1- Okkan S, Uzel R: The Radiosensitizing effect of Ornidazole in hypoxic mammalian
tissue: An in vivo study. Int. J. Radiation Oncology Biol. Phys. 8: 1735-1739, 1982.
2- Okkan S, Yazıcı Z, Uzel, Akçasu A, Turkan S, Hacıbekiroğlu M, Olgun P, Egehan I: Use of ornidazole in fractionated radiotherapy: Dose tolerance, serum and tumour tissue concentration. Radiother Oncol 5: 295-301, 1986
3- Yıldız İ, Ulukutlu L, Büyükünal C, Öber A, Aksoy F, Yeker D, Uzel R, Danişmend N, Okkan S, Öz F: Wilm's Tumor: Prognostic factory and survival. Chemioterapia 7: 140-143, 1987.
4- Uzel R, Okkan S, Töre G, Koca S: Results and Complications of high dose rate Intracavitary radiotherapy compared with conventional dose rate in carcinoma of the cervix. Sonderb Strahlenther Onkol 82: 132-136, 1988.
5- Okkan S, Uzel R, Öber A, Turan S, Turan N: A randomized study of ornidazole as a radiosensitizer in high-grade astrocytomas: Preliminary Report. Radiosensitization Newsletter 7: 1-3, 1988.
6- Atkovar G, Uzel Ö, Özşahin M, Koca S, Şahinler İ, Okkan S, Uzel R: Postoperative radiotherapy in carcinoma of the cervix: Treatment results and prognostic factors. Radiother Oncol. 35: 198-205, 1995.
7- Çakır Ş, Dinçbaş Öner F, Uzel, Ö, Koca S, Okkan S: Multivariate anlysis of prognostic factors in 75 patients with soft tissue sarcoma. Radiother Oncol 37: 10-16,1995.
8- Okkan S, Atkovar G, Şahinler İ, Turkan S, Uzel R: A randomised study of ornidazole as a radiosensitiser in carcinoma of the cervix: Long-term results. Br J Cancer 74 (Suppl.XXVII): 282-286, 1996.
9- Şenel-Beşe N, Uzel Ö, Turkan S, Okkan S: Continious hyperfractionated accelerated radiotherapy in the treatment of high-grade astrocytomas. Radiother Oncol.47: 197-200, 1998.
10- Yıldız İ, Yüksel L, Özkan A, Apak H, Celka T, Danişmend, Büyükünal, C, Söylet Y, Sarımurat N, Dervişoğlu S, Aksoy F, Atkovar G, Okkan S: Multidisiplinary approach to Wilms Tumor: 18 years of experience. Jpn. J Clin Oncol 30:17-20, 2000.
11- Şahinler İ, Uzel Ö, Tuncer, Tabak S, Atkovar G, Okkan S:Salvage radiotherapy in previsusly operated recurrent cervical cancer. Journal of BUON 6: 37-41, 2001.
12- Şenel-Beşe N, Öber A, Okkan S: Retrospective analysis of breast cancer patients treated with post-mastectomy radiation therapy and evaluation of prognostic factors for locoregional control and survival. Journal of BUON 6: 255-261, 2001.
13- Uzel Ö, Özgür-Yörük S, Şahinler İ, Turkan, S, Okkan S: Nasopharyngeal carcinoma in childhood: long-term results of 32 patients. Radiother Oncol.58:137-141, 2008
14- Şahinler İ, Erkal H, Akyazıcı E, Atkovar, G, Okkan S: Endometrial carcinoma and an unusual presentation of bone metastasis: A case report. Gynecol Oncol. 82:216-218, 2001.
15- Okkan S, Atkovar G, Şahinler İ, Öner-Dinçbaş F, Koca A, Köksal S, Turkan S, Uzel R: Results and complications of high dose rate and low dose rate brachytherapy in carcinoma of the cervix: Cerrahpaşa Experience. Radiother. Oncol. 67: 97-105, 2003.
16- Öner-Dinçbaş F, Akyazıcı E, Koca S, Öber A, Okkan S: Radiotherapy for benign disease: A retrospective analysis. Journal of BUON 9:57-61, 2004.
17- Şahinler İ, Çepni İ, Çolpan-Öksüz D, Çepni K, Köksal S, Koca A, Atkovar G, Okkan, S: Tandem application with transvaginal ultrasound guidance. İnt J Radiat Oncol Biol Phys 59:190-196, 2004.
