Cancer Treatment

Chemotherapy and caroplatin paclitaxel for thymic cancer

The thymus is a small organ located in the upper/front portion of your chest, extending from the base of the throat to the front of the heart. Thymic carcinomas are divided into low-grade (better prognosis) and high-grade (worse prognosis, that is, more likely to grow and spread quickly) categories. Around 25% of people with thymic carcinoma are cured.

Low-grade thymic carcinomas include well-differentiated squamous cell, mucoepidermoid, and basaloid types. High-grade thymic carcinomas include poorly differentiated squamous cell, small cell/neuroendocrine, clear cell, anaplastic/undifferentiated, and sarcomatoid types.

Several anticancer drugs have been used in the treatment of thymomas and thymic carcinomas. However, because thymic carcinoma is a rare neoplasm, treatment with chemotherapy has not been studied systematically. based on cse reprots and series, the drugs most effective when given alone are doxorubicin (Adriamycin), cisplatin, ifosfamide, and corticosteroids (prednisone). Often, these drugs are given in combination to increase their effectiveness. Combinations used to treat thymic cancer include cisplatin, doxorubicin, etoposide and cyclophosphamide, and the combination of cisplatin, doxorubicin, cyclophosphamide, and vincristine. Carboplatin is in phase II study, NCT00010257, with paclitaxel,

Although there is a paucity of information, one might consider singe agents or combianations that have been well-documented for therapy. However, carboplatin is not well documented and considering the state of knowledge about chemo in general and especially about carboplatin, as well as that it is either on a study or off-study but the combination is being studied, I conclude that this combiantion is experimental.

A. Kitami, T. Suzuki, Y. Kamio, and S. Suzuki
Chemotherapy of Thymic Carcinoma: Analysis of Seven Cases and Review of the Literature
Jpn. J. Clin. Oncol., December 1, 2001; 31(12): 601 - 604.

M. A. Greene and M. A. Malias
Aggressive multimodality treatment of invasive thymic carcinoma
J. Thorac. Cardiovasc. Surg., February 1, 2003; 125(2): 434 - 436.

IMRT and Tomotherapy

Lay Summary: An introduction to IMRT and Tomotherapy

IMRT is a rapidly evolving technique, which affords a more precise radiation dose delivery of escalated doses, in appropriate cases, to targeted tumors, while sparing nearby healthy tissue structures.  The FDA clearance of numerous devices for the technical delivery of IMRT is based on the capability of this technology to incorporate accurate dose calculation algorithms, associated with a verifiable dose distribution, as managed by the treating physician, (i.e., radiation oncologist). Although, to date, no randomized trials have matured to document long-term outcomes data and efficacy for IMRT, the scientific evidence currently available indicates that IMRT permits better treatment planning and sparing of surrounding tissues, which is of particular usefulness with “Radiosensitive” tumors of the head/neck, prostate and CNS lesions where the target volume is in close proximity to critical healthy structures that must be protected.   These results may be extrapolated to the treatment of other cancers at other anatomic sites; however, a number of technical issues need to be resolved before IMRT can be recommended routinely for lung cancer use, particularly the issue of tumor mobility must be addressed, (e.g., a lung tumor moving with respiration). The NCI wass uffieciently concerned aboyt these issues to issue a recently updated report for use in planning and design of clicnial trials. It can be found at http://atc.wustl.edu/home/NCI/NCI_IMRT_Guidelines_2006.pdf

A recent retrospective review of 53 uses of IMRT in anal cancer concluded: "Preliminary outcomes suggest that concurrent chemotherapy and IMRT for anal canal cancers is effective and tolerated favorably compared with historical standards." More studies are needed.

Tomotherapy delivers varying intensity radiation with a rotating device. The intensity is varied by the placement of “leaves” which either block or allow the passage of radiation. The rotating component of this technique allows for more specific targeting of the cancer. In conventional radiation therapy, the beam is usually delivered from several different directions, possibly 5-10. The greater the number of beam directions, the more the dose will be confined to the target cancer cells, sparing normal cells from exposure. Tomotherapy delivers radiation from every point on a helix, or spiral, instead of from just a few points. The same caveats apply.

Differences between the prescribed dose of radiation in intensity modulated radiation therapy (IMRT) and the dose that’s actually delivered may make comparison studies in lung cancer difficult to interpret. These findings were reported in the Journal of the National Cancer Institute.

Blue Cross Blue Shield Association.  Special Report: Intensity Modulation Radiation Therapy for Cancer of the Breast or Lung.  TEC Assessment.  Chicago, IL.  December 2005; 20 (13)

Das, I., Cheng, C., Chopra, K., et al. Intensity modulated radiation therapy dose prescription, recording, and delivery: patterns of variability among institutions and treatment planning systems. Journal of the National Cancer Institute. 2008.

Available data are insufficient to determine whether IMRT is superior to 3D-CRT for improving health outcomes of patients with breast or lung cancer.

Das, I., Cheng, C., Chopra, K., et al. Intensity modulated radiation therapy dose prescription, recording, and delivery: patterns of variability among institutions and treatment planning systems. Journal of the National Cancer Institute. 2008. Blue Cross

K . Ohnishi , H . Liu , Z . Liao , S . Yom , H . Jin , X . Wei , P . Allen , S . Tucker , R . Mohan , R . Komaki Clinical Outcomes and Treatment Planning Strategies for Advanced-Stage Non-Small Cell Lung Cancer (NSCLC) Treated With Intensity Modulated Radiation Therapy (IMRT) and Concurrent Chemotherapy (CCT)
International Journal of Radiation OncologyBiologyPhysics , Volume 69 , Issue 3 , Pages S522 - S522, 2007

http://atc.wustl.edu/home/NCI/NCI_IMRT_Guidelines_2006.pdf

Int J Radiat Oncol Biol Phys. 2001 Nov 15;51(4):880-914.   
Comment in:
Int J Radiat Oncol Biol Phys. 2002 Jul 15;53(4):1088-9.
Intensity-modulated radiotherapy

J. K. Salama, L. K. Mell, D. A. Schomas, R. C. Miller, K. Devisetty, A. B. Jani, A. J. Mundt, J. C. Roeske, S. L. Liauw, and S. J. Chmura
Concurrent Chemotherapy and Intensity-Modulated Radiation Therapy for Anal Canal Cancer Patients: A Multicenter Experience
J. Clin. Oncol., October 10, 2007; 25(29): 4581 - 4586.

Revised: 5/3/08