scholarly journals Analysis of Geometric and Dosimetric Effects of Bra Application to Support Large or Pendulous Breasts During Radiotherapy Planning: A Retrospective Single-Center Study

2021 ◽  
Vol 20 ◽  
pp. 153303382110279
Author(s):  
So Hyun Park ◽  
Jinhyun Choi
Keyword(s):  
Clinical Target Volume ◽  
Organs At Risk ◽  
Target Volume ◽  
Radiotherapy Planning ◽  
Homogeneity Index ◽  
Breast Volume ◽  
Breast Cancer Patients ◽  
Single Center Study ◽  
Radiotherapy Field ◽  
Dose Reductions

Purpose: To evaluate geometric and dosimetric effects of bra application during radiotherapy planning for breast cancer patients with large and pendulous breasts. Materials and Methods: Twenty patients with chest sizes >38 inches between April 2019 and July 2019 underwent radiotherapy planning with and without a radiation bra (Chabner XRT®). Geometric and dosimetric parameters included the breast volume, superior-inferior (SI) distance, separation (S) as the distance of the longest diameter of the clinical target volume (CTV), conformity number (CN), and homogeneity index (HI) of CTV. The organs at risk (OARs) were defined as the lungs, heart, and liver. Results: The use of the radiation bra provided mean changes of −0.51 cm for S, −1.45 cm for SI, and −61.18 cc for breast volume (all P < 0.05). Breast volume was correlated with bra-related changes in cross diameter (r = 0.641, P = 0.002) and volume (r = 0.680, P = 0.001). Significant dose reductions were observed for the lungs (mean V10: 19.58 cc, V20: 17.13 cc, Dmean: 86.24 cGy) and heart (Dmean: 170.23 cGy). No significant differences were observed for CN (0.62-0.67) and HI (0.19-0.20) of the CTV. Conclusion: The application of a radiation bra was associated with better geometric and dosimetric planning parameters, with a smaller CTV and lower doses to the OARs (lungs and heart) in the radiotherapy field. In addition, we expect that bra use during radiotherapy would provide emotional benefits.

Adaptive planning study of “plan of the day” versus “composite planning” for muscle-invasive bladder cancer (MIBC).

2012 ◽  
Vol 30 (5_suppl) ◽  
pp. 309-309
Author(s):  
David E McIntosh ◽  
Gareth Webster ◽  
Julia Stratford ◽  
Apurna Jegannathen ◽  
Richard Cowan ◽  
...  
Keyword(s):  
Clinical Target Volume ◽  
Organs At Risk ◽  
Target Volume ◽  
Radiotherapy Planning ◽  
Cone Beam ◽  
Planning Study ◽  
Adaptive Planning ◽  
Muscle Invasive Bladder Cancer ◽  
Adequate Coverage ◽  
Muscle Invasive

309 Background: Bladder motion during treatment can be considerable resulting in either inadequate coverage of planning target volume (PTV) or significant overdose to organs at risk (OAR). Adaptive radiotherapy planning using either “plan of the day” or “composite planning” may offer a method to reduce PTV, while optimizing the clinical target volume (CTV) coverage and reducing the dose to OAR. Methods: Patients were planned using a radiotherapy CT planning scan (RTP). CTV was defined as whole bladder and this was expanded by 1.5 cm to form the PTV. PTV was treated to 52.5 Gy in 20 fractions over 4 weeks. Off line correction was performed using cone beam imaging (XVI) taken on days 1-3 and weekly thereafter, as a minimum. We performed a retrospective planning study on 8 patients treated for MIBC. For “plan of the day,” 4 separate plans were created by expanding the superior CTV margin by 0.5 cm, 1 cm, 1.5 cm, or 2 cm. All other margins were 1.5 cm in all directions. Composite plans were created from the CTV drawn on the first 3 XVIs. This composite CTV was grown by 5mm to create PTV1 and by 10mm to create PTV2. Subsequent XVIs were assessed to determine if the CTV was encompassed by the 95% isodose for each plan. We compared the PTV for each plan with the standard RTP volume. Results: Preliminary data reveal that the composite plan using a 10mm margin resulted in adequate coverage for all remaining treatments as assessed by XVI. The composite plan with a 5mm margin failed to adequately cover the CTV. Using the composite plan with a 10mm margin the PTV is decreased by a mean of 27.5% compared with conventional planning. Plan of the day resulted in a mean decrease in PTV of 17.0%. Conclusions: This data suggests a potential advantage of adaptive planning with both techniques showing a reduction in PTV compared with conventional planning. This could lead to an associated reduction in dose and toxicity to OAR. Composite planning with a 10mm margin showed the greatest benefit in terms of reduced irradiated volume while adequately covering the CTV. Further studies are needed to investigate any effect on toxicity due to reduced dose to OAR.

