TY - JOUR
T1 - PET-guided IMRT for cervical carcinoma with positive para-aortic lymph nodes - A dose-escalation treatment planning study
AU - Mutic, Sasa
AU - Malyapa, Robert S.
AU - Grigsby, Perry W.
AU - Dehdashti, Farrokh
AU - Miller, Tom R.
AU - Zoberi, Imran
AU - Bosch, Walter R.
AU - Esthappan, Jacqueline
AU - Low, Daniel A.
N1 - Funding Information:
Supported in part by NCI R01 CA 84409 and R01 CA 85797 and a corporate grant from Computerized Medical Systems, St. Louis, MO.
PY - 2003/1/1
Y1 - 2003/1/1
N2 - Purpose: To evaluate a treatment planning method for dose escalation to the para-aortic lymph nodes (PALNs) based on positron emission tomography (PET) with intensity-modulated radiotherapy (IMRT) for cervical cancer patients with PALN involvement. One goal of this process was not to modify the traditional treatment of the pelvic region. Methods and Materials: PET images for 4 cervical cancer patents with PALN involvement were registered with their corresponding CT scans. Positive PALNs were identified on PET images, and the surrounding critical structures were delineated on CT images. The treatment machine central axis (CAX) was placed at the level of the L4-L5 vertebral body interspace. There were two distinct treatment regions: the para-aortic bed superior to the CAX and the whole pelvis region inferior to the CAX. IMRT was used for treatment planning of PALN bed irradiation. The positive PALNs identified on PET images were defined as the gross target volume, and the para-aortic bed was defined as the clinical target volume. The radiation doses were escalated from the conventional 45 Gy to 59.4 Gy for the gross target volume and 50.4 Gy for the clinical target volume in 33 fractions. The pelvis area was treated with conventional treatment methods, AP-PA beams to 50.4 Gy in 28 fractions with a brachytherapy implant boost. The placement of the CAX allowed the two treatment regions to be abutted using the treatment machine's independent jaws. Results: Dose escalation to positive PALNs, as identified on PET images, and the PALN bed is feasible with IMRT. Treatment plans for 4 patients revealed that escalated prescription doses could be delivered to target volumes while maintaining acceptable doses to the surrounding critical structures. Strategic placement of the treatment isocenter allows the IMRT region (PALN bed) and whole pelvis fields to be treated with a relatively uniform dose distribution in the abutment region. Conclusion: This study indicates that PET-guided IMRT could be used in a clinical trial in an attempt to escalate doses delivered to patients with cervical cancer who have positive PALNs.
AB - Purpose: To evaluate a treatment planning method for dose escalation to the para-aortic lymph nodes (PALNs) based on positron emission tomography (PET) with intensity-modulated radiotherapy (IMRT) for cervical cancer patients with PALN involvement. One goal of this process was not to modify the traditional treatment of the pelvic region. Methods and Materials: PET images for 4 cervical cancer patents with PALN involvement were registered with their corresponding CT scans. Positive PALNs were identified on PET images, and the surrounding critical structures were delineated on CT images. The treatment machine central axis (CAX) was placed at the level of the L4-L5 vertebral body interspace. There were two distinct treatment regions: the para-aortic bed superior to the CAX and the whole pelvis region inferior to the CAX. IMRT was used for treatment planning of PALN bed irradiation. The positive PALNs identified on PET images were defined as the gross target volume, and the para-aortic bed was defined as the clinical target volume. The radiation doses were escalated from the conventional 45 Gy to 59.4 Gy for the gross target volume and 50.4 Gy for the clinical target volume in 33 fractions. The pelvis area was treated with conventional treatment methods, AP-PA beams to 50.4 Gy in 28 fractions with a brachytherapy implant boost. The placement of the CAX allowed the two treatment regions to be abutted using the treatment machine's independent jaws. Results: Dose escalation to positive PALNs, as identified on PET images, and the PALN bed is feasible with IMRT. Treatment plans for 4 patients revealed that escalated prescription doses could be delivered to target volumes while maintaining acceptable doses to the surrounding critical structures. Strategic placement of the treatment isocenter allows the IMRT region (PALN bed) and whole pelvis fields to be treated with a relatively uniform dose distribution in the abutment region. Conclusion: This study indicates that PET-guided IMRT could be used in a clinical trial in an attempt to escalate doses delivered to patients with cervical cancer who have positive PALNs.
KW - Cervical cancer
KW - Intensity-modulated radiotherapy
KW - Para-aortic lymph nodes
KW - Positron emission tomography
UR - http://www.scopus.com/inward/record.url?scp=0037215314&partnerID=8YFLogxK
U2 - 10.1016/S0360-3016(02)03804-X
DO - 10.1016/S0360-3016(02)03804-X
M3 - Article
C2 - 12504033
AN - SCOPUS:0037215314
SN - 0360-3016
VL - 55
SP - 28
EP - 35
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 1
ER -