One century of radiotherapy in France 1896-1996

[The dawn of radiotherapy, between strokes of genius, dramas and controversies]

Radiotherapy is 120 years old. A few months only after the discoveries of Roentgen, Becquerel and Marie and Pierre Curie, a few scientists tried to use the newly discovered rays to treat patients. The question of the name of the first "radiation therapist" remains debated. Although often proposed, Emil Grubbé from Chicago seems to have been disqualified. Leopold Freund from Vienna treated a benign cutaneous lesion. Finally, Victor Despeignes from Lyon appears to be the most serious candidate, having treated in 1896 a gastric cancer, and obtaining a very significant tumour regression. The pioneers of radiotherapy paid a heavy tribute to the development of the specialty; a number of them appears on the - most probably incomplete - list of 352 names engraved on the monument dedicated to the "radiation martyrs" in Hamburg. We must keep in mind that it is only within a few years that a handful of brilliant pioneers built the foundations on which radiotherapy could emerge.

A quantitative overview of radiosensitivity of human tumor cells across histological type and TP53 status

PURPOSE

We have previously shown in a limited number of tumor cell lines derived from only two histological types that clonogenic survival patterns fall into radiosensitivity groups, each group associating with a specific genotype. We now establish a global, quantitative description of human tumor cells based on genotype-dependent radiosensitivity across histological types.

METHODS

We measure clonogenic radiosensitivity in 39 human tumor cell lines that vary in histological type (colorectal, glioblastoma, prostate, bladder, teratoma, breast, melanoma and liver) and expression of several genes purported to influence radiosensitivity: ATM (ataxia telangiectasia mutated), TP53 (tumor protein 53), CDKN1A (cyclin-dependent kinase N1A), 14-3-3sigma (an isoform of the 14-3-3 gene) and DNA mismatch repair genes . For each survival curve we use the linear-quadratic model and a linear-linear model to extract multiple coefficients and seek correlation across histological types.

RESULTS

Under one-parameter analysis, survival rate at circa 2 Gy, cell lines segregate into two major, statistically-significant groups that correlate with TP53 status (wildtype versus mutant). Under two-parameter analysis, cell lines segregate into four radiosensitivity groups based on correlations between response at lower doses (ca. 2 Gy) and a component of response to higher doses (>4 Gy).

CONCLUSIONS

Intrinsic radiosensitivity of 39 human tumor cell lines segregate into distinct genotype-dependent radiosensitivity groups that associate with mutATM, wtTP53, mutTP53, and an unidentified factor in some glioblastoma cells. Genotype-dependent radiosensitivity underlies histology-dependent variation in radiosensitivity. Our analysis establishes a quantitative overview of radiosensitivity that can predict possible response of human tumors to radiotherapy protocols.

Imaging in radiotherapy

Radiotherapy, more then any other treatment modality, relies heavily and often exclusively on medical imaging to determine the extent of disease and the spatial relation between target region and neighbouring healthy tissues. Radically new approaches to radiation delivery are inspired on CT scanning and treat patients in a slice-by-slice fashion using intensity modulated megavoltage fan beams. For quality assurance of complex 3-D dose distributions, MR based 3-D verificative dosimetry on irradiated phantoms has been described. As treatment delivery becomes increasingly refined, the need for accurate target definition increases as well and sophisticated imaging tools like image fusion and 3-D reconstruction are routinely used for treatment planning. While in the past patients were positioned on the treatment machines based exclusively on surface topography and the well-known skin marks, such approach is no longer sufficient for high-accuracy radiotherapy and special imaging tools like on-line portal imaging are used to verify and correct target positioning. Much of these applications rely on digital image processing, transmission and storage, and the development of standards, like DICOM and PACS have greatly contributed to these applications. Digital imaging plays an increasing role in many areas in radiotherapy and has been fundamental in new developments that have demonstrated impact on patient care.

Inauguration of radiotherapy as a new scientific speciality by Leopold Freund 100 years ago

There is an increasing acceptance and knowledge of the fact that the inauguration of radiotherapy as a new scientific speciality was performed by Leopold Freund 100 years ago. With a clear and logical rationale, Freund provided the first scientific proof of the biological effectiveness of X-rays on a 5-year-old patient and performed the world's first successful treatment with X-rays. Before Freund's historical experimental treatments, which started in Vienna on November 24th, 1896, there were several suggestions and attempts at the therapeutic use of X-rays, however none of these mostly one-of-a-kind attempts was successful, and there was no scientific proof of a therapeutic effectiveness of X-rays in these previous experiments.

On the controversies surrounding the origins of radiation therapy

In this study the authors analyze the documentation regarding the earliest known X-ray treatments with the objective of identifying the true origin of radiation therapy. The four most often quoted events, including X-ray treatments allegedly performed in 1896 are analyzed in the light of available published reports. From this it is concluded that Despeignes of Lyon, who in July of 1896 irradiated a patient with cancer of the stomach, is in all likelihood the first person to perform documented radiation therapy treatments with a scientific and logical basis.