scholarly journals Atlas Sampling for Prone Breast Automatic Segmentation of Organs at Risk: The Importance of Patients’ Body Mass Index and Breast Cup Size for an Optimized Contouring of the Heart and the Coronary Vessels

2020 ◽  
Vol 19 ◽  
pp. 153303382092062
Author(s):  
Xinzhuo Wang ◽  
Raymond Miralbell ◽  
Odile Fargier-Bochaton ◽  
Shelley Bulling ◽  
Jean Paul Vallée ◽  
...  
Keyword(s):  
Body Mass Index ◽  
At Risk ◽  
Body Mass ◽  
Clinical Target Volume ◽  
Organs At Risk ◽  
Automatic Segmentation ◽  
Coronary Vessels ◽  
Target Volume ◽  
Breast Volume ◽  
Mean Similarity

Objective: Delineation of organs at risk is a time-consuming task. This study evaluates the benefits of using single-subject atlas-based automatic segmentation of organs at risk in patients with breast cancer treated in prone position, with 2 different criteria for choosing the atlas subject. Together with laterality (left/right), the criteria used were either (1) breast volume or (2) body mass index and breast cup size. Methods: An atlas supporting different selection criteria for automatic segmentation was generated from contours drawn by a senior radiation oncologist (RO_A). Atlas organs at risk included heart, left anterior descending artery, and right coronary artery. Manual contours drawn by RO_A and automatic segmentation contours of organs at risk and breast clinical target volume were created for 27 nonatlas patients. A second radiation oncologist (RO_B) manually contoured (M_B) the breast clinical target volume and the heart. Contouring times were recorded and the reliability of the automatic segmentation was assessed in the context of 3-D planning. Results: Accounting for body mass index and breast cup size improved automatic segmentation results compared to breast volume-based sampling, especially for the heart (mean similarity indexes >0.9 for automatic segmentation organs at risk and clinical target volume after RO_A editing). Mean similarity indexes for the left anterior descending artery and the right coronary artery edited by RO_A expanded by 1 cm were ≥0.8. Using automatic segmentation reduced contouring time by 40%. For each parameter analyzed (eg, D2%), the difference in dose, averaged over all patients, between automatic segmentation structures edited by RO_A and the same structure manually drawn by RO_A was <1.5% of the prescribed dose. The mean heart dose was reliable for the unedited heart segmentation, and for right-sided treatments, automatic segmentation was adequate for treatment planning with 3-D conformal tangential fields. Conclusions: Automatic segmentation for prone breast radiotherapy stratified by body mass index and breast cup size improved segmentation accuracy for the heart and coronary vessels compared to breast volume sampling. A significant reduction in contouring time can be achieved by using automatic segmentation.

Technical illustration of Volumetric arc conformal radiotherapy planning in a case of paratesticular sarcoma

2021 ◽  
pp. 1-6
Author(s):  
Anil Gupta ◽  
Rambha Pandey ◽  
Seema Sharma ◽  
Vivek Ghosh ◽  
Ekta Dhamija ◽  
...  
Keyword(s):  
Organs At Risk ◽  
Target Volume ◽  
Radiotherapy Planning ◽  
Current Evidence ◽  
Lower Grade ◽  
Malignant Tumours ◽  
Target Volume Delineation ◽  
Volume Delineation ◽  
Delivery Technique ◽  
Technical Illustration

