Objective: The objective of this study was to prospectively collect and report treatment planning data in terms of organs at risk (OARs) sparing effect between deep inspiration breath hold (DIBH) and free breathing (FB) computed tomography (CT) scans. This study also aims to identify potential planning parameters that could help in selecting patients most likely to benefit from DIBH. Methods: Thirty-eight patients with left-sided breast malignancy indicated for adjuvant radiotherapy underwent DIBH and FB CT simulation. All patients were planned with a three-dimensional conformal radiation therapy (3D-CRT) for both scans. Comparisons of dosimetric variables include heart Dmean, left anterior descending coronary artery (LAD) Dmean/Dmax, left lung V30Gy, V20Gy, V10Gy, V5Gy, FB axial cardiac contact distance (FB-CCDax) and parasagittal CCD (FB-CCDps). Results: DIBH resulted in a statistically significant reduction of heart Dmean, LAD Dmean and Dmax. When DIBH was compared with FB, heart Dmean was 1.62 Gy versus 2.65 Gy; for LAD Dmean, 6.81 Gy versus 11.57 Gy; and for LAD Dmax, 22.66 Gy versus 31.93 Gy. Left lung dosimetry results consistently showed all the volume parameters of V5Gy to V30Gy for FB were significantly higher than that of DIBH. There was a significant positive correlation between FB-CCDax/FB-CCDps and mean heart absolute dose reduction. A meaningful positive correlation was observed for FB-CCDps beyond the cutoff length of 2cm. Conclusion Our study has confirmed the benefit of DIBH in reducing mean heart and lung dose in left-sided breast/chest wall radiotherapy. FB-CCDps is a potentially reliable parameter to guide us in selecting patients whom would benefit most for DIBH.

Cancer during pregnancy is a rare condition. We report here a case of a lady diagnosed with nasopharyngeal carcinoma (NPC) at University of Malaya Medical Centre during her first pregnancy conceived via In Vitro Fertilisation (IVF). A multidisciplinary (MDT) meeting among Oncology, Obstetrics, Rheumatology and Otolaryngology teams was conducted to discuss her treatment options. She opted for treatment with Complementary and Alternative Medicine (CAM). This case illustrates the unique challenges in the oncological management of a patient diagnosed with NPC during pregnancy. It also serves as a reminder that the use of CAM in cancer patients is prevalent. It is important for doctors to inquire about use of CAM and to be well-informed about it. Transparent communication and taking cognizance of the goals and concerns of the patients are essential in delivering patient-centred care.

Background: Set-up errors are errors which are inevitable in radiotherapy. However, they should be kept to a minimum to achieve the maximum radiation dose to a tumour as to maximise treatment efficacy. This study aims to quantify those errors and assess if they remain within the tolerance limit of 5 mm in all directions. This study will also determine the adequacy of the margins for set up error for 3DCRT of rectal cancers at University of Malaya Medical Centre (UMMC). Methods: A total of 20 rectal cancer patients (July 2018 to May 2019) who were treated with radiotherapy amounting to a total of 119 CBCT images were included in the study. Population systematic errors and random setup errors were calculated. Results: Population systematic errors and random setup errors in the vertical, longitudinal and lateral direction were tabulated in Table 1. There is a large deviation (>5 mm) noted in some patients’ setup between the first 3 days and the next successive day of imaging. Clinical target volume (CTV) to planning target volume (PTV) margin were calculated using Van Herk’s margin recipe (M=2.5Σ+0.7σ). The margins were 5.0 mm, 6.2 mm, and 4.0 mm for vertical, longitudinal and lateral directions, respectively. The systematic error for the population was 1.1 mm, 0.9 mm, 0.9 mm in the vertical, longitudinal and lateral directions respectively, while the random error is 3.2 mm, 5.7 mm and 2.5 mm in the vertical, longitudinal and lateral directions respectively. Conclusion All of the patients involved in the study were within tolerance limits at some point in their treatment. The results demonstrated that a larger margin is needed in the longitudinal direction. Weekly CBCT is also necessary after the initial 3-day imaging to ensure that patients are kept within the tolerance limits.
Radiotherapy