PMID- 37673075
OWN - NLM
STAT- MEDLINE
DCOM- 20230928
LR  - 20231002
IS  - 1361-6560 (Electronic)
IS  - 0031-9155 (Linking)
VI  - 68
IP  - 19
DP  - 2023 Sep 27
TI  - Innovative margin design and optimized isocenter to minimize the normal tissue in 
      target volumes for single-isocenter multi-target stereotactic radiosurgery.
LID - 10.1088/1361-6560/acf751 [doi]
AB  - Objective.Treating multiple brain metastases in a single plan is a popular 
      radiosurgery technique. However, targets positioned off-isocenter are subject to 
      rotational uncertainties. This work introduces two new planning target volumes 
      (PTVs) that address this increased uncertainty. The volume of normal tissue 
      included in these PTVs when paired with optimized isocenters are evaluated and 
      compared with conventional methods.Approach.Sets of 1000 random multi-target 
      radiosurgery patients were simulated, each patient with a random number of 
      spherical targets (2-10). Each target had a random volume (0.1-15 cc) and was 
      randomly positioned between 5 and 50 mm or 100 mm from isocenter. Two new PTVs 
      ('LensPTV' and 'SwipePTV') and conventional isotropic PTVs were created using 
      isocenters derived from the center-of-centroids, the center-of-mass, or optimized 
      per PTV type. The total volume of normal tissue in the PTVs for each patient was 
      calculated and compared using 1 mm translations and 0.5 degrees , 1.0 degrees , and 2.0 degrees  
      rotations.Main results.Using the new PTVs and/or using optimized isocenters 
      decreased the total volume of normal tissue in the PTVs per patient. The 
      SwipePTV, in particular, provided the greatest decrease. Compared to the 
      SwipePTV, the LensPTV and the conventional isotropic PTV included an extra 0.68 
      and 0.73 cc of normal tissue per patient (median), respectively, when using 50 mm 
      max distance to isocenter and 1 degrees  max rotation angle. Under these conditions, 25% 
      of patients had extra volume of normal tissue >/= 0.96 and 1.04 cc. When using 100 
      mm max distance to isocenter and 2 degrees  max rotation angle, 25% of patients had extra 
      volume of normal tissue >/= 4.35 and 5.75 cc.Significance.PTVs like those presented 
      here, especially when paired with optimized isocenters, can decrease the total 
      volume of included normal tissue and reduce the risk of toxicity without 
      compromising target coverage.
CI  - Creative Commons Attribution license.
FAU - Yock, Adam D
AU  - Yock AD
AD  - Department of Radiation Oncology, Vanderbilt University Medical Center, 
      Nashville, TN, United States of America.
FAU - Grees, Beshoi
AU  - Grees B
AD  - Department of Radiation Oncology, Vanderbilt University Medical Center, 
      Nashville, TN, United States of America.
FAU - Luo, Guozhen
AU  - Luo G
AD  - Department of Radiation Oncology, Vanderbilt University Medical Center, 
      Nashville, TN, United States of America.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20230927
PL  - England
TA  - Phys Med Biol
JT  - Physics in medicine and biology
JID - 0401220
SB  - IM
MH  - Humans
MH  - Radiotherapy Planning, Computer-Assisted/methods
MH  - Radiotherapy Dosage
MH  - *Radiosurgery/methods
MH  - Uncertainty
MH  - *Brain Neoplasms/diagnostic imaging/radiotherapy/pathology
MH  - *Radiotherapy, Intensity-Modulated/methods
OTO - NOTNLM
OT  - SIMT
OT  - SRS
OT  - brain metastases
OT  - single-isocenter multi-target
OT  - stereotactic radiosurgery
EDAT- 2023/09/07 00:41
MHDA- 2023/09/28 06:42
CRDT- 2023/09/06 18:42
PHST- 2023/06/13 00:00 [received]
PHST- 2023/09/06 00:00 [accepted]
PHST- 2023/09/28 06:42 [medline]
PHST- 2023/09/07 00:41 [pubmed]
PHST- 2023/09/06 18:42 [entrez]
AID - 10.1088/1361-6560/acf751 [doi]
PST - epublish
SO  - Phys Med Biol. 2023 Sep 27;68(19). doi: 10.1088/1361-6560/acf751.