Credentialing for participation in clinical trials.

The National Cancer Institute (NCI) clinical cooperative groups have been instrumental over the past 50 years in developing clinical trials and evidence-based clinical trial processes for improvements in patient care. The cooperative groups are undergoing a transformation process to launch, conduct, and publish clinical trials more rapidly. Institutional participation in clinical trials can be made more efficient and include the expansion of relationships with international partners.

Results of a multi-institutional benchmark test for cranial CT/MR image registration.

Purpose: Variability in computed tomography/magnetic resonance imaging (CT/MR) cranial image registration was assessed using a benchmark case developed by the Quality Assurance Review Center to credential institutions for participation in Children's Oncology Group Protocol ACNS0221 for treatment of pediatric low-grade glioma.

Methods And Materials: Two DICOM image sets, an MR and a CT of the same patient, were provided to each institution. A small target in the posterior occipital lobe was readily visible on two slices of the MR scan and not visible on the CT scan.

Processes for quality improvements in radiation oncology clinical trials.

Quality assurance in radiotherapy (RT) has been an integral aspect of cooperative group clinical trials since 1970. In early clinical trials, data acquisition was nonuniform and inconsistent and computational models for radiation dose calculation varied significantly. Process improvements developed for data acquisition, credentialing, and data management have provided the necessary infrastructure for uniform data.

Hybrid IMRT for treatment of cancers of the lung and esophagus.

Purpose: To report on a hybrid intensity-modulated radiation therapy (IMRT; static plus IMRT beams treated concurrently) technique for lung and esophageal patients to reduce the volume of lung treated to low doses while delivering a conformal dose distribution.

Methods: Treatment plans were analyzed for 18 patients (12 lung and 6 esophageal). Patients were treated with a hybrid technique that concurrently combines static (approximately two-thirds dose) and IMRT (approximately one-third dose) beams.

Radiation therapy toxicity to the skin.

Radiation therapy has been integral to cancer patient care. The skin is an intentional and unintentional target of therapy, and is sensitive to the volume of normal tissue in the radiation therapy treatment field, daily treatment dose (fractionation), and total treatment dose. We must understand the relationship of these factors to patient outcome as we move toward hypofractionation treatment strategies (radiosurgery).

Radiotherapy in pediatric medulloblastoma: quality assessment of Pediatric Oncology Group Trial 9031.

Purpose: To evaluate the potential influence of radiotherapy quality on survival in high-risk pediatric medulloblastoma patients.

Methods And Materials: Trial 9031 of the Pediatric Oncology Group (POG) aimed to study the relative benefit of cisplatin and etoposide randomization of high-risk patients with medulloblastoma to preradiotherapy vs. postradiotherapy treatment.

Hybrid IMRT plans--concurrently treating conventional and IMRT beams for improved breast irradiation and reduced planning time.

Purpose: To evaluate a hybrid intensity modulated radiation therapy (IMRT) technique as a class solution for treatment of the intact breast.

Methods And Materials: The following five plan techniques were compared for 10 breast patients using dose-volume histogram analysis: conventional wedged-field tangents (Tangents), forward-planned field-within-a-field tangents (FIF), IMRT-only tangents (IMRT tangents), conventional open plus IMRT tangents (4-field hybrid), and conventional open plus IMRT tangents with 2 anterior oblique IMRT beams (6-field hybrid).

Results: The 4-field hybrid and FIF achieved dose distributions better than Tangents and IMRT tangents.

Forward-planned, multiple-segment, tangential fields with concomitant boost in the treatment of breast cancer.

We report on the utility of forward-planned, 3-dimensional (3D), multiple-segment tangential fields for radiation treatment of patients with breast cancer. The technique accurately targets breast tissue and the tumor bed and reduces dose inhomogeneity in the target. By decreasing excess dose to the skin and lung, a concomitant boost to the tumor bed can be delivered during the initial treatment, thereby decreasing the overall treatment time by one week.

A systematic benchmark method for analysis and comparison of IMRT treatment planning algorithms.

Tools and procedures for evaluating and comparing different intensity-modulated radiation therapy (IMRT) systems are presented. IMRT is increasingly in demand and there are numerous systems available commercially. These programs introduce significantly different software to dosimetrists and physicists than conventional planning systems, and the options often seem initially overwhelmingly complex to the user.

Commissioning of mini-multi-leaf-collimator (MMLC) for stereotactic radiosurgery and radiotherapy.

Commissioning of a Radionics miniature multi-leaf collimator (MMLC) for stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) is reported. With single isocenter and multi static fields, the MMLC can provide better conformity of dose distributions to the target and/or irregularly shaped target volumes than standard arc (circular) field beams with multiple isocenters. Advantages offered by the MMLC over traditional LINAC based SRS and SRT includes greatly improved dose homogeneity to the target, reduced patient positioning time and reduced treatment time.

Current calibration, treatment, and treatment planning techniques among institutions participating in the Children's Oncology Group.

Purpose: To report current technology implementation, radiation therapy physics and treatment planning practices, and results of treatment planning exercises among 261 institutions belonging to the Children's Oncology Group (COG).

