The use of intensity modulated radiation therapy (IMRT) has been rapidly growing in the United States. This technology is now being used in a multitude of academic and community centers throughout the country and is being incorporated into the treatment of cancers in almost every anatomical site, most commonly head and neck cancer, central nervous system tumors, and prostate cancer. In addition, current protocols are investigating the use of IMRT for the treatment of breast cancer, lung cancer, abdominal/retroperitoneal malignancies, and gynecological diseases. This article presents a brief technical review of IMRT and addresses specific clinical concerns and caveats that radiation oncologists should be aware of when utilizing this technology.
MohanR.LowD.ChaoC.WuQ.DongL.Intensity-Modulated Radiation Treatment Planning, Quality Assurance, Delivery, and Clinical Application. Principles and Practice of Radiation Oncology, 4th Ed., pp 314–336. Eds., PerezC. A.BradyL. W.HalperinE. C., and Schmidt-UlrichR. K.Lippincott Williams & Wilkins, Philadelphia, PA (2004).
2.
MackieT. R.HolmesT.SwerdloffS.ReckwerdtP.DeasyJ. O.YangJ.PaliwalB.KinsellaTomotherapyT.: A New Concept for the Delivery of Dynamic Conformal Radiotherapy. Med. Phys.20, 1709–1719 (1993).
AlaeiP.HigginsP. D.WeaverR.NguyenN.Comparison of Dynamic and Step-and-Shoot Intensity Modulated Radiation Therapy Planning and Delivery. Med. Dosim.29, 1–6 (2004).
5.
Keller-ReichenbecherM. A.BortfeldT.LevegrunS.SteinJ.PreiserK.SchlegelW.Intensity Modulation with the “Step and Shoot” Technique Using a Commercial MLC: A Planning Study. Multileaf Collimator. Int. J. Radiat. Oncol. Biol. Phys.45, 1315–1324 (1999).
6.
YuC. X.Intensity-modulated Arc Therapy with Dynamic Multileaf Collimation: An Alternative to Tomotherapy. Phys. Med. Biol.40, 1435–1449 (1995).
7.
Intensity Modulated Radiation Therapy Collaborative Working Group.Intensity-modulated Radiotherapy: Current Status and Issues of Interest. Int. J. Radiat. Oncol. Biol. Phys.51, 880–914 (2001).
8.
XiaP.AmolsH. I.LingC. C.Three-dimensional Conformal Radiotherapy and Intensity-modulated Radiotherapy. Textbook of Radiation Oncology, 2nd Ed., pp 163–186. Eds., LeibelS. A. and PhillipsT. L.Elsevier Inc., Philadelphia, PA (2004).
9.
TsaiJ. S.EnglerM. J.LingM. N.WuJ. K.KramerB.DipetrilloT.WazerD. E.A Non-invasive Immobilization System and Related Quality Assurance for Dynamic Intensity Modulated Radiation Therapy of Intracranial and Head and Neck Disease. Int. J. Radiat. Oncol. Biol. Phys.43, 455–467 (1999).
10.
MohanD. S.KupelianP. A.WilloughbyT. R.Short-course Intensity-modulated Radiotherapy for Localized Prostate Cancer with Daily Transabdominal Ultrasound Localization of the Prostate Gland. Int. J. Radiat. Oncol. Biol. Phys.46, 575–580 (2000).
11.
WoelR.BeardC.ChenM. H.HurwitzM.LoffredoM.McMahonE.ChingJ.LopesL.D'AmicoA. V.Acute Gastrointestinal, Genitourinary, and Dermatological Toxicity During Dose-escalated 3D-conformal Radiation Therapy (3DCRT) Using an Intrarectal Balloon for Prostate Gland Localization and Immobilization. Int. J. Radiat. Oncol. Biol. Phys.62, 392–396 (2005).
12.
DirkxM. L.HeijmenB. J.KorevaarG. A.Van OsM. J.StroomJ. C.KoperP. C.LevendagP. C.Field Margin Reduction Using Intensity Modulated X-ray Beams Formed with a Multileaf Collimator. Int. J. Radiat. Oncol. Biol. Phys.38, 1123–1129 (1997).
13.
MohanR.WuQ.WangX.SteinJ.Intensity Modulated Optimization, Lateral Transport of Radiation, and Margins. Med. Phys.23, 2011–2021 (1996).
14.
MohanR.WuQ.ManningM.Schmidt-UllrichR.Radiobiological Considerations in the Design of Fractionation Strategies for Intensity-modulated Radiation Therapy of Head and Neck Cancers. Int. J. Radiat. Oncol. Biol. Phys.46, 619–630 (2000).
