Effect of Cisplatin on parotid gland function in concomitant radiochemotherapy.
OBJECTIVE
To determine the influence of concomitant radiochemotherapy with cisplatin on parotid gland tissue complication probability.


METHODS
Patients treated with either radiotherapy (n = 61) or concomitant radiochemotherapy with cisplatin (n = 36) for head-and-neck cancer were prospectively evaluated. The dose and volume distributions of the parotid glands were noted in dose-volume histograms. Stimulated salivary flow rates were measured before, during the 2(nd) and 6(th) weeks and at 4 weeks and 6 months after the treatment. The data were fit using the normal tissue complication probability model of Lyman. Complication was defined as a reduction of the salivary flow rate to less than 25% of the pretreatment flow rate.


RESULTS
The normal tissue complication probability model parameter TD(50) (the dose leading to a complication probability of 50%) was found to be 32.2 Gy at 4 weeks and 32.1 Gy at 6 months for concomitant radiochemotherapy and 41.1 Gy at 4 weeks and 39.6 Gy at 6 months for radiotherapy. The tolerated dose for concomitant radiochemotherapy was at least 7 to 8 Gy lower than for radiotherapy alone at TD(50).


CONCLUSIONS
In this study, the concomitant radiochemotherapy tended to cause a higher probability of parotid gland tissue damage. Advanced radiotherapy planning approaches such as intensity-modulated radiotherapy may be particularly important for parotid sparing in radiochemotherapy because of cisplatin-related increased radiosensitivity of glands.
Hey
Jeremias
J
Department of Prosthetic Dentistry, University School of Dental Medicine, Martin- Luther- University, Halle, Germany.
Setz
Jürgen
J
Gerlach
Reinhard
R
Vordermark
Dirk
D
Gernhardt
Christian R
CR
Kuhnt
Thomas
T
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000503:physiopathology / Q000532:radiotherapy; D002945:Cisplatin / Q000008:administration & dosage / Q000009:adverse effects*; D003131:Combined Modality Therapy / Q000009:adverse effects / Q000379:methods; D019583:Dose Fractionation, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000503:physiopathology / Q000532:radiotherapy; D006801:Humans; D007822:Laryngeal Neoplasms / Q000188:drug therapy / Q000503:physiopathology / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009062:Mouth Neoplasms / Q000188:drug therapy / Q000503:physiopathology / Q000532:radiotherapy; D010306:Parotid Gland / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D011446:Prospective Studies; D011832:Radiation Injuries / Q000139:chemically induced / Q000503:physiopathology; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage / Q000009:adverse effects*; D020266:Radiotherapy, Conformal / Q000009:adverse effects; D012472:Salivation / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects; D013997:Time Factors
D011838:Radiation-Sensitizing Agents; D002945:Cisplatin