scholarly journals Efficacy of a hydrogel spacer in three-dimensional conformal radiation therapy for prostate cancer

2020 ◽  
Vol 50 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Mami Ogita ◽  
Hideomi Yamashita ◽  
Subaru Sawayanagi ◽  
Wataru Takahashi ◽  
Keiichi Nakagawa
Keyword(s):  
Prostate Cancer ◽  
Computed Tomography ◽  
High Risk ◽  
Seminal Vesicle ◽  
Three Dimensional ◽  
Conformal Radiotherapy ◽  
Computed Tomography Scans ◽  
Before And After ◽  
Three Dimensional Conformal Radiotherapy ◽  
Dose Constraints

Abstract Objectives We aimed to compare the dose constraints fulfillment rate of the three-dimensional conformal radiotherapy treatment plan before and after a hydrogel spacer insertion. Methods The planning computed tomography scans of 39 patients who received stereotactic body radiotherapy for prostate cancer were used. All patients inserted a hydrogel spacer and underwent computed tomography scans before and after spacer insertion. The three-dimensional conformal radiotherapy plans according to NCCN classification, low-, intermediate- and high-risk, were made for each patient. Clinical target volume included prostate and seminal vesicle 2 cm for high risk, prostate and seminal vesicle 1 cm for intermediate risk and prostate only for low risk. Three-dimensional conformal radiotherapy including a seven-field conformal technique with 76 Gy in 38 fractions. Dose constraints for rectum and bladder were V70 Gy ≤ 15%, V65 Gy ≤ 30% and V40 Gy ≤ 60%. Results Among 39 patients, 35 (90%), 19 (49%) and 13 (33%) and 38 (97%), 38 (97%) and 34 (87%) patients before and after the spacer insertion fulfilled rectum dose constraints for low-, intermediate- and high-risk plans, respectively. A hydrogel spacer significantly reduced rectum dose and improved the rectum dose constraints fulfillment rate in intermediate (P < 0.01) and high (P < 0.01), but no difference was found in low-risk plan (P = 0.25). On multivariate analysis, spacer use was associated with the higher rectum dose constraints fulfillment rate. Conclusions A hydrogel spacer reduced rectum dose and improved the dose constraints fulfillment rate in three-dimensional conformal radiotherapy plan. Although IMRT is the standard treatment, 3D-CRT using a hydrogel spacer may be a treatment option.

scholarly journals Conformal radiotherapy of prostate carcinoma: Procedure description

2011 ◽  
Vol 64 (1-2) ◽  
pp. 51-54
Author(s):  
Marko Erak ◽  
Biljana Bugarcic ◽  
Dragica Erak ◽  
Dragan Arandjelovic ◽  
Ilinka Nadj ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Computed Tomography ◽  
Cancer Patients ◽  
Prostate Carcinoma ◽  
Three Dimensional ◽  
Conformal Radiotherapy ◽  
High Dose ◽  
Three Dimension ◽  
Advanced Planning ◽  
Three Dimensional Conformal Radiotherapy

Introduction. Today, three-dimensional conformal radiotherapy is a standard way in the radical treatment of localized prostate cancer, and it is an alternative to the radical prostatectomy. This method of radiotherapy treatment is widely accepted in the treatment of prostate cancer patients, and provides irradiation of targeted volume (prostate, seminal vesicles) with dose escalation sparing the surrounding healthy tissues (rectum, bladder) at the same time. That is not possible with the conventional twodimension technique. Procedure description. Three-dimensional conformal radiotherapy is a volumetric, visual simulation according to the computed tomography slices; it defines the tumour and organ at risk individually in each patient. Results of several studies have shown that there is a significant decrease in the development of acute toxicity when prostate cancer patients are treated with conformal radiotherapy. High dose irradiation gives excellent results in treatment of localized prostate carcinoma and improves treatment results in the patients with locally advanced carcinoma of prostate. Discussion. Prostate carcinoma irradiation techniques have been changed dramatically during recent years. Data obtained by computed tomography are important since the size and shapes of the prostate as well as its anatomic relations towards the rectum and bladder are considerably different in individual patients. The three-dimension plan of irradiation can be designed for each patient individually by performing computed tomography technique when planning radiotherapy. Conclusion. The advanced planning systems for conformal radiotherapy can reconstruct the anatomic structures of pelvis in three-dimension technique on the basis of computed tomography scans, which provides better conformality between the irradiation beam and geometrical shape of the tumour with minimal irradiation of the surrounding healthy tissue.

scholarly journals The correlation between the teardrop angle and anterior lunate facet displacement in plating distal radial fractures

2019 ◽  
Vol 44 (5) ◽  
pp. 462-467 ◽  
Author(s):  
Teun Teunis ◽  
Sjoerd Meijer ◽  
Jesse Jupiter ◽  
Daniel Rikli ◽  
Keyword(s):  
Computed Tomography ◽  
Surface Area ◽  
Plate Fixation ◽  
Three Dimensional ◽  
Anterior Plate ◽  
Distal Radial Fractures ◽  
Computed Tomography Scans ◽  
Before And After ◽  
Anterior Plating ◽  
Three Dimensional Models

This study aimed to determine the association of teardrop angle and anteroposterior distance with anterior lunate facet displacement and articular congruity before and after anterior plating of distal radial fractures. We included 36 patients with complete intra-articular distal radial fractures with separate anterior lunate facet fragments. On radiographs we determined the teardrop angle and anteroposterior distance. On digital three-dimensional models we measured proximal-distal, anteroposterior and ulnoradial anterior lunate facet displacement, and we outlined the gap surface area. Preoperatively, teardrop angle was highly associated with the extent of anterior lunate facet displacement. Increased anteroposterior distance was mainly associated with articular incongruity after anterior plate fixation. This information may reduce the need of preoperative computed tomography scans in fractures with a normal tear drop angle. This is particularly useful in low-resource settings.

scholarly journals Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer

2016 ◽  
Vol 49 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Ana Paula Diniz Fortuna Poli ◽  
Rodrigo Souza Dias ◽  
Adelmo José Giordani ◽  
Helena Regina Comodo Segreto ◽  
Roberto Araujo Segreto
Keyword(s):  
Prostate Cancer ◽  
Three Dimensional ◽  
Conformal Radiotherapy ◽  
Prostate Motion ◽  
Rectal Volume ◽  
Three Dimensional Conformal Radiotherapy ◽  
Interfraction Motion ◽  
The Impact ◽  
Anterior Posterior ◽  
3D Crt

Abstract Objective: To evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Materials and Methods: Fifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction. Results: The maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation ( p = 0.037). A baseline rectal volume superior to 70 cm3 had a significant influence on the prostate motion in the anteroposterior direction ( p = 0.045). Conclusion: The present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm3. Therefore, the treatment of patients with a rectal volume > 70 cm3 should be re-planned with appropriate rectal preparation.

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