PMID- 16143791 OWN - NLM STAT- MEDLINE DCOM- 20060403 LR - 20190513 IS - 1526-9914 (Electronic) IS - 1526-9914 (Linking) VI - 6 IP - 3 DP - 2005 Summer TI - Effects of field parameters on IMRT plan quality for gynecological cancer: a case study. PG - 46-62 AB - Traditional external beam radiotherapy of gynecological cancer consists of a 3D, four-field-box technique. The radiation treatment area is a large region of normal tissue, with greater inhomogeneity over the treatment volume, which could benefit more with intensity-modulated radiation therapy (IMRT). This is a case report of IMRT planning for a patient with endometrial cancer. The planning target volume (PTV) spanned the intrapelvic and periaortic lymph nodes to a 33-cm length. Planning and treatment were accomplished using double isocenters. The IMRT plan was compared with a 3D plan, and the effects of field parameters were studied. Delineated anatomical contours included the intrapelvic nodes (PTV), bone marrow, small bowel, bladder, rectum, sigmoid colon, periaortic nodes (PTV), spinal cord, left kidney, right kidney, large bowel, liver, and tissue (excluding the PTVs). Comparisons were made between IMRT and 3D plans, 23-MV and 6-MV energies, zero and rotated collimator angles, different numbers of segments, and opposite gantry angle configurations. The plans were evaluated based on dosevolume histograms (DVHs). Compared with the 3D plan, the IMRT plan had superior dose conformity and spared the bladder and sigmoid colon embedded in the intrapelvic nodes. The higher energy (23 MV) reduced the dose to most critical organs and delivered less integral dose. Zero collimator angles resulted in a better plan than "optimized" collimator angles, with lower dose to most of the normal structures. The number of segments did not have much effect on isodose distribution, but a reasonable number of segments was necessary to keep treatment time from being prohibitively long. Gantry angles, when evenly spaced, had no noticeable effect on the plan. The patient tolerated the treatment well, and the initial complete blood count was favorable. Our results indicated that large-volume tumor sites may also benefit from precise conformal delivery of IMRT. FAU - Fung, Albert Y C AU - Fung AY AD - Department of Radiation Oncology, Nebraska Medical Center, 987521 Nebraska Medical Center, Omaha, Nebraska 68198-7521, USA. afung@unmc.edu FAU - Enke, Charles A AU - Enke CA FAU - Ayyangar, Komanduri M AU - Ayyangar KM FAU - Thompson, Robert B AU - Thompson RB FAU - Zhen, Weining AU - Zhen W FAU - Raman, Natarajan V AU - Raman NV FAU - Djajaputra, David AU - Djajaputra D FAU - Li, Sicong AU - Li S FAU - Nehru, Ramasamy M AU - Nehru RM FAU - Pillai, Sushakumari AU - Pillai S FAU - Sourivong, Paul AU - Sourivong P FAU - Headley, Mary AU - Headley M FAU - Yager, Ann L AU - Yager AL LA - eng PT - Journal Article DEP - 20050812 PL - United States TA - J Appl Clin Med Phys JT - Journal of applied clinical medical physics JID - 101089176 SB - IM MH - Adenocarcinoma/*diagnostic imaging/*radiotherapy MH - Body Burden MH - Endometrial Neoplasms/*diagnostic imaging/*radiotherapy MH - Female MH - Genital Neoplasms, Female/diagnostic imaging/radiotherapy MH - Humans MH - Middle Aged MH - Quality Assurance, Health Care/*methods MH - Radiography MH - Radiometry/*methods MH - Radiotherapy Dosage MH - Radiotherapy Planning, Computer-Assisted/*methods MH - Relative Biological Effectiveness MH - Reproducibility of Results MH - Sensitivity and Specificity MH - Treatment Outcome PMC - PMC5723493 EDAT- 2005/09/07 09:00 MHDA- 2006/04/04 09:00 PMCR- 2005/08/17 CRDT- 2005/09/07 09:00 PHST- 2005/09/07 09:00 [pubmed] PHST- 2006/04/04 09:00 [medline] PHST- 2005/09/07 09:00 [entrez] PHST- 2005/08/17 00:00 [pmc-release] AID - ACM20046 [pii] AID - 10.1120/jacmp.v6i3.2087 [doi] PST - ppublish SO - J Appl Clin Med Phys. 2005 Summer;6(3):46-62. doi: 10.1120/jacmp.v6i3.2087. Epub 2005 Aug 12.