ESMO consensus guidelines for the management of patients with metastatic colorectal cancer

This document is the report of a task group of the AAPM and has been prepared primarily to advise medical physicists involved in the external-beam radiation therapy of patients with thoracic, abdominal, and pelvic tumors affected by respiratory motion. This report describes the magnitude of respiratory motion, discusses radiotherapy specific problems caused by respiratory motion, explains techniques that explicitly manage respiratory motion during radiotherapy and gives recommendations in the application of these techniques for patient care, including quality assurance (QA) guidelines for these devices and their use with conformal and intensity modulated radiotherapy. The technologies covered by this report are motion-encompassing methods, respiratory gated techniques, breath-hold techniques, forced shallow-breathing methods, and respiration-synchronized techniques. The main outcome of this report is a clinical process guide for managing respiratory motion. Included in this guide is the recommendation that tumor motion should be measured (when possible) for each patient for whom respiratory motion is a concern. If target motion is greater than 5 mm, a method of respiratory motion management is available, and if the patient can tolerate the procedure, respiratory motion management technology is appropriate. Respiratory motion management is also appropriate when the procedure will increase normal tissue sparing. Respiratory motion management involves further resources, education and the development of and adherence to QA procedures.

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The management of respiratory motion in radiation oncology report of AAPM Task Group 76.

Task Group 101 of the AAPM has prepared this report for medical physicists, clinicians, and therapists in order to outline the best practice guidelines for the external-beam radiation therapy technique referred to as stereotactic body radiation therapy (SBRT). The task group report includes a review of the literature to identify reported clinical findings and expected outcomes for this treatment modality. Information is provided for establishing a SBRT program, including protocols, equipment, resources, and QA procedures. Additionally, suggestions for developing consistent documentation for prescribing, reporting, and recording SBRT treatment delivery is provided.

https://aapm.onlinelibrary.wiley.com/doi/pdf/10.1118/1.3438081

Stereotactic body radiation therapy: The report of AAPM Task Group 101

Purpose: To provide an analytical description of the effect of random and systematic geometrical deviations on the target dose in radiotherapy and to derive margin rules. Methods and Materials: The cumulative dose distribution delivered to the clinical target volume (CTV) is expressed analytically. Geometrical deviations are separated into treatment execution (random) and treatment preparation (systematic) variations. The analysis relates each possible preparation (systematic) error to the dose distribution over the CTV and allows computation of the probability distribution of, for instance, the minimum dose delivered to the CTV. Results: The probability distributions of the cumulative dose over a population of patients are called dose-population histograms in short. Large execution (random) variations lead to CTV underdosage for a large number of patients, while the same level of preparation (systematic) errors leads to a much larger underdosage for some of the patients. A single point on the histogram gives a simple "margin recipe." For example, to ensure a minimum dose to the CTV of 95% for 90% of the patients, a margin between CTV and planning target volume (PTV) is required of 2.5 times the total standard deviation (SD) of preparation (systematic) errors (Σ) plus 1.64 times the total SD of execution (random) errors (σ′) combined with the penumbra width, minus 1.64 times the SD describing the penumbra width (σ p ). For a σ p of 3.2 mm, this recipe can be simplified to 2.5 Σ + 0.7 σ′. Because this margin excludes rotational errors and shape deviations, it must be considered as a lower limit for safe radiotherapy. Conclusion: Dose-population histograms provide insight into the effects of geometrical deviations on a population of patients. Using a dose-probability based approach, simple algorithms for choosing margins were derived.

The probability of correct target dosage: dose-population histograms for deriving treatment margins in radiotherapy

Purpose Surgical resection is standard therapy in stage I non–small-cell lung cancer (NSCLC); however, many patients are inoperable due to comorbid diseases. Building on a previously reported phase I trial, we carried out a prospective phase II trial using stereotactic body radiation therapy (SBRT) in this population. Patients and Methods Eligible patients included clinically staged T1 or T2 (≤ 7 cm), N0, M0, biopsy-confirmed NSCLC. All patients had comorbid medical problems that precluded lobectomy. SBRT treatment dose was 60 to 66 Gy total in three fractions during 1 to 2 weeks. Results All 70 patients enrolled completed therapy as planned and median follow-up was 17.5 months. The 3-month major response rate was 60%. Kaplan-Meier local control at 2 years was 95%. Altogether, 28 patients have died as a result of cancer (n = 5), treatment (n = 6), or comorbid illnesses (n = 17). Median overall survival was 32.6 months and 2-year overall survival was 54.7%. Grade 3 to 5 toxicity occurred in a total of 14 p...

https://ascopubs.org/doi/pdf/10.1200/JCO.2006.07.5937

Excessive Toxicity When Treating Central Tumors in a Phase II Study of Stereotactic Body Radiation Therapy for Medically Inoperable Early-Stage Lung Cancer

