Image-guided radiotherapy: rationale, benefits, and limitations.

Technological advances have greatly enhanced the specialty of radiation oncology by allowing more healthy tissue to be spared for the same or better tumour coverage. Developments in medical imaging are integral to radiation oncology, both for design of treatment plans and to localise the target for precise administration of radiation. At planning, definition of the tumour and healthy tissue is based on CT, augmented frequently with MRI and PET. At treatment, three-dimensional soft-tissue imaging can also be used to localise the target and tumour motion can be tracked with fluoroscopic imaging of radio-opaque markers implanted in or near the tumour. These developments allow changes in tumour position, size, and shape that take place during radiotherapy to be measured and accounted for to boost geometric accuracy and precision of radiation delivery. Image-guided treatment also enhances uniformity in doses administered in a population of patients, thus improving our ability to measure the effect of dosimetric and non-dosimetric factors on tumour and healthy tissue outcomes in clinical trials. Increased precision and accuracy of radiotherapy are expected to augment tumour control, reduce incidence and severity of toxic effects after radiotherapy, and facilitate development of more efficient shorter schedules than currently available.

[1]  D Yan,et al.  An off-line strategy for constructing a patient-specific planning target volume in adaptive treatment process for prostate cancer. , 2000, International journal of radiation oncology, biology, physics.

[2]  David Jaffray,et al.  Online image-guided intensity-modulated radiotherapy for prostate cancer: How much improvement can we expect? A theoretical assessment of clinical benefits and potential dose escalation by improving precision and accuracy of radiation delivery. , 2004, International journal of radiation oncology, biology, physics.

[3]  Robert E. Drzymala,et al.  Errors in radiation oncology: A study in pathways and dosimetric impact , 2005, Journal of Applied Clinical Medical Physics.

[4]  R. Mohan,et al.  Quantifying the predictability of diaphragm motion during respiration with a noninvasive external marker. , 2003, Medical physics.

[5]  David A Jaffray,et al.  Emergent technologies for 3-dimensional image-guided radiation delivery. , 2005, Seminars in radiation oncology.

[6]  D A Jaffray,et al.  A radiographic and tomographic imaging system integrated into a medical linear accelerator for localization of bone and soft-tissue targets. , 1999, International journal of radiation oncology, biology, physics.

[7]  Albert C Koong,et al.  Phase I study of stereotactic radiosurgery in patients with locally advanced pancreatic cancer. , 2004, International journal of radiation oncology, biology, physics.

[8]  G H Olivera,et al.  The use of megavoltage CT (MVCT) images for dose recomputations , 2005, Physics in medicine and biology.

[9]  M. V. van Herk,et al.  Tumor motion and deformation during external radiotherapy of bladder cancer. , 2006, International journal of radiation oncology, biology, physics.

[10]  Jean-Philippe Pignol,et al.  Correlation of lung tumor motion with external surrogate indicators of respiration. , 2004, International journal of radiation oncology, biology, physics.

[11]  R K Ten Haken,et al.  The reproducibility of organ position using active breathing control (ABC) during liver radiotherapy. , 2001, International journal of radiation oncology, biology, physics.

[12]  M. V. van Herk,et al.  Precise and real-time measurement of 3D tumor motion in lung due to breathing and heartbeat, measured during radiotherapy. , 2002, International journal of radiation oncology, biology, physics.

[13]  J H Siewerdsen,et al.  A performance comparison of flat-panel imager-based MV and kV cone-beam CT. , 2002, Medical physics.

[14]  James Wylie,et al.  X-ray volume imaging in bladder radiotherapy verification. , 2006, International journal of radiation oncology, biology, physics.

[15]  Rakesh Patel,et al.  Megavoltage computed tomography imaging: a potential tool to guide and improve the delivery of thoracic radiation therapy. , 2004, Clinical lung cancer.

[16]  Marcel van Herk,et al.  Portal imaging to assess set-up errors, tumor motion and tumor shrinkage during conformal radiotherapy of non-small cell lung cancer. , 2001, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[17]  Radhe Mohan,et al.  Increased risk of biochemical and local failure in patients with distended rectum on the planning CT for prostate cancer radiotherapy. , 2005, International journal of radiation oncology, biology, physics.

[18]  Ping Xia,et al.  Low-dose megavoltage cone-beam CT for radiation therapy. , 2005, International journal of radiation oncology, biology, physics.

[19]  J Alfred Witjes,et al.  The effect of an endorectal balloon and off-line correction on the interfraction systematic and random prostate position variations: a comparative study. , 2005, International journal of radiation oncology, biology, physics.

[20]  Kristy K Brock,et al.  Accuracy of daily image guidance for hypofractionated liver radiotherapy with active breathing control. , 2005, International journal of radiation oncology, biology, physics.