Abstract Introduction: Paratesticular sarcoma are extremely rare malignant tumours. Unlike other sites, they tend to be lower grade and have higher propensity of lymphatic spread. They tend to fail locally and occasionally in the regional lymph nodes. In the absence of target volume delineation guidelines and technical illustration of conformal planning, we have made an attempt to illustrate conformal planning methodology and define target volume based on current evidence in a case of paratesticular sarcoma. Methods: We are presenting a case of 62-year-old male who presented with 15-cm scrotal swelling and underwent high inguinal orchidectomy with ligation of spermatic cord. Histopathology presented a well-differentiated leiomyosarcoma of epididymis. Post-operative radiotherapy target volume included the tumour bed, ipsilateral inguinal nodes and lower pelvic nodes as the clinical target volume. Conclusion: Adjuvant radiotherapy using advanced delivery technique such as volumetric arc technique can provide good dose distribution with good sparing of organs at risk. The downside of conformal radiation delivery is that it is a resource-intensive and has no established target volume delineation guidelines.

Radiotherapy planning: PET/CT scanner performances in the definition of gross tumour volume and clinical target volume

2005 ◽  
Vol 32 (12) ◽  
pp. 1392-1399 ◽  
Author(s):  
Ernesto Brianzoni ◽  
Gloria Rossi ◽  
Sergio Ancidei ◽  
Alfonso Berbellini ◽  
Francesca Capoccetti ◽  
...  
Keyword(s):  
Clinical Target Volume ◽  
Tumour Volume ◽  
Target Volume ◽  
Radiotherapy Planning ◽  
Gross Tumour Volume ◽  
Ct Scanner ◽  
Pet Ct ◽  
Definition Of

scholarly journals Pattern of Recurrence of Glioblastoma Versus Grade 4 IDH-Mutant Astrocytoma Following Chemoradiation

2021 ◽  
Author(s):  
James Stewart ◽  
Arjun Sahgal ◽  
Aimee K.M. Chan ◽  
Hany Soliman ◽  
Chia-Lin Tseng ◽  
...  
Keyword(s):  
Gross Tumor Volume ◽  
Clinical Target Volume ◽  
Tumor Volume ◽  
Extent Of Resection ◽  
Target Volume ◽  
Radiotherapy Planning ◽  
Recurrence Pattern ◽  
Wild Type ◽  
Failure Patterns ◽  
Pattern Of Recurrence

Abstract Purpose To quantitatively compare the recurrence pattern of glioblastoma (IDH-wild type) versus grade 4 IDH-mutant astrocytoma (herein referred to as wtIDH and mutIDH, respectively) following primary chemoradiation. Methods Twenty-two wtIDH and 22 mutIDH patients matched by sex, extent of resection, and corpus callosum involvement were enrolled. The recurrent gross tumor volume (rGTV) was compared with both the gross tumor volume (GTV) and clinical target volume (CTV) from radiotherapy planning. Failure patterns were quantified by the incidence and volume of the rGTV outside the GTV and CTV, and positional differences of the rGTV centroid from the GTV and CTV. Results The GTV was smaller in wtIDH compared to the mutIDH group (mean±SD: 46.5±26.0 cm3 v. 72.2±45.4 cm3, p=0.026). The rGTV was 10.7±26.9 cm3 and 46.9±55.0 cm3 smaller than the GTV for the same groups (p=0.018). The rGTV extended outside the GTV in 22 (100%) and 15 (68%) (p=0.009) of wtIDH and mutIDH patients, respectively; however, the volume of rGTV outside the GTV was not significantly different (12.4±16.1 cm3 vs. 8.4±14.2 cm3, p=0.443). The rGTV metrics extending outside the CTV was not different between the groups. The rGTV centroid was within 5.7 mm of the closest GTV edge for 21 (95%) and 22 (100%) of wtIDH and mutIDH patients, respectively. Conclusion The rGTV extended beyond the GTV less often in mutIDH patients, suggesting limited margin radiotherapy could be beneficial in this group. The results support the study of small margin adaptive radiotherapy per the ongoing UNITED MR-Linac 5 mm CTV trial (NCT04726397).

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