The value of magnetic resonance imaging for radiotherapy planning

Challenges and opportunities in image guided particle therapy

The application of biomedical imaging and image processing to radiation therapy with accelerated particles has unique challenges. The potential of particle therapy to precisely tailor the dose distribution around the target volume needs to account for the intrinsic sensitivity to uncertainties in dose deposition. These peculiar features motivate the use of image guided methods to consistently verify the accuracy in dose delivery. Dedicated imaging and image processing methods are required, from treatment planning to treatment verification phases, in order to reduce the effects of uncertainties. The scenario is also complicated by the lack of standardized layouts of treatment bunkers, which implies the relatively increased use of custom solutions. Conversely, imaging can be applied to verify the actual delivered dose, representing a valuable opportunity to validate specific protocols and visualize the efficacy of the intended treatment. In this contribution, challenges and opportunities in image guided particle therapy are overviewed, with a clear focus on research perspectives in biomedical imaging and image processing.

Advances in Radiotherapy for Head and Neck Cancer

Over the last few decades, significant improvements have been made in the radiotherapy (RT) treatment of head and neck malignancies. The progressive introduction of intensity-modulated RT and the use of multimodality imaging for target volume and organs at risk delineation, together with the use of altered fractionation regimens and concomitant administration of chemotherapy or targeted agents, have accompanied efficacy improvements in RT. Altogether, such improvements have translated into improvement in locoregional control and overall survival probability, with a decrease in the long-term adverse effects of RT and an improvement in quality of life. Further progress in the treatment of head and neck malignancies may come from a better integration of molecular imaging to identify tumor subvolumes that may require additional radiation doses (ie, dose painting) and from treatment adaptation tracing changes in patient anatomy during treatment. Proton therapy generates even more exquisite dose distribution in some patients, thus potentially further improving patient outcomes. However, the clinical benefit of these approaches, although promising, for patients with head and neck cancer need to be demonstrated in prospective randomized studies. In this context, our article will review some of these advances, with special emphasis on target volume and organ-at-risk delineation, use of molecular imaging for tumor delineation, dose painting for dose escalation, dose adaptation throughout treatment, and potential benefit of proton therapy.

Retrospective study using MRI to measure depths of acupuncture points in neck and shoulder region

OBJECTIVES

There are safety issues associated with acupuncture treatment. Previous studies regarding needling depth of acupuncture points revealed inconsistent results due to vague depth definition, acupuncture point localisation and measuring tools. The objective of this study is to find and compare the differences of the mean depths of 11 acupuncture points in the neck and shoulder region between subjects, with variables including gender and body mass index (BMI).

SETTING

This study was conducted at a single medical center in Taiwan.

PARTICIPANTS

Three hundred and ninety-four participants were included in this study. Participants were grouped according to gender and BMI. Acupuncture points were localised by WHO standard and measured by MRI.

OUTCOME MEASURES

The distance from the needle insertion point (surface of the skin) to any tissues that would cause possible/severe complications.

RESULTS

Mean depths of 11 points were obtained in groups of different BMI and gender. Mean depths of all participants regardless of BMI and gender are as follows, in centimetres: GB21=5.6, SI14=5.2, SI15=8.8, GV15=4.9, GV16=4.6, GB20=5.0, ST9=1.6, SI16=1.8, SI17=2.4, TE16=3.1, LI18=1.3. Participants with higher BMI had greater measured depths in both gender groups. Male participants had larger mean depths than female participants regardless of BMI except in SI17 and LI18. When taking BMI into consideration, depths in male participants are greater than in female participants in most of the points except the following: GB21, TE16 in obesity group; ST9 in underweight and obesity group; SI16 in ideal body weight, overweight and obesity group; SI17, LI18 in each group.

CONCLUSIONS

Participants with higher BMI had greater measured depths and males tended to have greater depths in most of the points. Clinical practitioners are recommended to consider this information to prevent complications when applying acupuncture treatment to their patients.