Biological impact of geometric uncertainties: what margin is needed for intra-hepatic tumors?

<p>Abstract</p> <p>Background</p> <p>To evaluate and compare the biological impact on different proposed margin recipes for the same geometric uncertainties for intra-hepatic tumors with different tumor cell types or clinical stages.</p> <p>Method</p> <p>Three different margin recipes based on tumor motion were applied to sixteen IMRT plans with a total of twenty two intra-hepatic tumors. One recipe used the full amplitude of motion measured from patients to generate margins. A second used 70% of the full amplitude of motion, while the third had no margin for motion. The biological effects of geometric uncertainty in these three situations were evaluated with Equivalent Uniform Doses (EUD) for various survival fractions at 2 Gy (SF₂).</p> <p>Results</p> <p>There was no significant difference in the biological impact between the full motion margin and the 70% motion margin. Also, there was no significant difference between different tumor cell types. When the margin for motion was eliminated, the difference of the biological impact was significant among different cell types due to geometric uncertainties. Elimination of the motion margin requires dose escalation to compensate for the biological dose reduction due to the geometric misses during treatment.</p> <p>Conclusions</p> <p>Both patient-based margins of full motion and of 70% motion are sufficient to prevent serious dosimetric error. Clinical implementation of margin reduction should consider the tumor sensitivity to radiation.</p

Development of minimum standards of care for juvenile localized scleroderma

Juvenile localized scleroderma (jLS), also known as morphea, is an orphan disease. Pediatric guidelines regarding diagnosis, assessment, and management are lacking. Our objective was to develop minimum standards of care for diagnosis, assessment, and management of jLS. A systematic review was undertaken to establish the pediatric evidence for assessment and monitoring of jLS. An expert panel, including members of the Pediatric Rheumatology European Society (PRES) Scleroderma Working Group, were invited to a consensus meeting where recommendations were developed based on evidence graded by the systematic review and, where evidence was lacking, consensus opinion. A nominal technique was used where 75% consensus was taken as agreement. Recommendations for diagnosis, assessment, and management were developed. Due to a lack of pediatric evidence, these were primarily consensus driven. Careful assessment for extra-cutaneous manifestations including synovitis, brain involvement, and uveitis were key features together with joint assessments between Dermatology and Rheumatology to improve and standardize care. Conclusion: Management of jLS is varied. These recommendations should help provide standardization of assessment and care for those with this rare and potentially debilitating condition. What is Known: _ Children with juvenile localized scleroderma (jLS) are managed by a number of specialties including pediatric rheumatologists and dermatologists, sometimes in shared clinics. Studies have shown that management varies considerably and that there are notable differences between specialties [1]. _ There is very little published guidance on management of jLS. What is new: _ These recommendations aim to standardize diagnosis, assessment, and management through review of pediatric evidence and consensus agreement. Joint review of patients by both pediatric rheumatologists and dermatologists is recommended