Clinical Oncology (1992) 4:340 © 1992 T h e Royal College of Radiologists

Clinical Oncology

Correspondence Letters are pubhshed at the discretton of the Edztor. Opinions expressed by correspondents are not necessarily those o f the Edttor. Unduly" long letters may be returned to the authors for shortening. Letters in response to a paper may be sent to the author of the paper so that the reply can be pubhshed in the same issue Letters should be typed double spaced and should be stgned by all authors personally. References should be given in the style specified m the Instruction to Authors at the front of the Journal.

Hyperfraetionated Accelerated Radiotherapy for Carcinoma of the Oesophagus

Table 1. Time at risk and spinal cord dose in study patients

SIR - In view of the radiation under-dose incident involving the isocentric set-up technique in our d e p a r t m e n t , we wish to publish revised figures for our article on hyperfractionated accelerated radiotherapy for carcinoma of the o e s p h a g u s [1]. T h e majority of patients received radiotherapy via a two phase set-up, phase one using anterior and posterior parallel opposed fields and phase two a three-field isocentric plan. The total dose range has changed from 3990-5252 cGy to 2998-5190 cGy. The range of under-dosage in our patients is 0% to 30.1% with a m e a n of 12.9%. T h e higher values occurred in the seven patients who had an isocentric technique throughout. T h e range of m a x i m u m spinal cord doses, which was stated as 1353-5118 cGy, now changes to 951-4858 cGy, with the m e a n dose changing from 3441 cGy to 3222 cGy. T h e issue of the spinal cord dose is particularly important in view of the worries that have been expressed following the finding at M o u n t V e r n o n of four cases of radiation myelitis with continuous hyperfracnonated accelerated radiotherapy ( C H A R T ) [2]. Dische states that there is a possibility that there is a c o m p o n e n t of repair in neural tissue which m a y exceed a T½ for repair of 4 hours. W e have therefore recalculated the spinal cord dose for each patient and reproduced the table of our original article (Table 1). In addition, we have longer follow-up on p a n e n t s that were alive at the

Months

24

5 2 2 0 3

9 6 1 5 1

2 4 0 0 3

2 0 0 0 1

0 1 0 0 1

Dose (Gy)

time of our last report We have still seen no cases of radiation myelitis. In reply to the above letter from Chaturvedi, our study was primarily looking at local and s y m p t o m control and not survival, and therefore the presence of metastases was not an exclusion criteria. We believe that a high dose is reqmred to achieve optimal local and s y m p t o m control. Leslie et al. [3] have recently d o c u m e n t e d a dosedependence of duration of dysphagia relief and also state that 'the C H A R T schedule seems particularly well suited to these patients, it being completed in a short period of time with early relief of dysphagia and little morbidity of treatment' [3]. It is also interesting to compare our results with this study from M o u n t V e r n o n on radical radiotherapy for 110 patients without evidence of m e t a s t a n c disease. T h e two studies had a very similar age range and m e a n age. Dysphagia was improved in 77.3% at M o u n t V e r n o n and 81.2% at Stoke. The median survival was 8.2 m o n t h s at M o u n t V e r n o n and 8.3 m o n t h s at Stoke. If we exclude those with obvious metastatic

disease, it increases to 11.0 m o n t h s and there is an actuanal 4-year survival now of 12.9% in this group. A. M. BRUNT J SULE-Suso J. E. SCOBLE

Department o f Clinical Oncology North Staffordshtre Royal Infirmary Princes Road, Hartshill Stoke-on-Trent ST4 7LN

References

1 Sule-Suso J, Brunt AM, Lmdup R, Scoble JE. Hyperfracnonated accelerated radiotherapy for carcinoma of the oesophagus. Chn Oncol 1991;3:209-13. 2 Dlsche S. Accelerated treatment and radlatlon myehtis. Radlother Oncol 1991:20:1--2 3. Leslie MD, Dische S, Sannders MI, et al. The role of radiotherapy in carcinoma of the thoracic oesophagus: An audit of the Mount Vernon Experience 1980-1989. Clin Oncol 1992,4:114-8