Related Experiment Video
Updated: Jan 23, 2026
08:25
Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System
Published on: April 11, 2018
15.9K
Forward- and Inverse-Planned Intensity-Modulated Radiotherapy in the CHHiP Trial: A Comparison of Dosimetry and
O F Naismith1, C Griffin2, I Syndikus3
1Royal Marsden NHS Foundation Trust, London, UK.
Clinical Oncology (Royal College of Radiologists (Great Britain))
|June 11, 2019
Summary
Hypofractionated high-dose intensity modulated radiotherapy for prostate cancer showed inverse planning may reduce acute bowel toxicity. Both conventional and hypofractionated radiotherapy techniques demonstrated low rates of late side-effects.
Area of Science:
- Oncology
- Radiation Oncology
- Clinical Trials
Background:
- The CHHiP trial evaluated hypofractionated radiotherapy for localized prostate cancer.
- Both forward-planned (FP) and inverse-planned (IP) intensity-modulated techniques were utilized.
- Dose-volume histogram and toxicity data were analyzed to compare planning methods.
Purpose of the Study:
- To compare the effects of forward-planning (FP) versus inverse-planning (IP) in intensity-modulated radiotherapy for prostate cancer.
- To assess acute and late toxicity outcomes, specifically grade 2 or higher Radiation Therapy Oncology Group (RTOG) bowel or bladder toxicity at 2 years.
- To analyze dose-volume histogram differences between FP and IP techniques.
Main Methods:
- 337 participants with intermediate-risk prostate cancer were included.
- Patients were matched on prostate and rectum/bladder volumes and radiotherapy dose.
- Primary outcome: grade 2+ RTOG bowel/bladder toxicity at 2 years.
Main Results:
- Inverse-planned (IP) radiotherapy resulted in smaller irradiated rectal volumes (50-70 Gy) compared to forward-planned (FP) (P < 0.001).
- Forward-planned (FP) radiotherapy resulted in smaller irradiated bladder volumes (74 Gy) compared to IP (P = 0.001).
- Acute grade 2+ bowel toxicity was significantly worse with FP (52%) versus IP (21%) (P = 0.0002). No significant difference in acute urinary toxicity.
- Late toxicity rates were low for both techniques at 2 years.
Conclusions:
- Significant differences in dose-volume histograms were observed between FP and IP methods.
- Inverse planning (IP) may offer a slight reduction in acute bowel toxicity.
- Both conventional and hypofractionated radiotherapy techniques showed low rates of late radiotherapy side-effects.
Related Concept Videos
01:16Clinical Trials
10.2K
Clinical trials are prospective experimental studies conducted on humans to determine the safety and efficacy of treatments, drugs, diet methods, and medical devices. Using statistics in clinical trials enables researchers to derive reasonable and accurate conclusions from the collected data, allowing them to make wise decisions in uncertain situations. In medical research, statistical methods are crucial for preventing errors and bias.
There are four phases in a clinical trial. A phase one...
There are four phases in a clinical trial. A phase one...
10.2K
01:11Clinical Trials: Overview
4.7K
Clinical development focuses on how the drug will interact with the human body and encompasses four key phases of clinical trials, each serving a specific purpose in assessing the safety and effectiveness of new drugs. These phases overlap and build upon one another. Phase I involves a small group of healthy volunteers (typically 20-80 individuals) or, in cases where significant toxicity is expected, patients with the targeted disease, such as cancer or AIDS. The volunteers are tested for...
4.7K
01:12Trial and Error and Algorithm
403
A problem-solving strategy is a plan of action used to find a solution. Different strategies have distinct action plans. Trial and error involves trying different solutions until one works. For instance, to fix a broken printer, you might check ink levels, ensure the paper tray isn't jammed, and verify the printer's connection to your laptop. This method can be time-consuming but is commonly used. Thomas Edison, for example, used trial and error to find a suitable filament for the light...
403
01:23Sampling Plans
908
Sampling is a crucial step in analytical chemistry, allowing researchers to collect representative data from a large population. Common sampling methods include random, judgmental, systematic, stratified, and cluster sampling.
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...
908
01:25Inverse Hyperbolic Functions and Their Derivatives
54
The shape of a suspension bridge cable hanging under its own weight is described by a catenary curve, which is modeled using the hyperbolic cosine function. This mathematical model accurately captures the balance between gravity and tension acting along the cable. When a particular vertical position on the cable is known, the corresponding horizontal position can be determined using the inverse hyperbolic cosine function, allowing for a detailed analysis of the cable's geometry.Inverse...
54
02:57The Sense of Self: Reflected Self-Appraisal and Social Comparison
55.5K
According to Charles Cooley, we base our image on what we think other people see (Cooley 1902). We imagine how we must appear to others, then react to this speculation. We don certain clothes, prepare our hair in a particular manner, wear makeup, use cologne, and the like—all with the notion that our presentation of ourselves is going to affect how others perceive us. We expect a certain reaction, and, if lucky, we get the one we desire and feel good about it. But more than that, Cooley...
55.5K