Total scalp treatment of mycosis fungoides: the 4 x 4 technique

A technique for treating mycosis fungoides confined to the scalp using a method known as the 4 x 4 technique is presented.

Uniform dose distribution on the scalp and acceptable "hot spots" along five match lines is accomplished by using four sets of four fields (i.e., 4 x 4) on the patient. Precise and reproducible patient and field alignment was accomplished with a solid thermoplastic mask, which is the surface on which match lines are drawn. In-vivo dosimetry (thermoluminescent dosimeters and film) are easily attached to the mask which also provides a portion of the 7 mm bolus used to shift the characteristic 6 MeV electron depth dose toward the skin surface.

In-vivo dosimetry demonstrated that single fraction match line doses are within 25% to 30% of central axis dose. Shifting these match lines to four locations reduces these "hot spots" to satisfactory levels (less than 120%). Three patients have been treated with this technique and each patient continues to have a complete clinical response at 14 to 21 months post treatment. In addition, each patient has excellent cosmetic results with no evidence of acute or chronic side effects at the match lines.

The 4 x 4 technique has proven to be useful in the treatment of mycosis fungoides confined to the scalp.