Monday, May 20, 2019

PROTON THERAPY

Proton beam therapy is a type of radiotherapy that uses a beam of high energy protons, which are small parts of atoms, rather than high energy x-rays (called “photons”) to treat specific types of cancer.
Proton beam therapy enables a dose of high energy protons to be precisely targeted at a tumour, reducing the damage to surrounding healthy tissues and vital organs which is an advantage in certain groups of patients or where the cancer is close to a critical part of the body such as the spinal cord.


Proton therapy cancer treatment begins when each proton begins its journey at the injector located within an electric field. In the field, hydrogen atoms then separate into negatively charged electrons and positively charged protons. The protons travel through a vacuum tube within a pre-accelerator. This process boosts their energy to two million electron volts. The protons continue in the vacuum tube and begin their high-speed journey in the synchrotron. They travel around the synchrotron about 10 million times per second. Each time they circulate, a radiofrequency cavity within the ring delivers a boost of energy. This increases the protons' energy to between 70 and 250 million electron volts. The voltage achieved is enough to place them at any depth within the human body.


Fig shows the superconducting Synchrotron and the Proton Beam Transport System


Beam Transport System

 
After leaving the synchrotron, the protons move through a beam transport system, continuing in the vacuum tube through a series of steering and focusing magnets that guide them to the proton treatment rooms. Each proton treatment room has a beam delivery system, or nozzle, is the last device the protons travel through before entering the body. The nozzle shapes and spreads out the proton beam in three dimensions. 

Fig above shows Proton Magnet focus the beam and direct it into each treatment room.

Radiation oncologists must determine location, shape, and tissue density of the target tumor before determining the number of protons to deliver. They must also calculate the depth that the protons must travel in order to calculate the speed and shape of the beam. These decisions render a beam that is highly accurate and practically ‘tailor made’ for a specific treatments.

Treatment Gantry of a Proton Therapy System

After leaving the nozzle, the protons enter the patient's body.
The equipment in the proton therapy treatment rooms vary based on the conditions treated. One proton treatment room may have a stationary beam with two branches – one branch for irradiating eye tumors and the other for central nervous system tumors and tumors of the head and neck. The other treatment rooms may have gantries – wheels that are 35 feet in diameter that revolve around the patient to direct the beam exactly where needed. From the patient's perspective, all that is visible is a revolving, cone-shaped device.
Proton beam therapy is only suitable for certain types of cancer, such as highly complex brain, head and neck cancers and sarcomas as it does not lead to better outcomes for many cancer cases than using high energy x-rays, which is still considered the most appropriate and effective treatment for the majority of cancers.

Like high energy x-ray radiotherapy, proton beam therapy is painless, but patients may experience side effects similar to those experienced from other forms of radiotherapy.

How Does Proton Therapy's Effectiveness Compare to IMRT or Other X-ray Treatments?
Because proton beams can be delivered in higher doses and with far more accuracy, proton therapy typically can control cancer with fewer treatments than IMRT. This pinpoint accuracy also results in fewer long-term side effects (since the radiation does not spill over and damage healthy tissue and organs) meaning that patients treated with proton therapy experience a higher post-treatment quality of life as compared to IMRT and even conventional x-ray treatments.


Is Proton Radiation Therapy Ever Combined?
Yes. Conformal proton therapy is often used in conjunction with X-ray therapy. This method boosts the dose to sites of gross disease and allows irradiation of a large tissue volume. Depending on the amount of cancer within a particular lymph node and type of cancer that is present, a patient may be at risk for harboring microscopic nests of cancer cells within the nodes. These nodes may lie at some distance from the primary tumor and may not be irradiated if conformal proton treatment alone is delivered to the tumor.
The objective of the treatment plan is to treat both the primary tumor and any areas where a microscopic tumor might hide. X-ray treatment alone will limit the total dose of radiation that can be given due to the high doses it delivers to large amounts of healthy tissue. Therefore, conformal proton radiation therapy is used to treat the primary tumor, and is then followed by X-ray therapy to treat the regional nodes. By giving some of the treatment with conformal protons, the total X-ray dose can be reduced substantially.
This reduces the risk of complications and permits treatment of potentially involved lymph nodes. Microscopic cancer within these nodes might be missed if X-rays were not used.

Side-Effect
Since proton therapy allows the radiation to unfold directly in the tumour, the surrounding tissue and organs are protected to the best of their ability. If a reaction – i. e. a side effect – occurs, only the irradiated body region is usually affected. This can lead to irritation of the skin or mucous membranes, which usually recede completely within two to three weeks after treatment. Sometimes, however, a kind of permanent scarring can also occur as a late consequence.


Information on this page is provided for interest only on a "best efforts" basis and does not 
constitute personal advice. Always discuss medical conditions and related matters with your doctor.
 
Reference: https://protons.com/proton-advantage/how-does-proton-therapy-work

Saturday, November 26, 2016

HYBRID OPERATING ROOM

A hybrid operating room is where major procedures that combines a conventional surgical and interventional procedure guided by fluoroscopic or MRI imaging in a hybrid room without interruption.

