What Is Halcyon?
Halcyon is a new-generation radiotherapy device that can perform modern radiation therapy. It is a high-modulation particular radiotherapy device that combines dose-intensity modulated beam therapy (IMRT) and volumetric modulated arc therapy (VMAT) methods and 100% image guidance (IGRT) in one device. It provides ideal modern radiotherapy applications, from point irradiations to long field irradiations, from deep organ tumors to superficial skin tumors.
Treatment Methods Performed with the Halcyon System
VMAT- Volumetric modulated arc therapy: In this technique, at a minimum of every 2 degrees of device rotation, the shape of the multi-leaf collimator (MLC-Multi Leaf Collimator) is changed to match the shape of the area to be irradiated. It perfectly protects normal organs. It adjusts the dose intensity as desired by supporting full or partial arcs with variable dose rates throughout the device’s body movement.
IMRT- Intensity-modulated radiotherapy: It can perform both dynamic and static IMRT. Dynamic IMRT; MLC leaves move continuously to give dose-intensity adjusted radiotherapy. Static IMRT; The system emits beams by stopping at each step. These steps take up to 500 segments.
Spot treatments: Even targets smaller than half a centimeter can be treated with this system with total accuracy, sparing organs at risk. It can do this both in the brain and even in body parts that have respiratory movement visceral movement.
Image Guided Radiotherapy (IGRT-Image Guided Radiotherapy): During the treatment, breathing and organ movement changes can be detected quickly. The device can combine these images with the planned areas and give the treatment precisely as designed. Smaller margins of safety are given to the clinical target volume. Since the irradiation is provided as scheduled under the image guidance during the treatment, the organs at risk are fully protected, and the intended area receives the total dose. SBRT, SRT, and SRS are more effective in hypofractionated radiotherapies since the target sensitivity is at the maximum level. Halcyon’s image-guided accuracy and speed provide excellent safety and comfort to the patient.
Superficial Treatments: With the Electronic Compensators technique, skin cancers can be treated, as well as in cases where it is necessary to change the surface dose density. For example, it is possible to reduce the skin dose in breast treatments or to increase the superficial radiation dose in cases with mastectomy without using a bolus. It can provide external treatment with a sensitivity that will enable skin cancer treatment in the nasal wing without any nasal cavity problems.
Difference from Halcyon Other Radiotherapy Devices
The VMAT difference: Varian systems provide arc therapy with correct modulation with three technical parameters: Dose rate, MLC positions, and Device body speed.
Dose Rate: A particular “triode” electron gun is inside the beamforming system. In Varian treatment delivery platforms, the dose rate can be changed instantly. Thanks to its unique algorithm, it quickly reaches the highest possible dose and dose rates.
New generation MLC leaves: In Halcyon’s new generation double-layer multi-leaf collimator (MLC-Multi Leaf Collimator), overlapping and interlocking stepped leaves can form independent movements. The leaves have a low photon transmittance of 0.01%, a length of 16 cm, and a tungsten structure. With these new-generation MLCs, it is possible to shape thinner areas and create maximum dose modulation. Rounded and indented edges are more easily shaped.
Device Body (Gantry) Speed: Varian Halcyon can reach the gantry speed of 4 RPM, that is, four revolutions per minute, during the treatment. The motors in the Halcyon device allow faster, smoother, and quieter gantry speed transitions. During radiation therapy, especially in rotational treatments, the device’s dose rate, gantry rate, and MLC speed affect the treatment time. The Halcyon system has gantry rotation at 4 RPM per minute. This device speed shortens the treatment time, and considering the mask, vacuum beds, etc., used to fix the patient, the shortening of the treatment period provides excellent patient comfort.
Halcyon Precision And Speed
The Halcyon system rapidly delivers image-guided Intensity Modulated Radiation Therapy (IMRT) through a double-layered multi-leaf collimator to target the cancerous tumor precisely. The increased speed of this system allows for faster treatment times while minimizing the risk of exposure of tissues and organs close to the targeted tumor.
As treatment times are shortened, patients benefit from less time at the desk during treatments and greater flexibility in providing desired timeframes for treatment.
Patient Comfort
Halcyon therapy’s essential aspect is patient outcomes, safety, and comfort. The Halcyon is a closed unit like a CT machine. The patient table is lowered close to the ground, allowing patients to safely get on and off the table. The machine also has a wide opening, so patients do not feel constrained during treatment. Engineers also have built ambient lighting and noise-canceling controls, so treatments are quiet and comfortable. Noise suppression is also built into the intercom system between the device and the technical controls outside the treatment area. This allows radiation technicians to communicate clearly with patients undergoing treatment in the radiation room.