15.
WelshJ. S.PatelR. R.RitterM. A.HarariP. M.MackieT. R.MehtaM. P.Helical Tomotherapy: An Innovative Technology and Approach to Radiation Therapy. Technol. Cancer Res. Treat.4, 311–316 (2002).
16.
PuriD. R.ChouW.LeeN.Intensity-modulated Radiation Therapy in Head and Neck Cancers: Dosimetric Advantages and Update of Clinical Results. Am. J. Clin. Oncol.28, 415–423 (2005).
17.
ZelefskyM. J.FuksZ.HuntM.YamadaY.MarionC.LingC. C.AmolsH.VenkatramanE. S.LeibelS. A.High-dose Intensity Modulated Radiation Therapy for Prostate Cancer: Early Toxicity and Biochemical Outcome in 772 Patients. Int. J. Radiat. Oncol. Biol. Phys.53, 1111–1116 (2002).
18.
PirzkallA.DebusJ.HaeringP.RheinB.GrosserK. H.HossA.WannenmacherM.Intensity-modulated Radiotherapy (IMRT) for Recurrent, Residual, or Untreated Skull-base Meningiomas: Preliminary Clinical Experience. Int. J. Radiat. Oncol. Biol. Phys.55, 362–372 (2003).
19.
YamadaY.LovelockD. M.YeniceK. M.BilskyM. H.HuntM. A.ZatckyJ.LeibelS. A.Multifractionated Image-guided and Stereotactic Intensity-modulated Radiotherapy of Paraspinal Tumors: A Preliminary Report. Int. J. Radiat. Oncol. Biol. Phys.62, 53–61 (2005).
20.
ViciniF. A.SharpeM.KestinL.MartinezA.MitchellC. K.WallaceM. F.MatterR.WongJ.Optimizing Breast Cancer Treatment Efficacy with Intensity-modulated Radiotherapy. Int. J. Radiat. Oncol. Biol. Phys.52, 1336–1344 (2002).
21.
MundtA. J.LujanA. E.RotmenschJ.WaggonerS. E.YamadaS. D.FlemingG.RoeskeJ. C.Intensity-modulated Whole Pelvic Radiotherapy in Women with Gynecological Malignancies. Int. J. Radiat. Oncol. Biol. Phys.52, 1330–1337 (2002).
22.
SchwarzM.AlberM.LebesqueJ. V.MijnheerB. J.DamenE. M.Dose Heterogeneity in the Target volume and Intensity-modulated Radiotherapy to Escalate the Dose in the Treatment of Non-small Cell Lung Cancer. Int. J. Radiat. Oncol. Biol. Phys.62, 561–570 (2005).
23.
HollowayC. L.RobinsonD.MurrayB.AmanieJ.ButtsC.SmylieM.ChuK.McEwanA. J.HalperinR.RoaW. H.Results of a Phase I Study to Dose Escalate Using Intensity Modulated Radiotherapy Guided by Combined PET/CT Imaging with Induction Chemotherapy for Patients with Non-small Cell Lung Cancer. Radiother. Oncol.73, 285–287 (2004).
24.
Ben-JosefE.ShieldsA. F.VaishampayanU.VaitkeviciusV.El-RayesB. F.McDermottP.BurmeisterJ.BossenbergerT.PhilipP. A.Intensity-modulated Radiotherapy (IMRT) and Concurrent Capecitabine for Pancreatic Cancer. Int. J. Radiat. Oncol. Biol. Phys.59, 454–459 (2004).
25.
MilanoM. T.GarofaloM. C.ChmuraS. J.FarreyK.RashC.HeimannR.JaniA. B.Intensity-modulated Radiation Therapy in the Treatment of Gastric Cancer: Early Clinical Outcome and Dosimetric Comparison with Conventional Techniques. Br. J. Radiol.79, 497–503 (2006).
26.
WelshJ. S.LimmerJ. P.HowardS. P.DiamondD.HarariP. M.TomeW.Precautions in the Use of Intensity-modulated Radiation Therapy. Technol. Cancer Res. Treat.4, 203–210 (2005).
27.
FowlerJ. F.WelshJ. S.HowardS. P.Loss of Biological Effect in Prolonged Fraction Delivery. Int. J. Radiat. Oncol. Biol. Phys.59, 242–249 (2004).
28.
Figures reproduced with permission from editors. Image-Guided IMRT. Eds., BortfeldT.Schmidt-UllrichR.De NeveW., and WazerD. E.. Springer, Berlin, Germany (2006).
