Radiation Oncology - Latest Comments

Typo in Table 2

Reinhard Vonthein — 2013-02-25T19:19:33Z

In Table 2, there is an obvious switch of places in the first line of numbers between 21 observations and percentage 65.6.

trade-off between PTV coverage and OAR doses

Simon Thomas — 2011-06-12T11:29:49Z

Sir,

The recent planning study by Wiezorek et al (2011) is a commendable attempt to benchmark IMRT planning software and techniques in standardised cases of head and neck cancer. In order to minimise variation between the groups the planning objectives of the study are clearly defined with a requirement for at least 93% of the prescribed dose to a minimal 99% of the PTV and the authors state that ¿fulfilling the objectives of the dose criteria for the PTV is given highest priority for treatment planning, except the criteria for the spinal cord could not be met¿. Although one technology / treatment planning system achieved this objective (RapidArc), in figure 2 of the paper it is evident that the other groups had accepted much lower doses to PTV2 with most only achieving 90% or lower. This was presumably a compromise to allow them to attempt to keep parotid and mandible doses low. We have plotted the parotid doses from table 3 as a function of the PTV2 D99% values from figure 2. With the exception of one outlier, they are clustered around a trendline that shows the generally accepted trade-off between PTV coverage and OAR doses.

Unfortunately the results and the conclusion presented in this study have highlighted a problem of variable application of the dose constraints in different groups with different emphasis given to the PTV and OAR objectives. If all the centres had followed the objectives set out in the method, and prioritised achieving 93% or more to the D99%, it would be possible to compare the performance of the planning systems. The planning system that gave 14.11 Gy to the parotids (whilst failing the PTV objective) could probably, if parotid doses were allowed to rise to the 26Gy permitted in the objectives, have met the PTV objective for all patients. However this study fails to discover if this is so.

Regards

Simon Thomas and Richard Benson

Skin thickness data

Anthony Ying — 2011-02-09T16:04:06Z

I wonder whether all the skin thickness quoted in the article should be in cm instead of mm (for example 0.1845 cm instead of 0.1845 mm as quoted )because normal dermis of skin already measures 1-2 mm thick.

Perspectives for Radiotherapy of Non-Malignant Diseases: Where History Encounters Future

Oliver Micke — 2009-09-15T20:51:07Z

Dear Editor,

we like to thank Niewald et al. for their excellent and important contribution on radiotherapy for periarthritis of the shoulder [1]. Their retrospective evaluation showed that low dose irradiation is a very effective treatment method for painful periarthritis of the shoulder, exhibiting virtually no toxicity, and provides a good alternative to medication, injections, ESWT and surgery because of a high rate of long-lasting pain relief and improvement of mobility. Despite this excellent results and the fact that most patients were extensively pre-treated the criticism of a potential placebo effect could be never ruled out [1, 2, 3].
Therefore, even though treatment of degenerative and inflammatory diseases with low dose radiotherapy has a very long tradition in central Europe [4], there is deep scepticism about radiotherapy for benign diseases all over the rest of the world, in particular in the Anglo-American countries [2, 3, 5]. Another reason why colleagues from other specialities or other countries are reluctant to recommend radiotherapy are due to concerns about potential damage to gonads or tumour induction [3]. However, so far no increased tumour rate has been reported in the literature for the recommended dose range [5, 6]. In addition, the risks of pharmacological treatments such as NSAIDs, e.g. gastrointestinal, nephro- and hepatotoxicity, must be also taken into account [2, 6].
Radiotherapy for painful degenerative disorders, like osteoarthritis, plantar fasciitis, periarthritis of the shoulder or epicondylopathia humeri, is not well accepted on an international level, because its practice is based mostly on long-term experience rather than on well-defined clinical evidence. As most European literature on these topics is not written in English, it is rarely considered in reviews [2].
Conclusive controlled clinical trials are still missing, but there are three outdated randomized trials, performed more the 30 years ago, which are used to discredit radiotherapy for benign diseases and to demonstrate the ineffectiveness of the method [2, 3]: Goldie et al. [] treated in a double blinded study 399 patients with a large variety of different degenerative skeletal disorders (among which were nine heel spurs). Response rates for treated and untreated patients were 68% and 64%, respectively. Effectiveness of RT was considered questionable. However, the study was rightly criticised for its inadequate study design, the obvious flaws in outcome evaluation and the questionable results [2, 3].
Valtonen et al. [8] also performed a randomized double blinded study in 104 patients with 127 painful musculoskeletal disorders. They could not find any difference between the treatment arms, but they included many indications, which not suitable for low dose radiation (overall 49 patients!), e.g. intercostals neuralgia, spondylolisthesis, spinal spondyloses. The best effect of radiotherapy with some superiority versus placebo was observed in periarthropathia humeri, but with small patients’ number.
Plenk [9] published already in 1952 a small study with just 38 patients with tendonitis calcarea of the shoulder. They found a moderate advantage for the radiation arm with 88 % versus 71 % placebo. This difference did not reach statistical significance because of the small sample size.
All in all, these three studies have an absolutely insufficient methodical design in patient selection, statistical methods, endpoint definition, suitable follow-up as well as standardized documentation to answer the specific questions [2].
Nevertheless, in the Anglo-Saxon countries these studies were used again and again to discredit the radiation treatment of non-malignant disorders and as prove for the ineffectivity of this treatment [3].
However, even after extensive and numerous unsuccessful pretreatments of the patients a possible placebo effect of radiotherapy for pain treatment cannot be completely excluded so far [2, 5]. To overcome this scientific problem the German cooperative group on radiotherapy for benign diseases (GCGBD) initiated a randomized trial in painful heel spurs [10]. This is the first “modern” randomized trial using subjective as well as objective measures for outcome evaluation.

