A prospective study of changes in bone health in adult cancer patients treated with pelvic radiotherapy.

Background: Cancer is a major health problem in today's world. Many patients of pelvic malignancies need treatment by radiation therapy. Post-treatment morbidity due to loss of bone health is less commonly studied. Our study aims at studying the impact of pelvic radiation therapy on bone health including bone mineral density and blood parameters and time of maximum change in Indian patients after pelvic radiotherapy. Materials and methods: Patients suffering from histologically confirmed pelvic malignancies were included. Patients having metastasis, primary bone tumor or uncontrolled co-morbid conditions were excluded. Patients were treated with concomitant chemoradiation using conventional fractionation of external beam radiotherapy followed by brachytherapy where indicated. T score and Z score of bone mineral density, serum alkaline phosphatase, vitamin D3, phosphorus and calcium were measured before radiation therapy and 6 weeks, three months, and six months after completion of radiation therapy. A p-value ≤ 0.05 was considered statistically significant. Results: We found that there was a significant decrease in mean Z score and a significant rise of mean serum alkaline phosphatase at three months post radiation therapy. This was associated with an insignificant changes of mean T score, vitamin D3, phosphorus and calcium after radiation therapy. No pelvic insufficiency fractures were detected. Conclusion: In Indian patients, alkaline phosphatase rises, and Z score falls significantly after radiation therapy at three months after treatment. This suggests maximum bone turnover at three months after treatment. Pharmacological intervention, when necessary, may be considered by careful monitoring of patients by this time.