Carcinoma cervix is the second most commonly occuring cancer in India.
Brachytherapy forms the most important part radiation therapy
Low dose rate Brachytherapy – Gold Standard
Experience more than a century
The lower the dose rate of radiation a cell is exposed
to, the greater the likelihood of repair.
Late-reacting normal tissues seem more capable of
repair than tumor
The tumor is preferentially killed over normal tissue.
• Because of the duration of administration of
LDR, acute hypoxia corrects within the tumor
• Oxygen enhancement ratio is lower for LDR
than for HDR.
During the overall treatment time of LDR,
tumor cells may pass from the relatively
radioresistant phases of late S and early G2
to the more radiosensitive phases of G2 and
The continuous administration of LDR
prevents repopulation during treatment.
Biological equivalent dose
• Calculated from LDR
• a/b ratio…
• Based on formulas !!!!
High dose / Fraction
Increased Late complications
Dose per fraction?
Small tumor & good
Vaginal anatomy –
disease with high
chance of central
• Severely criticized
• Lacks any description of statistical methods,
• Were not randomized trials
• Many have never been published,
• None were referenced.
• Some of the LDR results used in the comparison are very poor, with
complication rates several times higher than those described by
Fletcher or Perez
• Patient’s expense…
• Source life…
• Need for intense QA…
• Setup up cost…
Dose, Fraction & Schedule
Long term survival
• Carcinoma cervix – Life threatening disease
• For the price of convenience …, survival should never
• LDR brachytherapy should be the standard of care in
carcinoma cervix until long term efficacy of HDR is