[21]  Patrick A Kupelian,et al.  Initial experience with megavoltage (MV) CT guidance for daily prostate alignments. , 2005, International journal of radiation oncology, biology, physics.

[22]  K. Langen,et al.  Organ motion and its management. , 2001, International journal of radiation oncology, biology, physics.

[23]  E. Hall,et al.  Radiation-induced second cancers: the impact of 3D-CRT and IMRT. , 2003, International journal of radiation oncology, biology, physics.

[24]  Patrick A Kupelian,et al.  A technique for adaptive image-guided helical tomotherapy for lung cancer. , 2006, International journal of radiation oncology, biology, physics.

[25]  Mark Oldham,et al.  Cone-beam-CT guided radiation therapy: A model for on-line application. , 2005, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[26]  Ralph Weissleder,et al.  Molecular imaging in the clinical arena. , 2005, JAMA.

[27]  Patrick A Kupelian,et al.  Influence of intrafraction motion on margins for prostate radiotherapy. , 2006, International journal of radiation oncology, biology, physics.

[28]  K L Lam,et al.  Automated localization of the prostate at the time of treatment using implanted radiopaque markers: technical feasibility. , 1995, International journal of radiation oncology, biology, physics.

[29]  Geoffrey Hugo,et al.  Changes in the respiratory pattern during radiotherapy for cancer in the lung. , 2006, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[30]  John Wong,et al.  A dose-escalation trial with the adaptive radiotherapy process as a delivery system in localized prostate cancer: analysis of chronic toxicity. , 2005, International journal of radiation oncology, biology, physics.

[31]  George Starkschall,et al.  Prostate cancer radiation dose response: results of the M. D. Anderson phase III randomized trial. , 2002, International journal of radiation oncology, biology, physics.

[32]  Christopher G Willett,et al.  Quantification of respiration-induced abdominal tumor motion and its impact on IMRT dose distributions. , 2004, International journal of radiation oncology, biology, physics.

[33]  G. Chen,et al.  Techniques and applications of image correlation in radiotherapy treatment planning. , 1987, Frontiers of radiation therapy and oncology.

[34]  R K Ten Haken,et al.  Conformal and intensity modulated irradiation of head and neck cancer: the potential for improved target irradiation, salivary gland function, and quality of life. , 1999, Acta oto-rhino-laryngologica Belgica.

[35]  Radhe Mohan,et al.  Four-dimensional radiotherapy planning for DMLC-based respiratory motion tracking. , 2005, Medical physics.

[36]  J. Fowler,et al.  Image guidance for precise conformal radiotherapy. , 2003, International journal of radiation oncology, biology, physics.

[37]  Radhe Mohan,et al.  Quantification of volumetric and geometric changes occurring during fractionated radiotherapy for head-and-neck cancer using an integrated CT/linear accelerator system. , 2004, International journal of radiation oncology, biology, physics.

[38]  D A Jaffray,et al.  Active breathing control (ABC) for Hodgkin's disease: reduction in normal tissue irradiation with deep inspiration and implications for treatment. , 2000, International journal of radiation oncology, biology, physics.

[39]  T R Willoughby,et al.  Short-course intensity-modulated radiotherapy for localized prostate cancer with daily transabdominal ultrasound localization of the prostate gland. , 2000, International journal of radiation oncology, biology, physics.

[40]  John M Buatti,et al.  Optically guided patient positioning techniques. , 2005, Seminars in radiation oncology.

[41]  L. Dawson,et al.  Radiation therapy for hepatocellular carcinoma , 2006, Cancer.

[42]  Ping Xia,et al.  Repeat CT imaging and replanning during the course of IMRT for head-and-neck cancer. , 2006, International journal of radiation oncology, biology, physics.

[43]  H. Shirato,et al.  Four-dimensional treatment planning and fluoroscopic real-time tumor tracking radiotherapy for moving tumor. , 2000, International journal of radiation oncology, biology, physics.

[44]  Jean Pouliot,et al.  Daily electronic portal imaging for morbidly obese men undergoing radiotherapy for localized prostate cancer. , 2004, International journal of radiation oncology, biology, physics.

[45]  Eric Strom,et al.  Ultrasound-based localization. , 2005, Seminars in radiation oncology.

[46]  Clifton D Fuller,et al.  Comparison of ultrasound and implanted seed marker prostate localization methods: Implications for image-guided radiotherapy. , 2006, International journal of radiation oncology, biology, physics.

[47]  J. Pouliot,et al.  Evaluation of ultrasound-based prostate localization for image-guided radiotherapy. , 2003, International journal of radiation oncology, biology, physics.

[48]  K. Forster,et al.  Image-guided radiosurgery for the spine and pancreas. , 2000, Computer aided surgery : official journal of the International Society for Computer Aided Surgery.

