PMID- 33981510
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20210514
IS  - 2168-8184 (Print)
IS  - 2168-8184 (Electronic)
IS  - 2168-8184 (Linking)
VI  - 13
IP  - 4
DP  - 2021 Apr 9
TI  - Radiobiological Comparison of Teardrop Technique for Breast Cancer Radiotherapy 
      Treatment Planning on a Tomotherapy System.
PG  - e14390
LID - 10.7759/cureus.14390 [doi]
LID - e14390
AB  - Breast cancer is one of the most common cancer worldwide with large morbidity. In 
      Mexico, it is the first cause of death by cancer in women. Radiotherapy has 
      proven to be a great tool to control such ailments and TomoTherapy is a 
      relatively new technology to accomplish it. To obtain good clinical outcomes, 
      tight dosimetric constraints are placed on organs at risk (OARs) to maximize 
      tumor control and minimize normal tissue complication probabilities. The teardrop 
      technique helps meeting these constraints by placing a virtual block over parts 
      of the ipsilateral lung and the heart but it contributes to lengthen the 
      treatment time. In this work, we present our experience in using this technique 
      and compare its radiobiological estimations with similar plans without it. Ten 
      patients diagnosed with breast cancer were planned twice, with and without the 
      teardrop technique. Dose-volume histograms were obtained and analyzed to get 
      uncomplicated tumor control probability (UTCP) and optimization estimator (fEUD) 
      parameters. Classical dosimetrical parameters for planning target volumes (PTVs): 
      conformity index, homogeneity index, and coverage were also recorded and 
      statistically described. Several dosimetrical parameters for OARs were recorded 
      and analyzed. The UTCP parameter had a mean value of 0.968 +/- 0.023 when no block 
      was used and 0.966 +/- 0.022 with the teardrop. The fEUD parameter values 
      were: 0.515 +/- 0.049 without blocks and 0.541 +/- 0.057 with the 
      teardrop. Optimization of every plan was stopped only after all constraints were 
      met, and it was easier to accomplish this goal with the teardrop technique. The 
      teardrop technique permitted a 5% gain in fEUD. The teardrop technique was 
      observed to have a net radiobiological benefit with little impact on patient 
      scheduling.
CI  - Copyright (c) 2021, Herrera et al.
FAU - Herrera, Higmar
AU  - Herrera H
AD  - Radiation Oncology, Centro Estatal De Cancerologia De Durango, Victoria de 
      Durango, MEX.
FAU - Reyes, Uvaldo
AU  - Reyes U
AD  - Radiation Oncology, Centro Estatal De Cancerologia De Durango, Victoria de 
      Durango, MEX.
LA  - eng
PT  - Journal Article
DEP - 20210409
PL  - United States
TA  - Cureus
JT  - Cureus
JID - 101596737
PMC - PMC8106967
OTO - NOTNLM
OT  - breast cancer
OT  - geud
OT  - radiobiological parameters
OT  - treatment planning
OT  - utcp
COIS- The authors have declared that no competing interests exist.
EDAT- 2021/05/14 06:00
MHDA- 2021/05/14 06:01
PMCR- 2021/04/09
CRDT- 2021/05/13 06:27
PHST- 2021/05/13 06:27 [entrez]
PHST- 2021/05/14 06:00 [pubmed]
PHST- 2021/05/14 06:01 [medline]
PHST- 2021/04/09 00:00 [pmc-release]
AID - 10.7759/cureus.14390 [doi]
PST - epublish
SO  - Cureus. 2021 Apr 9;13(4):e14390. doi: 10.7759/cureus.14390.