References
1. Niewald M, Fleckenstein J, Naumann S, Rübe C: Long-term results of radiotherapy for periarthritis of the shoulder: a retrospective evaluation. Radiation Oncology 2007, 2:34.
2. Micke O, Seegenschmiedt MH: Consensus guidelines for radiation therapy of benign diseases: a multicenter approach in Germany. Int J Radiat Oncol Biol Phys 2002, 52:496-513.
3. Muecke R, Micke O, Reichl B, Heyder R, Prott FJ, Seegenschmiedt MH, Glatzel M, Schneider O, Schäfer U, Kundt G: Demographic, clinical and treatment related predictors for event-free probability following low-dose radiotherapy for painful heel spurs - a retrospective multicenter study of 502 patients. Acta Oncol 2007; 46:239-246.
4. Sokoloff N: Röntgenstrahlen gegen Gelenkrheumatismus. Fortschr Röntgenstr 1898, 1: 209-213.
5. Schäfer U, Micke O, Glashörster M, Rübe C, Prott FJ, Willich N: [The radiotherapy treatment of painful calcaneal spurs]. Strahlenther Onkol 1995, 171:202-206.
6. Micke O, Seegenschmiedt MH: Radiotherapy in painful heel spurs (plantar fasciitis) - results of a national patterns of care study. Int J Radiat Oncol Biol Phys 2004; 58:828-843.
7. Goldie I, Rosengren B, Moberg E, Hedelin E: Evaluation of radiation treatment of painful conditions of the locomotor system. A double blind study. Acta Radiol Ther Phys Biol 1970; 9:311-322.
8. Valtonen EJ, Lilius HG, Malmio K. The value of roentgen irradiation in the treatment of painful degenerative and inflammatory musculoskeletal conditions. A double-blind study. Scand J Rheumatol 1975; 4:247-249.
9. Plenk HP. Calcifying tendinitis of the shoulder; a critical study of the value of x-ray therapy. Radiology 1952; 59: 384-389.
10. Niewald M, Seegenschmiedt MH, Micke O, Gräber S, the GCGBD (German cooperative group on the radiotherapy for benign diseases) of the DEGRO: Randomized multicenter trial on the effect of radiotherapy for plantar fasciitis (painful heel spur) using very low doses – a study protocol. Radiation Oncology 2008, 3:27.

High-dose-rate brachytherapy for soft tissue sarcoma in children

Daya Nand Sharma — 2008-04-28T08:40:47Z

Dear Editor,

I read the interesting article entitled “High-dose-rate brachytherapy for soft tissue sarcoma in children: a single institution experience” by Viani et. al. published in Radiation Oncology (Biomed central) on 19th April 2008. I will argue some of the points in this study as below.

