Got my hands on a copy of the paper that beat mine to publication.
The end result they come up with is the same as mine, although their work was done on just one gamma camera and had a little more focus on image quality than mine did. I was able to do some cross-camera comparisons with my data and had a little more analysis on the core question (is T1/2 the same between collimators). I think mine still has a good chance of being published. Hopefully the reviewers will also think it’s a worthy addition to this other paper. I just won’t have first post bragging rights.
The perils of procrastinating
So it seems a group of people at Ottawa Hospital in Ontario has just had a paper published in JNMT that covers pretty much the same material I worked on and just submitted to the same journal. My contact at GSK told me it was something they also sponsored (like my project), but wasn’t aware they had submitted it for publication.
Trying to get my hands on a copy of the article so I can read it and see what they looked at. Fortunately they come up with the same conclusions and results I did. From the abstract it seems like some of the things they investigated were different from what I looked at, so hopefully it’s different enough from mine that the reviewers decide it’s still worthy of publication.
My abstract:
Objective: Residence time measurements obtained by serial whole body conjugate view imaging are commonly used in patient specific dosimetry for radioimmunotherapy (RIT) applications. In order to determine the effect of collimator selection on residence time measurements for 131I, the accuracy of 131I half-life measurements using multiple gamma camera and collimator combinations was investigated. Method: Serial anterior and posterior whole body images were acquired over a period of 15 days using 4 different gamma cameras with medium and/or high energy collimators. Background corrected geometric mean counts from the images were fitted to a mono-exponential curve to determine the half-life of 131I for the different gamma camera/collimator combinations. Results: An average half-life of 8.15 days with a standard deviation (SD) of 0.07 days was obtained from all camera/collimator combinations. A half life of 8.12 days (SD 0.11 d) was obtained for the high energy collimators, and 8.18 d (SD 0.04 d) for the medium energy collimators. These values are all very close to the 8.02 day 131I physical half-life and were not found to be statistically different (p=0.44). Similar results were also obtained for the measured half-life for single head gamma camera configurations (mean half life 8.15 d, SD 0.12 d). The therapeutic 131I-tositumomab dose resulting from the differences in measured half-life ranged between 2.58–2.6 GBq (69.8–70.4 mCi). Conclusion: There is no significant difference in 131I half-life and residence time measurements made using medium or high energy collimators in dual head or single head imaging configurations.
Their abstract:
131I-Tositumomab has been used in treating patients with non-Hodgkin’s lymphoma. It is generally recommended that high-energy collimators be used to image patients before they receive 131I-tositumomab therapy, to determine the effective half-life for therapeutic dose and gross biodistribution. Because many nuclear medicine departments do not possess high-energy collimators, this study was designed to assess the suitability of using medium-energy collimators. The effect of scanning speed was also investigated, in an attempt to optimize the acquisition time. Methods: Measurements were taken using an elliptic anthropomorphic torso phantom and an organ-scanning phantom fitted with fillable spheres (1-5 cm in diameter) and organ inserts. Three phantom studies were performed with differing initial 131I concentrations in the organs, the spheres, and the thoracic and abdominal chambers. Images were acquired with both high-energy and medium-energy collimators and at acquisition speeds of 20 and 100 cm/min. The half-life for each combination (study/collimator/speed) was calculated from a linear fit of the data. The contrast of the tumor sphere was assessed using 2 identical regions, placed on and beside the sphere, and averaged over several time points. Biodistribution and image quality were visually assessed by 2 independent observers. Results: Measured half-life values and visual assessment of biodistribution showed no significant difference between the 2 collimators (P = 0.32) or acquisition speeds (P = 0.85). A significant difference in the contrast of the tumor spheres was observed between the 2 collimators (P < 0.01) but not between acquisition speeds. Visual assessment of the images showed increased noise on the image acquired at 100 cm/min, although this noise did not affect lesion detectability. Conclusion: Measured half-life is not significantly different between the 2 collimators; hence, calculation of the residence time would be nearly the same. Medium-energy collimators can be used to accurately calculate the 131I-tositumomab therapeutic dose and detect alterations in biodistribution.
Collaborative writing made easier?
An abstract I wrote up for the little archive project I’ve been collecting data for got accepted as a talk for the SIIM 2007 annual meeting. One of the things they ask accepted presenters to do is to also submit a paper for publication in JDI.
Anybody who’s ever written a paper with more than one author knows that keeping track of all the revisions and changes from one author to another can be problematic, especially if both authors are contributing different sections.
This time I’m going to try something different. I’m going to try using Google Docs for the writing. At least for the content anyway. Google Docs has some neat collaborative functionality and revision tracking capabilities that will probably come in handy. My co-author and I can open the document at the same time, we can both write and even discuss online while we’re editing. Once we get things written, I’ll convert it into a LaTeX document for typesetting and submission.
This should be an interesting experiment.
Time for more writing
Just finished submitting one paper to JNMT. A couple of days ago I found out that an abstract I submitted to the SIIM annual meeting was accepted, so now I have to write up a paper to submit to JDI and a 12 minute talk for the meeting.
Since the meeting’s not until June, I have some time for the talk. Need to get working on the paper pretty quick though.
The Interviewer
Tomorrow I have the task of interviewing a well known and prominent physicist in my field for a position here.
This is a strange position for me. I’ve never interviewed anybody before, and usually it would be me in the interviewee spot and him in the interviewer position. Admittedly, I’m a little nervous about what kinds of things to ask him and talk to him about. I have a few things, but I’ll need to come up with a more to fill up the 30 minute time slot I have with him.
This should be interesting.