Brazilian Head and Neck Cancer Study Group End results of a prospective trial on elective lateral neck dissection vs type III modified radical neck dissection in the management of supraglottic and transglottic carcinomas. Head Neck. 1999 Dec;21(8):694-702. doi: 10.1002/(sici)1097-0347(199912)21:83.0.co;2-b.
Chao KS, Deasy JO, Markman J, Haynie J, Perez CA, Purdy JA, Low DA A prospective study of salivary function sparing in patients with head-and-neck cancers receiving intensity-modulated or three-dimensional radiation therapy: initial results. Int J Radiat Oncol Biol Phys. 2001 Mar 15;49(4):907-16. doi: 10.1016/s0360-3016(00)01441-3.
Chao KS, Low DA, Perez CA, Purdy JA Intensity-modulated radiation therapy in head and neck cancers: The Mallinckrodt experience. Int J Cancer. 2000 Apr 20;90(2):92-103. doi: 10.1002/(sici)1097-0215(20000420)90:23.0.co;2-9.
Chao KS, Majhail N, Huang CJ, Simpson JR, Perez CA, Haughey B, Spector G Intensity-modulated radiation therapy reduces late salivary toxicity without compromising tumor control in patients with oropharyngeal carcinoma: a comparison with conventional techniques. Radiother Oncol. 2001 Dec;61(3):275-80. doi: 10.1016/s0167-8140(01)00449-2.
Chao KS, Ozyigit G, Tran BN, Cengiz M, Dempsey JF, Low DA Patterns of failure in patients receiving definitive and postoperative IMRT for head-and-neck cancer. Int J Radiat Oncol Biol Phys. 2003 Feb 1;55(2):312-21. doi: 10.1016/s0360-3016(02)03940-8.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
