An application of visible human database in radiotherapy: tutorial for image guided external radiotherapy (TIGER)

A randomised phase II trial of Stereotactic Ablative Fractionated radiotherapy versus Radiosurgery for Oligometastatic Neoplasia to the lung (TROG 13.01 SAFRON II)

Background

Stereotactic ablative body radiotherapy (SABR) is emerging as a non-invasive method for precision irradiation of lung tumours. However, the ideal dose/fractionation schedule is not yet known. The primary purpose of this study is to assess safety and efficacy profile of single and multi-fraction SABR in the context of pulmonary oligometastases.

Methods/Design

The TROG 13.01/ALTG 13.001 clinical trial is a multicentre unblinded randomised phase II study. Eligible patients have up to three metastases to the lung from any non-haematological malignancy, each < 5 cm in size, non-central targets, and have all primary and extrathoracic disease controlled with local therapies. Patients are randomised 1:1 to a single fraction of 28Gy versus 48Gy in four fractions of SABR. The primary objective is to assess the safety of each treatment arm, with secondary objectives including assessment of quality of life, local efficacy, resource use and costs, overall and disease free survival and time to distant failure. Outcomes will be stratified by number of metastases and origin of the primary disease (colorectal versus non-colorectal primary). Planned substudies include an assessment of the impact of online e-Learning platforms for lung SABR and assessment of the effect of SABR fractionation on the immune responses. A total of 84 patients are required to complete the study.

Discussion

Fractionation schedules have not yet been investigated in a randomised fashion in the setting of oligometastatic disease. Assuming the likelihood of similar clinical efficacy in both arms, the present study design allows for exploration of the hypothesis that cost implications of managing potentially increased toxicities from single fraction SABR will be outweighed by costs associated with delivering multiple-fraction SABR.

Trials registration

ACTRN12613001157763, registered 17th October 2013

Temporal Changes in IMRT Contouring of Organs at Risk for Nasopharyngeal Carcinoma — The Learning Curve Blues and a Tool that Could Help

With improved target conformality, the transition to IMRT for nasopharyngeal cancer (NPC) has moved contouring accuracy and consistency to the forefront. At NUH, IMRT for NPC was implemented in 2005, with more than 70 patients treated since then. The objective was to measure the accuracy and variability of contouring organs at risk (OAR) over time. The first 10 patients, 5 from each of the two head and neck (H&N) Radiation Oncologists, treated by IMRT in 2005 formed cohort A. Ten patients, matched by stage, treated by IMRT in 2007 formed cohort B. The RTOG 0225 protocol was followed. These 20 plans were retrieved from archive. A H&N Radiologist, who is a member of the UICC Expert Panel for the TNM Staging of NPC, reviewed the original OAR contours and developed a standardized OAR contouring template. Using the template, the OAR volumes were then re-contoured in all 20 cases, representing the gold standard against which the original volume was compared. For each patient, comparisons were made between the original and standardized contours using volumetric and spatial parameters. Cohort A was then compared with cohort B to determine whether accuracy and variability changed over time. Evaluated OAR volumes included the temporal lobes, brainstem, optic nerves, optic chiasm, pituitary, temporo-mandibular joint (TMJ), parotid glands, inner ears, eyes, and thyroid. While the original temporal lobe contours were significantly larger in cohort B (60.2 vs. 106.8 mL, p=0.02), the absolute difference between the original and standardized volumes was reduced by 53% (p=0.02) and there was no difference in the centroid coordinates and the overlapping fraction. While the inner ear was consistently contoured between cohort A and B, there was systematic exclusion of the cochlea in the contours. The original optic nerve contours decreased from cohort A to B (p=0.008), with an improvement in overlap fraction (p=0.06). The TMJ original volumes were smaller for cohort B than A, with a correspondingly significant improvement in overlapping fraction (p=0.02) with the standardized volumes. No difference was seen in the remaining OAR.

Anatomical bases for the radiological delineation of lymph node areas. Upper limbs, chest and abdomen

Cancer spreads locally through direct infiltration into soft tissues, or at distance by invading vascular structures, then migrating through the lymphatic or blood flow. Although cancer cells carried in the blood can end in virtually any corner of the body, lymphatic migration is usually stepwise, through successive nodal stops, which can temporarily delay further progression. In radiotherapy, irradiation of lymphatic paths relevant to the localisation of the primary has been common practice for decades. Similarly, excision of cancer is often completed by lymphatic dissection. Both in radiotherapy and in surgery, advanced knowledge of the lymphatic pathways relevant to any tumour location is an important information for treatment preparation and execution. This second part describes the lymphatics of the upper limb, of the thorax and of the upper abdomen. Providing anatomical bases for the radiological delineation of lymph nodes areas in the axilla, in the chest and in the abdomen, it also offers a simplified classification for labeling the mediastinal and intra-abdominal nodal levels, grouped in each location inside three major functional areas (called I, II and III) which are all divided into three sublevels (named a, b or c).

Virtual anatomy: An anatomist's playground

Virtual anatomy presents significant advantages over the reality of a cadaver as it can provide different views and perspectives, portability, longevity, standardization, diversity and most importantly the opportunity to learn the anatomy of the living human body instead of the corpse. Virtual anatomy is the life-like appearance of visible anatomy, a good example of which is the evolution of the Visible Human. Racial and statistical diversity is already developing as the population of photographic "Visible Humans" is now at least 10. Virtual anatomy should include additional diversity and therefore, consideration should be given to the preparation of more visible anatomy that will better support the virtual integration of all areas of physiology, kinematics, pathology and pathophysiology, development and evolution. Integration of anatomists with mathematicians, computer scientists, information scientists, physiologists, pathologists and clinicians (and LIST other basic scientist) is needed in order to facilitate this development. As this unfolds it is proposed, or challenged, that anatomists should maintain their position of responsibility for building anatomy as the foundation for all medical and healthcare education. In order to maintain that position they must understand and participate in this development and enjoy the rewards of teaching more visually empowering, functional, and clinical anatomy. The trip is a long one and is only about to begin but the train is leaving. Are you on board?