The nuances of brachytherapy taught by teachers from beyond: Questionnaire-based assessment of the first cadaveric hands-on brachytherapy workshop in India.

PURPOSE: A questionnaire-based assessment of a cohort of young radiation oncologists attending the first human cadaveric hands-on brachytherapy workshop in India. METHODS AND MATERIALS: The cadaveric workshop for hands-on training in head/neck and gynecologic cancers was a novel process conducted at M.S. Ramaiah Medical College and Hospital, for which 30 attendees from all regions of India took part with an opportunity to interact with experienced resource persons, individually perform the procedure, and indulge in all aspects of brachytherapy process. The questionnaire was part of the workshop and enquired on common practices for head/neck and gynecologic brachytherapy followed by the attendees at their hospitals and their opinion on avenues for learning the skill of brachytherapy and its future as a therapeutic modality. RESULTS: Twenty-seven of thirty attendees were practicing brachytherapy at their centers out of which only 14 (46%) were doing head/neck brachytherapy. In gynecologic procedures, 89% were performing only intracavitary brachytherapy. Twenty attendees (66%) felt lack of expertise was the primary reason for dwindling brachytherapy practice in India. Ten (33%) of them felt that advancements in external radiotherapy were the second major cause for it. Some less important reasons given were lack of suitable cases, fear of toxicity, and reduced remuneration. CONCLUSIONS: Cadaveric brachytherapy workshops may be a practical and cost-effective method to inculcate this unique skill set in the next generation of radiation oncologists. This questionnaire-based assessment has tried to validate this opinion.

Analysis of physical parameters and determination of inflection point for Flattening Filter Free beams in medical linear accelerator.

BACKGROUND: Medical Linear accelerators manufactured without flattening filters are increasing popular in recent days. The removal of flattening filter results in increased dose rate, reduced mean energy, reduction in head leakage and lateral scattering, which have shown advantageous when used for special treatment procedures. AIM: This study aims to analyze physical parameters of FFF beams and to determine the inflection point for standardizing the beam flatness and penumbra. MATERIALS AND METHODS: The beam profiles and depth dose patterns were measured using Radiation Field Analyzer (RFA) with 0.13 cc cylindrical ion chamber. The beam energy characteristics, head scatter factor (Sc) were obtained for 6FFF and 10FFF beams and compared with 6 MV and 10 MV photons, respectively. The symmetry and stability of unflattened regions were also analyzed. In addition, the study proposes a simple physical concept for obtaining inflection point for FFF beams and results were compared using the Akima spline interpolation method. The inflection point was used to determine the field size and penumbra of FFF beams. RESULTS: The Sc varied from 0.922 to 1.044 for 6FFF and from 0.913 to 1.044 for 10FFF with field sizes from 3 cm × 3 cm to 40 cm × 40 cm which is much less than FF beams. The obtained value of field size and penumbra for both simple physical concept and Akima spline interpolation methods is within the ±1.0 mm for the field size and ±2 mm penumbra. The results indicate that FFF beams reduce Sc compared with FF beams due to the absence of a flattening filter. CONCLUSION: The proposed simple method to find field size and penumbra using inflection point can be accepted as it is closely approximated to mathematical results. Stability of these parameters was ascertained by repeated measurements and the study indicates good stability for FFF beam similar to that of FF beams.