Traditional fixed C-arms produce 2D fluoroscopy or 3D rotational angiography but with the advanced technology nowadays, C-arms are able to acquire CT-like 3D images and used for image guided surgery and also in intra-operative imaging like flow analysis. With these newer fluoroscopic C-arms where the device image intensifiers are of the digital flat panel detectors has thus enabled the fluoroscopy techniques to transit into three dimensional CT-like imaging capability.

Hybrid operating rooms are currently used mainly in cardiac, vascular and neurosurgery, but could be suitable for a number of other surgical disciplines.



PLANNING THE HYBRID ROOM

Before planning a hybrid operating room, a clear vision of the utilization should be established. It should address the requirements and the needs of various surgical specialties, procedures and workflow. To ensure a smooth workflow in the room, all parties working together should state their needs and requirements, which will impact the room design and determining various resources like space, medical, and imaging equipment. This may require professional project management and several iterations in the planning process with the vendor of the imaging system, as technical interdependencies are complex. The result is always an one solution tailored to the needs and preferences of the interdisciplinary team and the hospital.
Reference: hybridoperatingroom.com

LIGHTS, MONITORS AND OTHER DEVICES

Multiple movable and flexible booms need to be installed in the OR. If there are 2 booms to be installed, a boom of every side of the operating table should be considered to serve the operating team. Collision of the ceiling mounted display with the surgical lights or other ceiling mounted devices should be avoided. Large displays are now available and capable of integrating multiple video inputs on various sizes and therefore decreasing the needs for multiple screens. A dedicated ceiling plan with all ceiling-mounted components including air conditioning should be drawn to ensure the function and usability of all devices. 

The hybrid OR facilitates a whole new spectrum of cardiac surgical therapies, and will therefore become an essential resource of every cardiovascular centre. The trend towards hybrid OR is more of a revolution than an evolution due to the rapid integration into the surgical techniques. The hybrid OR itself represents an extreme complex working environment that demands careful planning by all stakeholders. Bundling all clinical, technical and architectural expertise as well as a realistic view of what is achievable is key for a successful hybrid OR project. 






Reference: cardenjennings.metapress.com & hybridoperatingroom.com & www.maquet-hybridoperatingroom

Thursday, November 24, 2016

Wireless Telemetry System

The Philips MX40 Telemetry device combined with the PIIC iX central monitoring system, is an excellent choice for most hospitals that can expect to leverage the broad networking capabilities and configurability of the system. It may be especially advantageous for larger hospitals that want to access telemetry data and manage system configurations from multiple care areas.


The MX40 device offers most of the features that we believe transmitters with integrated displays should offer to enhance patient safety in many of today's telemetry settings, including:
  • The option to have alarms annunciated, and messages displayed, at the device;
  • A color display with up to two waveforms, and numeric patient data with alarm limits;
  • The ability to silence and pause alarms at the MX40;
  • The ability for the MX40 to transition to the functionality of a mini-arrhythmia detection capability and alarms.

Telemetry systems were developed to monitor patients who are at risk for cardiac events but not acutely ill enough to warrant continuous bedside monitoring. Today, they often offer additional measurements that can be used to monitor conditions like hypoxia and compromised respiratory status. Patients on telemetry monitoring are often ambulatory for part of the day.

The IntelliVue MX40 telemetry system comprises the following:

a) The patient-worn MX40 telemetry device, which is used to acquire patient data and relay it wirelessly using Philips' IntelliVue Smart-hopping 1.4 GHz WMTS network or the hospital's industrial, scientific and medical (ISM) 802.11a/b/g/n wireless network.
  • The device is powered interchangeably by either a rechargeable Li-ion battery or three AA alkaline batteries and is equipped with a 1.70 × 2.26-inch color display.
  • The MX40 monitors ECG, detects arrhythmias, and displays continuous ST and QT segments, SpO2, and impedance respiration, when connected to the PIIC iX or when communication is lost between the device and PIIC iX.
  • The display on the MX40 can show numerics and up to two waveforms (i.e., ECG, SpO2, or impedance respiration).

b) The PIIC iX platform, which can be used to control multiple types of Philips monitors across multiple care areas. The PIIC iX includes a telemetry central station, consisting of a PC and one or two flat-panel screens for clinical review. In a networked, multi-care-area configuration, the PIIC iX can be used to easily transfer patients from one care area to another or to allow overview monitoring of multiple care areas.
  • The PIIC iX can accommodate up to 32 patients (either single or dual displays, depending on PC screen size).
  • Central stations are usually located at unit nursing stations and hallways. Some facilities consolidate patient monitoring in remote areas, where a team of technicians is given responsibility for monitoring central station screens. The PIIC iX is adaptable to either of these models.
  • The following diagram depicts the workflow of the PIIC iX platform. Note that the "IBE" shown in the diagram is the IntelliBridge Enterprise, a bidirectional interface between the Philips clinical informatics system and the hospital information systems; it is used to  exchange admission/discharge/transfer (ADT) information, laboratory information, patient orders, and data between the Philips system and the electronic health record. (Image courtesy of Philips).


Information on this page is provided for interest only on a "best efforts" basis and does not 
constitute personal advice. Always discuss medical conditions and related matters with your doctor.
 
Source: ecri institute