Quantitative status of resources for radiation therapy in Asia and Pacific region.

PURPOSE: Resources for radiation therapy in Asian and Pacific countries were analyzed to obtain a better understanding of the status of radiation oncological practice in the region. METHODS AND MATERIALS: The data were obtained mainly through surveys on the availability of major equipment and personnel which were conducted through an International Atomic Energy Agency regional project. The study included 17 countries in South Asia, South East Asia, East Asia and Australasia. Data were related to national populations and economic and a general health care indices. RESULTS: Large differences in equipment and personnel among countries were demonstrated. The availability of both teletherapy and brachytherapy was related to the economic status of the countries. The shortage of teletherapy machines was evident in more countries than that of brachytherapy. Many departments were found to treat patients without simulators or treatment planning systems. The number of radiation oncologists standardized by cancer incidence of a country did not correlate well with economic status. CONCLUSIONS: There were significant deficiencies in the availability of all components of radiation therapy in the analyzed countries. The deficiencies were linked predominantly to the economic status of the country. Cognisance should be taken of the specific shortfalls in each country to ensure that expansion or any assistance offered appropriately match its needs and can be fully utilized. The information on the resources currently available for radiation oncological practice in the region presented in this paper provides a valuable basis for planning of development aid programs on radiation therapy.

Radiation therapy in Africa: distribution and equipment.

BACKGROUND AND PURPOSE: Africa is the least developed continent as regards radiation oncology resources. The documented ASR of cancer is of the order of 1 to 2 per 1000. With improving health care this is becoming more significant. This review was undertaken to help develop priorities for the region. MATERIALS AND METHODS: Radiation Oncology departments in Africa were identified and a survey of their equipment performed. These were compared to the reported situation in 1991. Population tables for the year 2000 were compared to available megavoltage machines. RESULTS: Of 56 countries in Africa, only 22 are confidently known to have megavoltage therapy concentrated in the southern and northern extremes of the continent. The 155 megavoltage machines operating represents over 100% increase over the past 8 years. The population served by each megavoltage machine ranges from 0.6 million to 70 million per machine. Overall, only 50% of the population have some access to Radiation Oncology services. CONCLUSION: Progress has been made in initiating radiation oncology in Ghana, Ethiopia and Namibia. There has been some increase in machines in Algeria, Egypt, Libya, Morocco and Tunisia. However, a large backlog exists for basic radiation services.

Role of radiotherapy in stage III invasive thymomas.

Twenty-five patients with malignant invasive stage III thymomas who underwent biopsy for tissue diagnosis were treated with primary radiotherapy (mean dose 46.36 Gy, range 32.4-58 Gy). These patients were followed up for a period of 10 years and survival/failure analysis was performed. Five prognostic variables were compared using the log rank test. There was no difference in survival between ages less than 50 and more than 50 years, presence or absence of myasthenia gravis, sex, histology and race. The mean follow-up was 39 months (range 1-86 months). The 5-year disease-free survival was 81% overall survival 72% and local failure rate 13%. Most local failures occurred in the first 3 months. Six patients died after a course of radiotherapy (2 intrathoracic relapse, 1 disseminated disease, 1 local failure and distant metastasis, 2 causes not related to disease). Hilar fibrosis was seen in 4 patients who are asymptomatic. No other complications were recorded. Radical external beam radiotherapy alone can give good results in malignant stage III invasive thymomas.

Radiotherapy for stage I and II testicular seminoma after orchidectomy.

A retrospective study was undertaken to evaluate the effect of irradiation on 65 patients with stage I, or II testicular seminomas treated at Hillbrow Hospital with irradiation following orchidectomy. Forty-seven patients presented with stage 1 and 9 with stage II disease. All patients received infradiaphragmatic irradiation. In addition 4 patients with stage II disease received prophylactic supradiaphragmatic irradiation. The 5-year overall and disease-free survival rate for all stages and for stage I and II compared favourably with other reports in the literature. The irradiation was well tolerated and severe long-term toxicity was rare. Seminomas were uncommon in black patients, of whom only 3 were seen in the 12-year period of this study.

Palliation of carcinoma of the oesophagus with brachytherapy and the Didcott dilator.

Forty-one patients with oesophageal cancer who developed strictures after high dose rate intraluminal brachytherapy were dilated using a slow continuous dilator (Didcott dilator). After dilatation, all patients were evaluated monthly for relief of dysphagia. At the end of the 1st month, 41 patients were evaluable: 28 had no dysphagia while 13 had improvement; at the end of the 2nd month, 40 were evaluable, 26 had no dysphagia while 14 had improvement; at the end of the 3rd month, 34 patients were evaluable, 24 had no dysphagia while 10 had improved. Three patients developed worsening of dysphagia owing to tumour recurrence among 32 patients who were evaluable at the end of the 4th month. Five patients developed worsening of dysphagia among the 26 patients who were evaluable at the 5th month due to tumour. These patients were dilated with the Didcott dilator and were treated with further brachytherapy. At the end of the 6th month, 14 patients were evaluable; seven had no dysphagia, while seven had improvement over their presenting dysphagia scores. Slow continuous dilatation using the Didcott dilator is very effective in the dilatation of strictures after high dose rate intraluminal brachytherapy. Dilatation is prolonged and sustained and a single dilatation is usually enough to maintain patency.