A stereotactic body frame with a fixation device has been developed for stereotactic radiation therapy of extracranial targets, a precision localization and positioning system in analogy with the stereotactic head frames used for intracranial targets. Results of the first 42 treated tumors in 31 patients are presented. Most of the patients had solitary tumors in liver, lung or retroperitoneal space. Clinical target volumes ranged from 2 to 622 cm3 (mean 78 cm3) and minimum doses to the planning target volumes (PTV) of 7.7-30 Gy/fraction (mean 14.2 Gy) were given on 1-4 occasions to a total minimum dose to the PTVs of 7.7-45 Gy (mean 30.2 Gy) to the periphery of the PTV and total mean doses to the PTVs of 8-66 Gy (mean 41 Gy). The central part of the tumor was usually given about 50% higher dose compared to that of the periphery of the PTV by a planned inhomogeneous dose distribution. Some of the patients received stereotactic radiation therapy concomitantly to more than one target, in others new metastases were also treated which appeared during the follow-up period. We observed a local rate of no progressive disease of 80% during a follow-up period of 1.5-38 months. Fifty percent of the tumors decreased in size or disappeared.

https://www.tandfonline.com/doi/pdf/10.3109/02841869509127197

Stereotactic High Dose Fraction Radiation Therapy of Extracranial Tumors Using An Accelerator: Clinical experience of the first thirty-one patients

A method for sterotactic high-dose radiotherapy of malignancies in the abdomen has been developed. A stereotactic frame for the body has been developed and a method for fixation of the patient in the frame is described. The reproducibility in the stereotactic system of tumours in the liver and the lung was found to be within 5-8mm for 90% of the patient set-ups. The diaphragmatic movements were reduced to 5-10 mm, by applying a pressure on the abdomen. An analytical method is used to calculate dose distributions for a continuum of beams in an isocentric treatment technique. The advantage of a heterogeneous target dose is demonstrated and proposed for the present application. A non-coplanar treatment technique, using eight individually shaped beams is proposed and has been used for patient treatments. The dose distribution for a patient with a metastasis in the liver is shown as well as dose volume histograms for the target and the liver. At the Karolinska Hospital non-malignant and primary malignant intracranial targets have been treated with radiosurgery using the ‘gamma knife’ since 1974. During recent years brain metastases have also been treated in several hundreds of patients. The treatment is given as a single irradiation of the target without any margin to the extension seen on CT. A prerequisite for this method is the sterotactic system used for localization and for patient set-up. The rigid connection between the stereotactic frame and the head is obtained by screws from the frame to the skull. The experience of tissue tolerance to localized single fraction high-dose radiotherapy stems from the early application of radiation therapy and more recently from radiosurgery for intracranial targets and intraoperative radiotherapy (IORT) for extracranial targets. In radiosurgery the target volume is generally in the order of from a few

https://informahealthcare.com/doi/pdf/10.3109/02841869409121782

Stereotactic Radiotherapy of Malignancies in the Abdomen: Methodological aspects

Specification of dose delivery in radiation therapy. Recommendation by the Nordic Association of Clinical Physics (NACP).

A method for extracranial stereotactic radiosurgery (ESRS) is described. For this treatment method a stereotactic body frame was developed and is described here. The ESRS method uses a hypofractionation schedule with 2–3 fractions with 10–20 Gy/fraction to the periphery of the target volume, at the 65% isodose. The heterogeneous target dose is used as a means to increase the probability of killing the hypoxic tumor cells. It is argued from in vitro cell survival data that the dose increase used will give a reasonable probability to eradicate at least moderate concentrations of hypoxic cells. A high reproducibility of the target position with the ESRS method is based on the definition of the patient reference system to the stereotactic system and not to the bony anatomical reference points as used in conventional radiotherapy. Important to the ESRS method is that the target position is verified by computed tomography (CT) examinations. The positional accuracy of the target in the stereotactic system is 3.1 mm (mean deviation) in the transversal plane and 5.5 mm (mean deviation) in the longitudinal direction. The setup accuracy, i.e., the correct alignment of the stereotactic system to the isocenter of the treatment unit, is within 1 mm. Other aspects of the ESRS method that are discussed are the treatment technique including collimation methods and dose distributions used, as well as target margins. ESRS has been in clinical use for several years at Radiumhemmet, Karolinska Hospital.

Ingemar Näslund

Papers

Stereotactic High Dose Fraction Radiation Therapy of Extracranial Tumors Using An Accelerator: Clinical experience of the first thirty-one patients

Stereotactic Radiotherapy of Malignancies in the Abdomen: Methodological aspects

Specification of dose delivery in radiation therapy. Recommendation by the Nordic Association of Clinical Physics (NACP).

Extracranial Stereotactic Radiosurgery of Localized Targets

Specification of dose delivery in radiation therapy