In the external beam irradiation of head and neck carcinoma, the junctionl area between the parallel opposed lateral upper neck fields and the anterior lower neck/supraclavicular portal can be a worrisome problem. The major concern involves the adequate treatment of the entire area at risk or recurrence without exceeding the 'tolerance' of the cervical spinal cord. This report describes a precautionary technique of junctional neck irradiation, its dosimetric aspects and its effectiveness in 47 patients given adjuvant post-operative radiotherapy at the Louisiana State University Medical Center during 1980-1984.

A comprehensive computer programme has been generated to calculate the photoelectric, Compton, pair production and triplet production coefficients and total mass attenuation coefficients for selected elements and compounds for photon energies from .01 to 50 MeV and elements with atomic numbers ranging from 1 to 92. In case of a compound the computer programme computes interaction coefficients and total mass attenuation coefficients if the constituent elements of the compound by weight is given as Input. Facility for plotting the interaction coefficients and attenuation coefficients with photon energy on a log-log scale has also been provided.

The effect of temperature on the stability of the FBX chemical dosimeter containing 0.20 mM ferrous ammonium sulphate, 5.0 mM benzoic acid and 0.20 mM xylenol orange in 0.07 N H2SO4 at different storage periods has been investigated. The unirradiated samples stored at 0°C did not show any appreciable increase in the absorbance measured at 548 nm even after 504 hours of storage when compared with the absorbance at 0 hour. On the contrary, an appreciable increase in absorbance at different temperatures was observed in the unirradiated samples. The study clearly demonstrates that the stability of the FBX chemical dosimeter can be improved if its dosimetric solution is stored at lower temperatures.

A programmable calculator, which may be easily afforded, can be used effectively in a small radiotherapy centre. In this paper input and output of some programs developed for such a calculator, which are useful for radiotherapy are discussed. The programs are developed in a conversational manner, so that even the radiotherapist or technician may use them for necessary calculations.

. Interstitial implants using lr-192 wire has vast applications in the management of head & neck, breast and gynecological malignancies. Since the availability of lr-192 wire from BRIT, major hurdle has been overcome in India. But still there is great difficulty in procuring protective devices like storage lead pot, transportation trolly, lead screens, wire cutter and loader, etc. Another problem faced is in procuring plastic tubes of required specification, specially the inner plastic tubes which carry the lr-192 wire, and various accessories required for special situations. Third group of problem is learning the technical skills in performing the therapy in various sites. Most of the radiotherapy teaching centers in India do not have this facility. Hence there is no practical training. Further comprehensive books on this subject giving details of techniques are also scarce. Last group of problems and equally important is the dosimetric aspects of implants. At Smt. Vasantben R. Desai Cancer Research Centre, Rajkot we established interstitial brachy therapy services starting from the beginning. After attending a workshop in Feb. '86 at TMH, Bombay and subsequent short term training there, we started the preparation. We designed and fabricated almost all the radiation protection devices and other accessories locally at a cost of 50% or less. Some of these items have been supplied to a few other centers in India. Because of their unique features certain devices have been named GUPTA-MATHUR devices. This paper deals with comprehensive needs of the department, the kinds of problems faced while establishing this facility and their solutions. We feel establishing and running interstitial brachy therapy services using lr-192 wire is quite cost effective and is of great therapeutic benefit.

The main aim of the article is to stimulate the interest of clinical radiobiologists to undertake research in the treatment of the anemic cancer patient. For this the physiology of oxygen transport in relation to Hb and tumour hypoxia is reviewed. Varying the timing of blood transfusion and use of normobaric oxygen breathing are suggested as two areas of research.