Hypoxic PET in treatment planningHypoxia imaging with [F-18] FMISO-PET in head and neck cancer: Potential for guiding intensity modulated radiation therapy in overcoming hypoxia-induced treatment resistance
Section snippets
Patients
A total of 102 patients with head and neck squamous cell cancer (HNSCC) were enrolled in a FMISO-PET imaging study of patients with newly diagnosed cancer between April 1994 and August 2007 as part of on-going research protocols. Ten of these patients were randomly selected for inclusion in this sub-analysis. These 10 patients had an average ⩾119 weeks of clinical follow up. They were recruited from the University of Washington Medical Center, Harborview Medical Center, and the Veterans
Results
Significant hypoxia was identified in all 10 patients in this subanalysis, as shown in Table 1. Data for doses to targets and critical structures in radiotherapy plans with and without the boost dose for the 10 cases included in this report are given in Table 2, Table 3. In all cases the IMRT planning technique permitted the dose escalation without exceeding the clinically acceptable limits for the critical structures. Contralateral parotid glands were spared, except in cases where the primary
Discussion
By inducing resistance to treatment, tumor hypoxia “protects” cancer cells, either as a direct effect (due to lack of molecular oxygen that dampens radiation toxicity) or an indirect effect due to the induction of aggressive phenotypes. Dose escalation to hypoxic sub-volumes with conventional photon radiation has been investigated in clinical radiation oncology practice to overcome this cure-limiting effect [14], [17], [37], [38]. In current clinical practice, boost treatment (beyond that
Conflict of interest
The authors confirm that there are no conflicts of interests, financial or otherwise, in conducting this research with FMISO-PET imaging and radiation therapy planning.
Acknowledgments
We would like to thank Paul Kinahan and all nuclear medicine technologists, radiochemists, and physicists in the division of Nuclear Medicine at the University of Washington Medical Center for their help in PET imaging. We would also like to thank Drs. Upendra Parvathaneni and Jay Liao for their contributions to head and neck planning. This study was supported by NIH Grants P01 CA42045 and S10 RR17229.
References (47)
- et al.
Evaluation of oxygenation status during fractionated radiotherapy in human nonsmall cell lung cancers using [F-18] fluoromisonidazole positron emission tomography
Int J Radiat Oncol Biol Phys
(1995) - et al.
Tumor hypoxia adversely affects the prognosis of carcinoma of the head and neck
Int J Radat Oncol Biol Phys
(1997) - et al.
Intra tumoral pO2 predicts survival in advanced cancer of the uterine cervix
Radiother Oncol
(1993) - et al.
Quantifying regional hypoxia in human tumors with positron emission tomography of [18F]fluoromisonidazole: a pretherapy study of 37 patients
Int J Radiat Oncol Biol Phys
(1996) - et al.
Prognostic significance of tumor oxygenation in humans
Cancer Lett
(2003) - et al.
Tumor control probability for selective boosting of hypoxic subvolumes, including the effect of reoxygenation
Int J Radiat Oncol Biol Phys
(2002) - et al.
Hypoxia dose painting by numbers: a planning study
Int J Radiat Oncol Biol Phys
(2007) - et al.
Optimization of radiation therapy, III: a method of assessing complication probabilities from dose-volume histograms
Int J Radiat Oncol Biol Phys
(1987) - et al.
Calculation of complication probability factors for non-uniform normal tissue irradiation: the effective volume method
Int J Radiat Oncol Biol Phys
(1989) - et al.
Comparative dosimetric evaluation of the simultaneous integrated boost with photon intensity modulation in head and neck cancer patients
Radiother Oncol
(2003)