[49]  Maria Hawkins,et al.  Reproducibility of liver position using active breathing coordinator for liver cancer radiotherapy. , 2006, International journal of radiation oncology, biology, physics.

[50]  E. Mendel,et al.  Phase I clinical evaluation of near-simultaneous computed tomographic image-guided stereotactic body radiotherapy for spinal metastases. , 2004, International journal of radiation oncology, biology, physics.

[51]  F Lohr,et al.  Extracranial stereotactic radiation therapy: set-up accuracy of patients treated for liver metastases. , 2000, International journal of radiation oncology, biology, physics.

[52]  K. Brock,et al.  Determination of ventilatory liver movement via radiographic evaluation of diaphragm position. , 2001, International journal of radiation oncology, biology, physics.

[53]  M van Herk,et al.  Fusion of respiration-correlated PET and CT scans: correlated lung tumour motion in anatomical and functional scans , 2005, Physics in medicine and biology.

[54]  David Jaffray,et al.  Assessment of residual error in liver position using kV cone-beam computed tomography for liver cancer high-precision radiation therapy. , 2006, International journal of radiation oncology, biology, physics.

[55]  Michael B Sharpe,et al.  Initial clinical experience with moderate deep-inspiration breath hold using an active breathing control device in the treatment of patients with left-sided breast cancer using external beam radiation therapy. , 2003, International journal of radiation oncology, biology, physics.

[56]  David W Townsend,et al.  From 3-D positron emission tomography to 3-D positron emission tomography/computed tomography: what did we learn? , 2004, Molecular imaging and biology : MIB : the official publication of the Academy of Molecular Imaging.

[57]  M. Uematsu,et al.  A dual computed tomography linear accelerator unit for stereotactic radiation therapy: a new approach without cranially fixated stereotactic frames. , 1996, International journal of radiation oncology, biology, physics.

[58]  Prakash Chinnaiyan,et al.  The impact of daily setup variations on head-and-neck intensity-modulated radiation therapy. , 2005, International journal of radiation oncology, biology, physics.

[59]  M. V. van Herk,et al.  Respiratory correlated cone beam CT. , 2005, Medical physics.

[60]  Jake Van Dyk,et al.  Image-guided adaptive radiation therapy (IGART): Radiobiological and dose escalation considerations for localized carcinoma of the prostate. , 2005, Medical physics.

[61]  M. Oldham,et al.  Digital tomosynthesis with an on-board kilovoltage imaging device. , 2006, International journal of radiation oncology, biology, physics.

[62]  H. von der Maase,et al.  Phase-II study on stereotactic radiotherapy of locally advanced pancreatic carcinoma. , 2005, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[63]  Clifton D Fuller,et al.  Daily ultrasound-based image-guided targeting for radiotherapy of upper abdominal malignancies. , 2004, International journal of radiation oncology, biology, physics.

[64]  R. Mirimanoff,et al.  Pediatric medulloblastoma: radiation treatment technique and patterns of failure. , 1997, International journal of radiation oncology, biology, physics.

[65]  K. Brock,et al.  Feasibility of a novel deformable image registration technique to facilitate classification, targeting, and monitoring of tumor and normal tissue. , 2006, International journal of radiation oncology, biology, physics.

[66]  John Wong,et al.  Assessment of residual error for online cone-beam CT-guided treatment of prostate cancer patients. , 2004, International journal of radiation oncology, biology, physics.

[67]  K. Brock,et al.  Adaptive Planning and Delivery to Account for Anatomical Changes Induced by Radiation Therapy of Head and Neck Cancer , 2005 .

[68]  Jan-Jakob Sonke,et al.  Automatic prostate localization on cone-beam CT scans for high precision image-guided radiotherapy. , 2005, International journal of radiation oncology, biology, physics.

[69]  Gunilla C. Bentel,et al.  Patient Positioning and Immobilization in Radiation Oncology , 1998 .

[70]  James M Balter,et al.  Daily targeting of intrahepatic tumors for radiotherapy. , 2002, International journal of radiation oncology, biology, physics.

[71]  John Wong,et al.  Accuracy of a wireless localization system for radiotherapy. , 2005, International journal of radiation oncology, biology, physics.

[72]  V. Khoo,et al.  X-ray volumetric imaging in image-guided radiotherapy: the new standard in on-treatment imaging. , 2006, International journal of radiation oncology, biology, physics.

[73]  Hiroshi Onishi,et al.  A new irradiation system for lung cancer combining linear accelerator, computed tomography, patient self-breath-holding, and patient-directed beam-control without respiratory monitoring devices. , 2003, International journal of radiation oncology, biology, physics.

[74]  D. Dearnaley,et al.  The impact of introducing intensity modulated radiotherapy into routine clinical practice. , 2005, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.