ABSTRACT
Objective To explore the feasibility of 3D printed individualized applicator for the intracavitary HDR-brachytherapy for nasopharyngeal carcinoma.Methods CT scan was performed in 1 case of recurrent rT1 nasopharyngeal carcinoma and 1 case of T2 residual nasopharyngeal carcinoma and the obtained images were transmitted to 3D image processing software.The geometric contour parameters of the nasopharyngeal cavity were obtained and a pipeline was designed to make it close to the recurrent gross tumor volume (rGTV).Individualized cavity applicators were created by using 3D printer.The applicator was inserted into the patient's nasopharyngeal cavity through oral cavity.The source tube and false source were inserted into the preset pipe of the applicator.CT scan was performed again and the images were transmitted to the 3D brachytherapy planning system.Mter delineating the target volume and organ at risk,treatment plan was optimized.After completing the first treatment,the applicator was removed.Before second treatment in a few days,CT scan was reviewed to confirm whether the position was correct.Results When the applicator was inserted into the nasopharyngeal cavity,it could be fully aligned with the nasopharyngeal wall and self-fixed without additional fixation measures.Comparing the location of false source in multiple reviews of CT scan,the error was ≤ 1 mm.No significant discomfort was reported throughout the treatment.In optimized three-dimensional treatment,100％ prescription dose curve included the full rGTV,maximum dose of the brain stem and spinal cord was＜30％ prescription dose.Recurrent patients were given with a prescription dose of DT 40Gy/8 fractions/4 weeks and patients with residual tumors were given with 12Gy/2 fractions/1 week.No tumor recurrence was observed at postoperative 3 months in two cases.Conclusions The 3D printed individualized nasopharyngeal intracavitary applicator has the advantages of self-fixation,accurate location,good repeatability and good patient tolerance.The short-term outcome is effective,whereas its long-term clinical effect and adverse reactions need to be further observed.
ABSTRACT
Introduction : Ca Cervix is the second most common malignancy in Indian women. Most of the cases present in advanced stage. Radiotherapy is an important modality of treatment. Combination of EBRT and ICRT is an effective strategy which is based on the principle that we are able to give high radiation dose to tumor while sparing surrounding normal tissue.Aim and Objectives :The aim was to evaluate the 3 year overall survival (OS) and disease-free survival (DFS) of patients treated by EBRT and ICRT. The objectives were to evaluate radiation toxicities and to evaluate rate of residual disease, recurrence and distant metastases.Materials and Methods : It is a Retrospective analytical study. We analyzed 468 newly diagnosed cases of Ca Cervix registered in department between January2009 to December2013. Out of which 382 completed radical radiotherapy (EBRT+ICRT).Results : At the end of 3 years 58(15.18%) patients lost to follow-up, 48(12.56%) residual disease, 60(15.70%) local recurrence and 26(6.80%) had distant metastases. The DFS was 73.91% in Stage-I and 62.8% in Stage-II while 51.38% in Stage-III and 29.82% in Stage-IV. The OS was 82.6% in Stage-I, 71.9% in Stage-II, 65.19% in Stage-III and 42.1% in Stage-IV. The difference between early and advanced disease is statistically significant with p-value of 0.016. Conclusions : EBRT and ICRT is effective treatment in terms of overall survival and disease-free survival. Associated radiation induced rectal and bladder toxicities are acceptable & manageable. Early stage and overall treatment time are favorable prognostic factors for 3 year DFS & OS.
ABSTRACT
This study, involving thirty-two patients with carcinoma of uterine cervix treated by high dose rate intracavitary irradiation using a remotely controlled afterloading system, compares the doss at point A and B with the Curie-minutes prescription. A linear least-square regression analysis was used to compare the two sets of date. Correlation coefficients between doses at points A and B arid the Ci-min prescription are 0.92(p<0.001) and 0.90 (p<0.001), respectively, and linear relationship is observed between these two system. The limitation and significance of the comparison of the two approaches to intracavitary dosimetry is discussed.
Subject(s)
Female , Humans , Cervix Uteri , Dioctyl Sulfosuccinic Acid , Prescriptions , Uterine Cervical NeoplasmsABSTRACT
In brachytherapy of uterine cervical cancer using a high dose rate remote afterloading system, it is of prime importance to deliver a accurate dose in each fractionated treatment by minimizing the difference between the pre-treatment planned and post-treatment calculated doses. The post-treatment calculated point A dose was not much different from the pretreatment planned dose (500 cGy). The average+/-standard deviation was 500+/-18 cGy and 84 percent of 82 intracavitary radiotherapy was within the range of 500+/-25 cGy.