• The title and the abstract section does not signify whether the high dose rate brachytherapy alone or in combination with external beam radiation therapy was used as definitive treatment or adjuvant to surgery. There is no mention of any surgical procedure in the title or the entire abstract section of the manuscript.

• The authors have not provided the distribution of patients according to the staging of the disease neither in the manuscript nor in the tabulated form. Any study pertaining to pediatric rhabdomyosarcomas should essentially provide information on the IRS staging.

• Chemotherapy is an integral part of the treatment of pediatric sarcomas. The authors have failed to provide the relevant information on the same. The sequence of the chemotherapy in relation to surgery or radiotherapy and the chemotherapy regime used should have been mentioned at least.

• Some of the details of brachytherapy are missing in this study e.g. how many planes of brachytherapy (single or multiple) catheters were implanted and on which postoperative day the brachytherapy was started.

• The authors have given some contradictory information in the manuscript and Tables. In the Abstract section, it is mentioned that “eight patients were treated with HBRT alone; the remaining 10 were treated with a combination of HBRT and EBRT” while Table 1 describes the vice versa (10 patients received HBRT alone and 8 received EBRT plus HBRT.

• The authors have not provided the details of EBRT e.g. the machine used (Linear accelerator or cobalt), the number of fields used and whether 3D-CRT/IMRT was used?

Dr DN Sharma,

Radiation Oncologist,

All India Institute of Medical Sciences,

New Delhi, India

Expression of Concern regarding the paper by Viani et al.

Issa Dahabreh — 2007-10-10T17:14:25Z

Sir:

We would like to express our concerns regarding the meta-analysis by Vianni et al, entitled “Breast-conserving surgery with or without radiotherapy in women with ductal carcinoma in situ: a meta-analysis of randomized trials”, published in the Radiation Oncology Journal (Radiat Oncol 2007;2:28).

We critically read the manuscript by Viani et al and noticed that the events used in the analysis are substantially fewer than those reported in the most recent follow-up reports of the eligible studies. As an example, for the NSABP-B17 study, regarding breast cancer metastases, Viani et al have reported one event per arm (Figure 5) when in the latest follow up of this study (Semin Oncol 2001;28:400-418) there are 10 events in the radiotherapy arm and 7 in the control arm. This observation compelled us to investigate all data presented and analyzed and led to the discovery of several major mistakes that render the findings of Viani et al irrelevant. We list the most important here:

1.Viani et al. extracted data from older publications of the following studies for ALL outcomes:

a. NSABP-B17: they used NEJM 1993;328:1581-1586 rather than Semin Oncol 2001;28:400-418,

b. EORTC-10853: they used Lancet 2000;355:528-33 rather than J Clin Oncol 2006;24:3381-3387.

A meta-analysis of published studies is expected to provide a quantitative summary of all available evidence. The authors obviously failed to do that by ignoring thousands of patient-years of follow-up for no good reason.

2.Obvious mistakes in data extraction:

a. In the outcome “ipsilateral invasive” the number of patients used for the NSABP-B17 and EORTC-10853 studies are wrong.

b. The number of patients used for odds ratio estimation for the NSABP-B17 trial is wrong (for ALL outcomes).

c. For the outcome “overall mortality rate” the events abstracted from the SweDCIS trial are in fact breast-cancer specific deaths.

d. For the outcome “ipsilateral invasive cancers” the authors used ipilateral non-invasive cancers for the SweDCIS and NSABP-B17 trials.

e. The number of events and the number of patients used for the UKCCR trial are wrong for ALL outcomes. Viani et al state that the UKCCR trial design is “complex”. Although the handling of factorial trials in meta-analysis is somewhat controversial, Viani et al, by using the numbers reported in Table 1 of the UKCCR manuscript, have reduced a randomized trial to an observational study! To make things easier for readers the authors of this trial have noted in the table legend that “Data for descriptive purposes only. For comparison of treatment effects, factorial analysis as shown in tables 2 and 3 should be used.” Viani et al. have completely disregarded this suggestion; consequently their data abstraction is heavily biased.

Given the above examined methodological flaws, we wonder how the paper by Viani et al was accepted for publication. We believe the paper should be retracted or, at least, associated with an official editorial expression of concern.

Yours sincerely,

Issa J. Dahabreh (issa@dahabreh.gr)

Konstantinos P. Economopoulos (economopoulos@gmail.com)

National University of Athens,

Athens, Medical School, Greece