Factors influencing the evaluation of an article in cancer literature.

Casual Interpretation of results in a given article has several pitfalls. In order to assess the strengths and limitations of a given article several factors need to be considered. This review article is intended to list, classify and describe briefly the factors that should be considered in the evaluation of an article. The three primary criteria which help in proper assessment of an article are (1) Accurate and adequate description of material and methods; (2) Data on the total sample size and elimination criteria; (3) Statistical methodology employed.

Role of electron beam treatment in postoperative management of carcinoma of the breast.

The aim of post operative radiotherapy to chest wall and drainage areas in advanced breast cancer is to sterilize the possible microscopic disease. Fifty cases of post surgical breast cancers were evaluated in a prospective study of chest wall radiation therapy by electrons. Fifty women of histologically proved post operative invasive breast cancers underwent simple mastectomy with axillary dissection followed by post-operative radiotherapy (Electron) to chest wall +/- drainage area. The chest wall and IMC was treated by a direct electron beam (9/12 MeV and 12 MeV) at fixed angle. 6 MV X-ray beam was used to treat axillary apex and supraclavicular area. In some cases, supplement RT was given by 6 MV X-rays through small posterior axillary portal. The energy of electron beam was 9 MeV or 12 MeV depending on the thickness of treated area. The supraclavicular and axillary lymphatic regions were treated, by direct custom shaped anterior portal. The dose delivered was 50 Gy over 5 weeks at 2 Gy per fraction. Adjuvant chemotherapy was given to patients who were pre-menopausal with histologically proved axillary node involvement as Cyclophosphamide, Methotrexate and 5-Fluorouracil (CMF) after radiotherapy. Post menopausal patients received adjuvant tamoxifen 10 mg.bid. The overall time varied from 26 to 87 days with a median of 41.5 days (SD 11.7). The followup period varied from 4-32 months with a mean of 22 months (SD 6.4). All the fifty patients developed dense pigmentation towards the end of radiation therapy, along with patchy dry desquamation. Moist desquamation occurred in 6 patients. The median OTT in the patients who developed moist desquamation was 34.5 days. The moist reaction healed over 10-15 days after completion of radiotherapy. Lung Fibrosis (Apical lobe) occurred in four patients. The fibrosis was evident at a median of 12 months of follow up. Lymphoedema of the ipsilateral arm occurred in six patients. None of 50 patients developed late sequalae like Cardiac effects, Rib fracture, Brachial Plexopathy, Shoulder joint impairement and Soft tissue effects. Local control in this study was 96% (48 patients). The two year actuarial overall survival was 80%. In early stages survival was significantly better compared to late stages. The actuarial two year DFS was 72%. In early stages DFS was significantly better compared to late stages.

Prognostic factors for spinal cord myelitis--an analysis of compiled literature data.

The effectiveness of radiotherapy in the treatment of malignant tumors in the head and neck, thorasic and upper abdominal regions is frequently limited by the tolerance of the spinal cord. Therefore knowledge of the factors that influence the tolerance of the spinal cord to radiation is of the upmost important. Safe limits for irradiation of the spinal cord determined in a number of clinical studies is on the conservative side from the point of view of tumor control probability. The bioeffect of a physical dose takes into account the treatment variables and the radiobiological characteristics of the relevant tissue; hence deciding spinal cord tolerance on the basis of bioeffect models would be better approach. The aim of the present study was to analyze the relationship of the prognostic factors with percentage incidence of spinal cord myelitis and to arrive at a spinal cord tolerance bioeffect dose TDF and ERD for optimum incidence of radiation myelitis.

Extrapolated response dose as a potential tool in radiotherapy and chemo-radiotherapy of head and neck cancers.

An analysis of head and neck cancer patients treated by radiotherapy (RT) alone (114 patients) and by chemo-radiotherapy (RT + CT) (115 patients) was carried out; the doses varied from 40-77 Gy and 35-71 Gy in RT and RT + CT groups respectively. The chemotherapy (CT) (induction/concurrent) drugs used were 5-FU, cisplatin, methotrexate either single or in combination. Extrapolated response dose values were evaluated with alpha/beta values of 10, 2.5 and 6 Gy for acute, late complications and tumour response, respectively. Dose enhancement factor (DEF) and Therapeutic gain factor (TGF) values were evaluated on the basis of ERD for patients receiving 5-FU RTCT (72 patients). ERD vs late complication rate and response rate curves were drawn for RT, RT + CT (< 7 cycles), RT + CT (> 6 cycles) and RT + CT (cumulative). DEF values for response rate were 0.95, 0.95 and 0.82 for the three RT + CT groups respectively. Similarly DEF values for late complication rate were evaluated as 0.87, 0.93 and 0.88. TGF values for RT + CT were 1.09, 1.02 and 0.93. TGF values indicated lack of significant influence of CT on clinical outcome. The correlation of ERD with late complication, response and status at last follow up (NED) was statistically significant for both groups (P < 0.01). ERD did not correlated with acute complication in RT group (P > 0.01). From the present analysis, in RT + CT treatments of head and neck cancers, an ERD value of 69 Gy is suggested as the limit for an acceptable 5% late complication rate.

Intraluminal brachytherapy in carcinoma of the oesophagus: comparison of afterloading techniques.

For improved local control or palliation of oesophageal cancers, Intra-luminal brachytherapy (ILB) has emerged as an increasingly popular treatment modality of therapy in recent years. In combination with external radiotherapy, afterloaded ILB can increase local control rates and may prolong survival of these patients. In this paper two techniques of ILB viz., manual and low dose-rate remote after loading methods, using Caesium-137 tubes and pellets respectively, are described in detail. On comparison of these two techniques it was found that both of them were similar with respect to their physical characteristics (dose rate, dose fall-off, maximum spinal cord dose, total reference air kerma, etc.). Clinically, the manual afterloaded ILB technique was found to be easier to use when compared with the low-dose rate remote afterloader. In addition, the number of patients with uterine cancers being high in a developing country, it was found that it was inappropriate to use the low dose remote afterloaders, designed for use in gynaecological cancers, for ILB of oesophageal cancers. Therefore, in the absence of high dose rate afterloaders, which can be utilized for intracavitary treatments of both uterine and oesophageal malignancies effectively, the manual after-loading ILB system as described in this paper could be a practical alternative. Cancer Oesophagus, Intraluminal radiotherapy technique.

The dose time relationship in the radiotherapy of carcinoma of the cervix--application of CRE formalism.

A retrospective analysis of 291 patients with cancer of the uterine cervix treated with a combination of external and intracavitary radiotherapy was carried out. Patients were either treated with 45 Gy in 20 fractions by five fractions per week or with 42 Gy in 14 fractions by three fractions per week or with 42 Gy in 14 fractions by three fraction per week schedule by external radiotherapy. For brachytherapy the total dose was 24 to 32 Gy at a dose rate of 1.4 to 2.2 Gy per hour. Complication were correlated with total CRE values for point A (CRE TA) and for rectum CRE TR. Correlations of CRE TA with overall complication rate (p value < 0.05) and rectal complication rate (p value < 0.01) were excellent. Lack of correlation was observed between CRETR and overall complication rate (p value > 0.1) as well as rectal complication rate (p value > 0.1). In order to limit Grade II and III rectal and bladder complications to acceptable level, in combined external and intracavitary treatments, CRETA value of less than 2500 reu is suggested.