The invention provides a method for reconstructing dose distribution of a pen tip proton beam scanning system for radiotherapy.Step 1: the detector is placed in the scanning area of the pen tip proton beam scanning system；Step 2: irradiating the pencil tip proton beam on the overlapping area of the first detection part and the second detection part；Step 3: measure the intensity of the pencil tip proton beam on the second sensing element to obtain the first dimension intensity data of the first sensing section；Step 4: measure the intensity of the pencil tip proton beam on the first sensing element to obtain the second dimension intensity data of the second sensing section；Step 5: combine the first one-dimensional intensity data with the second-dimensional intensity data to obtain the two-dimensional intensity data associated with the pencil tip proton beam.According to this, a person skilled in the art can correct or compensate the dose of the pen tip proton beam scanning system according to the two-dimensional intensity data.本發明提供一種用於放射治療的筆尖式質子束掃描系統的劑量分布重建方法。步驟1：將偵測器放置於筆尖式質子束掃描系統的待掃描區域中；步驟2：將筆尖式質子束照射在第一偵測部和第二偵測部的重疊區域；步驟3：量測筆尖式質子束在第二感測元件上的強度而取得第一感測區段的各別第一一維強度數據；步驟4：量測筆尖式質子束在第一感測元件上的強度而取得第二感測區段的各別第二一維強度數據；步驟5：合併第一一維強度數據以及第二一維強度數據得到關聯於筆尖式質子束的二維強度數據。據此，本領域技術人士即可根據二維強度數據對筆尖式質子束掃描系統的劑量進校正或補償。