18- Dobrowsky W, Huilgol N.G, Jayatilake R, Kizilbash N, Okkan S, Tsutomu K, Tatsuzaki H.: AK-2123 (Sanazol) as a radiation sensitizer in the treatment of stage III cancer cervix: Initial results of on IAEA multicentre randomized trial. J Cancer Res Ther 1:75-78, 2005.
19-Dobrowsky W, Huilgol NG, Jayatilake RS, Kizilbash NI, Okkan S, Kagiya VT, Tatsuzaki H: AK-2123 (Sanazol) as a radiation sensitizer in the treatment of stage III cervical cancer: results of on IAEA multicentre randomised trial .Radiother Oncol 82:24-29, 2007
20- Iğdem S, Okkan S, Unalan B, Iğdem A, Ferhanoğlu B.: Cervical cancer coexisting with small lymphocytic lymphoma detected during positron emission tomography/computed tomography simulation: a case report. Eur J Gynaecol Oncol 29(4): 405-407, 2008
21- Sorbe B, Nordström B, Maenpaa J, Kuhelj J, Kuhelj D, Okkan S, Delaloye J F, Frankendal B: Intravaginal brachytherapy in FIGO stage I l ow-risk endometrial cancer: A controlled randomized study. Int. J. Gynecol. Cancer 19: 873-878, 2009
22- İğdem Ş, Ercan T, Alço G, Zengin F, Özgüleş R, Öber A, Turkan S, Okkan S: Dosimetric comparison of pelvic IMRT with 3D conformal radiotherapy in patients with gynecologic malignancies. Eur J Gynaecol.Oncol. 30(5): 547-551, 2009.
23-İğdem Ş, Akpınar H, Alço G, Ağaçayak F, Turkan S, Okkan S. Implantation of fiducial markers for image guidance in prostate radiotherapy: patient-reported toxicity. Br J Radiol 82:941-945, 2009.
24 –Alço G, İğdem Ş, Dinçer M, Tecimer C, Şentürk R, Vural M, Okkan S: Gemcitabine induced radiation recall myositis: Report of two cases. Int J Hematol Oncol 19:249-253, 2009.
25- İğdem Ş, Abacıoğlu U, Çetin İ, Alço G, Akgün Z, Şengöz M, Bekiroğlu N, Turkan S, Okkan S. Impact of Percent Positive Random Biopsies on Biochemical Outcome in Prostate Cancer Patients Treated with External Beam Radiotherapy With or Without Androgen Deprivation. J.BUON 14:629-634, 2009.
26-.İğdem Ş, Alço G, Ercan T, Ünalan B, Kara B, Geceer G, Akman C, Zengin FO, Atilla S, Okkan S. The application of positron emission tomography/computed tomography in radiation tratment planning: Effect on gross target volume definition and treatment management. Clin Oncol 22:173-178, 2010.
27- İğdem Ş, Spiegel DY, Efstathiou J, Miller RC, Poortmans PMP, .Koca S, Kılıç Ünsal D, Okkan S, Zietman A. Prostatic duct adenocarcinoma: Clinical characteristics, treatment options, and outcomes- a Rare Cancer Network Study. Onkologie 33:169-173, 2010.
28- Ercan T, İğdem Ş, Alço G, Zengin F, Atilla S, Dinçer M, Okkan S. Dosimetric comparison of field in field intensity modulated radiotherapy technique with conformal radiotherapy techniques in breast cancer. Jpn J Radiol 28:283-289, 2010.
29-Alço G, Iğdem SI, Ercan T, Dinçer M, Sentürk R, Atilla S, Oral Zengin F, Okkan S:Coverage of axillary lymph nodes with high tangential fields in breast radiotherapy.Br J Radiol. 83:1072-1076, 2010
30-Sahinler I, Atalar B, Tecer GM, Calay Z, Koca S, Atkovar G, Okkan S. Postoperative radiotherapy in the treatment of uterine sarcomas:long-term results and analysis of prognostic factors. J BUON 15:480-488, 2010
31-Iğdem S, Alço G, Ercan T, Barlan M, Ganiyusufoğlu K, Unalan B, Turkan S, Okkan S.Insufficiency fractures after pelvic radiotherapy in patients with prostate cancer. Int J Radiat Oncol Biol Phys. 77: 818-823, 2010