Quo Vadis Radiotherapy? Technological Advances and the Rising Problems in Cancer Management

Table 2

Predictive assays for tumours: past, present, and future.

Primary tumour			Systemic disease
Oxygen status	Proliferative potential	Intrinsic cellular radiosensitivity	Micrometastases tumour dormancy
Past
(i) Electrodes; (ii) Biopsy (vascular density); (iii) Endogenous markers; (iv) Exogenous markers	(i) Measurement of Tpot, TS, and LI and correlation with outcome; (ii) Adjustment of treatment schedule as a function of Tk	(i) Comet assay; (ii) Cell survival curves; (iii) Functional assays	??
Present
(i) Oxygen-specific PET markers (FMISO, FAZA); (ii) BOLD MRI	(i) Proliferation-specific PET markers (FLT)	(i) Functional/genomic assays	(i) Immunocytochemical and molecular assays to detect occult metastatic tumour cells
Future
(i) Oxygen-specific PET markers with higher specificity (FMISO, FAZA, FETNIM, and F-EF3,5); (ii) BOLD MRI	(i) Proliferation-specific PET markers with higher specificity (FLT, F-ISO-1)	(i) Functional/genomic assays	(i) Immunocytochemical and molecular assays to detect disseminated and circulating tumour cells; (ii) Biomarkers to indicate the state of dormancy