The Dosimetric Outcome of a Rotational Planning Target Volume in Patients With Oropharyngeal Cancers

Dysphagia ◽  
2021 ◽  
Author(s):  
Mona Arbab ◽  
Gregory Bartlett ◽  
Benjamin Dawson ◽  
Jeffrey Ge ◽  
Mark Langer
Keyword(s):  
Planning Target Volume ◽  
Target Volume

Anisotropic Bladder Planning Target Volume in Bladder Radiation Therapy

2019 ◽  
Vol 9 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Khaled Adil ◽  
Marija Popovic ◽  
Fabio L. Cury ◽  
Sergio L. Faria ◽  
Marie Duclos ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Planning Target Volume ◽  
Target Volume

scholarly journals Use of a Head-Tilting Baseplate During Tomotherapy to Shorten the Irradiation Time and Protect the Hippocampus and Lens in Hippocampal Sparing-Whole Brain Radiotherapy

2021 ◽  
Vol 20 ◽  
pp. 153303382098682
Author(s):  
Kosei Miura ◽  
Hiromasa Kurosaki ◽  
Nobuko Utsumi ◽  
Hideyuki Sakurai
Keyword(s):  
At Risk ◽  
Planning Target Volume ◽  
Irradiation Time ◽  
Organs At Risk ◽  
Absorbed Dose ◽  
Whole Brain Radiotherapy ◽  
Target Volume ◽  
Whole Brain ◽  
Brain Radiotherapy ◽  
Hippocampal Sparing

Purpose: The aim of this study is to comparatively examine the possibility of reducing the exposure dose to organs at risk, such as the hippocampus and lens, and improving the dose distribution of the planned target volume with and without the use of a head-tilting base plate in hippocampal-sparing whole-brain radiotherapy using tomotherapy. Methods: Five paired images of planned head computed tomography without and with tilt were analyzed. The hippocampus and planning target volume were contoured according to the RTOG 0933 contouring atlas protocol. The hippocampal zone to be avoided was delineated using a 5-mm margin. The prescribed radiation dose was 30 Gy in 10 fractions. The absorbed dose to planning target volume dose, absorbed dose to the organ at risk, and irradiation time were evaluated. The paired t-test was used to analyze the differences between hippocampal-sparing whole-brain radiotherapy with head tilts and without head tilts. Results: Hippocampal-sparing whole-brain radiotherapy with tilt was not superior in planning target volume doses using the homogeneity index than that without tilt; however, it showed better values, and for Dmean and D2%, the values were closer to 30 Gy. Regarding the hippocampus, dose reduction with tilt was significantly greater at Dmax, Dmean, and Dmin, whereas regarding the lens, it was significantly greater at Dmax and Dmin. The irradiation time was also predominantly shorter. Conclusion: In our study, a tilted hippocampal-sparing whole-brain radiotherapy reduced the irradiation time by >10%. Therefore, our study indicated that hippocampal-sparing whole-brain radiotherapy with tomotherapy should be performed with a tilt. The head-tilting technique might be useful during hippocampal-sparing whole-brain radiotherapy. This method could decrease the radiation exposure time, while sparing healthy organs, including the hippocampus and lens.

scholarly journals Planning target volume as a predictor of disease progression in inoperable stage III non-small cell lung cancer patients treated with chemoradiotherapy and concurrent and/or sequential immune checkpoint inhibition

2021 ◽  
Author(s):  
Julian Taugner ◽  
Lukas Käsmann ◽  
Monika Karin ◽  
Chukwuka Eze ◽  
Benedikt Flörsch ◽  
...  
Keyword(s):  
Planning Target Volume ◽  
Immune Checkpoint ◽  
Target Volume ◽  
Continuous Variable ◽  
Stage Iii ◽  
Checkpoint Inhibition ◽  
Immune Checkpoint Inhibition ◽  
Platinum Based Chemotherapy ◽  
Stage Iii Nsclc ◽  
Nsclc Patients

SummaryBackground. The present study evaluates outcome after chemoradiotherapy (CRT) with concurrent and/or sequential Programmed Cell Death 1 (PD-1) or Ligand 1 (PD-L1) immune checkpoint inhibition (CPI) for inoperable stage III NSCLC patients depending on planning target volume (PTV). Method and patients. Prospective data of thirty-three consecutive patients with inoperable stage III NSCLC treated with CRT and sequential durvalumab (67%, 22 patients) or concurrent and sequential nivolumab (33%, 11 patients) were analyzed. Different PTV cut offs and PTV as a continuous variable were evaluated for their association with progression-free (PFS), local–regional progression-free (LRPFS), extracranial distant metastasis-free (eMFS) and brain-metastasis free-survival (BMFS). Results. All patients were treated with conventionally fractionated thoracic radiotherapy (TRT); 93% to a total dose of at least 60 Gy, 97% of patients received two cycles of concurrent platinum-based chemotherapy. Median follow-up for the entire cohort was 19.9 (range: 6.0–42.4) months; median overall survival (OS), LRFS, BMFS and eMFS were not reached. Median PFS was 22.8 (95% CI: 10.7–34.8) months. Patients with PTV ≥ 900ccm had a significantly shorter PFS (6.9 vs 22.8 months, p = 0.020) and eMFS (8.1 months vs. not reached, p = 0.003). Furthermore, patients with PTV ≥ 900ccm and stage IIIC disease (UICC-TNM Classification 8th Edition) achieved a very poor outcome with a median PFS and eMFS of 3.6 vs 22.8 months (p < 0.001) and 3.6 months vs. not reached (p = 0.001), respectively. PTV as a continuous variable also had a significant impact on eMFS (p = 0.048). However, no significant association of different PTV cut-offs or PTV as a continuous variable with LRPFS and BMFS could be shown. The multivariate analysis that was performed for PTV ≥ 900ccm and age (≥ 65 years), gender (male), histology (non-ACC) as well as T- and N-stage (T4, N3) as covariates also revealed PTV ≥ 900ccm as the only factor that had a significant correlation with PFS (HR: 5.383 (95% CI:1.263–22.942, p = 0.023)). Conclusion. In this prospective analysis of inoperable stage III NSCLC patients treated with definitive CRT combined with concurrent and/or sequential CPI, significantly shorter PFS and eMFS were observed in patients with initial PTV ≥ 900ccm.

A critical evaluation of the planning target volume for 3-D conformal radiotherapy of prostate cancer

1998 ◽  
Vol 42 (1) ◽  
pp. 213-221 ◽  
Author(s):  
Alfred Tinger ◽  
Jeff M. Michalski ◽  
Abel Cheng ◽  
Daniel A. Low ◽  
Ron Zhu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Planning Target Volume ◽  
Critical Evaluation ◽  
Conformal Radiotherapy ◽  
Target Volume
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