Methods And Materials: The Radiation Therapy Committee of the newly formed COG mandated that each institution demonstrate basic physics and treatment planning abilities by satisfactorily completing a questionnaire and four treatment planning exercises designed by the Quality Assurance Review Center. The planning cases are (1) a maxillary sinus target volume (for two-dimensional planning), (2) a Hodgkin's disease mantle field (for irregular-field and off-axis dose calculations), (3) a central axis blocked case, and (4) a craniospinal irradiation case.

Miniature multileaf collimator as an alternative to traditional circular collimators for stereotactic radiosurgery and stereotactic radiotherapy.

Purpose: To evaluate the miniature multileaf collimator (MMLC) as an alternative to traditional circular collimators for radiosurgery.

Materials And Methods: 'Circular' fields were created with the Radionics MMLC (leaf width 3.53 mm at isocenter).

Intensity modulation for breast treatment using static multi-leaf collimators.

Purpose: To achieve more uniform dose distributions in breast cancer treatment using multiple sets of multi-leaf collimator (MLC) defined fields. Dose uniformity for many breast cancer patients can be significantly improved by using two or more sets of portals and the "hot" regions of a traditional treatment can be significantly reduced.

Methods And Materials: Patients for breast cancer treatment are immobilized with alpha cradle in the traditional arm-up position and have a CT scan in the treatment position.

Neuropsychological function in adults after high dose fractionated radiation therapy of skull base tumors.

Purpose: To evaluate the long term effects of high dose fractionated radiation therapy on brain functioning prospectively in adults without primary brain tumors.

Methods And Materials: Seventeen patients with histologically confirmed chordomas and low grade chondrosarcomas of the skull base were evaluated with neuropsychological measures of intelligence, language, memory, attention, motor function and mood following surgical resection/biopsy of the tumor prior to irradiation, and then at about 6 months, 2 years and 4 years following completion of treatment. None received chemotherapy.

Conformal irradiation of the prostate: estimating long-term rectal bleeding risk using dose-volume histograms.

Purpose: Dose-volume histograms (DVHs) may be very useful tools for estimating probability of normal tissue complications (NTCP), but there is not yet an agreed upon method for their analysis. This study introduces a statistical method of aggregating and analyzing primary data from DVHs and associated outcomes. It explores the dose-volume relationship for NTCP of the rectum, using long-term data on rectal wall bleeding following prostatic irradiation.

A pencil beam algorithm for proton dose calculations.

The sharp lateral penumbra and the rapid fall-off of dose at the end of range of a proton beam are among the major advantages of proton radiation therapy. These beam characteristics depend on the position and characteristics of upstream beam-modifying devices such as apertures and compensating boluses. The extent of separation, if any, between these beam-modifying devices and the patient is particularly critical in this respect.

Comparison of proton and x-ray conformal dose distributions for radiosurgery applications.

Highly focused dose distributions for radiosurgery applications are successfully achieved using either multiple static high-energy particle beams or multiple-arc circular x-ray beams from a linac. It has been suggested that conformal x-ray techniques using dynamically shaped beams with a moving radiation source would offer advantages compared to the use of only circular beams. It is also thought that, generally, charged particle beams such as protons offer dose deposition advantages compared to x-ray beams.

Advanced prostate cancer: the results of a randomized comparative trial of high dose irradiation boosting with conformal protons compared with conventional dose irradiation using photons alone.

Purpose: Following a thorough Phase I/II study, we evaluated by a Phase III trial high versus conventional dose external beam irradiation as mono-therapy for patients with Stage T3-T4 prostate cancer. Patient outcome following standard dose radiotherapy or following a 12.5% increase in total dose to 75.

Late rectal bleeding following combined X-ray and proton high dose irradiation for patients with stages T3-T4 prostate carcinoma.

Purpose: Dose escalation for prostate cancer by external beam irradiation is feasible by a 160 MeV perineal proton beam that reduces the volume of rectum irradiated. We correlated the total doses received to portions of the anterior rectum to study the possible relationship of the volume irradiated to the incidence of late rectal toxicity.

Methods: We have randomized 191 patients with stages T3 and T4 prostatic carcinoma to one of two treatment dose arms.

Probable causes of recurrence in patients with chordoma and chondrosarcoma of the base of skull and cervical spine.

Purpose: 141 patients with chordoma and chondrosarcoma of the base of skull and cervical spine were treated with proton and photon irradiation between 1980 and 1989. The local disease was controlled in 111 of these patients. This study reviews the 26 patients who have had their disease recur, and who have evaluable diagnostic studies to examine for probable causes of recurrence.

Potential improvement of three dimension treatment planning and proton beams in fractionated radiotherapy of large cerebral arteriovenous malformations.

The treatment of large cerebral arteriovenous malformations is a surgical challenge, especially for deep seated brain locations. Furthermore, these lesions are unfit for radiosurgical approaches due to a high risk of complications secondary to high radiation doses to large brain volumes. Fractionated precision radiotherapy can potentially deliver high, uniform, target-contoured dose distributions optimizing the dose reduction to the critical surrounding brain.

Proton beams in radiation therapy.

The rationale for study of proton radiation therapy is that, for some anatomic sites and tumors, the treatment volume is smaller; i.e., there is less irradiation of nontarget tissue while the target is included in three dimensions at each treatment session.