Table 2.

Monotherapy versus combined therapy: median effect analysis and CI

A. Comparison of monotherapy (photodynamic therapy or CDDP) versus combined therapy (photodynamic therapy and CDDP) at a constant light fluence (CI < 1 indicates synergy)
Monotherapy
Combined therapy
1
2
3
4
5
6
7
(Dx)1 Fluence (J/cm2)(Dx)2 CDDP (μmol/L)Observed effect cell viability (%)D1 fluence (J/cm2)D2 CDDP (μmol/L)CICombined effect
001000.54
0.18ND82
0.361.568.5
0.542.55001Additive
0.613.0450.251.02Additive
0.734.0360.500.96Additive
0.811.5331.001.04Additive
0.995.0251.500.90Additive
1.086.0202.000.85Additive/synergistic
1.259.0122.250.76Synergistic
1.4410.072.500.74Synergistic
B. Comparison of monotherapy (photodynamic therapy or gemcitabine) versus combined therapy (photodynamic therapy and gemcitabine) at a constant light fluence (CI = 1 indicates an additive effect)
Monotherapy
Combined therapy
1
2
3
4
5
6
7
(Dx)1 Fluence (J/cm2)
(Dx)2 Gemcitabine (nmol/L)
Observed effect cell viability (%)
D1 Fluence (J/cm2)
D2 Gemcitabine (nmol/L)
CI
Combined effect
0.281.5800.2801
0.382.0722.01.03Additive
0.605.5444.01.06Additive
0.808.0306.00.97Additive
0.9212.5228.00.99Additive
C. Comparison of monotherapy (photodynamic therapy or gemcitabine) versus combined therapy (photodynamic therapy and gemcitabine) at a constant gemcitabine concentration (CI = 1 indicates additivity)
Monotherapy
Combined therapy
1
2
3
4
5
6
7
(Dx)1 Fluence (J/cm2)
(Dx)2 Gemcitabine (nmol/L)
Observed effect cell viability (%)
D1 Fluence (J/cm2)
D2 Gemcitabine (nmol/L)
CI
Combined effect
0.544.05004.01
0.656.0410.181.05Additive
0.726.5370.281.01Additive
0.9811.0210.360.99Additive
1.214.5150.540.98Additive
  • NOTE: (Dx)1 and (Dx)2 are the doses of light or drug necessary to obtain a given effect when used alone; (D1) and (D2) are the doses of light and drug needed to obtain the same effect when used in the combination. Column 3 shows the residual cell viability on irradiation at the indicated light fluences [column 1, (Dx)1] or drug treatment at the indicated concentrations [column 2, (Dx)2], respectively. Columns 4 and 5 (D1 and D2) report the light fluences and drug concentrations used in combination. Columns 6 and 7 show the CI and the type of effect ensuing from combination. Monotherapy data in Table 2A–C are taken from Figs. 2 and 3, which provide the relative SD. Combined therapy data were obtained in separate experiments (data not shown).