifen and LNG-IUS was evaluated.Transvaginal ultrasound was used to measure the thickness of endometrium, hysteroscope was used for pathological examination of endometrium and the measurement of ER/PR expression, and blood lipid level was also detected.All above was done before the treatment of tamoxifen and LNG-IUS, 1 year after treatment and 2 years after treatment.Results:Before the therapy, there were no statistically significant differences between the two groups in general condition and uterine cavity condition(all P>0.05). After 1 year, the incidences of endometrial polyp, endometrial hyperplasia/secretion, benign lesion and endometrial atrophy in the treatment group were 2.6%, 5.1%, 15.4%, 76.9%, respectively, which in the control group were 6.7%, 20.0%, 17.8%, 55.6%, respectively.the differences between the two groups were statistically significant(χ 2=4.06, 4.22, all P<0.05). After 2 years, the incidences of endometrial polyp, endometrial hyperplasia/secretion, benign lesion and endometrial atrophy in the treatment group were 0.0%, 2.6%, 84.6%, respectively, which in the control group were 11.1%, 15.6%, 60.0%, respectively, the differences between the two groups were statistically significant(χ 2=4.608, 4.092, 6.203, all P<0.05). Conclusion:LNG-IUS can prevent the benign endometrial lesions of breast cancer patients caused by tamoxifen therapy after surgery, and can decrease the incidence of endometrial polyp and endometrial hyperplasia/secretion, while increase the incidence of endometrial atrophy, without increasing the recurrence risk of breast cancer.