A feasibility and pilot study of the clinical efficacy of a custom designed handgrip device to improve patient immobilisation for the external beam radiotherapy of oesophageal cancers

Abstract

The primary aim of radiotherapy is to eradicate tumour cells within the clinical target volume (CTV), at the same time while sparing surrounding organs at risk (OAR) which is often accomplished by conforming to the treatment fields, i.e. target volume and by using appropriate margins for accounting the treatment uncertainties. Furthermore, for accurate radiation dose delivery, perfect immobilisation is required to keep the patient within the same position at each treatment fraction. There has always been a need for perfect immobilisation which should provide minimal patient movement, patient comfort, reproducible patient positioning during radiotherapy and be less expensive. The main objective of the present study was to design, fabricate and evaluate a handgrip board immobilisation device for the thorax region to boost the efficiency of the external beam radiotherapy in oesophageal cancer patients and evaluate the set-up error. Our indigenously fabricated handgrip baseboard device is made of poly-methyl methacrylate (PMMA), which consists of the main baseboard with an adjustable central T-bar and separate right and left single hand poles. In the present study, fifteen patients with oesophageal tumours were included. Patients were positioned using the indigenously fabricated handgrip immobilisation device; portal images were performed prior to the treatment and matched with the digitally reconstructed radiographs (DRR). The population systematic (Σ) and random (σ) patient set-up errors were calculated along the direc­tions of Anterior-Posterior (AP), Medial-Lateral (ML) and Superior-Inferior (SI). The values for the planning target volume (PTV) margins were calculated using ICRU 62, Van Herk’s and Stroom’s formulae. The population systematic (Σ) errors of AP, ML and SI were 0.12, 0.20 and 0.20 cm, respectively while the population random (σ) errors of AP, ML, SI were 0.17, 0.31 and 0.17 cm, respectively. The PTV margins were calculated according to ICRU 62, Van Herk’s, and Stroom’s and it was observed in the range of 0.2–0.7 cm in the three acquisition directions. The use of a handgrip immobilisation device allowed for relatively small set-up errors and ensured the patient’s comfort. Also, the technique showed satisfactory accuracy and reproducibility.

KEYWORDS:

• Oesophagus cancer
• handgrip immobilisation device
• portal image
• set-up errors

Acknowledgements

The authors would like to thank Dr. Pugalagiri Vadamalayan Chairman and Managing Director, Integrated Cancer Centre, Vadamalayan Hospital, Madurai, India. In addition, I extend my gratitude to Mr. K. Kumarasamy, and Mrs. V. Ramalakshmi, Radiotherapy Technologist Vadamalayan Hospital, Madurai, India.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Kesavan Govindaraj

Kesavan Govindaraj received his MBA (Hospital Management) degree at Alagappa University in 2013. He also received his M.Sc (Medical Physics) degree at the Department of Medical Physics of Bharathiar University in 2009 and his B.Sc (Physics) degree from the Bharathidasan University in 2007. His research interests include several areas related to radiotherapy applications, radiation detection and measurement. He is currently the Chief Medical Physicist and RSO, Department of Radiotherapy, Vadamalayan Hospitals Integrated Cancer Centre, Madurai, India. He is also a research scholar at the Centre for Research and Evolution, Bharathiar University, Coimbatore, Tamil Nadu, India.

Senthilkumar Shanmugam

Dr. Senthilkumar Shanmugam received his Ph.D degree from MK University, India in 2009. He received his M.Sc degree from Anna University, India in 1998 and his B.Sc (Physics) degree from the University of Madras, India in 1995. His research interest includes the development of innovative radiation quality improvement devices, respiratory gating device and sensors for radiotherapy applications. He is currently working as Senior Assistant Professor of Radiology Physics in the Regional Cancer Center, Madurai Medical College & Govt. Rajaji Hospital, Madurai, Tamil Nadu, India.

Sowmiya Sampathrajan

Dr. Sowmiya Sampathrajan received her MD (Radiation oncology) at PGIMER, Chandigarh in 2013 and she received her MBBS degree at Madurai Medical college / Goverment Rajaji Hospital-Madurai in 2008. Her research interest is innovative treatment approaches to manage many cancers types and also interested in brachytherapy for gynecological cancer. She is a certified pain and palliative care specialist and she did her senior residency from Max Vaishali Hospital, New Delhi. She is currently a senior consultant, Department of Radiotherapy, Vadamalayan Hospitals Integrated Cancer Centre, Madurai, India.