Proton Therapy for Maxillary Sinus Carcinoma
ABSTRACT To compare the dose-volume data of three-dimensional conformal proton therapy (3DCPT) versus intensity-modulated radiotherapy (IMRT) for a paranasal sinus malignancy.
3DCPT and IMRT plans were created for a T4N0 maxillary sinus carcinoma.
The target volume dose distributions were comparable for 3DCPT and IMRT. The mean and integral doses for all normal tissues were lower for 3DCPT. The maximum doses for both plans to the ipsilateral optic nerve/retina/lens, temporal lobe, pituitary, and brain exceeded tolerance doses. The contralateral parotid, lacrimal gland, and lens were avoided with 3DCPT. Neither 3DCPT nor IMRT exceeded the maximal tolerated dose for the brainstem, optic chiasm, contralateral temporal lobe, parotid, or lacrimal gland.
Both 3DCPT and IMRT sufficiently covered the target volume(s). Although 3DCPT reduced the mean and integral dose to all of the normal tissues, both 3DCPT and IMRT irradiated the ipsilateral optic structures beyond acceptable tolerance doses.
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ABSTRACT: Proton therapy is associated with significant benefit in terms of normal tissue sparing and potential radiation dose escalation for many patients with malignant diseases. Due to recognition of these qualities, the availability of this technology is increasing rapidly, both through increased availability of large centers, and with the possibility of smaller, lower cost proton therapy centers. Such expansion is associated with increased opportunity to provide this beneficial technology to larger numbers of patients; however, the importance of careful treatment planning and delivery, deliberate patient selection, rigorous scientific investigation including comparison to other technologies when possible, and mindfulness of ethical issues and cost effectiveness must not be forgotten. The obligation to move forward responsibly rests on the shoulders of radiation oncologists around the world. In this article, we discuss current use of proton therapy worldwide, as well as many of the factors that must be taken into account during rapid expansion of this exciting technology.Frontiers in Oncology 09/2011; 1:24. DOI:10.3389/fonc.2011.00024
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ABSTRACT: To evaluate feasibility and toxicity of carbon ion therapy for treatment of sinonasal malignancies. First site of treatment failure in malignant tumours of the paranasal sinuses and nasal cavity is mostly in-field, local control hence calls for dose escalation which has so far been hampered by accompanying acute and late toxicity. Raster-scanned carbon ion therapy offers the advantage of sharp dose gradients promising increased dose application without increase of side-effects. Twenty-nine patients with various sinonasal malignancies were treated from 11/2009 to 08/2010. Accompanying toxicity was evaluated according to CTCAE v.4.0. Tumor response was assessed according to RECIST. Seventeen patients received treatment as definitive RT, 9 for local relapse, 2 for re-irradiation. All patients had T4 tumours (median CTV1 129.5 cc, CTV2 395.8 cc), mostly originating from the maxillary sinus. Median dose was 73 GyE mostly in mixed beam technique as IMRT plus carbon ion boost. Median follow-up was 5.1 months [range: 2.4-10.1 months]. There were 7 cases with grade 3 toxicity (mucositis, dysphagia) but no other higher grade acute reactions; 6 patients developed grade 2 conjunctivits, no case of early visual impairment. Apart from alterations of taste, all symptoms had resolved at 8 weeks post RT. Overall radiological response rate was 50% (CR and PR). Carbon ion therapy is feasible; despite high doses, acute reactions were not increased and generally resolved within 8 weeks post radiotherapy. Treatment response is encouraging though follow-up is too short to estimate control rates or evaluate potential late effects. Controlled trials are warranted.Radiation Oncology 04/2011; 6:30. DOI:10.1186/1748-717X-6-30 · 2.36 Impact Factor
Article: Proton therapy in clinical practice[Show abstract] [Hide abstract]
ABSTRACT: Radiation dose escalation and acceleration improves local control but also increases toxicity. Proton radiation is an emerging therapy for localized cancers that is being sought with increasing frequency by patients. Compared with photon therapy, proton therapy spares more critical structures due to its unique physics. The physical properties of a proton beam make it ideal for clinical applications. By modulating the Bragg peak of protons in energy and time, a conformal radiation dose with or without intensity modulation can be delivered to the target while sparing the surrounding normal tissues. Thus, proton therapy is ideal when organ preservation is a priority. However, protons are more sensitive to organ motion and anatomy changes compared with photons. In this article, we review practical issues of proton therapy, describe its image-guided treatment planning and delivery, discuss clinical outcome for cancer patients, and suggest challenges and the future development of proton therapy.Chinese journal of cancer 05/2011; 30(5):315-26. DOI:10.5732/cjc.010.10529