The neutron therapy clinical programme at the National Accelerator Centre (NAC).

A total of 721 patients were treated in the neutron therapy programme at NAC from February 1989-March 1995 with a p(66)/Be isocentric unit. The preliminary results showed: 3-year local control and survival probabilities of 57 and 79% respectively for advanced salivary gland tumours; increased local control for twice-daily neutron therapy for advanced head and neck cancer compared with photon therapy; local control rates of 68 and 83% for locally advanced breast cancer treated with 17 and 19 Gy respectively; complete response rates of 67% for macroscopic residual soft tissue sarcomas and those with irresectable disease of less than 10 cm; complete response rate of 56% for macroscopic residual uterine sarcoma with a median follow up of 38 months; 2-year local control rate and survival of 44 and 38% respectively for advanced squamous carcinoma of the maxillary antrum; complete response rate of 38% for advanced osteosarcomas and chondrosarcomas.

Carotid body tumour--a case for radiotherapy?

Carotid body tumours are rare tumours in the head and neck region. Treatment has been surgery with little or no role for radiotherapy. We describe 5 patients with carotid body tumours seen in our department in the last 10 years. Two patients were treated with postoperative radiotherapy after incomplete surgery, 2 had inoperable tumours and were treated with radiotherapy alone, and 1 had a complete excision and required follow-up only. In the 4 patients who received radiotherapy, the disease was stable in 1 patient at 1,1 years and progressive in 2 at 0,6 and 5,6 years respectively; 1 patient did not complete treatment. The patient who had surgery alone for a small tumour was free of disease at 1 year. Small carotid body tumours should be treated with surgery alone. When the tumour is large or the patient is older we propose radiotherapy as initial treatment because of the high morbidity of surgery. A review of the literature and the results with radiotherapy alone in varying doses support this view.

Jugulotympanic paragangliomas.

Eleven patients with glomus jugulotympanicum tumours were seen in our department between January 1983 and December 1993. Nine patients received a full course of radiotherapy with doses ranging from 35 to 54 Gy. Four patients were available for assessment after 48 months. All were alive and asymptomatic at the time of writing. In 4 other patients, pain had improved although cranial nerve function had not at the last follow-up (1-9 months). One patient died 1 month after treatment. Radiotherapy can provide long-term local control and survival in the treatment of glomus jugulotympanicum tumours. The details of clinical presentation, follow-up and the methods of investigation are presented together with a review of the literature.

Von Recklinghausen's disease associated with a primary malignant schwannoma of the breast.

A case of a primary malignant schwannoma of the breast is reported. This case and the review of the literature illustrate the problems of diagnosing and treating this rare malignancy.

Radiation therapy services in South Africa.

A survey of both private and public sector radiation therapy facilities in South Africa shows that they are available in only 7 major urban centres. About 20,000 cases are treated yearly by 58 therapists and 190 therapy radiographers, with 37 megavoltage and 24 X-ray machines. Brachytherapy, imaging and planning equipment is also inadequate. With limited epidemiological data it appears that less than 50% of all patients appropriately treated with radiation therapy present for such treatment. Increased referrals from sub-Saharan Africa place further strains on the system.

Determining locations of intracerebral lesions for proton radiotherapy.

Using an external view of the head, the ability to direct a proton radiotherapy beam at an intracerebral lesion is described, using a biostereometric (BSM) technique. The positions of markers, recognizable on computed tomography (CT) or magnetic resonance (MR) images, at known locations on the skin of a patient's head are related to the site of the lesion seen on the images. The markers' positions are determined by a BSM device, incorporating six video cameras coupled to a computer. A transformation from a coordinate system, defined by the CT or MR images, to another coordinate system, that of the BSM device, allows the proton beam to be directed towards the lesion. Markers used in this work were solid steel spheres for CT and plastic spheres containing oil for MR images.

Potential for gain in the use of proton beam boost to the para-aortic lymph nodes in carcinoma of the cervix.

The management of para-aortic lymph nodes (PALN) in carcinoma of the cervix by surgery and adequate conventional radiotherapy (55 Gy +) is associated with an unacceptably high incidence of major morbidity (greater than 30%) discouraging this therapy. The addition of a proton boost to photon treatment will permit the delivery of 60 to 70 Gy to PALN with a morbidity expected to be equal to that observed with 45 Gy photons (13%). The potential for improved control rates at the increased dose may be of the order of 10 to 20% depending on the initial stage of disease. Suitable selection criteria may increase this further in some subgroups.

Chordoma: a 20-year clinicopathologic review of the experience at Groote Schuur Hospital, Cape Town.

Eighteen chordomas (11 females and 7 males) were seen over a 20-year period; 61% of the tumors occurred in the sphenoid region. The youngest patient was 3 years old and had a family history of chordoma. Histologically, the tumors were divided into classical (epithelial) and chondroid variants, which in this series, had no effect on outcome. Follow-up on 12 patients ranged from 3 to 170 months, and they were treated with various combinations of surgery and radiotherapy. One patient was administered the neutron beam and died after 94 months. The mean survival of this series is 73.4 months, with a survival rate of 50% (6 out of 12 patients alive). Surgical resection offers the best chance of survival, but chordomas have a propensity to metastasize, hence have a poor prognosis.