ABSTRACT
We have previously introduced anatomic biologic contouring (ABC) with PET/CT, using a distinct "halo" to unify contouring methods in treatment planning for lung and head and neck cancers. The objective of this study is to assess the utility of PET/CT in planning and treatment response for cervical cancer. Forty-two patients with stages II-IIIB cervix cancer were planned for irradiation using PET/CT. A CT-based Gross Tumor Volume (GTV-CT) was delineated by two independent observers while the PET remained obscured. The Planning Target Volume (PTV) was obtained by adding a 1.5 cm margin around the GTV. The same volumes were recontoured using PET/CT data and termed GTV-ABC and PTV-ABC, respectively. The values of GTV-CT and GTV-ABC and the absolute differences between the two observers were analyzed. Additionally, 23 of these patients had PET/CT performed 3 months after treatment. The anatomic biologic value (ABV) was calculated using the product of maximum diameter and mean SUV of the cervical tumor. The pre- and post-treatment ABVs were compared. A "halo" was observed around areas of maximal SUV uptake. The mean halo SUV was 1.91 ± 0.56 (SD). The mean halo thickness was 2.12 ± 0.5 (SD) mm. Inter-observer GTV variability decreased from a mean volume difference of 55.36 cm(3) in CT-based planning to 12.29 cm(3) in PET/CT-based planning with a respective decrease in standard deviation (SD) from 55.78 to 10.24 (p <0.001). Comparison of mean pre-treatment and post-treatment ABV's revealed a decrease of ABV from 48.2 to 7.8 (p<0.001). PET/CT is a valuable tool in radiation therapy planning and evaluation of treatment response for cervical cancer. A clearly visualized "halo" was successfully implemented in GTV contouring in cervical cancer, resulting in decreased inter-observer variability in planning. PET/CT has the ability to quantify treatment response using anatomic biologic value.
ABSTRACT
PURPOSE: The purpose of this study is to evaluate current assessment practices of malnourishment by radiation oncologists among the head and neck cancer patient population. METHODS: A cross-sectional descriptive study was conducted. A 14-question survey was mailed to 333 radiation oncologists self-identified as "interested in the treatment of head and neck cancer." RESULTS: About 87% of radiation oncologists indicated that they used bodyweight as the sole determinant of malnourishment in head and neck cancer patients at initial consultation. Radiation oncologists with 0 to 10 years experience were found to have a higher level of formal nutrition education than those with 11 to 20 years (p=0.0052). A significant difference was found between radiation oncologists with formal nutrition education vs. those without, in answering whether nutrition interventions play a significant role in the prognosis of such cancer patients (p=0.0013). In addition, a significant difference was noted in methods used to determine proper caloric intake when the oncologists were stratified by their beliefs about nutrition being a significant variable affecting the prognosis of head and neck cancer patients (p=0.0024). CONCLUSION: Assessment or screening for malnourishment in the head and neck cancer patient should be a routine part of the initial consultation. Radiation oncologists and their medical team, including nutritionists, should use an appropriate nutrition screening and assessment tool in addition to the body weight as an indicator of malnourishment. Nutrition education provided to radiation oncologists should be improved to better communicate the positive effects of nutrition interventions on prognosis.